Insert bearings

[oldredford]

The last 2 Model A engines that I had inserted the rear main bearing failed due to lack of lubrication. The bearing spun cutting the oil flow. The insert shell actually welded onto the crank journal. A big mess. Has this happened to you? The first engine the bearing failed at 1000 miles and the second engine the bearing failed after 10 minutes of running in the garage. I believe inserts are not designed with a gravity flow oil system. Why is it the center main and forward main not effected? Now the first engine has been repaired with new inserts and this engine is running fine for the past 2 thousand miles. The second engine is being repaired, so I will have to wait the outcome.

[BRENT in 10-uh-C]

Originally Posted by oldredford

Has this happened to you?

Not to me, but yes I have seen/heard this.

[Dave in MN]

Yes, it has happened to me. The correction to this is that additional oil clearance needs to be achieved.

You say the bearing spun and cut the oil flow...I disagree. The bearing to shaft clearance was likely too little and it was the lack of oil that heated up the surfaces to the point of rubbing and melted the bearing material to the crankshaft The spinning of the insert in the block housing bore was the last thing that occurred as the engine locked up.

The manufacturer of the bearings I use stated .00175" as the correct clearance for the main bearings. That clearance did not work well for me when he switched the final surface of his insert shells from Babbitt to bearing grade aluminum. I find that the aluminum lined rear main insert should have .002" to .0022" to be reliable, (means no lock-up) and leak free. The front and center mains can finish at .00175" and not be an issue with running tight. JMO: The best clearance for all three journals is .002".

I have a Sunnen precision honing machine with the proper sized mandrels to hone the aluminum insert bearing shells for the proper clearance. The Sunnen rep. advised me as to the correct stones and hone oil to use for the aluminum. I built a fixture to clamp and hold the bearing shells at the same tension (crush) they are installed from two rear main caps. The final fitting of the mains requires about 10-30 minutes depending on how many need to be adjusted but the precise clearance is worth the time.

The description you give about the insert shells welding themselves to the crankshaft is a very real occurrence. The inserts, I use with an aluminum bearing surface, are prone to this happening if there is inadequate clearance. I discovered the lock up issue when breaking the engines in on a dyno at full operating loads and high rpm after an extended session of operation.

How to save your crankshaft if this happens: I discovered that the aluminum bearing material can be removed from the crankshaft journal by careful use of muriatic acid. Be careful when using this stuff, it is nasty. Goggles, gloves and a well ventilated area (best outside and stand upwind of the acid bath). Carefully knock the shell from the journal by using a chisel at a low angle on the seams. They will pop off. Next, submerge the end of the crank in muriatic acid for 5 minutes, remove and scrub with a bronze wire brush. Repeat until it is all removed and rinse well with water. Do not leave the end of the crank submerged for an extended period of time or it will ruin the surface of the journal (believe me...don't ask!) Some may suggest you neutralize the acid with baking soda, I did not bit washing it with a slurry of baking soda and water would do so.
After all the aluminum is removed, polish the journal and you are ready to fit the new bearing.

I am sorry for your trouble...it is frustrating. Inserts have been a good product for me when they are installed with the correct oil clearance. I have over 150 of them operating very well with insert bearings.

PM me if you need more info or help.
Good Day!

www.durableperformance.net

[jm29henry]

My engine has around 2000 miles on it at how many miles did you have your failure do I need to worry is,there Anything I could do,to,prevent it

[George Miller]

One problem is it is a long ways for the oil to get to the back of the bearing with out pressure oiling. The way I fix the problem is a oil groove in the upper bearing.

[KMeredith87]

Sponsored Links (Register now to hide all advertisements)

I had it happen to me. Granted not sure if it was really due to lack oil in my case...had a blown head gasket and also the crank pulley broke on me so the water pump wasn't turning. I got lucky somehow and was able to turn the crank and swap the inserts and all was well...that was a few thousand miles ago...hate to hear it happened to you but I am building another engine now and will be doing inserts again...

[Art Newland]

Dang... I hate to hear this, was thinking going this direction on a rebuild. I wonder how wide spread a problem this is?

[James Rogers]

This is the exact reason I quit doing inserts. Like most modern "improvements", these engines are not designed to work with them. Babbitt only.

[Bruce Adams]

I have enjoyed my Inserted Bearing Engine from Antique Engine Rebuilders in Skokie, IL for about five years and 10,000 trouble free miles. I would say many others share my experiences with Inserts.

[CarlG]

I have close to 2,000 miles on my inserted engin. No complaints.

[CT Jack]

I have to ask Dave from MN a question. Is it possible the machinist preparing the block for the inserts didn't install the proper dimensions for a good fit for the OD of the inserts?Taking this possibility into consideration along with a tight bearing fit initially and also maybe the engine wasn't dynamically balanced properly could have all contributed to the failure. If this did happen it had nothing to do with the inserts.

[Dodge]

Dave in MN,
I have seen this problem with modern engines also that have aluminum bearings in them, they don't seem to be a forgiving as the old type clevitte 77 bearings.
The problem is mostly on the rods. It must be from some sort of temporary lack of oil.
I haven't inserted any motors yet but will take your advise when I do.

[BRENT in 10-uh-C]

Originally Posted by CT Jack

I have to ask Dave from MN a question. Is it possible the machinist preparing the block for the inserts didn't install the proper dimensions for a good fit for the OD of the inserts?Taking this possibility into consideration along with a tight bearing fit initially and also maybe the engine wasn't dynamically balanced properly could have all contributed to the failure. If this did happen it had nothing to do with the inserts.

I'm not Mr. Gerold, but you are very correct in that the OD tolerance is only 0.00025" either way, ...which takes a good machinist with good equipment to be able to repeat that 3 times per block. Not all engine rebuilders have the skill and/or equipment to pull that off. Babbitt is much more forgiving.

