VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 '38 exhaust manifold repair/replace advice

Hi - I've been mostly lurking here, but now I'd appreciate some advice.

I was unsuccessful in freeing the heat riser on my '38, with the exhaust manifold still installed, so tonight, I pulled the manifolds off and separated them. The reason that I was having no luck became obvious. Once upon a time, somebody apparently stuck a pry bar up the manifold outlet and bent the heck out of the flapper and its shaft. Upon further inspection, I found a crack in the exhaust manifold. Now I'm weighing my options.

Option ONE would be to repair the manifold. I could braze the crack. Then I could cut the heat riser out and reconstruct it. Reconstruction would require a new flapper, since I don't think I can get the original out intact. I don't know where to find another flapper (is the flapper in a 235 the same?). I could make/buy an new rod.

Option TWO would be to buy another exhaust manifold. That's a possibility, but I would like to know what part number or range of model years match the original '38 part. I can't read the casting number due to corrosion. I've seen some online, but don't know which match the original '38. Having said that, if somebody has a source for a replacement manifold, that would make my life way easier.

I should say that I don't want to eliminate the heat riser; I'd rather have a working one.

I'd kind of like to get this fixed up quickly, since I'm expecting some out-of-state visitors who would like to go for rides. Any help you can offer would be appreciated.

Thanks,

Joe

The exhaust manifold is the same from 1937 thru 1939 except for the COE. The casting number is 838397.

On the heat riser, you can have the flapper and the rod made by a machine shop out of stainless steel.

Joe,

My 29-50 parts book shows 1937 -39 ALL (exc. COE) casting no. 838397.

I don't know if other years will fit or not.

Best,
Charlie

Joe,

My 29-50 parts book shows 1937 -39 ALL (exc. COE) casting no. 838397.

I don't know if other years will fit or not.

Best,
Charlie

Why two of the same posting Charlie??

What does COE mean?

COE is Cab over Engine. They are 1 1/2 ton or larger trucks. Used an updraft carburetor due to the lack of space between top of manifold and truck floor board.

for a later 216 8835358

http://www.ebay.com/itm/49-50-51-52...arts_Accessories&hash=item1c34ce0ddb

JD,

There was a delay after I hit the "submit" key and I didn't think it got sent. I didn't wait long enough, I suppose. In other words I screwed up.

I notice that we both were replying at about the same time. I didn't know that either or I wouldn't have needlessly posted the same information that you did. Sorry.

Best,
Charlie

Hey Charlie:

I have had the delays happen too from time to time so I always check the forum page after I make a post to see if the post is there before I make a duplicate post. If a duplicate post is made you can delete one of the posts up to an hour after you make the post.

JD,

Ok, thanks.

Charlie

I have not looked on this site to see if there is a parts for sale area or one for parts wanted. I know there are members on this board who have a lot of parts and sell them from time to time. Over on the Sovebolt.com they have a forum for selling and buying parts. I think someone over there would have one for you.

This caused me to wander out into the shed to check my numbers.838397 is an exhaust manifold for 37-39 of which I have four. 838396 is an inlet manifold for 37-39 of which I have four. These accumulated while I was working on my 38 roadster. Sorry I'm so far away.
I also have two exhaust manifolds 839130 and two inlet manifolds numbered 3835150 and 839279 which from memory came as spares with a 48. I do know that the 41-48 inlet manifolds fit the 38 BUT the carburettor mounting is different. The 38 motor sits flat so the mounting plinth is flat. On the 48 the motor sits nose up so the mounting plinth is cast at an angle to compensate. Looking at all the exhaust manifolds side by side they look the same. What I am ultimately saying is that later manifolds fit but there are differences that may or may not be important
So far as the heat riser is concerned they are a nuisance. If they jam shut and the heat doesn't get to the carburettor all will be well unless you live somewhere really cold. Quite often they do jam shut and people want them to work so they apply heat, lubricant etc. and ultimately they swing free and leak around the spindle which is a pain.
I am sure that you won't have problems finding one.

Thanks for the help on this, particularly with the part no. I ended up putting a posting in the parts wanted section, and somebody came up with one. Now I'm anxiously awaiting its arrival. Thanks again!

Joe

Kinda makes the annual dues worth while doesn't it.

Roger that!

Brazing is not the typical way to repair it...Can cause warping for one...Plus it's hard to get clean enough...Grinding the crack is not recommended as it just smears carbon in the groove...Nichol arc welding rod is the way to go...but without preheat and a sandbox to slow the cooling, your probably better off having a good welding shop do the repair...or you'll end up with a new crack next to it, or a "running crack" without holes drilled at each end before the welding...