smoke on deceleration (vacuum)
smoke on deceleration (vacuum) Hey guys I have a problem ive been working on for some time now. I build cars on the side, last build was a 93 m6 camaro, custom built rear mount turbo kit. Motor fully built etc, etc etc…. right when we started to drive it, it smokes on Hey guys I have a problem ive been working on for some time now. I build cars on the side, last build was a 93 m6 camaro, custom built rear mount turbo kit. Motor fully built etc, etc etc…. right when we started to drive it, it smokes on deceleration (under vacuum) only time it smokes. I unhooked turbo, wasn’t that, but new intake gaskets in, didn’t help, no im on to valve seals. I know numbers 1, 2, and 7 burn oil. I started with intake on #1 this is what I found. All new on this build about 2k miles. Think they are patriot springs. Has 3 springs.. (under vacuum) only time it smokes. I unhooked turbo, wasn’t that, but new intake gaskets in, didn’t help, no im on to valve seals. I know numbers 1, 2, and 7 burn oil. I started with intake on #1 this is what I found. All new on this build about 2k miles. Think they are patriot springs. Has 3 springs.. looks like it is getting pushed on by inner spring. is that pushing it over far enough and making is it not seal on the other side?
I cant really see the biasing over of the seal as being the root cause of the smoking. Could be wrong. But clearly the inner coil should NOT be contacting the seal.
This is the reason I had my LT1 stock guides cut down to .500" so that I could easily run any dual valve spring required with no risk of contacting the guide. When I have installed dual springs on stock diameter guided heads, the clearance between the seal and the inner spring is around .020" or so which is very tight but not really an overbearing concern unless there is contact. I saw one car where the inner coil actually pulled the valve seal off of the seat. Not good.
This is the reason I had my LT1 stock guides cut down to .500" so that I could easily run any dual valve spring required with no risk of contacting the guide. When I have installed dual springs on stock diameter guided heads, the clearance between the seal and the inner spring is around .020" or so which is very tight but not really an overbearing concern unless there is contact. I saw one car where the inner coil actually pulled the valve seal off of the seat. Not good.
Are the heads ported to the point where the rocker stud holes are open to the intake ports?
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See the hole in the upper left hand corner? If you have the heads ported extensively enough you will break into these holes for the rocker studs and if you dont seal the threads I could see it pulling oil through them on heavy vacuum
Might be something to check out, from the look of the valve seals you have something going on, but may not be the whole story
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[/IMG]See the hole in the upper left hand corner? If you have the heads ported extensively enough you will break into these holes for the rocker studs and if you dont seal the threads I could see it pulling oil through them on heavy vacuum
Might be something to check out, from the look of the valve seals you have something going on, but may not be the whole story