[Jon]

So my take from this is if the inserts need to be fit by machining then the advantage of having inserts so they can be changed out quickly just got thrown out the window.

[BRENT in 10-uh-C]

Originally Posted by Jon

So my take from this is if the inserts need to be fit by machining then the advantage of having inserts so they can be changed out quickly just got thrown out the window.

That has always been a sales pitch used by the ones who were promoting inserts, but generally what I have seen is the crank journal pin is worn/scratched when the inserts are worn-out where the crankshaft really needs to be machined again. Where this has the potential to be troublesome is the inserts only come in nominal sizes (Std., 0,010", 0.020", 0.030", 0.040") so if the crankshaft journal pin is worn 0.0025", the crankshaft would need to be removed and machined to the next undersize, whereas a babbitted bearing can have the crankshaft machined to 0.003" undersize and the new babbitt machined to fit the journal pin diameter. Another way to say this using the above scenario is, you potentially have the ability to machine the crankshaft 3 times with babbitt vs. 1 time with the inserts. (.003" x 3 = 0.009" vs 0.010" with the inserts)

[1929]

I have inserts, no problem.

[Fullraceflathead]

If the Bearing Crush is machined correctly you will not have a problem.
This is the Key and requires a Sharp Machinist.
Any Bearing will eventually fail if it doesn't have adequate oiling.

[Dave in MN]

Originally Posted by CT Jack

I have to ask Dave from MN a question. Is it possible the machinist preparing the block for the inserts didn't install the proper dimensions for a good fit for the OD of the inserts?Taking this possibility into consideration along with a tight bearing fit initially and also maybe the engine wasn't dynamically balanced properly could have all contributed to the failure. If this did happen it had nothing to do with the inserts.

All the factors you mention could contribute to a failure.
The main point I was trying to make is that the clearances for insert bearings are a narrow range and very much less forgiving than Babbitt bearings.

When line boring the Model A block for inserts, we find that the impurities in the cast iron are very abrasive to the tooling. Another complication to the process is that the front, center and some of the rear caps are steel. This requires tooling that will work well with both materials. We have found that if you are not using a tool that can stand up to the rigors of these materials, the bit will wear and the resulting bore is significantly tapered. Always tight near the end of the cuts. We also note spots in the cast iron and caps that are hard and deflect the boring bar slightly. These small areas create hot spots in the bearing fit due to reduced clearances as the insert is distorted over these "bumps". We have found the most durable tooling is manufactured by: Micro 100 Tool Corporation The tooling we use: M100 series AL-6 Bit. (5/16") C5 Grade. The tooling is available in sizing to fit most boring bars.

When starting to assemble an engine, the first thing I do is carefully measure the line boring of the block. I have cylindrical ring gauges that are equal to the maximum block housing bore suggested by the bearing manufacturer. This gauge allows me to quickly calibrate my bore gauge and accurately measure the housing bores. I often find that a bore may be slightly cone shaped due to bit/tooling wear on the last pass of the line boring machine. I also detect the occasional small spot that deflected the boring bar. I have Sunnen portable hones set up for "A" and "B" line bores and I adjust/straighten the bores to the upper limit with very coarse stones. This honing step along with specifying a mid-range journal sizing on the crankshaft results in good bearing fit with little final honing of the insert shells necessary. Even with this extra work and tight grinding spec, about 50% of the assemblies require a light honing of the rear main inserts. I usually open them up about .0003" and they are perfect.

When assembling, if one is tight, I could ask the crank grinder to take a few tenths off the journal diameters but that takes time and running. I purchased a Sunnen precision honing machine and built a fixture that holds the inserts, with proper crush, to be able to adjust the final clearances. With the honing machine in my shop, the process takes just under 10 minutes per journal to complete the fitting. It is usually only the rear main that needs this adjustment.

I have not had a bearing failure since I increased the clearance to .002" from .00175" on the rear main. As I stated earlier, I set the clearance between .002" and .0022" for the rear main. If the front and center Plastigage out to .00175", I do not adjust them.

Side note: Inserts, when installed correctly, offer excellent service. I have over 90,000 miles on my inserted engine in my Phaeton. I have never had the pan off the engine since assembling it! I do not "baby" this engine and it has always made it home.

Summary:
JMO: If you are not able to complete this final adjustment to the clearances, you are probably better off using Babbitt instead of inserts.
Good Day Guys!

www.durableperformance.net

[modelAtony]

I HAVE OVER 70,000 MILES ON MY PETE'S AUTOMOTIVE engine and I haven't been driving this car for about 2 years now, working on interior and paint. I have never had one problem. Averaged about 1500 miles per month after retiring only run about 1,000 per month. My oil system is bone stock. Speeds on interstate 63-65 mph , when I get a whild hair I have run it up to 96 mph only for about 3 miles. see my info for more. Have fun modelAtony tony white Lafayette, LA

[1929]

Originally Posted by modelAtony

I HAVE OVER 70,000 MILES ON MY PETE'S AUTOMOTIVE engine and I haven't been driving this car for about 2 years now, working on interior and paint. I have never had one problem. Averaged about 1500 miles per month after retiring only run about 1,000 per month. My oil system is bone stock. Speeds on interstate 63-65 mph , when I get a whild hair I have run it up to 96 mph only for about 3 miles. see my info for more. Have fun modelAtony tony white Lafayette, LA

Are you using a fuel pump at that high speed?

