The Stovebolt Site Forums The Shop Area Engine Shop New to this!!!

I will start with what I have.....1937 chevy 1/2ton truck that dates back to my great grandfather and now is in my care. My uncle had the truck since the 1980s and did a nice job with a beginner restoration ending in about the 1990s sometime. Here is my issues....it has what I believe is a 235 motor in it and it has developed some problems since I picked it up over the labor day weekend. I have drove it only around the neighborhood and never over 20 mph. I have broke a rocker arm and bent a push rod as of last night. I am looking for some help/guidance on this motor! Any diagrams or pictures would be great so I now what I am looking at. I am concerned I may have a bigger problem on the inside.
Let me know if anyone can help.

Thanks!!
Charlie, MN

Welcome to stovebolt Charlie. Maybe you could post some more info on the engine (casting numbers and such) so it can be identified, then some of these guys can help you out. Sounds like you had and maybe still have a stuck valve.

Charlie,

Sounds like you have a nice truck with a good history. You might wants some shop manuals for both the truck and the engine, if it is not the original. Here is a link to the manuals on the Old Online Chevy site, and here is a link to a source for later (post 1955) manuals, some on CDs.

You need to find out which 235 you have, as there are different methods for getting oil to the rocker arms.

Are you getting good lubrication to the rocker arms. That can also be a cause for broken rocker ars and bent push rods.

Hoyt

Another cause of broken rockers and bent push rods is running old fuel.

Here are some numbers I found after taking off the valve cover.
GM 3835409
CONV12 E189

Also this is the number on the lower part of the motor on the passengers side....5GKK71851

Thanks,
Charlie

3835409 indicates a '49 216 or 235 head. Use this link and get the number from the block which will also be a 7 digit number to determine more.

http://clubs.hemmings.com/clubsites/chevytalk/GMhistory/1916-57cast.html

You may very well see one of these numbers on the block.

1948-49 3835497 216 Passenger, Truck

1048-49 3835309 235 Truck

Keep us posted and provide pics!

Here are some pics of the truck and the issues I am trying to figure out. When I disconnect the copper line that feeds the rocker arms from the block, antifreeze runs out....is that normal?

http://i543.photobucket.com/albums/gg447/Seykoras/1937%20Chevy/Fall20101937Chevy021.jpg

http://i543.photobucket.com/albums/gg447/Seykoras/1937%20Chevy/Fall20101937Chevy020.jpg

http://i543.photobucket.com/albums/gg447/Seykoras/1937%20Chevy/Fall20101937Chevy024.jpg

http://i543.photobucket.com/albums/gg447/Seykoras/1937%20Chevy/Fall20101937Chevy027.jpg

No, that is not normal. Oil should be in that line.

That is one beautiful truck.

Could a blown head gasket allow the antifreeze in there?

Check your oil and see if any antifreeze is in the oil pan. If you pull the drain plug the anitifreeze will come out first if there is any in there.

That is a very nice vehicle. Don't run it until you make sure there isn't coolant in the oil. It will ruin bearings in a hurry.

From your head number it doesn't appear to be the original engine in the truck. That having been said, if I were you, with what also appears, having a limited knowledge of the 216/235 engines, I would look for a replacement engine. Look for a 1955 or later 235 or 261 Chevy engine. It takes a different breed of "cat" to work on and keep a 216 running. Take that 216 and sell it or give it to somebody that enjoys playing with them. You will be dollars and donuts ahead, and a whole lot happier. --- Just DON"T drop a SBC into it. Would really ruin a cool truck.

I have to kind of agree with 61chevygal. That truck is almost too original to consider putting the wrong engine in it. I would even go so far as to say stick with the original engine if at all possible. Of course it's your truck and you have the final say on what happens.

So I did some more investigating and I think i need to clarify something. Oil does not come out of the copper line it comes out of the fitting that goes into the block when I try to remove it from the block. Question #1: Where does the copper line come from? When I try to take it out of the bottom location I can get the fitting loose but the line does not come out. Question #2: Is it possible that the copper line passes threw the block where there is antifreeze for some cooling purpose and that is why antifreeze comes out when I loosen the fitting?

http://i543.photobucket.com/albums/gg447/Seykoras/1937%20Chevy/Fall20101937Chevy027.jpg


Thanks,
Charlie

The answers to your questions are in the Shop Manual. It is quite possible that the feed tube is leaking. Not easy to replace or work around.

Unless you really want to keep a 216 in the truck, a full-pressure 235 or 261 would be a great engine. The 1953-54 engines are are an easy replacement, and the 55-62s are not much of a problem to install.

