jduke

Hey so I've searched around and couldn't find anything definitive to help my problem. I have a sr20 red top just rebuilt about 1500 miles ago. 10.1 je pistons manley rods, tomei 256 cams, s15 bb turbo, oil catch can, hmic, axepi fc l jetro tuned, e85 etc. When i was letting the car break in i turned boost down to 8psi but it was tuned for 15psi. Slight puff of blue smoke would happen at warm up then go away once warm. Well after a 1000 miles i decided to turn it back up to 15. Accidentally turned it to 20 psi for a few pulls and turned it back down. This is when it started to smoke all the time. No matter if i was accelerating decelerating idling under hard boost it doesn't matter she just smokes. Still pulls just as hard as it did before the smoke so im highly doubting it to be a ring issue. So is this a valve seal problem or a turbo seal problem? Also head was rebuilt during the block rebuild.

jr_ss

Turbo seals or valve stem seals are worn. Pull the down pipe and see if the turbine looks wet. If it does you need new seals in the turbo, which means a new CHRA.

__________________
My SR20VET

quickdiversion

How many miles were on it originally?
Did you replace the head studs or reuse the old ones?
If you used the old ones you could have lifted the head slightly enough to Ruin the head gasket. Also at the boost levels you are talking about, above 15 psi, this is very possible on stock had studs, even if new, if they were tighten incorrectly.

I am going agree with jr and say valve stem guides.
But you could have lifted your head.

jduke

Arp head studs apexi head gasket. And when i did my throwout bearing i had to take off the o2 housing nad it was all dry back there on the turbo. Most likely the valve stem seals then huh. Fun for me lol. Thanks guys.

quickdiversion

Valve stems are simple. Put a breaker bat on the crank bring piston 1 to tdc. So valves from cylinders one and four don't drop in. Than do the same for 2 &3. Obviously after your strip the head. Lol

jduke

Yea its a year old but i hate when im searching and people never say how the got the issue resolved or sold it etc. Anyways my motor had low miles but those were all drift miles. So the motor rings were worn. Got it Bored out .5 over and should be all finished the rebuild sometime next month.

quickdiversion

Just simply boring the cylinders .050 over isn't going to solved your problem, you are going to need .050 over pistons as well.

Boring out the cylinders is done for 2 reasons, performance and fixing a problem. In the case of oil getting past the rings, it is cause the cylinders have gone out of round and the rings do not seal properly. And Performance is to get more surface area out of the pistons. If you do not use pistons that are larger compared to stock when you increase cylinder bore. The gap between the piston will rattle in the cylinder and be a; noticeably loud and b; it will distroyer the cylinder. Plus I don't know if you know this but when you replace piston rings, they do not come precut for your motor. You have to cut each bring individually per the specified gap on the incomes paperwork for the new pistons. Different applications have different gaps.

If you already know all this.

Good luck!

After reading your original post, not the entire thing so it might have been said already. The reason your fried your rings is your compression is way to high for your boost. The higher the compression in a boosted application the less area there when the piston goes up the compression cycle before the ignition cycle. There is not enough room for it all and it has to go somewhere, usually forcing past the rings. Add drifting and constant abuse sessions and your gonna fry rings. If you were running less the 1 bar aka 14.3 psi you could possibly get away with 9.0:1 pistons. Running more than that your gonna need 8.5:1 which is actually stock compression. I ran 27ish with 40 psi spikes on a holset hx35 rated at 60 lbs/min and never had a problem.

I would suggest if you have the head off to do the rings. Do the valve seals anyway. It's like 60 bux for intake and exhaust. It will give you peace of mind.

jduke

Sorry i didnt make it clear but the whole motor is getting rebuilt so yes new pistons and rings are going in along with the head getting cleaned new bronze guides valves seals etc. And i lowered the compression back down to 8.5:1 with the new set.

quickdiversion

Are you modifying the combustion chamber of the head at all to meet the shape of the new oversized bore? If you do it will drop your compression. So if modifying the heads combustion chamber is in your build i would stay with 9:0.1 pistons so your end compression with be 8:7.1 or 8:8.1. Dropping below 8:5.1 will make you lose a ton of low end power and your high end will never top out to what you hope.

I learned the hard way.
Plan everything if you are not going to have it blueprinted. The smallest things you might not have thought about can starve your power gains. While doing upgrades for gains. Not knowing everything that upgrade effects can yield little to nothing or negative results if your not careful.

quickdiversion

And yawn....