Smoke coming out the breathers

[Paul_G]

There is a lot of smoke coming out the breathers from both valve covers. This is on my Indy Cylinder headed 69 RR 528 Hemi. The valve covers have breathers with a hose connection. They ran the hose down to the under side of the car, like a road draft system. It smokes the worst after a good romp on the throttle, smoke in my rear view mirror. And at idle, wafts of smoke coming out from under the car. The hoses even drip a small bit of oil after it is parked.

How much would be considered normal? There is no PCV system on the engine. It is supercharged, so would a PCV be plumbed in the same way, to the intake?

Hopefully it is not internal.

 

[Cranky]

Is this a fresh engine that hasn't completely broken yet? If it has Molly rings it should break in really fast but if they're not Molly it can take longer....

 

[Kern Dog]

Steam is condensation boiling off. Smoke is blowby that means the rings are worn or not sealing.

 

[Paul_G]

Is this a fresh engine that hasn't completely broken yet? If it has Molly rings it should break in really fast but if they're not Molly it can take longer....

I have no information on the car at all. I bought it a few months ago. Finally have enough of the major issues sorted to start safely driving it. My guess is, it likely could not be broken in yet. I dont think the car has been driven at all since 2006. The tires on the car are the biggest clue. They are dated from 2006, all four. Yet all four have like new tread on them. Who builds a super charged Hemi and doesn't roast the tires? It could be the engine has not broken in yet. Another clue was the fuel system, grossly undersized for the combo. Only got a few seconds of WOT before it ran out of fuel and layed down. I just finished installing a new EFI ready Tanks Inc tank with big internal pump, -10 lines. Now it is getting enough fuel to safely say it wont go lean.

 

[dan juhasz]

have a competent mechanic do a cylinder leak down test. It will quickly tell you what's going on. My guess is you won't be happy.

 

[Cranky]

I have no information on the car at all. I bought it a few months ago. Finally have enough of the major issues sorted to start safely driving it. My guess is, it likely could not be broken in yet. I dont think the car has been driven at all since 2006. The tires on the car are the biggest clue. They are dated from 2006, all four. Yet all four have like new tread on them. Who builds a super charged Hemi and doesn't roast the tires? It could be the engine has not broken in yet. Another clue was the fuel system, grossly undersized for the combo. Only got a few seconds of WOT before it ran out of fuel and layed down. I just finished installing a new EFI ready Tanks Inc tank with big internal pump, -10 lines. Now it is getting enough fuel to safely say it wont go lean.

Like Dan said, do a leak down test. That will tell you much more. I have very little experience in blower motors but ring seal is pretty important to them too. One question I have is does it smoke when you are on the throttle somewhat hard? You did mention seeing smoke when you let off and that can be valve stem seals. I would think if the rings were not sealing, you would see smoke when you are on the throttle too. I also would like to take a peek into the cylinders with a bore scope camera. These days, they are pretty cheap compared to what they used to be.....

 

[RJRENTON]

IMO...I always thought that blower engines, used a "head land" top piston ring assembly (L shaped) to provide a positive pressure behind the ring, that literally expanded ring for a tighter fit in the bore and to reduce or eliminate ring flutter, to achieve less blowby. There were small holes drilled in the piston crown, near the outside diameter, to the top ring land. These small holes applied combustion pressure behind top ring, forcing it to expand slightly to seal. Personally, I've not built a blower engine, but observed the building and asked a lot of questions.....do these techniques work??.....presumably so....talking out loud....
BOB RENTON

 

[pnora]

There is a lot of smoke coming out the breathers from both valve covers. This is on my Indy Cylinder headed 69 RR 528 Hemi. The valve covers have breathers with a hose connection. They ran the hose down to the under side of the car, like a road draft system. It smokes the worst after a good romp on the throttle, smoke in my rear view mirror. And at idle, wafts of smoke coming out from under the car. The hoses even drip a small bit of oil after it is parked.

How much would be considered normal? There is no PCV system on the engine. It is supercharged, so would a PCV be plumbed in the same way, to the intake?

Hopefully it is not internal.

Are the vents baffled? That might help raw oil but not the smoke. My bets are the rings are hurt. Running lean on a blower motor is bad. Who knows how it was run before you got it. My Hemi has no PCV and I get very little haze if any out of the breathers. You could do an oil change and get some easy run time on it to see if the rings do seat in. Most likely it will not help. I would run compression and leak down tests.

 

[Cranky]

Also, what does the oil smell like? If it smells like gas, change it and hope the rings haven't been washed down and hurt.

 

[HEMI-ITIS]

What weight oil do you use? I use 20/50.

 

[Paul_G]

Are the vents baffled? You could do an oil change and get some easy run time on it to see if the rings do seat in. Most likely it will not help. I would run compression and leak down tests.

