The Stovebolt Site Forums The Shop Area Engine Shop New to the forum- engine advice needed

Hello, I am 19 and am new to the world of vintage trucks and this forum. I am not totally new to engines, however, as I have rebuilt two older tractor engines.
The vehicle in question is a 1951 (I believe it's a 3800) Chevy dually grain truck. It has the original 235 engine with the "JEA" code on the block. This truck is my grandpa's, and everything on it is original. It is in good shape for its age, but the engine is tired. It has 90,300 original miles, and the only major thing that has been done was a valve job at 85,000 miles. The engine has 110 # of compression in cylinder 1 & 6, but 2 through 5 are much lower- averaging out at about 50# each. I added some oil to the cylinders and performed another test, and a few cylinders went up in PSI by 2 or 3 pounds, but some stayed the same, indicating valve trouble. I am going to have the engine apart to replace the front and rear mains, so I was wondering if installing new piston rings and lapping the valves would be a good idea. I'm not sure of the bearing condition, as I've never had it apart, but it has decent oil pressure I think. 15 pounds when hot and cruising down the road. If it's hot and just idling it has about 7 or 8 pounds.
Anyways....keeping in mind I won't be able to replace the bearings, do you experts think I will be okay just replacing the rings and lapping the valves? I'm on a college student budget, so a re-power is not an option. This truck doesn't see much use...just 3 or 4 times a year hauling grain to town. I only go about 45-50 mph when driving, because I've heard that's a good speed for these old tired engines. Also, the truck doesn't have the power to go any faster. Haha! I can get out on the road and hold the foot feed down to the floor for several miles straight and never make 55 mph.
I've asked several of my trusted friends, and most say I will be fine. One guy said he used to put only new rings in old 216's and babbitt bearing 235's with 100,000+ miles and never had an issue (as long as the bearings looked good and the clearances weren't too large). However, other guys warn me if I re-ring the engine and lap the valves, the engine will end in catastrophic failure due to the increase in compression.
What do you guys think? I don't have experience of my own, so I'm in the middle being pulled both ways, unsure what to do.
Thanks!

I believe you are off by a series or 2 as most grain trucks around Okla were 4100-6400 series. A 3800 would be a 1 ton and kind of small for hauling wheat. Anyway, what you are proposing is a bandaid at best. Yes it's been done hundreds of times by farmers who needed to get ole Betsy back to the field asap. The real fix would be a complete overhaul including machine work to bring the block up to specs. Get you a good glaze breaking hone to deglaze the cylinders and a copy of the shop manual (available on line) and go for it.🛠

Sorry about that. I'm not sure how to tell what size the truck is, as the only emblems on the sides of the truck are the "Chevrolet" emblems. The serial number inside the driver door says 5UY1-2208, and I looked it up. If I'm right, it was built in Kansas City, Mo (5) in 1951 (U) and is a 2 ton truck (Y).
Your last line talking about getting the hone and going for it...are you saying go with my idea or just do a total overhaul? If it was the latter, could you suggest a place to get the babbitt bearings re-poured?
I've asked around here, and no one knows of any place that still does that. There used to be a shop not too far that did that, but the guy retired.

Finding a 90K mile 235 without a noticeable amount of cylinder taper is sort of like finding a chicken with lips- - - -it's not likely to happen. If there's more than .005" of taper in the cylinders, a re-ring job will be a very short-lived fix. Rings must expand and contract constantly to maintain contact with a bore that's not perfectly straight, and at 2,000 RPM that flexing is happening 66 times a second. Once the cylinders are rebored and new oversize pistons are fitted, the ring flex goes away because the cylinders are straight again. Another advantage is that the replacement pistons will be aluminum, and the lighter piston weight means less pounding on the Babbit rod bearings. The original pistons were cast iron.

Another option would be to find a later model 235 in running shape, drop it in temporarily, and make the original engine a long term rebuilding project. There's nothing wrong with Babbit-pounder engines- - - -as long as they're built up properly and the connecting rod oil clearance is kept to a minimum by adjusting the shim pack periodically.
Jerry

Thanks for the reply! Do you know of any places that could re-build the original babbitt bearings? Like I said, I know of none.

