65 fi

For you engine experts: I have a ZZ 383 crate engine which is blowing smoke (grey/white) out the valve cover on the passenger side and smoke out the exhaust. The pressure at each cylinder is 175-185 lbs. There does not seem to be any indication of loss of pressure on a leak down test. The engine will put out enough smoke in the passenger area to cloud the inside of the car and there are times when oil is exiting the dip stick tube at the oil pan. It would seem the engine is pressurizing but no indication of oil in the water or water in the oil. Any ideas? This motor is not running well at all and only has about 10,000 miles.

64 roach

silly question but what are you running for vents and what kind of intake I ran the same engine in a boat (soon going in the 64) at a constant 5800-6000 rpm and never had a problem except for the small oil pan volume (dropped oil pressure after 3-4min WFO) maybe provide some pictures, Keith

65 fi

My son's car, so photos are not practical. He is using an Accel Superram, BBK 52mm trottle body, 42lb injectors.

mikem350

Strange that all cyls show same compression...I would bet a blown piston/rings or major carnage...any plug(s) look destroyed...is PCV system hooked up and working?

Is it possible that crankcase is WAY OVERFILLED w oil? Or injectors flooding w gas? Might explain it..PLEASE post what the problem was

Poorhousenext

From color of smoke, and oil out dip stick, sounds like a blown head gasket are cracked block and/or head.

What does smoke smell of, antifreeze or oil?

Shurshot

Sounds to me like you are building up to much pressure in the crankcase that could come from either a missing PCV ventilation system or a blocked ventilation system.

If there is no ventilation system eventually the motor will find its own way to vent and that is not good

Doug

Frankie the Fink

A good possibility...friend of mine got a 350, ready to install in a '62 and completely forgot about crankcase ventilation...already purchased 'closed' valve covers and a non-PCV air cleaner and non-breathing oil filler cap. Bad recipe.

Crankcase vapors are explosive!

65 fi

The smoke smells of oil. The PCV was replaced as well as the smog pump. Strangely, my son said all of this occurred in the wake of the original smog pump going bad. The smog pump and PCV were then replaced, smoke started pouring out the hose feeding into the PCV on the passenger's side, with that same hose attached smoke is coming out the center bolt holes in the valve cover-bolts secured in place (driver's side PCV and hose supplying such seem to be fine with no smoke), and smoke out the exhaust pipes (his car has a Y-Pipe). I spoke with a local mechanic who felt it could be an oil ring on one of the pistons but wouldn't that show in either the compression or leak-down test?

65 fi

Doug, the stock ventilation system is in place. The only change is a recent replacement of the smog pump and aftermarket valve covers (which have been in place prior to having this problem).

65 fi

Mike, the dipstick reads between the lines. Some of the plugs look fouled. They appear gas fouled.

amtronic1

I'm gonna ask a real obvious question. Is the PCV valve installed right? There is no chance it was installed backwards?
Another thought is an oil ring problem, they only control oil not compression so the compression readings would still be in line even with a broken oil ring.
Good luck tracking this one down.

Shurshot

As far as your plugs looking gas fouled I see you have "FI" in your username and if that means you have an FI car I cannot offer any advice regarding fouled plugs.

As far as the ABILITY to breathe with everything else sealed against escape if you have one breather on each valve cover and with the said breathers removed (or PCV removed) you should be able to push air into the one side and a corresponding amount of air (or close to it) come out the other side. I have noted that just by squeezing plastic oil containers and pushing air into the motor when trying to get the last bit of oil out from a container and seeing the puffs come out the other side's breather. Anyway that will that will determine if air is able to vent through your motor.

PCV valves are simple one way persian valves but they MUST be installed correctly and not 180 degrees off.

I know nothing about smog pumps....... sounds like something sacrilegious like a robber of HP

That is about the extent of any advice I can think of. :o

I wish you luck and I am looking forward to hearing a happy ending to your problem



Doug

bb62

It would not be the smog pump if the smoke is emanating from the valve cover. The smog pump is nothing more than an air injection pump to the exhaust to allow for more oxygen in the exhaust. This promotes burning up a greater percentage of the unburned hydrocarbons and yielding a cleaner exhaust.

65 fi

The PCVs are installed correctly (as far as I know you can only install them one way).

The f.i. in my site name is really about my 65 fuelie (which by the way, I just got my fuel unit back. So it goes to the engine shop next week; the engine goes into the frame next week, leads to the body going back on the car. With any luck, the car may be able to drive this summer).

The engine is question is not in the same car but is a current day fuelie (newer day technology).

silverslashstreak

We put a ZZ 383 424 horse crate engine in my sons 73. Went by the book, cleared it with the dealer that if we installed it they would warranty it if any problems.

From the very first start up it smoked badly on the right side. GM said run it a little and see what happened. At the same time it had a lot of piston noise in it like a too much clearance.

Took it to the dealer and they pulled the right head and found all the rocker studs where loose letting oil into the cylinder. When they gave it back to us I said that did not fix the clearance issues.

To make a long story short, the knocking got much worse in a few hundred miles and they replaced the engine with a new ZZ 383 that has been a very good engine.

My suggestion would be get it to a dealer before it runs out of warranty and let them replace or fix it.

Jeff

mikem350

Out of curiosity, what year car/FI setup is this in? Was assuming a C2 w/no emission stuff...but shouldn't matter too much!!

65 fi

1990 Chevrolet Camaro.

65 fi

We now have found some evidence of abrasion on the inside side wall (bottom) of the valve cover.