II rebuilt my b18c a few weeks ago, and I gapped both my compression rings at 17 thousandths.

Yesterday, I noticed that I get a very very sliught about of smoke from the valve cover. I ran a compression test, and hit 162 162 162 162 (approx. 9.1:1 at ~5500 feet elevation). How much blowby is normal for a motor like this? Is it bad that there is a very slight about of smoke coming from the valve cover, or is this acceptable?

 

a slight smoke is fine, when you have oil spitting out of it, is when you need to look at it again.

Another test I usually do just to make sure, is take out your dipstick whiel the motor is running, if you're having an excessive blow by, you'll smoke out of the dip stick tube

stan

 

The breather filter felt dry..... so that's good.

So, if the ar smokes at all out of the dipstick hole... then the blowby is excessive?

 

yeah, that means you have an excessive crankcase pressure

stan

 

stan how'd you get so smart

 

falcon i have the same problem as you on a rebuilt b18c1. mine smokes from the dipstick hole as well as the breather. Mine doesn't smoke from the exhaust at all and i'm actually not burning that much oil, about a court every 1500-2000 miles. My compression is fine as well, i just ordered a leakdown tester so i will see if that will shed some light on the valve cover smoking thing

 

a lot of it depends on the way your end gap rings measurement.
Here are a 3 factors that may contribute smoking out of the VC eventhough your Compression comes out normal, there may be more, but I am only limited to what I have seen and experienced.

your ring end gap, the top, bottom and oil rings
the way you staggered the rings
the way the rings are seated.


Joe: lol

stan

 

Could a leaky headgasket contribute to this in any way?

 

a leaky headgasket would throw your compression somewhat off..., I'd checked your coolant and oil to see if there are any mixes.
FYI, a leaky headgasket will eventually eats up your head, it'll creates a water channel and eventually the coolant will start eating away the aluminum materials...

just as precuations..

stan

 

Ouch... I didn't know that.

The problem is: I had the block decked and the head resurfaced... with a new gasket and it STILL leaks!!! I can't figure out why. Could it be because I didn't shorten the alignment dowel pins... (I've shaved a total of 14 thousandths off my setup)

 

give your car 1000 miles or so, the idle smoke will most likely dissapear.

nothing out of the ordinary... which of course has been said about the past 30 times.

 

Any thoughts on the leaky HG? I don't want to pull the head just to put a new one on and have it leak again!

The only thing I can think to do it shorten the dowel pins and copperspray the gasket this time.... but I'm concerned because I don't think I should have to do that

 

Any thoughts on the hg issue?

 

Flamenco-T, will a leakdown test show if the ring staggering/seating is not correct?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by servion &raquo;</TD></TR><TR><TD CLASS="quote">Flamenco-T, will a leakdown test show if the ring staggering/seating is not correct?</TD></TR></TABLE>

Doesnt really matter as far as where the rings are positioned now----they will move around and rotate during normal engine operation. As far as seating of the rings is concerned----it depends if they actually broke in or not.
I went too big on ring gap and that's why I smoke. I went really big thinking I was gonna run a big shot and lots of boost. Oh well, this winter Im gonna tear it down and go 83mm.

 

What did you end up gapping your rings at? I gapped mine pretty large as well...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Flamenco-T &raquo;</TD></TR><TR><TD CLASS="quote">a slight smoke is fine, when you have oil spitting out of it, is when you need to look at it again.

Another test I usually do just to make sure, is take out your dipstick whiel the motor is running, if you're having an excessive blow by, you'll smoke out of the dip stick tube

stan
</TD></TR></TABLE>

could this still be blowby problem:

i didn't really step on it last night, just reach .13bar=1.9psi. while waiting for the garage door to open there was slight smoke but when the car was parked already with engine still idling, there was a huge smoke like something is burning underneath the car. my dad also noticed it even if it's night time already.

i kneel down and saw the muffler blowing smoke out so i took out the dipstick and there was no smoke at all. could it still be blowby?

could a piston ring blow by cause sludge in the exhaust pipe?

 

Pull your spark plugs and see if they are covered in oil! That is a definate sign oil is in the camber. Then it's either rings or valve seals.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by abraunb16 &raquo;</TD></TR><TR><TD CLASS="quote">Pull your spark plugs and see if they are covered in oil! That is a definate sign oil is in the camber. Then it's either rings or valve seals. </TD></TR></TABLE>

no sign of oil at all on the spark plugs, they all burn equally.

 

I do lave a very slight amount of smoke coming from the dipstick hole. It's much less noticible after I run it hard to expand the rings.

Could my 16 thousandths ring gap cause this smoke out of the dipstick tube?

 

yes could a larger ring gap cause slight amounts of smoke to come out

 

yes cause the combustion gases will go right through the gap into the oil pan