VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Engine replacement for 31 Chevy

Hi,
Can anyone tell me which engines fit directly into a 1931 Coach? The original engine is a 194 cui 6 cylinder. My old engine has a cracked head and I have to either find a new head or a new engine. Which changes are needed if you would put a later engine in?

There is/was a listing on Ebay for a 31 head that one of the VCCA members was selling. Should be a lot easier to just change the head.

Welcome to Chevy Chatter!

If your cracked cylinder head does not have major issues the cylinder head can be repaired and re-used. Do not replace the engine because of the cracked cylinder head.

Have you checked to see if your head can be welded? It is possible your head could be saved.

Hi,
I will take a look at the head when I get it back from the shop. The owner tells me that it is very hard to weld these heads. The crack is adjacent to exhaust port no 2.

Hi,
My first priority i of course finding a new head, but they are not easily found. That is why I wonder which engine year/models that can just "slip" into place.

1929 and 1930 will slip into place but that would be a step backwards. If you find an engine the chances are good that the head on the replacement engine will also be cracked since those cylinder heads are notorious for cracking. You are better off repairing the head that you currently have.

The head on EBAY has a starting bid of $199.99 and has a couple of days left and no bids. I believe the seller is a regular visitor on this site. I would suggest you view the listing and contact the seller if you have any questions. The item number is 261299896379.

head has been sold.....

There is a 1931 complete engine 100.00 ebay

[img:left]https://www.facebook.com/photo.php?...p.612474298795628&type=1&theater[/img]
Here is the crack in my old engine head. It is adjacent to the exhaust port in cylinder no 2. It goes straight through to the water side. The shop owner tells me, that if I weld here, the material will get hardened so it can't be machined for the valve afterwards.

I would do some research on line for shops that specialize in head repair. I am not an expert , but I think it could be repaired, although replacing with a good head would be a better solution.

The crack in the photo does not appear to be all that bad. I have seen cylinder heads a lot worse than that be repaired and my cylinder head was one of them.

A qualified machine shop will cut out the valve seat area and insert a new valve seat. That is a common practice. Then the remainder of the crack can either be welded or pinned. My 1930 cylinder head had five small cracks similar to the crack shown in your photo and my cylinder head was repaired to like new, which included all new valve seat inserts as well.

You might want to look around for a machine shop that knows how to do the job correctly.

If you bought another head chances are it might be cracked. I believe it is always better to repair what you have, if possible, instead of taking a chance on buying another used part.

Hi Junkyard Dog!
Interesting thougts. I just have to find someone able and willing to try it out. Since I ain't native in English, could you explain your suggestion to "pin" the remaining crack? Weld and solder I know, but pinned?

Here are a couple of sites to check out regarding pinning:

http://www.freeasestudyguides.com/engine-block-repair.html

http://www.atpengines.com/cylinder_head_crack_repair_florida.html

An excellent explanation with photos is available at:
www.moparmusclemagazine.com click on tech articles and in the search box type " cold stitch crack repair".

What Junkyard Dog said about welding is in my opinion is the best way to tackle the problem. I just went through what you are going through. Or better, I am still going through it. I have a cracked 29 head. I found a good head from one or our members from a 30. The head I had, if I wanted it welded was going to cost $600.00 to weld. If you go to the right person he will build a furnace around the head and heat it up to what ever temp is needed. Then he will open a hole and weld the head while it is hot. Done this way it will not crack after welding. The 1930 head even though it is in good shape. Putting in valve seats and valves, replacing worn valve guides is going to cost as much as getting my old head welded. And I am still waiting on my head to be finished. If I had gone the other way I would already have the head on the car. Live and learn. I worked in a truck shop and had a CAT head welded this way. The truck ran 300,000 plus miles after with no problem.

Hi all, Concering the advices about "pinning" the head. I find it enticing compared to welding. Where could I find this kind of pins? Which diameter? Do they have threads like ordinary screws or bolts? Are they cylindric or cone shaped? The Engine head is cast iron, should the pins be of the same material, or could I use any steel screw with suitable diameter?

Hi Nicholas,

Here is a company that sells stitch repair kits, Lock_N_Stitch:

http://www.r-f.com/lock_n_stitch_repair.asp

http://www.locknstitch.com/Products.htm

I know nothing about the company or its products, other than what has been posted on the web, but it might be worth looking at.

Happy Motoring,

Dan

Hi Dan!
I followed the links you provided and found out that Lock-N-Stitch has a representative in Norway, which is almost "next door" to my homeland Sweden. There are some really good film clips showing the procedure. I'll get in touch with them on Monday too see if I can buy the necessary pieces from them.

Happy motoring!

Good to hear, Nicholas. Good luck and let us know how it turns out.

Dan