Hey everyone, great site!
I have an issue with blow-by. I have a carb'd 89 gt with a 306 stock bottom end, Windsor 200 heads with stock cam, Weiand stealth intake below a 670 carb, Hooker headers, and all that other good stuff. I am happy with the car right now, until it starts smokin' out the back but only once in a while. Could this be blow-by? I am not running a PCV valve but an open through crakcase breather with the hose running to my carb. If I run my finger underneath the oil breather there is oil around the rim. Any thoughts or suggestions?
Could be blow by or could be worn valve seals also. When do you see the smoke happen. If only smokes after idling awhile then you take off and see smoke I would guess valve seals. If ring blow by I have a trick to remove some ring land deposits. take spark plugs out and into chambers let BG 44k or similar cleaner set inside cylinders overnight. Crank over next day to remove liquid before reinstalling plugs. This procedure has shown less blow by on a leakdown guage.
__________________
Mustang GT : $26,000
V-8 Insurance : $145/mo
Beating "Riceburners" At The Track : PRICELESS
I see it only when I stomp on it, or in between gears. Doesn't do it at idle. The heads aren't old at all and they have new umbrella seals on them from crane cams. I also have oil deposits on my plugs as well. The block isn't that old either, has about 10k miles on it. Could I need different valve stem seals? What would be causing the oil around the breather though?! I will try the cleaner as well as see how that goes!
While the engine is running take the oil filler cap off and see how much is blowing out. Excessive amounts could be bad as this would be ring blow by and not valve seals. Also a leakdown test will show what cylinders are bad. Not like a compression test. I had a engine once with 4 broken rings and it didn't even run bad just smoked. Good Luck. I have heard of deleting the PCV causing bad ring sealing because the loss of vacuum inside the block. Some bigger cams with low vacuum have same problem and run a belt driven vacuum pump.
__________________
Mustang GT : $26,000
V-8 Insurance : $145/mo
Beating "Riceburners" At The Track : PRICELESS
You need to have that metered orfice and check valve installed. I mean the PCV valve. You may be sucking excessive oil vapors and/or oil into the carb contributing to the smoking.
The oil that you are finding under the breather may be caused by the lack of a baffle where the breather mounts on the valve cover.
I'd still do a leak down test, but the above may be contributing to your problem. If you have the hose running from the crankcase to a point under the carb, you are creating a good vacuum leak and will be sucking oil into the engine without the PCV installed. If you decide to install one, get the one listed for your engine, because they are not all the same. ---Chuck
The Greek is right I thought you meant the hose running to your carb was a filtered supply to the breather not a hose attached to a vacuum source w/ pcv deleted. If you are doing that then of course your sucking oil into the carb.
__________________
Mustang GT : $26,000
V-8 Insurance : $145/mo
Beating "Riceburners" At The Track : PRICELESS
Yeah, I have pretty much a straight through oil breather with a hose running to the PCV port on the bottom of my carb. I have a PCV valve and I will try that! As for the valve seals, I am noticed that when I look at my springs the umbrella seals are not all the way down on the valve guide. They are about middle ways up on all the valves. Is this normal? Oh and one more thing... one of my roller tips on my rockers (Proform full rockers) split in half. I found one half, ut cannot locate the other. I have issues.
That piece of the roller might be in the oil pan, or stuck in an oil galley. Replace that rocker ASAP. Question is why did it fail? Most roller tips are made of stainless steel, was it discolored in any way? It might've been oil starved, overheated, and cracked, losing the bigger half of it.
I can't stand umbrella seals. They're made of plastic... how are they supposed to control the oil is what I'd like to know. And they're supposed to be all the way down at the base of the valve and is probably where the smoke out of the pipes is coming from. If you can, move them all back down to the bottom.
__________________
MOOG Certified Tech. For mods and sound clips, see profile and gallery.
Ask me why I ran "only" a 13.54.
Member: NMRA Member: White Mustang Registry #362 Member: Fuzzy Dicer
That's what I have been trying to figure out all along. It did in fact look like it had some 'burn rings' on the inside of the piece that I found. Doesn't look like stainless steel though. They are Proform 1.6 rockers that I bought from Summit.
For the seals, I moved them all down carefully with a small screwdriver and it was fine for a while. Then after I pulled the valve covers all of the seals were middle ways up again?! They suck in my book. Which do you reccomend?
Blow-by troubles?! 1989 Mustang GT 
