221 connecting rods

[P-15]

I am rebuilding an engine for a friend from his 38 coupe. It spun 2 rod bearings and damaged the crankshaft and of course the 2 rods. I am rather new at rebuilding flatheads, just wondering if it is possible to upgrade the connecting rods to the later style with the locating tabs instead of the free floating bearings. I am having trouble finding a machine shop that will resize the original rods to fit the crank. Any suggestions? Thanks, Tim

[Brian]

Some Canadian and English rods had the notches for lock in shell type bearings, so they are out there....however, finding the C41A prefix shell bearings to suit is nigh on impossible. Set up correctly, the original floater type rod bearings and rods are superior anyway....
Try placing a classified advert in the swap meet column...

[JWL]

There are aftermarket rods which can be used for the 38, two inch, diameter crank pins. However there are other considerations. I am not aware of any rods made by Ford, which used lock-in bearings, for that small crank pin. The 2.138 diameter used in the later engines certainly will not work.

[Andy]

I believe you would need the later crank with two oil holes for the later rods. I have one if wanted.

[JSeery]

Originally Posted by P-15

It spun 2 rod bearings and damaged the crankshaft and of course the 2 rods. Tim

Ok, am I showing my ignorance here? How do you "spin" a rod bearing when using floater bearings? Are we talking about locking up a bearing somehow?

[Bored&Stroked]

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Even if you used the later H-beam 2.00 inch rods, they are designed for a crankshaft with dual/2 oil holes per journal. So - you can't replace the single journal floating rod-bearings with any tanged bearing in the earlier engines . . . unless you change the crankshaft out to a typical 49-53 Ford . . . or a stroker Mercury crankshaft. As JWL mentioned - there are multiple "considerations" that you need to know about. There are a few ways to skin the 38 cat - with different amounts of time, money and work (let alone parts) involved.

[Brian]

Or...you use the corresponding two hole Canadian/English 221 crankshaft. Yes, they exist

[Brian]

P-15, exactly which engine is in the 38? 21 stud or 24? Both engines were available in 38.

[Ol' Ron]

I'm sure you can get a used 91a or 21a rod for someone. I don't have any spares. Then a reground crank and a new set of floaters will fix it. Now the late 59/8ba crank will not drop right into the early 38 as it has the small main. it will on the late 38 but the rods won't go thru the 3.06 bore. now add up alll the money your going to spend on the repair. Maybe you can find a later engine for it.

[Chuck Kuntz]

I have some new rods for the early V8 if you are interested. $35 each

[P-15]

Its the 24 stud. Can't find the engine serial #, but the head casting # is 81A-8050. Evidently the rod bearing must have started seizing to the crank as it wore the outer shell of the bearing, although its companion rod from the opposite bank did not wear its half of the bearing. This happened to the front 2 cylinders on each bank. The crank is about .003 below spec on the front 2 journals.

[P-15]

Thanks for the suggestions, I will get the crank out and check things further. Nice to know there are experienced people out there

[JSeery]

Originally Posted by P-15

Can't find the engine serial #, but the head casting # is 81A-8050.

Flatheads in general do not have serial numbers on the blocks. The serial number was stamped into the transmission bellhousing area. When the engine/transmission assembly was installed into a frame, the serial number was added to the frame. Sounds like the heads might be original, but keep in mind that most of these engines go through at least one rebuild during there life and more often several. Bolt-on engine components were often mixed up during a rebuild or repair, so it is difficult to depend on these parts for IDing and engine. It is also very common for a complete engine swap during a vehicles lifetime.

So, the point is it can be a little difficult to pin down the actual year of an engine. In addition Ford switched from 21 stud engines to 24 stud engines during the 38 models. You need to pay attention to what the internal components are and go from there.

[Bored&Stroked]

If the crank is only .003 out of spec, then the journals are not really damaged and you should able to turn the crank .010. Check the sides of your rods, they are most likely labeled "91A" - though they could be "21A". If it were mine, I'd pickup a couple of the same type rod, have the crank ground .010, have the rods potentially rebuilt/resized (by somebody who knows flatheads!) and then have the rods balanced (again, make sure they know how to balance flathead rods correctly - there are no 'balance pads' to grind on). You probably wouldn't even need to balance the engine unless you want too.

You would still be running full-floater bearings - and the new set needs to be "hand setup" to properly float - you can't just throw them in the engine and go. Not a big deal - checkout YouTube - I have posted some of the details.

The total amount of work kind of depends on your plans for the engine, the amount of time/money you want to put into it and the results you're looking for. It is one thing to do a stock style rebuild, another to start chasing performance upgrades, finned heads, dual carbs, new cams, etc..

If you're doing a full rebuild, then make dang sure whatever machine shop you take it too really knows flatheads, understands the complexities of the valvetrain (and has the correct flathead-specific pilots), etc.. Anybody can run a boring bar - but most shops have no experience in the REST of the flathead engine . . .

Also, since you're new to flatheads - pickup a couple books on them . . . so you can learn the details and the nuances of building these engines. They are not complex, but there are a lot of tricks/techniques to know about. Search this site for book recommendations.

Good luck!
B&S

[P-15]

B&S Thanks for the info. I did some calling and found a machine shop that has experience with sizing rods to the crank on flatheads. This is going to be a stock rebuild. The machinist I talked to seemed familiar with the floating rod bearings. Again, thanks for the help

[supereal]

Be sure that the crank is not damaged, and the journals are properly sized We grind a lot of cranks at our shop, and many, if not most, have been reground at some time. It is not rare to find that all the journals are not the same size. Checking them with a caliper is not
sufficient.

[Tinker]

Where you at Tim?

[Bored&Stroked]

Originally Posted by supereal

Be sure that the crank is not damaged, and the journals are properly sized We grind a lot of cranks at our shop, and many, if not most, have been reground at some time. It is not rare to find that all the journals are not the same size. Checking them with a caliper is not
sufficient.

I've seen the same things with some of these old engines. People repaired them to get them back on the road - with whatever means they had at their disposal. They did things like grind a single journal, throw in new bearings and be on their way.

Calipers are not good mics for checking journals and bearing sizes - other than to know what you're CLOSE too!

[P-15]

Tinker, I am located in the northwest corner of South
Dakota. I operate a farm equipment diesel repair shop, but in off hours generally work at restoring old mopars, occasionally taking on an old Ford

[Bored&Stroked]

Originally Posted by P-15

Tinker, I am located in the northwest corner of South
Dakota. I operate a farm equipment diesel repair shop, but in off hours generally work at restoring old mopars, occasionally taking on an old Ford

My family is from the Black Hills as well as the White River areas . . . I spend a lot of time in good ole' SD!