Restoring 1946 ZTU.

DFZ · May 20, 2013

I have a "46 ZTU and plan on starting to restore it soon.
I would like some advice on rebuilding the engine. I don"t want to make a puller tractor out of it, I personally hate seeing that. I want to restore it as a very strong Stock tractor with as strong of engine as I can rebuild it to have without sacrificing dependability.
Can you fit a crankshaft for a ZA or ZB in the crankcase for a ZT for the extra stroke? Or since I assume I need to have the crank ground, can it be stroked for any noticeable difference?
.060 oversize pistons are available, if any larger are available would I start to sacrifice dependability? Or can a person safely go to .120 over?
How much do you dare shave the head and/or blocks for added compression?

What have you all done to beef up a stock ZTU?

Thanks for any advice. I just want to keep the stock crankcase and stock appearance and make the engine stronger than factory but just as dependable so it can be used for another 67 years.

Dennis P · May 21, 2013

The crankshaft in your RE block cannot be changed out with one of the later engines. The main bearings in a ztu crank consist of a roller bearing in the front & rear, whereas a za or zb crank uses a different type roller in the front with an insert bearing in the middle & rear. You mention that a puller is not what you want, but why the the need for longer stroke & 120 over pistons? Personally, I would rather have the later engine, it gives you more stroke & has a stronger crank. Yours is a 185cid & the later is 206cid stock.
You could use the .120 over pistons and an LP head in the ztu engine, but I would be concerned about the added stress on the bottom end. This is just my 2 cents worth. However you go, good luck! I think ZTU"s are the greatest!

Jerry Grant · May 23, 2013

I recently restored a 1946 ZTN 2 years ago. The engine had been bored out to 40 over before I got it but the engine was froze up. When I opened it up, I found a fist size hole through one of the cylinder walls into the water jacket. I have no idea how long it ran with 40 over pistons, but the cylinder wall finally gave in. It vary well could have been a faulty block. The cylinder wall was very thin at the hole. Since I had heard of boring them out 60 over and more, I replaced both cylinder blocks and bored both out to match my pistons. It is running very well. However, I have not had it on a dyno to see if it produces more HP than original.

Restoring 1946 ZTU.

DFZ

Member

Dennis P

Member

Jerry Grant

Member

Similar threads