Hello,

You could indicate the transformations to me to be carried out to mount a crankshaft of Ford model A in a motor block of Ford model T ?

Tank

Olivier
http://www.ford-t.fr

Olivier
1. The A crank is longer than the T crank (5/8" I believe), so you either must shorten the back end or move the block forward on the pan/crankcase. Both methods work but neither is simple. Other machining is required on the front as well but is relatively simple.
2. You need new main caps as the T main caps can not be opened up enough to hold the A crank. At one time cast bronze caps were available from Townsend Automotive but I believe this is no longer the case. Either way you need to machine out the main saddles of the block to the edges off the bolt holes.
3. Most people use A connecting rods and special pistons for this application. The oil control with these pistons is not wonderful as the oil ring is around the piston pin but it is livable considering the added torque and reliability of this conversion.
4. If you can do the work yourself it is economical way to make a strong T engine.
5. search "a crank in t block" on the forum for pictures and more opinions

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quote:

Most people use A connecting rods and special pistons for this application.

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Oliver,

It's not something you can do in your backyard on a Saturday. Ask about it for your own education, then hire someone that has already done it to do the work.

There used to be a guy in Socalif who shortened the tail end of Model A cranks by heating and squishing them.

The T wristpin is what, 5/8" diameter, and clamped to the rod. The A wristpin is full floating, and about 15/16" diameter. That would take some creative engineering to adapt.

I've run an A crank, and I prefer the Chevy crank.

rdr

From another thread I got the link to a video of a recently restored model A engine with a "Burlington Crankshaft" indicating a new aftermarket supplyer of crankshafts. Gooling got me to http://www.burlingtoncrankshaft.com/
"Now, after nearly 80 years, there is an integrally forged counter-slung crankshaft available for Model A engines built between 1928 and 1931 by the Ford Motor company"
"Introductory price is $950.00 plus packing and shipping"

Now, perhaps these guys could be interested in making a better T crank?
Integrally forged sounds like the way to go.

I'm already talking to him about making a T crank. There are some expensive issues to overcome first.

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quote:

There are some expensive issues to overcome first.

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I only have a basic idea of what is involved, but I guess a different mold is needed to do the shorter smaller T crank. The A crank journals and stroke are a problem everyone here is aware of. A lengthy list of pan, block, and piston modifications to make the new crank work properly is something I would like to avoid. A new mold specifically for the T cranks would probably be best, but it takes money. They are the experts on this, I'm just along for the ride when it comes to molds and molten metal. The main thing I want from this is to be able to provide you guys with a replacement crankshaft that doesn't require a second mortgage on the house. Running 10 or 20 under cranks is un-acceptable by my standards and pretty soon we're going to run out of good "close to standard" replacements completely.

Would anyone on here would like to pre-buy a few cranks to help us move forward? I can get a target price for initial investors if anyone is interested. With enough orders I know we can make it work. The technology is not the problem, it's the financing.

Brent
Crower has now made me 8 cranks for T. They work great but they are not cheap as they are made from billet 4340.
If Burlington wants to tool up to make new forged counterweighted cranks for T that would be wonderful. As Tim has mentioned there are some expensive issues to deal with;
1. Design; do you go with stock bearing sizes or oversize to 1 7/16 mains and 1 3/8 throws (this the maximum you can go using stock T main caps and rods)
2. Tooling.
3. Production inventory
4. Marketing inventory
5. T guys are notoriously cheap, is there enough potential volume at a price that generates a profit!
I will stay away from heating and "squishing" rods and cranks. I like my shrink on hub method of shortening the rear of the crank and the high pin pistons are acceptable in my book. I am NOT a fan of welding on Ford's cranks and rods. Others my disagree!
The problem with the NZ cranks is that ductile iron is not a great choice for the skinny bent coat hanger that fits in a model T. The material works great in modern short stout 5 main plus engines with large diameter bearings
Olivier
Don't let Tim scare you; if you are a skilled machinest/fabricator you can do it yourself. I did my first one back in the '70's including bolt on counterweights. That engine would twist 4500 rpm just fine. I had welded on the flywheel flang and after about 5-6000 miles the weld gave up. Everything hung together as the flywheel just turned on the crankshaft. I had sold the car by this time but it has been repaired and mostly sits on display in a museum now. The guy had gotten a ticket doing 92 mph in it (that and only rear wheel brakes)

Left to right:
28 Chev drilled for oil not shortened but machined to fit a modified T block.
Model A with pressed on flange
Schubert-Crower 4340 billet
Sure Mike
Late Model T
Early Model T

Don Lang already has a new USA Counter balanced crank available for about 1400.00. I have seen it held it and bought it.

Brent -

I have the rod press you are talking about. This was one of Ellis Gray's creations. No, I have not tried it yet, but have been intrigued by the idea for years. Ellis also did the rear main "squish" Ralph describes.

The story I got is that the engine built with these short rods didn't perform the way it was expected to. I believe they thought that there was some issue with the angle of the shortened rod creating too much friction on the thrust side(s) of the pistons.

Oliver, here are a couple photos to give you a better idea of the process - after shortening the A crank.