[Dave in MN]

Originally Posted by modelAtony

I HAVE OVER 70,000 MILES ON MY PETE'S AUTOMOTIVE engine and I haven't been driving this car for about 2 years now, working on interior and paint. I have never had one problem. Averaged about 1500 miles per month after retiring only run about 1,000 per month. My oil system is bone stock. Speeds on interstate 63-65 mph , when I get a whild hair I have run it up to 96 mph only for about 3 miles. see my info for more. Have fun modelAtony tony white Lafayette, LA

96 mph! That's impressive and a bit crazy. Crazy like me...I once held mine at 78 mph for a full tank of gas on a Michigan freeway; that was the speed the left lane was rolling. Other than a full flow oil filter my oil system is stock also....no pressure. I have slowed down since then and typically hold it to keeping up with the slow lane on the freeway.
BTW: I ran that speed with a stock Zenith and "B" intake manifold with the Phaeton's top up. Top up on a Phaeton = pulling a deployed parachute!
Good Day!

[modelAtony]

Originally Posted by 1929

Are you using a fuel pump at that high speed?

Yes, in 2003 august, I added a web carb it was good up to 55 mph. It would not have good acceleration if you wanted to gouge on it a little . I added the 6 volt pump and it was great. my engine didn't have inserts then. One thing I had problems with was running up to speed was Vapor Lock at temperature out side at about 85-92 degrees, the electric pump really helped then. in 2008 I had my engine inserted. All has been well. Have fun modelAtony tony white Lafayette, LA

[modelAtony]

Originally Posted by Dave in MN

96 mph! That's impressive and a bit crazy. Crazy like me...I once held mine at 78 mph for a full tank of gas on a Michigan freeway; that was the speed the left lane was rolling. Other than a full flow oil filter my oil system is stock also....no pressure. I have slowed down since then and typically hold it to keeping up with the slow lane on the freeway.
Good Day!

Dave , when I would play with timing I would always go out on Interstate and open it up a little, I would always run a 2 mile hit and my buddy would always run the stop watch. The fastest I would ever go was 88 mph , one day Dennis said, was that the fastest i had ever ran ? I said yes but I had about another 1" OF THROTTLE LEFT. I said lets see what I got , Good clear Sunday no wind so we started my 2 mile run at about 55 mph. 2 mile he hit the stopwatch after pulling over I figured the time and I said, Holly Shit Dennis that's 96 MPH. Wednesday morning I was at automotive shop on dyno . 2900 rpm, 96 mph, 117 lbs torque and 65 HP .

[Dave in MN]

Originally Posted by modelAtony

Dave , when I would play with timing I would always go out on Interstate and open it up a little, I would always run a 2 mile hit and my buddy would always run the stop watch. The fastest I would ever go was 88 mph , one day Dennis said, was that the fastest i had ever ran ? I said yes but I had about another 1" OF THROTTLE LEFT. I said lets see what I got , Good clear Sunday no wind so we started my 2 mile run at about 55 mph. 2 mile he hit the stopwatch after pulling over I figured the time and I said, Holly Shit Dennis that's 96 MPH. Wednesday morning I was at automotive shop on dyno . 2900 rpm, 96 mph, 117 lbs torque and 65 HP .

Tony, Great stories...thanks for sharing. I have one more for you...on my Phaeton run of a tank full at 78 mph, I noticed the ride/car got real smooth and the steering very easy at 75 mph. It was like it was riding on air and I think it was. Like you, I also had a bit more pedal but unlike you, no reserve on the nerve.
Have a great day!

[old31]

Tony and Dave very cool.

I cant imagine what it would be like to see an A going down the highway at those speeds.

[René W]

Sponsored Links (Register now to hide all advertisements)

Tony and Dave cool story,could you tell us about the fish you caught too????must be humongeous too....................

[40 Deluxe]

Originally Posted by René W

Tony and Dave cool story,could you tell us about the fish you caught too????must be humongeous too....................

Size of fish only limited by length of arms!

[quickchange]

Tony , 96 mph ??? what body style ??? The world record on a stock closed car flat head blown is 97.1 ?? so with only 65hp was you coming down hill on pikes peak ?

[Mitch//pa]

For the details, specifics look at Tony's album in his profile page

You da man Tony

[40 Deluxe]

Originally Posted by modelAtony

Dave , when I would play with timing I would always go out on Interstate and open it up a little, I would always run a 2 mile hit and my buddy would always run the stop watch. The fastest I would ever go was 88 mph , one day Dennis said, was that the fastest i had ever ran ? I said yes but I had about another 1" OF THROTTLE LEFT. I said lets see what I got , Good clear Sunday no wind so we started my 2 mile run at about 55 mph. 2 mile he hit the stopwatch after pulling over I figured the time and I said, Holly Shit Dennis that's 96 MPH. Wednesday morning I was at automotive shop on dyno . 2900 rpm, 96 mph, 117 lbs torque and 65 HP .

Could I suggest making this run using a GPS to record the speed? Using a stopwatch and hiway mile posts leaves a lot of room for potential error. After working for AZ DOT for 27+ years I know mile posts are not accurate!
A run in both directions will compensate for any downhill effect (a slight grade is not always noticed). A cellphone shot of the GPS screen for posterity, too!

[quickchange]

So you are saying 95mph in a stock body tudor with 65 hp what weed are you on . Sorry im a disbeliever, & I hold the record at Mojave mile in a stock body 30 cpe, with a lot more HP than that .

[Synchro909]

Originally Posted by 40 Deluxe

Could I suggest making this run using a GPS to record the speed? Using a stopwatch and hiway mile posts leaves a lot of room for potential error. After working for AZ DOT for 27+ years I know mile posts are not accurate!
A run in both directions will compensate for any downhill effect (a slight grade is not always noticed). A cellphone shot of the GPS screen for posterity, too!

