Shinobi'sZ

Well I got the fuel pump on and decided to lay the hammer down....as I watched the boost gage climb to 10, my 335's were spinning at 90-100 mph in 3rd gear. All of sudden much white smoke coming from the rear...I thought...oh crap I screwed something up big time...what I found was the dip stick pushed up 2" out of place, and I took the rubber hose off between the valve cover and the airbridge and threre was also oil in it going to the blower....
What is going on???
I don't think oil is getting past the rings because there is no oil coming out of my tail pipes..the white smoke was from the oil burning on the headers...help please..what do I need to do?

Sean@OCCorvette

Sounds to me like a weak PCV valve. You should ask Andy if has had this problem before.

Bill Reid

Positive crank case pressure during high boost... it happens.

Tie the dip stick down by attaching a spring to it and mount a "U" hook to the tube... so the spring has somthing to attach to on the tube.

Davidmax's LPE C5R 427 TT has one... and anybody attempting this kind of boost should have one too :)

:cheers:

Shinobi'sZ

Bill,
How the hell do I do that..sounds like a good idea..the pressure pushed the dipstick up and sprayed oil like a pop up sprinkler. I want to do what you suggested...it also sounds like I need some sort of PCV mod. I need more instructions..I bore scoped the cylinders and did not really see anything..thought I spotted some spyder webbing on top of the one of the pistons..but it is not coming out of the tail pipe so I don't really think anything is getting past the rings..
Thanks

Dave00C5

I have seen this happen on diesel trucks. They're puttin out 30 lbs of boost so you have a dipstick that actually clamps down to avoid a oil bath! :cool:

LANJET

There is a hole on either side of the dipstick cap, put one end of the spring through this hole. Next to the dipstidk tub, down a little lower there is a coolent line or refigerant line that has a clamp on it. Take the other end of the spring and stick it through the ear of the clamp. If you are standing on the left side of your car looking at the dipstick this clamp is on the left side of the dipstick tube(the line runs along the frame or inner fender I think). My car has one of these springs also. If you look closely at pictures of LPE's Twin Turbo cars you will see the spring. Hope this helps.

LPE TT650

Shinobi'sZ

Great info..I am going to start looking at the fix...keep the ideas coming guys.
Thanks

MelloYellow

Do you have a high psi checkvalve installed between the intake and the PCV valve?

Shinobi'sZ

No, I need a check valve.

jbsblownc5

One of my first Mods after the SC was a high pressure PCV check valve. Cole checked the stock one and found it would give way at only a few pounds of boost. I found a very good one though mike at RAMChargers.com. It is a brass one that is good for up to 30#s of boost. They used it for the old Grand National Turbos. I also have a custom Catch can that Cole made for me to separate the oil in the PCV line. I would consider the spring on the dip stick a bandaid of sorts, since you would still be pressurizing the crank case, not good. I have no spring and run about 8.5 #s of boost with no problem, as long as you have the check valve. I can't comment on boost pressures at 10 or more.
Good Luck,
JB

Shinobi'sZ

Joel,
I think Vetterdstr just ordered both of us one.
Thanks

jbsblownc5

:cheers:

C5-VERT

Yes that happened to me before(on another car). Turns out I had a small hole in my piston causing boost blowby which in turn blew the dipstick out and sprayed oil over everything like you said. The difference is the oil got on my exhaust manfold and caught fire! :eek:

Don't mean to scare you but I would do a compression check just to make sure. All it takes is a faulty injector or something else to cause a cylinder to run lean and bam, you have a burned piston.

You will not see oil or smoke coming out of the exhaust if this happens b/c oil is not coming up from the pan through the piston but quite the opposite. Air(boost) is going from the intake port down past your piston, which prevents oil from coming up.

This was on a talon awd 4 cylinder w/ forged internals running 26lbs of boost and making 500hp. Built the engine myself so I know what I am talking about.

I hope I am wrong...


[Modified by C5-VERT, 12:02 AM 11/4/2002]

evil-1

Who is the manufacturer of the PVC check valve? Thanks. :confused

Shinobi'sZ

C5-Vert..
I have been suspecting this and am going to do a compression check just to be sure. I could not find any holes in my pistons...however there was some spyder webbing on top of one of them,,and I was not sure if they were cracks...somebody told me that those could be normal?????? I am going to do all the PCV stuff, and a Krankvent on the valve cover in place of the filler cap. I will also do the compression check.
Thanks

One more thing C5-Vert..when you had a hole in your piston..did the car miss or knock at all? My car is running fine..thats why it is difficult to believe that maybe my pistons are cracked unless of course they are such fine cracks that no pressure gets through them until under boost????


[Modified by Shinobi'sZ, 7:40 AM 11/4/2002]

vetterdstr

Yep, I sure did! This way we can both fix this problem right away!! :smash:

vetterdstr :cheers:

BlackSun!

I feel you pain Shinobi'sZ... Had the same thing happen... What a mess!!!!

QuickSilver2002

I modified to keep the boost in and the oil out.




[Modified by QuickSilver2002, 4:05 PM 11/4/2002]

ganson

Shinobi'sZ: Isn't 10 PSI too much for the LS6 (according to ATI, anyway)? Or did you lower your compression?

Shinobi'sZ

Remember manufactures attempt to sell you something that will hopefully last. The ATI kit for a Z06 comes with a 5lbs pulley (4.50"). Nothing compares to way the car continues to hit at 8-10lbs of boost except maybe for more boost. I am very happy with the power the car is making..but not particular happy about potential damages. But I will just rebuild the motor when its all said and done...if it ain't broke I aint worried about fixing it..if it breaks..in go the recessed forged pistons (drop CR), the crank is strong enough..the rods are so so...I will go to Katech Rod Bolts though. So to answer your question YES...to be safe 5-7 lbs is probably good..but I didn't do mods for safety...I did it for extreme power.