Oil Smoke driving me crazy
Moderator: Team
Oil Smoke driving me crazy
Brand new 383 I just built for a truck. AFR heads flat top engine. Runs great, once its up to operating temps it has some smoke coming from exhaust on both banks. I changed intakes, gaskets looked oily and there was oil in runners. Same thing happened. Checked studs to make sure they had sealer. Comp check looks good. I am pulling the intake again first thing in the morning to reseal. If that doesn't fix it I am tearing it down.
Just wanted to run it by some of you to see what you may think.
Just wanted to run it by some of you to see what you may think.
Re: Oil Smoke driving me crazy
there are many threads on here concerning intakes not sealing. check them out
Re: Oil Smoke driving me crazy
If you’re running a pcv valve, try removing it and installing another breather.
Check to see if the hose has oil residue in it.
I’ve seen it where oil would run out of the pcv hose.
Check to see if the hose has oil residue in it.
I’ve seen it where oil would run out of the pcv hose.
Somewhat handy with a die grinder.
Re: Oil Smoke driving me crazy
Given thought to oil getting past the rings or valve stems?
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire
Re: Oil Smoke driving me crazy
I have, If it sits it blows out a big puff of smoke on start up. when I took the intake off it had a puddle of oil behind the intake valve. Brand new AFR heads.
Leak down test is next. Its a 10.5:1 383 on 93 octane. I could have broke some pistons but unlikely.
Re: Oil Smoke driving me crazy
You do not have the required permissions to view the files attached to this post.
-
- Guru
- Posts: 1944
- Joined: Tue Sep 15, 2015 2:25 pm
- Location:
Re: Oil Smoke driving me crazy
Your oil smoke can have several causes, intake leaks, faulty valve stem seals, rings that did not seat. etc. You are getting good advice on checking those items.
I never run open breathers on anything any more, and the open breathers most likely are not the whole issue, but getting rid of blow-by gasses is part of the engine package. blow-by gases will make your oil get dirty quicker, promote moisture contamination, and cause oil consumption. If you have pressure in the crankcase, you have pressure on the bottom side of the ring, on the intake stroke, you have vacuum on the topside of the ring, so oil wants to go into the combustion chamber. At a minimum on a street engine run a PCV system, or backfire valves in the headers. You can look at the number of OEM service bulletins on oil consumption, and redesigns of valve covers and PCV systems to know their can be a lot of issues with crank case pressure causing problems. The old draft tube used air rushing by it to create a suction to help vent the crankcase better.
I never run open breathers on anything any more, and the open breathers most likely are not the whole issue, but getting rid of blow-by gasses is part of the engine package. blow-by gases will make your oil get dirty quicker, promote moisture contamination, and cause oil consumption. If you have pressure in the crankcase, you have pressure on the bottom side of the ring, on the intake stroke, you have vacuum on the topside of the ring, so oil wants to go into the combustion chamber. At a minimum on a street engine run a PCV system, or backfire valves in the headers. You can look at the number of OEM service bulletins on oil consumption, and redesigns of valve covers and PCV systems to know their can be a lot of issues with crank case pressure causing problems. The old draft tube used air rushing by it to create a suction to help vent the crankcase better.
Re: Oil Smoke driving me crazy
Check the fit of your intake with no gasket and see if there are gaps while you have it off it may need to be surfaced.
-
- Guru
- Posts: 6381
- Joined: Tue Jul 24, 2012 11:15 am
- Location: Roseville, Michigan (just north of Detroit)
- Contact:
Re: Oil Smoke driving me crazy
I would check the intake rocker studs to make sure they have a good thread sealer where they thread into the head.
Personally, I use "Right Stuff".
http://www.rmcompetition.com
Specialty engine building at its finest.
Specialty engine building at its finest.
Re: Oil Smoke driving me crazy
What part number intake gasket are you using? From the pics it looks like a stock replacement gasket, I do believe they recommend performance gasket with aluminum intakes.
A bad day of racing is better than a good day of work
Re: Oil Smoke driving me crazy
I had my own issues with my AFR headed 383, I used steel core FelPro intake gaskets.
- Edelbrock TPI base on previous 355 did not have any issues with being zero decked, FIRST TPI base needed to be machined as I did not want to touch AFRs, still had rear china wall issues fixed with 'the right stuff' and attention.
- I feel there may be a cylinder glaze issue with oil found in plenum floor.
- stuffed pcv baffles on factory valve covers with ss wool.
- purchased (could only afford with group buy) Wagner pcv valve, along with a quality air/oil separator tank.
Haven't driven enough to guage difference yet, but did not strike me as an oil burner and no puffs of smoke- it was more evident I think in tuning last year with detonation. We'll see.
- no issues with supplied valve seals.
- Edelbrock TPI base on previous 355 did not have any issues with being zero decked, FIRST TPI base needed to be machined as I did not want to touch AFRs, still had rear china wall issues fixed with 'the right stuff' and attention.
- I feel there may be a cylinder glaze issue with oil found in plenum floor.
- stuffed pcv baffles on factory valve covers with ss wool.
- purchased (could only afford with group buy) Wagner pcv valve, along with a quality air/oil separator tank.
Haven't driven enough to guage difference yet, but did not strike me as an oil burner and no puffs of smoke- it was more evident I think in tuning last year with detonation. We'll see.
- no issues with supplied valve seals.
Re: Oil Smoke driving me crazy
If I recall with these AFRs- even though I did use thread sealer- the threads are blind.Walter R. Malik wrote: ↑Sun May 17, 2020 11:42 amI would check the intake rocker studs to make sure they have a good thread sealer where they thread into the head.
Personally, I use "Right Stuff".
Re: Oil Smoke driving me crazy
Also, perhaps rings (particularly Second) are installed wrong ?
Second intended to scrape oil down; if ring's upside-down, it can push oil up.
Hope it's simply leaking intake gaskets.
Second intended to scrape oil down; if ring's upside-down, it can push oil up.
Hope it's simply leaking intake gaskets.