While all of that might be so, it is clear that he was doing a high speed - too high for my liking.
Back to the OP, I've run inserts for tens of thousands of hard miles towing a camper) without trouble. As for inserts only being available in 0.010" increments, I agree, that is a big minus. Maybe vendors would be well advised to offer them in 0.005" increments.
When i was in my early teens, I remember my father working on the engine in his Austin daily driver to work. For the bearings, he interchanged top and bottom shells and took up the excess clearance by putting cigarette papers under the non load bearing shell. Each paper reduced the clearance by about 0.001". I've heard of the same being done with aluminium foil or thin brass shim. That motor went for years until my sister got her licence and travelled too fast for too many miles when it put a leg out of bed. I haven't completely dismissed doing similar in my A engine - packing the bearings, that is.

[Dave in MN]

Originally Posted by René W

Tony and Dave cool story,could you tell us about the fish you caught too????must be humongeous too....................

Well I used to fish with my brothers quite a bit but it seemed that whenever I joined them the fish didn't bite...so I do not get invited much anymore.

But for the tale of 78 mph in a '29 Phaeton with the top up...well I did have a good bit of a tail wind as I recall. The fuel economy was terrible at about 15 mpg. But true story, I had some pedal left. The air coming in under the front fenders and the reactionary force of the top being up was lifting the front end up and I chickened out to go any faster. The speed limit at that time was 70mph but like I said, the left lane was really moving that Sunday morning. We were on our way to a National as I recall and fell behind the group we were traveling with because my wife wanted to stop and see Mackinaw Island.
I wanted to make it to the opening day swap meet.

I guess I'm not telling the whole story. I also have a counterweighted crank, a 26% Mitchell, "B" grind new cam, 5.9 Brumfield shaved once to flatten it, maxed out pistons @ .125 over by choice, performance Aries muffler, 4:11 rear ratio, electronic ignition and a "B" intake manifold with a stock Model A Zenith carb. I also have cast iron brake drums on all four wheels, set up tight and they will lock up on pavement if I bear down.

It was fun watching the double takes of the drivers in their "moderns" in the right lane as I sailed by them!
True story...honest!
Good Day!

[Mitch//pa]

I run and recommend all insert motors over babbitt.. if the motor is rebuilt / machined correctly for inserts your good to go. I like being able to service the engine myself and not be held hostage by the babbit gods.

[René W]

Originally Posted by Dave in MN

Well I used to fish with my brothers quite a bit but it seemed that whenever I joined them the fish didn't bite...so I do not get invited much anymore.

But for the tale of 78 mph in a '29 Phaeton with the top up...well I did have a good bit of a tail wind as I recall. The fuel economy was terrible at about 15 mpg. But true story, I had some pedal left. The air coming in under the front fenders and the reactionary force of the top being up was lifting the front end up and I chickened out to go any faster.

I guess I'm not telling the whole story. I also have a counterweighted crank, a 26% Mitchell, "B" grind new cam, 5.9 Brumfield shaved once to flatten it, maxed out pistons @ .125 over by choice, performance Aries muffler, 4:11 rear ratio and electronic ignition.

It was fun watching the double takes of the drivers in their "moderns" in the right lane as I sailed by them!
True story...honest!
Good Day!

That explains a bit,my thought were you were running a stock Model A with a bigger carb.
My A is done by 65 mph............

[Dave in MN]

Quote from Synchro909
"Back to the OP, I've run inserts for tens of thousands of hard miles towing a camper) without trouble. As for inserts only being available in 0.010" increments, I agree, that is a big minus. Maybe vendors would be well advised to offer them in 0.005" increments."

I guess I would agree it would be nice to see sizing increments of .005" but the tooling to create another size in between the existing sizes may be costly. With the extra sizes each close size would only sell at about half the present rate. The cost of the present inserts would have to be more to cover these costs.

Having built over 150 of these engines with inserts, I think if two sizes could be added to the present mix of availability the most needed sizes would be: .025" and .035".
I find I use .020" and .030" sizes at a ratio of 2:1 over .010" and .040".

I just received an order from my supplier on main bearing inserts. The next time I talk to him, I will ask him if it would be economically feasible.

Good Day!

[dansluck]

Thanks for all the information.

[modelAtony]

Originally Posted by quickchange

Tony , 96 mph ??? what body style ??? The world record on a stock closed car flat head blown is 97.1 ?? so with only 65hp was you coming down hill on pikes peak ?

Flat ground. 31 Tudor, 3;27 rear, Mitchell, gps and always stopwatch, 60 mph 1800 rpm, I hve been thinking about my bucket list , I would like to run Salt flats just to see what happens. I saw the 30 coupe Lickety- Split set speed at around 97 mph a few years ago and last year I think I saw and last I checked it was over 120 mph. Have fun modelAtony tony white Lafayette, LA All can say what they want, The car stands on its own merit and runs as Ive said.

[Big hammer]

Well that answers my question! 3.27 rear gear + Mitchell overdrive, would that combo work
And very well thanks Tony :-)

[quickchange]

Modelatony . yes pet holds the record at 97.1 also ohv record at 116 mph , takes around 190 hp to push a stock body too that speed , Look forward too seeing run at speed week this year , we hope to have our ,( Cyrils ), 30 cpe to run too. We should get together & chew the fat , Derek in a hot NZ

[modelAtony]

Originally Posted by quickchange

Modelatony . yes pet holds the record at 97.1 also ohv record at 116 mph , takes around 190 hp to push a stock body too that speed , Look forward too seeing run at speed week this year , we hope to have our ,( Cyrils ), 30 cpe to run too. We should get together & chew the fat , Derek in a hot NZ

Always wanted to ask you questions about the flats but didn't want to bug you about it. I really like seeing your post. Have fun modelAtony tony white Lafayette, LA

[Dave in MN]

Originally Posted by George Miller

One problem is it is a long ways for the oil to get to the back of the bearing with out pressure oiling. The way I fix the problem is a oil groove in the upper bearing.

