Question-------------------------
Followup To
Question -
I came upon your website and thought you might be able to help us with some of your expertise.
My husband, Brad, operates a classic car mechanical restoration business in Cottam, Ontario, Canada. He has been in the business for 25 years and is well known and respected in our community for the work he does with antiques, classics, street rods, etc.
In the 26 years I've known him I've rarely seen him stumped, but he is right now...big time.
So, I'm trying to contact people like yourself who may have ideas about what he can try.
He is currently working on a 58 Chev Impala - 282 engine
Brad totally rebuilt the engine; bored 30 over to OEM specs.
After completion he had a problem with excessive smoking and oil consumption.
He thought the rings were not seeding, so he tried the normal ways of getting the rings to seed.
Excessive smoking and oil consumption continued.
He took the engine apart again, replaced the rings with different rings, installing cast iron rings. He deglazed the cylinders and reassembled the motor.
The smoking and oil consumption problem continues. The spark plugs indicate oil is getting past the rings.
He checked the crank case vent and draft tubes to ensure they are clear, and they are.
He checked the intake for leaks…the intake runner is becoming oil saturated.
Magniflux and pressure testing show no leaks.
He is just at a loss for what to try next or what could be causing the oil consumption and smoking.
If you have any ideas he could try, we would greatly appreciate your advice.
Thank you so much.
Answer -
I doubt I can think of anything he hasn't already considered, but I would bet that if there is oil in the intake manifold passages, it has to be getting past the intake valves in the head, which would indicate that the valve to guide clearance is too high, or else the valve stem seals are not able to hold the oil back, meaning that there must be an excessive amount of oil in the head. I would check to see that the head drain passages are clear so that oil can rapidly drain off back into the crankcase, and that the oil supply to the head is properly fitted.
I am not familiar with the "282" engine - in the US, most Impalas came with the "348" engine (which I happen to have in one of my trucks, and it uses no oil at all). Perhaps this is one of the Chevrolet years where Canadian cars used engines from other brands - most likely Pontiac - although I'm not familar with a Pontiac 282 either - is it a 6 cyl overhead valve engine?
Let me know if this is of any help, and what the problem turns out to be, OK?
Thanks,
Dick.
Hi Dick:
thanks, and sorry you ended up getting two copies of my inquiry. I was emailing all over this morning trying to figure this out.
Thanks also for your suggestions. It confirms to Brad that he is doing the right things. Unfortunately, he has tried everything you suggested, to no avail. The engine, by the way, is a 283...I hit the wrong button.
At any rate, we're still quite frustrated as is, of course, the car's owner.
So we will continue....
Thanks for your help
Diane
AnswerI did have one further thought, and that was that if he had originally installed chrome rings, and the cylinders were honed for that installation, then changing over to cast iron rings (which I do agree with) would require a different honing procedure. I'm sure he knows this, but I should have mentioned it.
At this point, I'd do a leakdown test to see what the compression is, and find any leakage paths that may not be obvious (like a hidden crack somewhere).
Dick
