The Stovebolt Site Forums The Shop Area Engine Shop 58 Apache 3200--283/4spd

I just did a compression check on my 53 year old 283. The manual says minimum of 140 psi. All cylinders were between 145 and 160 psi. Two cylinders on each bank increased 5 psi after squirting oil into the cylinder. I get smoking from the road draft tube (I think that is what it is called). When I got the truck it had a receipt for an oil change--after a few short drives (10 miles or less) the oil was black, so, I changed it--10/40 castrol. With less than 100 miles the oil is black again. When doing compression check, all plugs were carboned up with less than 100 miles on them. I am thinking a valve problem--am I crazy? What do you guys think?

if the engine had 145+ compression it's real unlikely it hasn't been rebuilt in 53 years ... the road draft smoke is blow by, rings worn .... black plugs [sooty black] mean running rich, with blow by, that could be why the oil is dirty quickly .... if the engine has sat for a long time the valve seals are likely shot and the guides may be worn, but that would cause exhaust smoke on first starting, and oily black plugs

Bill

Hy LeeBeckman, if you got an increase in compression by adding oil to the cylinders, that indicates worn rings. Excessive fumes from the road draft tube also indicate worn rings. Your compression could be artificially high because of carbon buildup in the combustion chamber. You did say that your plugs carboned up extremely quickly. I'm afraid that you are looking at an engine rebuild, I have a lot of respect for 283s, as I worked one for many years in my 57 one ton. Unfortunately 283s cost a lot more than 350s to overhaul, just because of parts availability and popularity. You could replace your 283 with a 350 with just a few adaptions, or you could have your 283 rebuilt, good luck.

If you believe it is carbon buildup, try this...If you have it running, I would get it warmed up and get a spray bottle filled with water. Run it at a high idle and squirt water directly in the carb. As much as you can with out killing the engine. That will knock the carbon buildup off and out your exhaust. Just do it outside.

Adding oil will add to the compression reading of any engine. I'm not sure it indicates anything to me accept that oil is in the cylinders. Do a leak down test on the engine and determine if it is rings or valves.
If you can find a scope that will fit into the spark plug holes, you could look for oil wash. That would be where the oil washes the piston clean around the edges near the rings. That would indicate bad rings.
Also look for oil clouds coming out of the exhaust when driving and pushing in the clutch when shifting. That would also indicate a worn engine.

Thanks guys--I was thinking that a rebuild would be necessary. I would like to keep it as original as reasonable. If rebuilding the 283 isn't prohibitively expensive I will probable go that way. I know a 350 is a good engine--on the other hand they are like noses, or asses, everybody has one. Any way, thanks guys
Lee

Amen.

When you are building a 283 vs 350, you are talking about $50-150. Not a bank breaking deal in my book. The pistons are more. I love my 283's and 327's. Build the 283, stick in a RV cam and call it good. You could even stick with the original carburetor or a small 350-550cfm carb.
I just sold a 283 to a guy who has a '65 Corvette that he stuck it in. He built a nice daily driver that gets better mileage and has enough power to get him out of trouble.
You'll love your 283.

another vote for the 283, about the best small block ever

Bill

Dittos on the 283......!

I've rebuilt many...great little motors.

If you want a little more Ummph.... Most of the cam manufacturers
still build the stock Chevy spec "350hp-327" cam & kit, using hydraulic lifters. It's a sweet spec. Just the right lift and duration
for a bored 283 that has an aftermarket intake and a small 4bbl carb. and dual exhaust.

Have fun!
Mike

Thanks guys. All your input has reaffirmed what I wanted to do all along--rebuild the 283. Thanks again.
Lee

If your block is original, you may even be able to bore it out further too. I made mine .080" over. I believe it is safe on those to go .125" over.

Im running a corvette 327 cam in my 283 punched .125 over. good all around small block cam. what a rumble...