George, I tried the same thing by extending the oil "wells" along the seams of the two insert halves. I extended the well (both sides) to within .25" of the back end of the bearing. I put the engine back on the dyno and had the same failure on the first heavy pull. Granted, placing a groove at the top may be better than both sides but I did not try your method. At this point, it is not something I am going to try as I have found a solution that works for me....more clearance.
It was at this point, I invested in a Sunnen precision honing machine and increased the clearances.
No problems since.

FYI: This experimental engine had a Burlington crank, Lion Speed head III delivering north of 80 hp at 3000 rpm. So the temps and pressures were beyond normal Model A. A wisp of smoke was coming from the bellhousing as I finished the first pull and when I cut the throttle, the rear main locked up. (Strike Two!) The rear journal cleaned up, using muriatic acid, with no damage.

[George Miller]

You need to start the groove at the top front of insert at the pass side of the oil well, and end it at the driver side oil well at the rear of the insert. Then the oil will be forced under the bottom insert with hyd wedge. The oil getting into the bearing at the front is the wrong place. the oil should be interring at the center of the bearing.

[Dodge]

Have you guys talked to the manufacturer about doing this process to future bearings?

[Tom Wesenberg]

On the oil well on the right side, at the seam of the block and cap, does the bottom edge (cap edge) have a nice radius to allow the oil to get rolled into the clearance?
A sharp edge would be more likely to scrape away the oil.

[Dave in MN]

Sponsored Links (Register now to hide all advertisements)

Here are some photos of the fixture I built to hone the aluminum lined insert bearing shells.

The fixture is bored .00015" below the maximum block housing bore specified by the bearing manufacturer. Note there are a split dowels, like I use on all the mains, to hold position between cap and block incorporated into the fixture.

The insert shown is either the center or front main insert. The rear main insert fills the entire fixture end to end. Note the radial oil delivery groove in the insert.

[hardtimes]

Originally Posted by Dave in MN

Here are some photos of the fixture I built to hone the aluminum lined insert bearing shells.

Hey Dave,
Very nice ingenious setup !
Inserts look to be ONE piece. Who supplies these one piece ?
Do you ever use TWO piece bearings per main ?

[Dave in MN]

See post #46: These inserts, designed specifically for the Model A, are supplied by Antique Engine Rebuilding (AER), Skokie, IL. They have worked very well for me.

If you look close, you will see the Plastigage marking on one half of the shell. The initial clearance was between .0015" and .00175" before honing. Between .002" and .0022" when honed to proper clearance.

hardtimes: I used two piece (two wide set with a radial oil ring between them) Clevite & Fed Mog bearings on about 16 engines but have not done so for the last 5 years. The supply for these bearings was getting difficult to find readily. They were constantly being backordered when I would order multiple sets. The two piece inserts worked good also. They were tri-laminated. Babbitt over copper on steel. I have two piece Fed Mog inserts in my Phaeton and have had no issues after 90,000 miles.
Good Day!

[sphanna]

It seems like there are different opinions about inserts. It looks like the quality varies between shops. I just want to mention that I have inserts by AER in Skokee. Very satisfied after 11,000 happy miles

[hardtimes]

Originally Posted by Dave in MN

See post #46: These inserts designed specifically for the Model A are supplied by Antique Engine Rebuilding (AER), Skokie, IL.
They have worked very well for me.

If you look close, you will see the Plastigage marking on one half of the shell. The initial clearance was between .0015" and .00175" before honing. Between .002" and .0022" when honed to proper clearance.

hardtimes: I used two piece (two wide set with a radial oil ring between them) Clevite & Fed Mog bearings on about 16 engines but have not done so for the last 5 years. The supply for these bearings was getting difficult to find readily. They were constantly being backordered when I would order multiple sets. The two piece inserts worked good also. They were tri-laminated. Babbitt over copper on steel. I have two piece Fed Mog inserts in my Phaeton and have had no issues after 90,000 miles.
Good Day!

Hey Dave,
Thanks much for your helpful response !
I have a full set of main bearing shells for the B engine that I'm planning. Two sets per main. That is why I asked your input. You apparently are a successful A/B engine builder and post helpful pictures of your work ! There will have to be TWO tangs for each half, rather than the one tang on a one piece shell set. Next time, I'll check out AER shells for purchase.

One other question. I have a real nice set of B rods and have been told that inserts are available, if the rods are cut 2.140 (I think?). Do you know of anyone who does this work on original B rods ?

[Dave in MN]

Originally Posted by hardtimes

Hey Dave,
Thanks much for your helpful response !
I have a full set of main bearing shells for the B engine that I'm planning. Two sets per main. That is why I asked your input. You apparently are a successful A/B engine builder and post helpful pictures of your work ! There will have to be TWO tangs for each half, rather than the one tang on a one piece shell set. Next time, I'll check out AER shells for purchase.

One other question. I have a real nice set of B rods and have been told that inserts are available, if the rods are cut 2.140 (I think?). Do you know of anyone who does this work on original B rods ?

Ron Kelly would likely do this type of work. In the past, he machined original "A" rods for inserts. "B" is the same work...just different sizing.

[Synchro909]

I know this is an old thread but I take back anything favourable I said in it earlier. I have just set about relacing the inserts throughout my engine. The big ends were good but the mains are a mess. The lower insert on both the front and middle main bearings had a piece of babbit missing from the slot for the oil to enter to the edge (about 3/8"). This is not the first time this has happened to me but the big disaster was the rear main. The babbit was wiped all around the bearing due to lack of oil. These inserts are incredibly poorly designed. There is waaaay too far for the oil to travel to get to the whole length of the bearing as George Miller said early on. I intend cutting a spiral groove in the top insert and maybe the bottom too to get oil to the back of the bearing. Comments on that would be appreciated.
Why on earth did the makers not do what has been done for many decades with babbit bearings and cut an oil groove in them??? Sheer incompetence, in my book.
This thread is old enough now that maybe someone has made this modification and done a lot of miles on it. How did it go?
In an effort to make sure the bearing is able to get enough oil, I tried blowing air from the lower end with one side of the gap where the insert would have been blocked with the old insert and looking for something at the top. I didn't find much at all. Is anybody able to describe to me where the top end of the oil hole to the rear main bearing is located - perhaps in relation to the cam follower bosses. I can't get to my spare bloch at the moment.

