26 Tmotor

[visionary]

Just got my motor back from the machine shop and started checking things over and noticed that there isn't any end play in the crank (none at all) also the front cam bearing seems very loose, you can actually grab the cam gear and move the cam a good 1/16" in all directions. the bearing looks loose in the bore. i would think that there should be a few thou end play and that the front cam bearing should be held firmly in place.

Also noticed on the area of the timing cover that holds the felt seal .that the gap between the crank snout and cover isn't consistant, it's tight on one side and a good size gap on the other. is that acceptable? and will the felt seal make up for an imperfect gap.

Thanks for your help
Scott

[Steve Jelf]

No, the cam shaft isn't supposed to wander around. I don't have the engine book handy to check the numbers, but 1/16" of play sounds pretty drastic. The timing gear cover is supposed to be installed with a tool that centers it on the cam shaft. If it's off center a roller timer may be erratic.

[visionary]

Thanks Steve, i don't have the tool but i bolted the cover on and visualay centered it with the cam. i know that's not close enough for a finished product but i was just fiddleing around seeing how things go back together and it doesn't look as though the crank snout will be centered in the timing cover opening. maybe i'm getting ahead of myself and should get the centering tool befor continuing, but if it does come down to the snout not being centered perfectly will the felt seal work ok?

[J Franklin]

Use the tool, Ford did.

[yachtsmanbill]

Originally Posted by J Franklin

Use the tool, Ford did.

Luke used the Force... LOL

Make sure the cam bearing retaining bolt is installed behind the generator mount casting on the front. On the crank thrust, did you use a bar and a dial indicator? The shop that installed the rear main mite have put a film of grease on the thrust faces which will use up that .002- .003" and without a little "force" youll never see the clearance. Thats only about a "red" hair... ws

[Jack Innes]

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Originally Posted by visionary

Just got my motor back from the machine shop and started checking things over and noticed that there isn't any end play in the crank (none at all) also the front cam bearing seems very loose, you can actually grab the cam gear and move the cam a good 1/16" in all directions. the bearing looks loose in the bore. i would think that there should be a few thou end play and that the front cam bearing should be held firmly in place.

Also noticed on the area of the timing cover that holds the felt seal .that the gap between the crank snout and cover isn't consistant, it's tight on one side and a good size gap on the other. is that acceptable? and will the felt seal make up for an imperfect gap.

Thanks for your help
Scott

The felt seal & the tool will not cure the play in the cam gear. The spec. is maximum .004 end play & .003" side play on the front cam bearing. Did they leave the front cam bearing out?


It sounds like some time spent with Plastigage now will save a lot of heartache later. The end play should be checked with feeler gages - .002 to .004". A new bearing job may initially feel tight enough to not allow the crank to be easily moved through the end play. .001 to .0015" is a good clearance on the mains & rods. They will quickly run in to a little more than that.

It might be wise to check that all of the oil holes have been opened in the bearings as well.

[visionary]

The thrust surface is very uneven, i did use a pry bar to try and move the crank rearward, and i can't detect any movement. however you can fit .002 feeler guage into one small area in the middle of the thrust surface but the majority of the thrust has no clearance at all tight.

As far as the cam bearings go i had asked him if he replaced the cam bearings and he said he only replaced the rear as the others were in spec, but for some reason you can grab the timing gear and move the cam around so much that you can see daylight between the outer bearing surface and the block casting. and i'm wondering if this was done on purpose to allow the cam gear to move uppward to compensate for a bad line bore job.

[Steve Jelf]

I don't like the cam being loose. Sounds like a recipe for trouble. While we're at it, I hope you're not using one of those old fiber timing gears.

[visionary]

Steve, he did put a steel gear on it, but after pulling it down i did find that one of the cam lobes is worn down pretty bad. i'll put a new cam and fresh bearings in her, and then use the proper tool for the timing cover and then see how everything fits.

$3,400 and the cam and bearings are worn,the block deck and cyl head was never surfaced the block itself is still rusty and greasy, and what was done is done poorly.

I could have done better doing an in chassis rebuild, live and learn i guess. i think i'll be dropping this motor off at snyders to let them go through it properly.

[Farmallcub49]

$3,400 does that include all parts and a completely rebuilt/balanced transmission/engine? Was the pan straightened? Rebuilt hogshead?

New cam bearings are slightly oversized and usually compensate for a worn bore in the block. The new bearings and some locktite should hold everything in check. We do a much better and thorough job for around the same price.

[redmodelt]

If you pull the rear cap off to take a look, the thrust surface on the crank it's self should be just as smooth as the rest of the crank. If this area is ruff or has rings it will act like a file and quickly wear the babbett away. This is one area overlooked by some engine re-builders when doing the crank. Did your babbetter use the correct tool to line bore? It should have a false cam so as to set the center to center distance of the cam and crank.
The seal area on the front cover for the crank is a "as cast" area so there could be some miss alignment in relation to the crank. As long as it does not rub and has room for some wear in the babbett you should be ok.
yachsmanbill, asked a good question, are the cam bearing retaining bolt tight? Pull the cam and bearings out and inspect the holes that those bolts fit into, are them nice and round or do they look like they have been hammering back and forth. If they look good there are several ways to take care of the loose fit to block. You can shim the bearings or build up the outside with babett or solder then turn down to size. Try doing a fit of just the bearings (front and center) in the block without the cam to see if it is indeed the bearing to block fit or just worn cam/babbett.

