i've been getting gas in the oil since i rebuilt the motor. (355 w/ stock crank and rods, forged pitons)

I've tried different injectors. 30 & 24# SVO's and the stock 22#er's and each time gas in oil.

I checked that the diaphram on the fuel pres. reg. hadn't burst.

what has happened is the gas gets in the oil and thin it out. then eats the bearings/journals up and then i lose oil pressure. this has happened three times and i've tried everything i know.

2 times the motor never got an hour run time the third it ran about 1500 miles

i built a motor just like this ~3 years ago and it never gave me any trouble

thank for any replies(i tried everything i found searching)

 

Do you have a nitrous system?

 

I would guess you assembled the rings incorrectly. Either that or you've got too much ring gap, or a broken ring/land? That is an odd scenario, let us know when you figure it out.

 

i was gonna say that

 

This is a WAG,

Have you checked for a leaking fuel injector? The system is still under pressure when the the motor is shut down. It could be draining all of the fuel out of the fuel rails.

If you connect a fuel pressure gage and note the running pressure.

Then shut it down and watch the quage, it should not drop quickly.

If it does drop quicky to no pressure, an injector could be the problem.

That is about the only other way fuel could get in, besides NO2 and the rings mentioned earlier.

Good Luck

 

sounds like cylinder wash, possible causes are incorrectly installed rings, worn cylinder walls /bad bore or hone causing rings not to seat.

 

I take it the return line from the fuel reg too tank flow's nice a free with a gas cap off?
I've seen it more than once where this line has a kink and the reg can not do it's job and the bores get washed.

 

sorry it took a while to reply, had computer troubles too

no N2O

i think injectors leaking with engine off are ruled out as i've had 3 different sets in there(both sets of SVO's were brand new) I did check this with stock injectors and they just barely leak(maybe one drop)when left under pressure for several hours. not enough to see drop on pressure gauge

rings were installed as instructions directed. I'm not sure about clearance between piston and cyl. wall now but the problem first occured with stock pistons and stock bore & stock replacement rings.

I will try the return line, but wouldn't the pressure guage show a funny rise in pressure if it was blocked.

I may put back in the stock cam and try a new set of stock injectors w/ the stock chip

 

Quick suggestion, check your IAT and coolant sensor and make sure they are within range. If the ECU thought its -10 outside your car would go WAY rich and wash the cylinders down with fuel that would end up in the crankcase.