[BRENT in 10-uh-C]

When conversions were in their infancy on the Model-A/B blocks, and when we were using multiple bearings within the main bearing web, machinists would use an end mill and create a way for the oil to feed the hole in each of the bearing shells. When Rich created the one-piece bearing, this eliminated this op.

My personal take is that the 'art' of casting bearings has improved greatly to the point where the longevity of casting bearings exceeds what is available for the inserted bearings. The availability of top-quality "Babbitt", the knowledge of how to pour, peen, and burnish properly, -and the use of good quality line-boring machines (such as Tobin-Arp or Berco) that are rigid and use a hydraulic feed have been the game changer. For these reasons, we are seeing owners with failed bearings converting back to cast bearings. I liken insert conversions to electronic ignition conversions, powder painting, and hydraulic brakes where each had their day where they were considered necessary, yet all have seemingly failed the test of time and now deemed not superior or necessary.

On your own engine, two things that would scare me as an engine rebuilder. If the soft metal has failed on your bearings due to lack of oil, I would want to inspect/mic the crank journals carefully as I would expect to see a surface finish deterioration and wear that would cause the journal pin to be out-of-round. Also, when you 'carve' a groove for the oil to transfer, you will likely disturb the bond of the soft metal which could cause flaking and you will likely cause the soft metal on both sides of the groove to rise above the surrounding areas potentially causing scoring on the crankshaft.

One other thing to keep in mind is ensure you do not allow an insert bearing to roll or spin in the cap or in the block as this will distort the cap or block generally requiring both to be line-bored again.

[Jack Shaft]

Technology has greatly aided the poured bearing process. Infrared temperature guns has taken the 'art' out of tinning and babbit pour temperatures.

The hydrodynamic principle requires adequate oil feed on the un loaded side of the bearing gravity or pressure. Insert bearings perform best when pressurized,it helps keep them clean and cool and will reduce the incident of failure with an A engine.Vendors love insert bearings,its straight forward work,line bore the block,snap in the bearings,ship the job.The risks are way less than the pouring process risk..and when they do fail its well out of warranty..win-win from a business perspective.What amuses me is how they sell inserts by propagating myths about poured bearings..they wont handle compression,they don't last,you name it.No bearing tolerates the torsional vibration inherent in a model a engine,Ford Engineering identified the issue in development..throwing in inserts and a counterbalanced crankshaft doesn't exempt you from that hard and fast rule.

[Pete]

"One other thing to keep in mind is ensure you do not allow an insert bearing to roll or spin in the cap or in the block as this will distort the cap or block generally requiring both to be line-bored again."

Very true.
Most people do NOT realize that the tang on a bearing shell is there ONLY to locate the shell on assembly. It does NOT keep the shell from spinning. The crush holds the shell in place.

[Synchro909]

The reason I asked about this is the concern in my mind about the bearing surface of the insert cracking or flaking near the groove. I don't think it would be a problem on the top insert but what of doing it on the bottom too? Comments sought, please.
I see no point reinstalling the current setup - it will only happen again. The inserts didn't spin in the block. I understand about the tabs. The bearing material was almost gone in places so I got in there just in time to prevent the inserts welding themselves tot he crankshaft journal. The pournal looks worse than it is. I can just feel slight ridges on it so I think I'll go again with it.
I do my best thinking while I'm asleep and I have awoken this morning with an even stronger leaning towards putting a groove in the top insert and reinstalling.
I PMed George Miller (who made comments above) but he hasn't replied yet. I'm not even sure he still posts here.

[Dave in MN]

Synchro,
I made a series of tests on an engine I was building for myself on my dyno some years back related to the required oil clearance for the insert bearings I use. I found I needed to increase the oil clearance for the rear main to between .002" to .0022". Any tighter and I could experience a failure (lock up) when the engine was heavily loaded. The manufacturer suggests .00175" and that will work for the front and center bearings, I prefer a bit more between .00175 to .002".
I tried increasing the oil groove at the parting line of the inserts approaching .25" from the rear of the bearing but it also failed. The only thing that worked was more oil clearance.
Hope you solve your issue.
Good Day!

[Synchro909]

Originally Posted by Dave in MN

Synchro,
I made a series of tests on an engine I was building for myself on my dyno some years back related to the required oil clearance for the insert bearings I use. I found I needed to increase the oil clearance for the rear main to between .002" to .0022". Any tighter and I could experience a failure (lock up) when the engine was heavily loaded. The manufacturer suggests .00175" and that will work for the front and center bearings, I prefer .002".
I tried increasing the oil groove at the parting line of the inserts approaching .25" from the rear of the bearing but it also failed. The only thing that worked was more oil clearance.
Hope you solve your issue.
Good Day!

Thanks, Dave. This motor has done about 40,000 miles, mostly while working hard towing a camper that weighs about the same as the car at 50mph all day long. The journals are slightly worn so I hope that will give a little more clearance for now.
I'm only mildly surprised that widening the gap between the inserts didn't work. I think a spiral groove would work much better because the rotation of the crank shaft would help the oil along it

[Jack Shaft]

Spiral grooving and increasing clearance can have a negative effect on the oils ability to support the crankshaft.Modern oils have better load carrying properties,so opening the clearance to .002 works but resist the desire to do more.Any grooving on the bottom of the bearing (center of the cap) reduces the cushion effect in the area of the groove.Given what your experiencing Id say is a failure of the babbit adhering to the copper of the insert,not a lubrication issue.