[CharlieB]

Damn, it's one horror story after another with some of these "re-builders". What the hell did they expect to happen if you hadn't done some checking? That bouncing camshaft will be jumping teeth in no time at all. Pull that rear main and make sure they didn't just slap in a new cap and you have half a thrust surface.

[visionary]

Yachtsmanbill: thanks and yes the cam bearing retaining bolts were tight and in good shape.

Farmallcub49: The $3,400 ended up being just for the motor. when i originally contracted this guy he said $3,000 for a complete rebuild. and after looking on the internet and seeing that the industry standard was around that for engine and trans i gave him the go ahead thinking he would perform the same services as everyone else. the job ended up taking 6 months and everytime i would call to check on progress he would answer the phone with a big sigh and act disturbed and agitated.

I did the hogshead myself and will be doing likewise with the trans, he didn't balance anything either but i'm not sure if that'll matter on one of these.

Redmodelt: good call. i did as you mentioned and pulled the cam and installed the bearings and yes they are extremelly loose you can clock them back and forth. i'm not sure what equipment he used to bore the mains but i was there after he did and noticed he had hand scraped the oil grooves with a bearing scraper and not the proper tool, the grooves were very shallow and i questioned him on that and he said that he didn't like to scrape them very deap as the babbit is very thin?

CharlyB: I'm glad you mentioned that about the thrust. yes it's only on the cap half, this is my first T motor and i was wondering why it's only on the cap side and as you said this would have made a Hell of a mess with the cam gear bouncing around, and probably eratic timing, both valve and ignition.

Thanks for the info fellas

Scott

[40 Deluxe]

Have you gone back to this "rebuilder" to see if he stands behind his work? Maybe the owner just hired a new guy who is proving to be an incompetent hack (and crook) and the owner failed to do any quality control follow-up. Try for a refund. If they can't do it right the first time, how can they do it over?

[visionary]

Very good point 40 deluxe. i have been in contact with the rebuilder and he has offered me a $1,000 refund so i can take corrective measures. just not sure how far that'll get me though.

[Farmallcub49]

Six month turn around isn't a bad time for someone who is good and therefore busy. Our engines average about that turn around for a complete rebuild. I would ask for a total refund, because it sounds like you need to start over. Was the block even checked for cracks? Was the oil pan straightened? Balancing them is important, it makes everything run so much smoother and helps with preventing crankshaft breakage and transmission problems. Make sure you balance the transmission also.

[redmodelt]

All the thrust is built into the cap for the 3ed main. There is no thrust in the block part of the 3 main. Right or wrong, I match the rods for weight and balance the flywheel/magnet assembly. Unless you are building a speed machine, most Model T run in the 1500 RPM or less range. I just can't get my head around the removal of material from the all ready thin casings of the drums.

[visionary]

Quick update and another question on my 26 T motor, i purchased a new cam and bearings, and that has corrected the lack of any backlash between timing gears and has allowed for a decent fit of the timing cover.

I used the tool to align the cover properly with the cam. but it's still slightly off center with the crank, (favoring one side by.010). i'm thinking this will be ok and that the felt crank seal will center itself. please let me know your thoughts on this.

I decided to pull the rest of the shortbock apart for inspection and found the center main bearing oil passage packed full of babbit scrapings, after cleaning that out i decided to check bearing clearances, and found .003 on the rods and .002 on the front main and .003 on the center and rear main. not sure but that seems a little on the big side for a fresh engine, but i'm new to model T's so i'm looking for advice on this.

Also after pulling the valves i discovered a small crack through one of the valve seats, will this be ok to leave alone or should i have the seat replaced?

Thanks again
Scott

[Jack Innes]

The rods & mains should have .001 to .0015 clearance on a fresh engine - the clearances you mentioned are too great & will get greater quickly.

Have you checked the end play wit a bar & indicator as Bill suggested?

Did they grind the crank shaft & is it round?

The cracked block at the valve seat is asking for trouble as well.

Does this shop do many engines? Should we be warned?

[visionary]

Jack, i tried moving the crank back and forth with a pry bar but there is no give. however you can insert a feeler guage about 1/2 way around between the crank and thrust bearing, it's just dead nuts tight at a couple spots, he said it should just wear in.

The crank has been turned, and the rods are new with shims, so i guess he'll have to remove shims and hone the rods to fit better. as far as the main saddles go he didn't use any shims in the rebuild so may have to re babbit and i didn't mention it but the rear main cap has a large void in the babbit from contamination most likely.

The builder in question is located in Warrsaw NY and is called valve-en-blocks and came highly recommended by Macs auto parts .

Thanks
Scott