Ok I have 600 miles on the newly built 350, and still have abit of a problem. The problem has lessened but still concerns me. I was told by the engine builder and a cpl guys who build engines for a living to give it till around 1k b4 I worry about it, but I am still worried. They say that my rings are probablly still breaking in (chromolly rings take longer sometimes I heard).

Anyways what concerns me is that I only get a little smoke from the right side once the engine is warmed up. It does not smoke in the morning when I crank it up, but will smoke slightly if I run down the road to the gas station, cut it off and cut it back on. So it seems to me one the oil is circulating abit it starts doing this.

The amount of smoke has lessened since the install and no longer does it on the left side. I am trying to figure out if it might be the heads or rings. I hope this info helps someone give me a better idea.

THX~

 

Well thanks for the replies, I take it either ppl here have no clue or just decide to ignore request for help, unless its a flashy subject.

Bah, I am done here I reckon.

 

For starters, if your engine builder told you you have "chromolly" rings you may have a problem right there.
There is no such thing. There are iron rings with a moly coating and iron rings with moly embedded in them.
There are also chrome rings that are generally used where a particular engine apllication may ingest a lot of dirt and grit, but there is no such thing as chromolly rings.
All things being close to correct modern piston rings should seat almost instantly.
Your smoke problem could be from a number of things. The first thing I would do is perform a leak-down test and go from there...

 

Sounds like you run the motor, get it warm, then shut it off and let it sit for a few minutes, then it smokes a little when you start it, right?

If the smoke goes away in a few minutes time, then they messed up the valve guide seals. I've seen where people will oil the seal/stem in order to slide the new seal on the stem...that makes them come right back off :(

Then again, did they put seals on all valve? If not, and you did not buy BRAND new heads...that's the problem.

 

I am going to get a leak down test ran, however for some reason I keep thinking its the heads. As for the chrome molly rings, All I know is the parts list refers to :"Sealed Power Chrome Molly Rings". Now as to the issue of true chrome molly or what I dunno, but lets just leave it at they are what I said they are.

As to the smoking it continues to smoke when idling at a stop light also out the right side. The smoke is a small amount, but enough for me to see a slight smoke pattern back there. I dunno if its the the weather or what, but it does not look like its smoking when its cool out, this smoke only is noticable when its warm.

Sorry if I am getting testy, but this is geting on my damn nerves. The car runs great and sounds great, and smokes great. What a combo, eh? I have been looking at heads and wanted a pair of world prod. sportsman II's for a while, but would be really upset if the upgrade did not fix the problem. Because then I still have the problem to solve.
:(


[Modified by 1976C3, 3:43 PM 11/9/2001]

 

As someone already said, moly rings seat almost instantly and you should never see any smoke.

Chrome rings are another animal all together and do take a rather long time to seat, but I don't believe anyone is using them any more in a street engine.

Cast rings - without the moly in-lay - take a little longer to seat, but still, no smoke. You just don't get quite as good leak down numbers with them as you would with moly rings - until they do seat.

Cylinder wall finish must be very smooth when using moly in-lay rings or the moly can chip and cause a loss of seal.

If you're smoking, you've got a problem that will need to be corrected.

Any stated earlier, smoking can be caused by a number of things, none of them good.

Valve guides worn
Valve stem seals leaking
Leaking injector or power valve opening at idle (carbed engine)
Too high fuel level (carb)
Ring gap too large, but they need to be WAY to large to cause smoking
Ring(s) installed upside down
Ring(s) stagger or installed in wrong groove on the piston
Oil ring expander overlapped rather that butted

You've first got identify the smoke, is it oil or gas. From there isn't a matter of running down the cause.

Sorry for the bad news.

Jake





[Modified by JAKE, 8:02 PM 11/20/2001]

 

If it keeps smoking at idle, chances are it is NOT the valve guide seals.

But, I've also seen a damaged intake manifold cause smoking by sucking oil into the engine through the bottom of the plenum side.

That was a weird one, but more likely even could be a torn or misplaced intake gasket. I would at least pull the intake off and inspect for signs of gasket misalignment or oil in the runners.

 

i'd check the intake manifold for oil leaks at the front and rear china walls.. i had a leak from the rear china wall that would drip onto the headers that would smoke like a train once it warmed up. out of curiousity, are you running a high output, high volumn oil pump?

 

Do you have a TH350 Auto trans? Is the smoke white?

If yes to both, it may be just the trans vacuum shift modulator, which is a 10 minute replacement part.

 

Did you identify whether it's oil or gas yet? You may be able to tell which it is by running your fingers inside the muffler tips for the residue.

Another point, too, is that teflon PC type valve stem seals, (the white plastic looking ones) are a bad choice for the street. They allow too much oil to enter the valve guide and will result in smoking.

I don't know if you've had any head work done, but if you have it could be the type or installation of the valve stem seals.

If it is the valve guide/seals or intake manifold gasket leaking on the underside, you'll notice an oily deposit in the intake port, backside of the intake valve, combustion chamber and piston.

Your plugs may or may not show evidence of oil fouling, depending on how bad it's leaking. Sometimes if it's just a very small amount, the plug will burn it off and not readily show up on the porcelain.

If the intake manifold gasket is leaking from the valley side, you should see a flucuation in your vacuum readings too. The vacuum gauge won't show a steady vacuum reading but will show a drop in vaccum each time the effected intake valve opens.

 

Ok, a few questions to answer I see, thats good.

We removed the intake and all looked ok and re-installed to ensure no leaking, everything there is cool.

The heads I know little about sadly. I know they are 882 heads and have z-28 springs and had a 3way valve job done.

Yes I am using a new th350 TCI streetfighter transmission. Yes the smoke is white looking to me. The modulator is new, but I am still trying to adjust it since they set the modulator for stock vacuum, and my cam is slighly off from stock.

I am only seeing slight smoke after a couple minutes of oil circulation from the right side exhaust. No residue being left in the exhaust tip.

The smoke is slight and not heavy like a crop duster, but just enough for me to be irked by it. Nothing like having a vette with a lopey idle sit and smoke @ a stop light. :(

I also have 1 oily spark plug on the right side. The other plugs looked to be burning fine, I reckon this plug is the cyl. giving me my smoking issue.

 

So have you compared the compression test pressures to that one against other cylinders?

 

I had a very similar problem many years ago. Bought a "fresh" engine that had never been fired and when I installed it and fired it up, it blew oil out the tailpipe like you wouldn't believe. Completely emptied the oil pan in a few miles of driving!

It was a BB and when I pulled it I found that it had 396 rings in a .060 over 427 block. Ring end gaps were huge.

One wrist pin lock had come out and left a long deep gouge in the #8 wall too. Had to have it sleeved it was so deep.

My problems were worse than yours, but I'll bet you'll find something similar when you do the autopsy.

Jake