Hoyt

That line runs through the cooling system on its way to the other side of the block. It seems that it's developed a leak, and the coolant and oil will be mixing. Don't run it again until you get this sorted out! It's difficult, but not impossible to replace that line, but the old one has to be cut out, or at least one solder joint needs to be melted away. Several of the obsolete parts vendors who advertise here have kits to do the oil line replacement, with instructions on how to do it right.
Jerry

Charlie, I don't have an answer for you (sorry). But I wanted to comment on what a neat looking truck you have. She's a beauty!!!!!

THANKS!! for all the great info. My next question would be what should I look for or be concerned about with the broken rocker arm and bent push rod? I don't want to fix things only to have more of the same problems because I didn't solve the issues.

thanks,
Charlie

There are a bunch of half-donkey fixes that will be reccomended soon, but the only right way to do it is to take the head off, and have a good machine shop do a full valve job, including whatever is necessary to get the valve stem-to-guide clearance right. Sometimes that includes installing new guides and/or valves. The rocker arm and pushrod problems come from gummy deposits or varnish from stale gasoline that accumulates in the guides and locks up the valve stems. If you're still running the original gas tank, have it professionally cleaned, or replace it to prevent the crud from the tank from causing the same problems again.
Jerry

Still trying to figure things out. Any ideas on why I am bending push rods? The truck ran great for a week and now all of this is happening.

Charlie

Valve stems might be sticking. This happened to me. Shoot penetrating oil down the valve stems on top of the valve guides. Also, remove the side cover and rotate the engine by hand and be sure everything is moving correctly (might as well spray a little penetrating oil around the mechanical lifter bodies, too).

I ended up doing what HRL suggests above - take it apart and take the head to a shop for reconditioning. They will most likely tell you the valves are bad and the valve guides are out-of-spec. Try to get the valve guides replaced or sleeved - knurling the guides is a weak plan-C in my uneducated opinion.

Like I said at the start of the thread and Jerry said right before your last post, stale gas. Did you drain and flush the tank before driving it for a week?

I did drain the tank but did not give it a good cleaning. I will be doing that first thing!!! What I need now are some new push rods. Anyone have some lying around?
Another question I have is I was told that the truck as a 235 motor but the block numbers come back as a 216 block. Is it possible to make a 235 from a 216 block?

Head # 3835409
Block # 3835849

I did drain the tank but did not give it a good cleaning. I will be doing that first thing!!! What I need now are some new push rods. Anyone have some lying around?
Another question I have is I was told that the truck as a 235 motor but the block numbers come back as a 216 block. Is it possible to make a 235 from a 216 block?

Head # 3835409
Block # 3835849

There are 2 or 3 different lengths of pushrods, depending on which design of valve lifter the engine has. Just about anytime I look on Ebay, (antique engine parts category) there are several sets of 216/235 pushrods listed, so they're definitely not a scarce item. Just be sure to get the right length ones. Most of the restoration parts places offer new pushrods and/or rocker arms, also.

There's only a 1/16" difference in the bore size between a 216 and a 235, and I believe the crankshaft is the same, so a "pseudo-235" could be made by boring out a 216 .0625" and installing 235 pistons, I suppose. OOPS! Big mistake! I just checked the specifications, and the stroke is WAY different! 216: 3 3/4" stroke. 235: 3 15/16" stroke, so no, there's no way to make a 216 into a 235. If you've got a 216 casting number, that pretty much tells the tale, but the only way to know for sure is to take the head off and measure the cylinder size and stroke. While the head is off- - - - -get it reconditioned and the pushrod-bending problems will go away for good.

Edit: the Hemmings Motor News site lists your block as a 52-53 216 for passenger car and truck application, and the head as a 1949 216 and 235 application. Looks like the head has been swapped at some time in the past.

http://clubs.hemmings.com/clubsites/chevytalk/GMhistory/1916-57cast.html
Jerry

The 216 is 3.75" stroke, the 235 is 3.9375". The 235 block is taller. The 216 pushrods are shorter.
Stale gas does not break rocker arms.

I found a 1960 235 that I may be interested in. How would this work with my 1937 tuck. Would it bolt in or am I looking at some modifications to make it work.
Thanks for the great help! I would be lost at this point if not for all the advice and info from this board.

Thanks Again!!!
Charlie

I found a 1960 235 that I may be interested in. How would this work with my 1937 tuck. Would it bolt in or am I looking at some modifications to make it work.
Thanks for the great help! I would be lost at this point if not for all the advice and info from this board.

Thanks Again!!!
Charlie

There will need to be some minor modifications, such as adapting the 216-style water pump to the 235 engine. Otherwise, the fan sits too low for good airflow through the radiator, or there might be fan-clearance problems. One of the advertisers on this site sells a kit that allows the 216 pump to bolt onto the 235 with only minor mods, drilling and tapping a couple of bolt holes. There are some flywheel/clutch/bellhousing issues, I believe, but they're not terribly difficult to deal with, just a matter of finding and bolting on the right year parts. I'm sure somebody will be along shortly with details on that!
Jerry