[Dave in MN]

Synchro, Is it possible that the timing was a bit too far advanced for the load at times? It only takes a short run with too much advance to damage a bearing. Would you be able to share some photos of the insert shell? Thanks.

[Synchro909]

Originally Posted by Jack Shaft

Spiral grooving and increasing clearance can have a negative effect on the oils ability to support the crankshaft.Modern oils have better load carrying properties,so opening the clearance to .002 works but resist the desire to do more.Any grooving on the bottom of the bearing (center of the cap) reduces the cushion effect in the area of the groove.Given what your experiencing Id say is a failure of the babbit adhering to the copper of the insert,not a lubrication issue.

There is no copper evident in the insert. What you say about a groove in the bottom compromising lubrication, I suspected. That is why I asked.

[Synchro909]

Originally Posted by Dave in MN

Synchro, Is it possible for that the timing was a it too far advanced for the load at times? It only takes a short run with took much advance to damage a bearing. Would you be able to share some photos of the insert shell? Thanks.

I'll ask my grandkids to help me get some pictures up.
Your question about timing might be on the money but not because I advanced it too far but because it developed the Model A 3/4 crossfire and it took me a while to find it. The symptoms were pinging at any time -- no relationship to load or advance or speed or octane of the fuel etc. Then, a few miles down the road I'd come to a hill and the car would fly up it with no sign of trouble - the very time you'd expect it to ping. The latter observation tells me that the timing was good. There is another complication here though. If there is a cross fire, number 3 fires at the same time as #4. The firing order is 1,2,4,3 which means that when #4 fires, #3 is at the beginning of its compression stroke and that would cause mayhem in there. When #3 fires, #4 is at the bottom of its power stroke which would be a bit of a non event. Clearly, it is the middle main bearing that would get the harder time of it, not the rear one. The middle main was fine but it is pressure fed at 25 psi. Was it protected by the pressurised oil feed even though it is much smaller than the rear (gravity fed) bearing?

[Pete]

Maybe we are using the wrong material for bearings. My Dad told me that his buddy had to get from Omaha, Ne. to Lincoln, Ne. one night and 2 rod bearngs went out along the way.
They fixed it with 2 pieces of a leather belt and made it with time to spare. The engine was junk though.

[Synchro909]

Originally Posted by Pete

Maybe we are using the wrong material for bearings. My Dad told me that his buddy had to get from Omaha, Ne. to Lincoln, Ne. one night and 2 rod bearngs went out along the way.
They fixed it with 2 pieces of a leather belt and made it with time to spare. The engine was junk though.

These are the inserts being sold by the vendors. I agree trimetal would be better but they wouldn't make as much profit
I'd rather keep the leather belt holding my strides up!

[updraught]

I take it these are AER bearings sold by the vendors? I haven't heard of any AER engines having problems with their bearings. What is being done differently there?
http://www.fordgarage.com/pages/AERbearinginserts.htm

[Synchro909]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by updraught

I take it these are AER bearings sold by the vendors? I haven't heard of any AER engines having problems with their bearings. What is being done differently there?
http://www.fordgarage.com/pages/AERbearinginserts.htm

Those are the bearings and I can't see anything done differently in my engine but the front and middle bearings don't last either. A piece breaks out of them from the end of the oil slot to the edge of the bearing on the bottom insert. That hasn't been fatal but I got to the rear one just in time to avoid a more expensive exercise.I'm being serious when I ask "Is it possible to go back to babbit bearings now that the block has been machined for inserts?" I would be happy enough to stick with the bronze thrust faces but these inserts haven't been what I had hoped.

[Jack Shaft]

Standard insert bearings are of laminated construction, the babbit is applied to a base metal,usually copper or steel.With copper sometimes the copper is applied to steel,then the babbit is applied to copper.It appears the thin layer of babbit on your bearings is delaminating.

Leather belt? the story I was told was the tongue of a shoe,They also ran them on penny a quart 'drain' oil,Oil saved from regular customers cars service.

[Chuck Sea/Tac]

Originally Posted by Pete

Maybe we are using the wrong material for bearings. My Dad told me that his buddy had to get from Omaha, Ne. to Lincoln, Ne. one night and 2 rod bearngs went out along the way.
They fixed it with 2 pieces of a leather belt and made it with time to spare. The engine was junk though.

Hi Pete. A couple years ago I had my A up at Lowe’s and this older employee saw my car and Proceeded to tell me his leather belt story. Unfortunately, the leather doesn’t last for too many miles,- - - but the stories do!

[SAJ]

Originally Posted by Jack Shaft

Standard insert bearings are of laminated construction, the babbit is applied to a base metal,usually copper or steel.With copper sometimes the copper is applied to steel,then the babbit is applied to copper.It appears the thin layer of babbit on your bearings is delaminating.

Leather belt? the story I was told was the tongue of a shoe,They also ran them on penny a quart 'drain' oil,Oil saved from regular customers cars service.

AER inserts are described as bimetal, steel backing with aluminium silicon bearing surface. No babbitt in them. This information is from various sources including a long description from Vince Falter quoted by Updraught above in this topic.
SAJ in NZ

[Jack Shaft]

Aluminum alloy bearing? they can delaminate as well. Torsional vibration on well supported and correctly applied poured bearings should be tolerated better than on laminated shell bearings.Torsional vibration (and improper timing) act like a hammer on a bearing,a two or three piece laminated shell 'snapped' into a bearing cap might have just enough instability to be susceptible..if we are theorizing..

[Lawrie]

Arnold.
Arnold, those bearings were just going into lockdown.
Lawrie

[Jeff/Illinois]

Wow good thread, good info here

[johnneilson]

Don’t you mean lock up?

