Idle oil smoke

[TomShea]

Engine smokes at idle. Fresh everything. Eliminated possibility of fuel or coolant. Definitely oil smoke. Turbo is fresh and not damaged from break in of engine. It has a special no bypass filter set-up. PCV is now vented as a "road draft tube". Both valve covers vented to atmosphere. Plugs fouled black in short time use. Wet black oil at header flange to head seal. This engine is very fresh with only a few hours of running time, and no high load operation. I pulled it back out and on inspection I found oil on the valve stems. The head gaskets were a poor match at the oil drain holes. The block and heads both do not align well with gasket holes. I am relieving the block area near the oil drain holes to enlarge the passages for better gravity oil drain.I have opened up the old head gaskets to use as a mock up and template for the new ones. I will be opening up the new head gaskets's drain holes to max. I have bell mouthed the oil drain holes in the heads. The heads are now at "Head werks" for a thorough check. I believe I am not the only one who is having some issues with poor oil drain from the heads. I'll update this thread when I get it back together.

 

[Sleeper-6]

Check the turbo

Have you checked the turbo?Puffing smoke at idle is a classic symptom if a turbo going south. You say it's fresh, but have you confirmed there is no oil there? Was the oil on both DS and PS header flanges? There shouldn't be a need to go nuts optimizing your drain back passages. These engines aren't exactly known for delivering excessive amounts of oil.

 

[Powder]

Are you running stock valve seals or did you modify the heads to use positive style valve guide seals? If modified, are the seals all in place? I had seals on rebuilt heads come off the guide allowing oil to be drawn through the guides especially at idle when vacuum is high. HTH

 

[Turbo-Archie]

The only way it could be the turbo would be on the intake side which would be easy to check.


Sounds more like a guide issue as Tom points out.

I could see the drain back being an issue if he has a high volume set up with the big pan, loose bearings, low Wt oil, ect..




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[TomShea]

oil smoke at idle

I appreciate the input. I have stated that it is not the turbo and what I suspected it was. I believe Archie may know more about this me & this car since we have met a long time ago. The oil drain paths are very important. If the oil is not allowed to flow from gravity alone, it can cause smoking. This can happen with the turbo as well as in the engine at the head to block oil drains. The turbo oil drain is not intended to be forced evacuated, which would be the case if the oil drain was not sufficient. Valve guides and seals are not intended to operate submerged. If either of these things are wrong on your car it will smoke. Guess how I know this. I should state that this car is not your standard run of the mill TR. It has a stg 2 with M&A heads and a 72 turbo. I think the stage blocks have a little more meat in the area (that I am relieving) than a stock 109. I believe that the more serious nature of this piece leaned towards strenght rather than street manners like good head oil drain. The stage blocks can be and are modified quite a bit to be a street motor. The original intended use of these was for racing and there was not much concern for oil drain from solid lifters. I do believe that the 109 blocks are not good in this area either, and could benefit from some attention to oil drain from the heads.

 

[Turbo-Archie]

Hey Tom, Didn't think you would remember me.

I knew this would not be a generic question coming from you.



I just ported my drain backs on a block I was working on. I agree that it seemed that the gasket was the biggest restriction.


In your case two things come to mind:

1) oil drain back- you must be flowing alot of oil for it to flood your heads at idle?? Imagine how much you must be flowing at full RPM???


2) Bad seal- if its a bad seal, it might not have anything to do with oil drain back. It just leaks all the time.



When you take the heads apart, would the valve show signs of a faulty seal?





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[TomShea]

oil smoke at idle

Archie, I remember you and Mike. I think I got some wheels from you. I see your car and some of your posts now & then. Good to hear from you. In regard to the engine. I do have a Precision front cover with the larger pump. I am running the comp hyd roller cam & lifters. I think there was always some smoking like this, even with the previous build. Streezo built it with the solid roller I supplied but we used hyd lifters. We had about 9.5 to 1 CR at that time. It was hard to control on the street. The power came on too fast when it hit. Pedaling it was almost impossible. The car mostly sat, since I was busy with other stuff. I finally got around to pulling the engine out last winter. I had it freshened with 8.5 to 1 pistons and a less agressive cam. I don't have any real testing time on it due to this issue. The engine is on the stand waiting for the heads to come back. The heads have those white teflon seals on all valves. I'm pretty sure they were doing what they were designed for but could not keep oil out when submerged. I expect the heads back next week. I will post when I get it back in & running.