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Old 03-12-2016, 09:16 PM   #1
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1947 Chevy Truck, Engine Needs Help, Advice?

Hey everyone,

I purchased this truck for just under $10k, which I thought was a decent deal until I got an oil change and was informed about multiple oil leaks. The lead mechanic recommended I have the engine (350 Chevy) pulled and resealed. After heading to the shop he recommended, the man in charge seemed very calm and approachable about rebuilding the engine, but the cost he is estimating is ranging from $1500-3500, depending on what comes up.

I must admit pretty heavy ignorance when it comes to understanding what is essential to keep me on the road safely, and what is more of a luxury at this point.

If anyone has been in this position, or has experience on rebuilding engines, please offer any advice or guidance. I'll provide any additional info. or pictures if you need them. When daylight comes again, I'll post pictures of the engine.


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Old 03-12-2016, 09:58 PM   #2
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Re: 1947 Chevy Truck, Engine Needs Help, Advice?

First off what is leaking?lots of older vehicles have small leaks here and there.. If its just a couple of gaskets and that's all it needs then that's high. Does it need a rebuild?.sounds like you got a price for a full blown rebuild which is about priced right depending on what needs done.oh. And they usually charge more for upsidedown vehicles..makes it harder to pull the engine..haha..once the blood ran back outta my head from standing upside down to look at your pics got a pretty nice truck there.
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Old 03-12-2016, 11:48 PM   #3
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Re: 1947 Chevy Truck, Engine Needs Help, Advice?

First remember one of the jobs of the lube guy is to sell other jobs on your rig. That said you now need to see exactly what needs to be done to correct the oil leaks and what if any major work needs to be done.

On the engine I'd first clean up the engine so the outside of it was reasonably clean top and bottom and watch for fresh oil leaks. A leaky valve cover gasket or rear seal on the intake can get the whole engine pretty nasty looking real quick. Then I would run a compression test and see what the compression was like and watch the oil pressure gauge to see what it was like. You have to have a solid idea of what you are dealing with before you proceed with repairs or what not.
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Old 03-13-2016, 08:34 AM   #4
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Re: 1947 Chevy Truck, Engine Needs Help, Advice?

Mr 48 hit the nail dead on...
I also agree if the lube guy was the one to point out the leaks, maybe an oversell. Pulling it out for a re seal makes no sense. Valve cover, oil pan gaskets etc can in most installs be done with engine in car. Get a good degreaser and spray it all clean, then as advised already, watch for leaks.
Also, you mentioned your concern for safety/luxury. If you are new to this, safety rules...check or have someone (trustworthy) check your brake pads, brake lines etc. upgrade to front discs always a plus. You want to go, but more important, stop. Maybe someone here will see you post in your area and stop by for a visit. I would certainly if you were closer...
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Old 03-13-2016, 11:50 AM   #5
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Re: 1947 Chevy Truck, Engine Needs Help, Advice?

Hey everyone,

Thanks for the replies! The place I visited is called Legend Racing, website:

Mongo: You addressed my first concern: I can't tell if I need a rebuild or if they are overselling a much simpler job of resealing. Apparently, they have Yoda on staff, so flipping trucks requires little force.

Mr48Chev: Thank you for correcting the pictures. I believe that both the rear seal and valve cover gasket are leaking, from what the mechanic at Legend told me. He also suggested to do a compression test first before planning any repairs. My problem still is that I don't know how to interpret his suggestions. If they are needed to keep me on the road, of course I'll do it.

Fiftee3: I would love to have the engine worked on without pulling it, but both the Chevy mechanic and the Legend mechanic seem convinced of it. I can only hope that as you said, someone around Chicago sees the thread and comes by to point fingers at what I need to know.
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Old 03-13-2016, 01:03 PM   #6
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Re: 1947 Chevy Truck, Engine Needs Help, Advice?

Valve cover gaskets are no big deal to change ,usually a 15-20 minute job depending on ease of access... rear main..whole other thing. To change it would mean pulling the engine, oil pan and loosening the crank shaft to replace..I did one in a 72 4x4 blazer I had once without pulling the engine but I wouldn't recommend it. Thats probably not a option on your truck anyway. Once again how bad its leaking will tell the story. Clean it up ,drive it ,keep an eye on your oil level, and get a second opinion..they are right though if the rear mains leaking bad enough for an engine pull , I would have a compression check done..if you have to pull the engine just to replace a rear main it would only make sense to rebuild while you had it out...if it needs you know if your engine has the older version 2 piece rear main or the newer one piece?
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Old 03-13-2016, 02:51 PM   #7
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Re: 1947 Chevy Truck, Engine Needs Help, Advice?

I would not rush into a complete rebuild if the compression is good and there are no obvious knocks or noises. If the rear main is bad enough to foul the clutch or making a major mess underneath, or a drip now and then just bugs you, pull the engine and fix the rear seal, pull the timing cover to check the timing chain (usually worn, I always replace mine). While the pan is off put in an new oil pump. You can check a random main and rod bearing using plastigauge to see if a rebuild in warranted. You can also check for stamps that indicate previouis rebuilds (bored mains, turned crank and rods). You can also check the cylinders for signs of piston scuffing if the compression is down. If the intake is leaking, that is a good opportunity to check the condition of the cam and lifters for wear. If all looks good, install new gasket set and drive another 50K.
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Old 03-14-2016, 08:23 PM   #8
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Re: 1947 Chevy Truck, Engine Needs Help, Advice?

First, I would get a fresh piece of cardboard, and put it under the truck over night.
If the cardboard has a couple drips, you can schedule a reseal at your leisure. if it has teaspoons full , it is a top priority thing.
Look on the bright side, that much oil will discourage rust!

You did not tell us if your truck has a one piece rear seal or two piece.
A one piece seal can be pried out and tapped back in place with a new seal. You can get it out by removing the trans, and bellhousing if a stick shift, .... Flywheel and torque converter if auto.

Then decide if the engine needs a rebuild. Like previously mentioned, compression check will tell the tale.
Next, have someone other than you start the engine cold. Does it smoke?
Then shut it off, and start it in 5 minutes. Does it smoke now?
If your anser is no to both, you don't need a rebuild.

If your answer is it smoked after sitting all night, it might just be valve seals.
In your truck, a fair amount to pay for that might be $200, depending on how fast they get it done.

Does the engine use a lot of oil if you drive it for a couple days, and not much on the floor?
If so, it might be pumping oil past the rings. Compression check will tell you more here.

If you take a compression check, and you have low compression, say 115 or lower, take a small syringe, and inject some oil into the cylinder through the plug hole. If the compression goes up about 20 pounds, you have bad rings. If it doesn't, you have probably bad valves.

Now with an air hose screwed into the plug hole, listen for air leaking out the tail pipe, or coming out the carb. If it's the tail pipe exhaust valve is bad. If from carb, it's the intake valve.

If the leak is not severe, and this is the first you notice it because somebody said something, then keep on driving it, because apparently the leak didn't bother you.

I would change rocker cver gaskets and maybe timing cover and pan gasket, but replace the pan gasket with a one piece pan gasket for your engine. They make them in both varieties, single rear seal and two piece seal engine gaskets.

The Chevy engine is a tinker toy. You got the right engine to learn if you are so inclined.

Last edited by Coupeguy2001; 03-14-2016 at 08:30 PM.
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Old 03-15-2016, 08:51 AM   #9
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Re: 1947 Chevy Truck, Engine Needs Help, Advice?

Check out this link , jeggs will deliver a new engine to your door for less than that
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