radar

That is what I was thinking, but pressure is still building up in the crank.

I double checked everywhere and its definitely oil coming out the rear vent on higher boost....

This is annoying because I'm headed to the rollers tomorrow and would like to break the 540whp record for a KL engine....

radar

Well at 15psi the car made 400.8 whp and 407ft/lb of torque which I'm happy with, but there is still a major crankcase venting issue. All day on the dyno for 30ish pulls never head a drop of oil in my waterbottle of a catchcan. Each run on the dyno was done in 4th gear though....

As soon as I pulled off the rollers and drove it on the street, it spit oil. A 15psi pull from 3rd-4th gear a few times = about a 1/2 pint of oil in the bottle

I'm really at a loss at this point. The leakdown came back great, compression was nice and even, valveseals are BRAND NEW...the machine shop said maybe it was the seal on the compressor from the center section leaking into the drain line of the turbo causing pressure there....that sounds retarded to me. The turbo is a year or two old (very low miles) from Garret via Full Race and I've been its only owner.

Since the entire block is completely vented....any ideas?

darkhorizon

Try moving the PCV off the valve cover, like put a fitting in, and run a 5inch tube to the PCV from the valve cover. You might be getting a bit of splash on the valve causing it to fill up and spit when it closes.

CXyD

No, on my setup the pcv is about 7" from the black box on the side of my engine block. And when boost gets to about 8 psig and WOT around 2.5k rpms or higher my engine starts using oil. I have the fresh crankcase air coming from the air inlet to my supercharger.

the 13th round

ummm, slash cut exhaust anyone?

either that or just run the ---- to the ground, ---- a catchcan. and ---- complicating things, slash cut is proven to be effective and is simple to set up. also you wont be sucking nasty ---- fumes into your intake

Tom-Guy

Because it's full of crankcase blowby gasses, like any normal turbo or high CR NA car. If those are stock vent lines... fail, dude. Your engine hates you and ring seal is being degraded by crankcase pressure.


Not all engines blowby as much as others. Having your car on the dyno where you can induce load without air rushing past the car dissipating exhaust emissions will give you a very good idea of how well your crankcase breather is working. This being primarily a Honda site, and me being primarily a Honda guy, I'll give you a nice turbo D16 example. They typically smoke a little under boost and/or on decel - nothing you notice unless you stand next to the tailpipe during a dyno pull or start pushing past 250 whp, but it *is* noticeable. I tuned a somewhat ragged D16 setup last week that had a -10 and a -12 AN vents tapped into the valvecover, vented through a catchcan to atmosphere. If you aren't up on AN sizes, -x/16" or 10/16 (5/8") and 12/16 (3/4") lines. At 281 whp the car smoked not at all.

I have two 700+ whp drag cars I babysit. One has four -10 AN lines from the valvecover with a single -10 return to the back of the block as an oil drain. The other car's owner refuses to vent his block correctly, and after a pull on the dyno or the dragstrip the pistons are wet with oil due to crankcase pressure degrading ring seal and feeding oil across the rings. It won't last long. :1

FYI:

Tom-Guy

BTW, your solution doesn't have to be the baller braided stainless route... after all, this is HMT, bitches! Just get the job done.

TurboG

electrical tape does this job

confUsed

If you didnt have any issues on the dyno, but once you were back on the street, it could be the way you have tapped your head. Acceleration could cause the oil to puddle up around where you have tapped it, and when the pressure escapes, it spits oil.

radar

Thanks for the advice JD. I'm aware of what crankcase pressure can do which is why i'm trying to fix this POS.

As for the rear vent hose vacuum question....I was referring actually to the side that is connected to the turbo inlet. Obviously there won't be vacuum on the block side of the rear vent due to the pressure buildup. Physics escape me on the other side though. If I pull the hose from the vent and just leave it to atmosphere, I can't feel any suction on the hose when I open the throttle....

Why is the inlet of the turbo not creating a negative pressure area? Too close to the filter I suppose?

A another forum member has done this: to his drag only car....

Looking at it, the ID of the hose he's planning to use isn't much bigger than what I have no on the stock front PCV line AND he capped the vent on the rear valve cover (center/top of picture). Doesn't appear to be much more venting than stock :-/

I'm going to add another port to vent the front valve cover further and see how it goes.

btw....

I'm very familiar with the HMT way....here was the old car/engine bay

Megasquirt FTW

You can also see by comparing the two above pics, my old engine/valve cover had a 2nd vent on the front valve cover that Mazda deemed unnecessary in later years....probably trying to save $ on the fititng, rubber hose, and pipe