I have noticed you have changed your location to the same as mine. Where are you located. Maybe we can put our heads together and figure this out. Listen to what Jerry says. He's one of those been there done that kinda guys.🛠

Martin...I am in Yukon. I would PM you, but I guess since I'm new, it won't let me send a PM yet.
Thanks

You should be able to PM now, since you've had four posts approved. If not, post one more time, and you'll be good to go.

Tried to send you a PM this morning but it says you are not accepting PM's. We are 15 miles apart I live in El Reno. There is a 235 on craigslist right now but being from a car it will take a bit of parts swapping to work in your truck.

Thanks Martin!
Not sure why it says I'm not receiving PM's...I'll check my profile and see if something needs changed.
I just found the engine on Craigslist...what all would I need to swap over, other than the obvious missing parts? I'm not aware what is different about a pickup engine vs a 2-Ton engine. Are they built heavier?
- Edit - I changed the option to receive PM's, so I can receive them now. Thanks

I don't know of anyone who is reconditioning Babbit rods any more, but there are a lot of them available on Ebay, etc. The process GM used to apply the bearing material to the rods was known as "centrifugal casting"- - - - -the rod was heated and spun in a lathe-like fixture, and molten Babbit metal was sprayed into the big end of the rod. The result was a thin, very durable layer of bearing material that bonded itself to the rod. Most reconditioning procedures involved casting a layer of metal into the rod and boring it to whatever diameter was needed, standard or undersize according to whether or not the crankshaft had been reground. Final oil clearance adjustment was accomplished by adding shims between the rod and the cap. As rods wore a little, shims were removed to correct the clearance.

Rods can be bored out to accept insert-type bearings, but those bearings are getting hard to find, also. .020" undersize conversion bearings are impossible to find, according to several machinists I know, so crankshaft rod journals must be reground to either .010" or .030" undersizes. There is also a rod bearing available for a Massey-Ferguson tractor engine that can be fitted to the stovebolt Babbit rod with a different crankshaft diameter, .060" smaller than standard. That bearing can be used to reclaim a crank that has already been reground 30 under, one that would normally be scrapped.
Jerry

Several on here will know what you need to change to make the car engine work. When you can post the engine serial number stamped on the machined flat spot just to the left of the distributor hole. That will help the experts (I'll admit I'm not one) help you. It is done all the time and it's not that complicated.🛠

Where's Pre68Dave when you need him?

Where to begin?
First, 216's and early splash 235's used cast iron rings which were very easy on the cylinders, along with the amount of oil that is thrown around in a splash engine kept cylinder wear at a minimum. Re-ringing a splash engine was very common because of this.
Because of the heavy cast iron pistons in these early engines rod bearing and journal wear is a concern.
If one mics the rod journals and they are not more than a couple of thousands out of round, and enough shims are removed to set the oil clearance at a minimum, things should last a long time with minimal use.
Replacing the pistons with aluminum at this time will also extend bearing and journal life with there lighter weight.
Putting a later full pressure 235, whether a car or truck engine is a pretty straight forward job. There are a few thing that would need to be addressed depending on the year of the replacement engine. Car or truck engine is of little concern. The main difference in car engines is that in some years they came with hydraulic lifters, but they will still work fine in a truck.

Thanks, Dave! While this engine is a high-mileage engine (90,300 miles), it doesn't see much use these days. Usually only about 100 miles a year, if that. Also, all the miles are below 50 mph. Because of that, do you think leaving the cast iron pistons in would be a bad idea? If it was necessary, I could get a set of aluminum pistons to put in, but I'd rather not if I didn't have to. I will check out my rod bearings and journals when I get everything torn apart and see what kind of measurements I've got. I may not get those numbers very quickly, as I've been busy with other things and school is about to start back up, but I will get them.
Also....do you know of any place that can build up the babbitt bearings in these engines? If so, about how much do you think it would cost? I really would like to keep the original engine in the truck, but if it would cost too much I might get a newer engine to swap in.
Thanks!

235Kidd, Dave doesn't check in as often now that he has retired. You have enough posts to be able to send him a PM directly and also Hotrod Lincoln. Both are well versed in the mechanical side of these engines. HRL mentioned reconditioned babbited rods on ebay if you decide to go that route. Good luck with the old farm truck.

