Even with a "tight" engine its possible to get some crankcase pressure/oil issues with the FP chra and aftermarket 2618 alloy pistons since they have to grow and expand during warm up. This can push some oil pass the turbochargers rings and pool in the compressor housing or into the exhaust system.
The location of the turbo, high oil pressure and level, crank case pressure and chra design are all factors. I've got a proper -10 crankcase vent and large baffled can recirculated to the intake and get a small amount of smoke every so often. I've also measured oil going to the chra and its not very much once warmed up . Going to a small restrictor isn't really an option if you are already running a 5-40 oil

I had some oil issues on my stock engine on 20-50 oil when it was cold as well.

If I were to build another engine with a stock style bolt on turbo I would run some 4032 Mahle pistons that are high silicon, low expansion alloy and run them much tighter. They would handle the power just fine and the ring seal would be almost as good as the stock pistons.

Thanks for the detailed info! We do have similar setups, I see what you mean by running the driver side valve cover vent exposed. I am surprised that no oil has sprayed out from there, even with the baffling.


I did not think about the piston material expansion rate itself. Now i'm curious if people who have run 4032 pistons have had a much easier time solving crank case pressure issues. Thanks for sharing.

-pal215

How about running this crankcase evacuation fitting in to the exhaust an thereby creating suction from the sealed OCC?
Dont forget to put a large check valve in between.

https://s13.postimg.org/6xvc4not3/28321_E_VAC.jpgimage hoster
https://s13.postimg.org/crg54rpyf/28321_E_VAC2.jpgscreen shot windows 7

I haven't found that top be needed with running a proper PCV valve to the intake mani, and a proper recirc line to the intake pipe.

You have stock pistons so as long as your motor is healthy you would have less chances of having any smoke issues.

The last two 4g63's I build with wiseco HD's had better leak down numbers than my stock pistons currently. My motor isn't perfect. 10-15% leak down across all four cylinders.

I actually like this idea and will keep it in mind if necessary. Check valve would definitely be needed. Interested to see how much vacuum such a setup is capable of. We see cars blow over fans, dyno wideband sticks, with their exhaust pipes, so I am sure that this would suck the hell out of the valve cover/crank case gases haha!

-pal215

Update! For those who were interested in watching the tune, it has been moved to 11am tomorrow. sorry for such late notice!

-pal215

Great build, cant wait to see the numbers

just checking to see if you came down to tune

I stopped by, shop was closed ???

Hey lonestarr20,

I sure did! I'll be posting final numbers and some videos tonight. Strange, I was at the shop until about 3:50pm when the tow truck came (foreshadowing ;) )

-pal215

Yesterday was a motor sports masterpiece. Top Gear (now known as "The Grand Tour") has returned. Several of my friends hit the race track for an awesome time and I finally got tuned on speed density at RRE with Rick Barcena

Within the first 3 pulls, the car destroyed its old ethanol record pushing 442hp and 353 lbft of torque using only 91 pump gas! After that I drained the tank and poured in the much higher octane E85, at which point it really came alive.

The 10 year old Mitsubishi laid down nearly 650awhp and 511lbft of torque. All this with a full interior, sound system, sound deadening, and AC! I couldn't be more proud :)

Injector duty cycle was at 80% with 35 psi, 37psi peak boost and a single hard wired walbro 450. The fuel is there for 700hp, there is no doubt in my mind. We decided to keep it at 650 for the day.

Final dyno graph for 91/E85


https://cimg8.ibsrv.net/gimg/www.evo...e54a75332c.jpg


I filmed a few short videos for you guys with my cell phone, sorry for the crappy quality. At some points the dB's are too high for the microphone to process so you might hear a skip in audio lol.





The bad news is, the rear diff is toast. It had always made a grinding noise from time to time, but I shrugged it off as normal. After doing the weir 12 plate conversion and bushur diff mounts it became even more apparent , but the oil always came out clean so I kept using the diff. Last night the diff began screaming at me whenever I was in decel. I took it apart today and found some play in it, but the ring and pinion looked fine :dunno:. The pinion bearing did have resistance to it and it did have a tendency to lock up whenever I pushed it in. Again the noise only shows itself in decel. An RRE shop tech and I found it to come from the back of the car, hopefully we were right. This means the car was making more power than was measured.

Enjoy gents! You know I will after I fix this bad boy.

-pal215

Sounds like a fighter jet, CONGRATULATIONS, and be safe with it..