ring blow by or valve stem seals

[fastrthanurs]

ok i have excessive crank case pressure and it smokes at first start up and tends to quit or atleast lessen while running. i havent done a compression test yet but how common is it for a mod motor to have a valve stem seal go out or ring blow by. the car was running fine until i put the charger on then things got worse. i have the stock 3.60 pulley on the blower and the car has high milage. what do you guys think?

also, is it possible to change valve stem seals with the engine n the car? maybe pressurize the cylinder with an air compressor and change the seals or what? thanks in advance.

 

[01Steeda]

most probably ring blowby. I have seen a few Modualrs with blowers have that problem due to the sideload on the rings.

 

[DropTopPony]

Are you burning alot of oil? Valve stem seals are common on high milage mods. A blower i guess could speed up the process. One of the reasons I went with new valves/seals/in my VT heads.

 

[laxdman20]

You would have to do a compresion and leak down test to find out for sure if its the rings. Like said earlier, on high mileage mods, the valve stem seals do go bad on the mod motors.

 

[fastrthanurs]

is it possible to change the valve seals with the engine in the car.

 

[ACSPONY]

I think the blower is causing the problem, or at least increasing it. Sounds like valve guide seals. With the increased air coming into the engine, more oil would get sucked in on the intake stroke past the seals. Any oil seepage around the head gaskets?

 

[fastrthanurs]

did a compression check and i have 140, 145, 140, 145 on one side and 60, 40, 30, 0 on the other. could be a head gasket but i have oil on the 0 and 20 psi cylinder so i dont know. gotta pull the engine to pull the heads any ways so i might as well do a new short block since the high miles. anyone know where the best and cheapest place to get a short block?

 

[Shiroelex]

You can get those heads off while the engine is still in the car. It's been done a bunch of times. I'd suggest trying a good head gasket kit. Most come with new viton valve stem seals, and of course the head gaskets. There's a chance that will help, but most of the cases where I've seen excessive crankcase pressure, it's been the rings. I'd just yank off that head and slap a gasket down, and recondition the head (stem seals, brush up the valves, clean the gunk out of the head), and slap it back on and hope for results. It's alot cheaper and easier than yanking the engine, in my opinion.

 

[fastrthanurs]

yea its cheaper but how long before the rings and pistons go with 100k miles. i'm going to do a dss rod and piston kit and just use my gt crank. polish it and slap it back together. change the stem seals and run some good head gaskets i should be ok.

 

[01Steeda]

could be a head gasket.. but i am thinking those rings are probably half the width they use to be.