Ok guys...I've got a new problem...I found out why I had 110# of compression on cylinders 1 & 6, but only 20-40# on 2-5. I took the head to a shop to get it rebuilt, and it turns out it is cracked under the exhaust seats on those cylinders. Great. It will cost $700 to get it welded and rebuilt, but that sounds expensive. My question is will a 1954/55 235 head work on a 51 235 engine? I found one that looks nice (seller says its a 54, but the casting says it's a 55) but it looks like the hole for the oil line that lubes the rockers is moved about 1/2" back from where the hole in my head is. I'll try to get pics.
Thanks!

1950-52 235 heads are one of a kind. 1953-62 heads will not fit.

Several I-6 on OKC Craigslist.🛠

I think you should do the budget build of the Babbitt engine. Mainly because I'd love to do one myself.

But finding a decent running engine and dropping it right in is probably the cheaper play.

I am with JW on fixing the babbit slinger. I upgraded my '50 with a '53 full pressure, insert rod bearings, hydraulic lifters engine from a car. I wished that I would have had a rebuildable 216 to go back in it at the time because I miss the ticking rocker arms and the sound of twelve sewing machines under the hood.
Carl

I'm definitely leaving this engine in the truck...I figure when the time comes I can have the rods machined for insert bearings, and since the mains have replaceable bearings, that should be easy enough. If I understand though, the mains have to be line bored. I'll do all that someday when the funds are there for it. Until then, I'm just doing a valve job and re-ring, plus some seals. So far the bottom end is coming right along, even though most of the rod bearings have all the shims pulled. I'm getting plastigauge clearances of .001-.002. I'd say that's good for now, no more miles than I'm going to be putting on it.
I've searched high and low, asking at least a half a dozen guys around here if they knew where I could get a head, but all inquiries have come up short, unfortunately. All I need is a good head. It doesn't need valves or rockers with it, I just need a head that is for sure good with no cracks. I'm going to place an ad in the classifieds for a '50-'52 head, in case anyone here has one they would part with.
I have checked on Okc Craigslist, but I haven't found any heads there. I did find a complete 235 (think it was a '59), but the guy sold it out from under me after I obligated to buy it, which was probably a good thing as I'd like to keep the original engine.
I'm hoping I can find a new head ASAP, as I'd like to have this done by grandpa's 90th birthday (since it's his truck), and so it can be in a parade coming up in early October.
Thanks!

If I interpret Dave's post correctly....even a 216 head won't work?

Maybe the tall side cover has something to do with it? I have no idea...

216's will not fit.

What is the casting number of the head that's needed? Sounds like a pretty specific item, but shouldn't be impossible to find.

Wait to hear from Dave, but here is a list of casting codes gleaned from Internet sources.
http://www.1954advance-design.com/Stovebolt-engine/casting-numbers.html

The 3835499 is what my 1950 parts book shows as the correct casting number.
The 3835909 in Tim's link could also be correct, I would need to do more research to confirm this.
I have heard that Canadian 216's used this same head.

Just a precaution- - - -if you happen to find a head you're interested in buying, have it pressure tested, not necessarily just magnafluxed. They can crack in some places that magnafluxing doesn't always find.
Jerry

Jerry,

How is a pressure test performed?

Thanks,

To add to this, the 1950-52 head is easily identified by the smooth outward curvature of the head between number one and two spark plugs, and number five and six.
See picture.

Wow. THAT right there is why pre-68 Dave is so awesome.

Obscure, but important, stovebolt factoids.

I guess the 50-52 head from the 235 used in powerglide cars would work as well?

I have a guy willing to sell me a head for $100, but the only catch is it's in a non-running truck. No way to know if it's cracked or not until I buy it and have it removed from the engine, then checked.

The 1950-52 splash 235 was used in Powerglide cars and large trucks.

That sounds like a big crap shoot to me. Is he willing to refund your $100 if it's cracked. Then you would only be out the fees to check it. Problem is there is a large percentage of these that are cracked. Good luck.🛠

Offer him the same amount for the whole engine- - - -it might be worth the risk even if the head happens to be trashed. Dave, other than having 10MM spark plugs, would a head off a 1946 235 work?
Jerry

1941-49 235's used the same head as the 216, so, no.

Dome VS flat top pistons, or some other reasons?
Jerry

All 1941 and later engines had flat top pistons.
Hope I am answering your question.