Have a 54' chevy with a 235 in it. Ive put about 4000 miles on it in the last few months and it hasnt missed a beat the whole time. It leaks oil, but ive just been adding it as needed. Noticed the other day its starting to smoke pretty bad out the tail pipe on deceleration (white/blue color). Its still runs fine and seems to have no noticable loss of power. I just need it to get me by till fall, cause im throwing in a small block swap. Any quick fix or ideas how to get her by for the season. Probly put another 4000 miles on it till fall if she will last.
My understanding is that smoke on deacceleration is valve guides. I'd throw in a can of Lucas or similar additive that is designed to cut down on smoking. May not work, but for a few bucks on an engine you are just trying to get some time out of, it might help. Maybe move up a little on the viscosity of the oil too. Don
Pull the valve cover and make sure your oil drain back holes are open. What do the plugs look like? Crusty deposits = intake guides and/or rings. Long as it seems otherwise to be running OK press on.
What transmission are you running? Could be sucking fluid up the vacuum modulator valve tube. Change the valve, may have a hole in the diaghram. Check so see if your trans fluid level has dropped also.
Id try a set of valve guide seals first & see what that does. If they are the originals they must be pretty hard by now. That was my first car until a girl in a bikini riding a bike came past in the other lane. When I looked back to the front the new Pontiac in my lane had stopped and I drilled him. Mine smoked so bad a kid told me my car was on fire when I was at a stop sign
DECELERATION? Why? Is'nt ACCELERATION more fun? But seriously, like everyone else has said, valve guides. Butch/56sedandelivery.
Like '56 Delivery Said "De-accelerate ? ..............Why ? Just be Sure your Hood is Shut TIGHT ! Mine Was'nt, no......it did'nt break me W/shield ! Was'nt Smoked up ! Either, Ether !!
Also, ive done some searching and cant seem to get an honest answer, should i get an oil filter hooked up?
You already got good answers. Keep adding oil and drive sensibly for the next 4,000 mi. and do your swap. Face facts, you got a wore out mill that aint worth the bandaids.
Only reason i ask is i have a buddy that has a 53' chevy and he is going to use my 235 after i make the swap. He has said if its reasonable he would cover the cost of the head rebuild.
I think you would be opening a can of worms to just do the valve job. Once they are seating you might see ring blowby. Just nurse it along for the next 4,000 miles and let your buddy do a proper rebuild when he gets it. Sometimes when you do one thing to a motor it affects something else. Don
Run it like it is and keep adding oil. When you guys pull the motor for the swap, do what we used to do. Pull the valve covers off, stuff a clean nylon rope into the cylinder thru the spark plug hole, leaving a knotted end to pull it out later. Rotate the engine till the rope is snugged up against the head, use a valve spring compressor to pull the spring off each valve, replace the valve guide seal, put the spring back on, rotate the engine back a little after doing each set, pull the rope and do the next cylinder. When you're done, he can do the swap and rebuild it properly when time/funds permit. You might want to do the seals in the right firing order so both valves are closed on each cylinder you do. That way you can also set the valve lash when you put the springs and rockers back on.
The high manifold vacuum on de-acceleration pulls the oil past the guides. New stem seals should help, try a heavier straight weight oil first as a cheap fix. Now the weather is warmer a straight 40 or 50 will help. Back in the day, I'd add a can of Alemite CD2 to oil changes in my smoky cars, it really helped, haven't seen it in years though. Bob
Just drive it dude. If it's smoking a little bit, don't worry about it. Of it's smoking alot, maybe a valva job.
Does it have a PCV valve for crankcase ventilation? If so, the valve may be going bad, sucking blowby up into engine excessively. If no PCV, then valve seals/guides. One last place to look too is vacuum booster on fuel pump. Might be sucking oil up through vacuum booster diaphragm.
Umbrella seals from an SBC should solve it if it is due to the guides/bad old seals. If you put a vac gauge on it and the needle is bouncing all over, that would indicate bad valve seats/guides and time for a redo. If you want to know what it's going to cost, check with the place you are planning on having do the work. I wouldn't bother with hardened seats, but it's up to you. I would spend the time on bowl porting it while it's off, but then I tend to build them up a bit.
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