Got to pull the breathers off and look see if there are baffles under the breather hole. Can do this today.

Also, what does the oil smell like? If it smells like gas, change it and hope the rings haven't been washed down and hurt.

When I got it home the oil was changed first thing. I put Driven 20W50 in it. The old oil was diluted with fuel from the carb overflowing, bad needle /seats, probably from sitting for such a long time. Carb rebuild was done at the same time.

I will do a quick compression test, and take a look in the cylinders. I have to look in to doing a leak down test. Might have to buy some new tools for that. If I see scoring up and down the cylinders, I think I know what that means. Might be a week till I get to that. I am installing the Dakota Digital Cluster this week.

 

[Paul_G]

IMO...I always thought that blower engines, used a "head land" top piston ring assembly (L shaped) to provide a positive pressure behind the ring, that literally expanded ring for a tighter fit in the bore and to reduce or eliminate ring flutter, to achieve less blowby. There were small holes drilled in the piston crown, near the outside diameter, to the top ring land. These small holes applied combustion pressure behind top ring, forcing it to expand slightly to seal. Personally, I've not built a blower engine, but observed the building and asked a lot of questions.....do these techniques work??.....presumably so....talking out loud....
BOB RENTON

I am no expert at anything, But I do know that blown and any power adder engine must have larger ring gaps. How much larger, I don't know? The larger gap keeps the ring from expanding under boost to the point of seizing in the bore, and suffering catastrophic failure. Along with the larger ring gap, can we expect more blow by? I would think the larger ring gap comes in to play under full throttle cylinder pressure. Normal driving is just a big ring gap, causing more blow by? I dont know?

 

[Cranky]

I am no expert at anything, But I do know that blown and any power adder engine must have larger ring gaps. How much larger, I don't know? The larger gap keeps the ring from expanding under boost to the point of seizing in the bore, and suffering catastrophic failure. Along with the larger ring gap, can we expect more blow by? I would think the larger ring gap comes in to play under full throttle cylinder pressure. Normal driving is just a big ring gap, causing more blow by? I dont know?

A buddy of mine likes turbos, centrifugal blowers and even adds some of the funny gas so I've been around his engines and helped build one some years back....his first big inch engine on N2O in a heavy car. So far, there's been no excessive blow by or even bb that's noticeable. Hate to rain on your problem but even with more gap for the increased pressure and heat, there still shouldn't be smoke like you are talking about so long as the gaps are not huge.

 

[wagonman]

The breather hoses should be plumbed into the hedders with a check valve for pan evacuation like a PCV. Thats if you have hedders. Pretty much a Race car application. I have a Leakdown tester if you want to borrow. How far is Suprise? Near Phoenix? Might be a little far. See if you can rent one from Oreillys. See if you can seat the rings by a hard acceleration then let of and let the Rs come down, repeat as necessary.

 

[beanhead]

You did say "a lot of smoke.." that's not normal nor good especially on a boosted engine. Rings, head gasket would be the first suspects.

 

[Paul_G]

You did say "a lot of smoke.." that's not normal nor good especially on a boosted engine. Rings, head gasket would be the first suspects.

Head gasket? I was watching an older episode of Road Kill, Finn was having the Hemi for BlaspHemi dynoed at West
Tech. Stated it started pushing smoke out the breathers and dropped power. Then stated it was a head gasket. Smoke was gone and picked up power.

How could a head gasket blow and cause smoke out the breathers.

 

[pnora]

Head gasket? I was watching an older episode of Road Kill, Finn was having the Hemi for BlaspHemi dynoed at West
Tech. Stated it started pushing smoke out the breathers and dropped power. Then stated it was a head gasket. Smoke was gone and picked up power.

How could a head gasket blow and cause smoke out the breathers.

The gasket would blow out in the intake valley area.

 

[Cranky]

Head gasket? I was watching an older episode of Road Kill, Finn was having the Hemi for BlaspHemi dynoed at West
Tech. Stated it started pushing smoke out the breathers and dropped power. Then stated it was a head gasket. Smoke was gone and picked up power.

How could a head gasket blow and cause smoke out the breathers.

Saw an episode where a /6 blew a gasket and it did the same thing....blew lots of smoke out the breather when it did that.

 

[beanhead]

The gasket would blow out in the intake valley area.

Saw an episode where a /6 blew a gasket and it did the same thing....blew lots of smoke out the breather when it did that.

Yep and a buddy's turbo'd B engine had it happen too, which is why I mentioned it. I hope it's not the OPs issue but it sounds like it's more than just a little blow-by..

 

[Paul_G]

I hope it's not the OPs issue but it sounds like it's more than just a little blow-by..

If it is just a head gasket I will be lucky. Much easier to fix than rebuilding, or even reringing the engine.