I hesitated using King brand bearings because matl is aluminum
Finally had to use them, no problems at all
Just ensure clearances and lube

John

[Dave in MN]

Synchro909,
I have used AER bearing shells for the past 12 years in over 180 engines. Since I started using them I can only recall 4 engines that had the experience of the bearing material breaking loose from the steel shell like you describe. It was determined in all cases, the problem was too much advance while running under a high load or speed. One gent had his timing north of 40 degrees advance, the others were well over 30 degrees with higher than standard compression heads. In three of the cases, the repair was to polish the mains, replace the inserts and set the timing correctly. The fourth crank needed to be turned to the next size smaller.

In all cases, the engine also had insert bearings in the rods. The rod bearings showed excessive pressure marking on the inserts so they were also replaced as a precaution. The engine with the damaged crankshaft showed little bits of bearing material deposited on the rod bearings. Apparently, the oil carried some of the pulverized center main bearing material into the rods.

During this same period of 12 years while taking engines in for rebuilding, I have seen well over 75 percent of the engines with Babbitt bearings broken up and delaminating. That’s not to say that there is a problem with Babbitt bearings though as it would be normal the engines brought to my shop have bearing problems. The high percentage of failure exhibiting bearing fracture is typical of Babbitt because the clearances increase to the point where the oil film cannot support the loads and the crankshaft journal comes into contact with the bearing material causing it to fracture.

I specialize in installing insert bearings in engines. I do not pour Babbitt bearings. If someone wants Babbitt bearings, I refer them to another shop. If there was a shop pouring Babbitt correctly, close to me, I would be using Babbitt if the customer desired. I think either Babbitt or insert bearings will work well in our Model A or B engines if installed and fitted correctly. The debate continues as to which material is more suitable, I don't see the end to the debate anytime soon. I think of greater importance than the choice of Babbitt or insert is the precision of the installation. For those readers considering Babbitt or insert bearings: Choose a shop that is the best at what they use and one that stands behind their work. Keep in mind, oil clearance is critical for either type of bearing. Too much clearance and the oil film will be lost at high loads. Too little and the bearings run hot and are in danger of seizing if inserts.

Synchro, leading up to this failure, you know there was a “cross-fire” problem between cylinders 3 & 4 because you heard the pinging. Now that you are familiar with the cross-fire problem, you would be very quick to recognize it should it happen again. You understand the importance of proper timing and know how to set it. Lastly, you know to retard your timing slightly when pulling the camper up a long hill. I believe your bearing failure occurred during the cross-fire event. I also believe you would have done damage to any bearing material during this event.

You have gotten almost 40k trouble free miles on a set of insert bearings and would likely still be running if it were not for the cross-fire event. If the engine were mine, I would polish the journals, replace the inserts, make sure you have about .002” oil clearance at the rear main and run it. With the additional bearing width at the rear main, it can handle and actually needs the additional clearance. The pressure oil you feed to the center main is a very good solution to keep this often abused bearing well oiled. Keep your timing in check and you will very likely greatly exceed your previous 40k. (I have 98k on my Phaeton insert bearings with pressure oil to the center main and filtered oil.)
Sorry for the length of the post...it is long but hopefully helpful!
Good luck with your project and Good Day!

[Synchro909]

Dave,
Your comments in the last 2 paragraphs are 100% correct. I would recognise a cross fire very quickly now and as you say, I understand how to adjust the timing. Until your comment where you mentioned the timing, I hadn't connected the crossfire with the failure (that was 4 years ago and I haven't done many miles in that car since). I have been told by many that the middle main bearing is no weak point in these engines. Experience said it was so I fed it anyway.
I am about to complete the reassembly of the engine today but we are back in lockdown so I won't be able to give it a good drive for a while. If I get another 40K miles out of it, I would be happy. I realise I ask a lot of the engine when I'm towing. Our longest day so far was 700 miles before we collapsed into slumber. I fully expect that my engine would be still going fine for many miles yet if it weren't for the demands I make of it.
Again, thanks for your input here.

[Synchro909]

Dave,
Your comments in the last 2 paragraphs are 100% correct. I would recognise a cross fire very quickly now and as you say, I understand how to adjust the timing. Until your comment where you mentioned the timing, I hadn't connected the crossfire with the failure (that was 4 years ago and I haven't done many miles in that car since). I have been told by many that the middle main bearing is no weak point in these engines. Experience said it was so I fed it anyway.
I am about to complete the reassembly of the engine today but we are back in lockdown so I won't be able to give it a good drive for a while. If I get another 40K miles out of it, I would be happy. I realise I ask a lot of the engine when I'm towing. Our longest day so far was 700 miles before we collapsed into slumber. I fully expect that my engine would be still going fine for many miles yet if it weren't for the demands I make of it.
BTW, I use a full flow filter.
Again, thanks for your input here.

[Lawrie]

Arnold , have a think about full pressure lube to all the mains.
Lawrie

[Jack Shaft]

Ford made a number of improvements with B engine design to deal with the main bearing issues with the A.The most influential one was the mechanical advance distributor,taking engine timing from the operator does two things,it insures proper timing at all rpm ranges and eliminates the operator input...both beneficial in avoiding detonation,which works like a sledgehammer on bearings.

[Synchro909]

Originally Posted by Lawrie

Arnold , have a think about full pressure lube to all the mains.
Lawrie

I've seen a couple of descriptions on how to do that and they both look very complexicated (?!) I'm sure pressure would help and I will probably look into it at the next rebuild. You know how well this engine runs and longevity is about the only thing I'd like to improve. Pressure would do that and knowing what the crossfire symptoms are, I'm sure that won't compromise things again.
Which system for pressure is favoured by the members here. Plumbing in the valve chamber or in the crank case?
I think I prefer the latter so that oil can get to the top of the engine after going through the bearings and then get to the timing gears.