Hi guys looking for some guidance. We are drag racing our car which has in a Evo 9 engine( it's in a Mirage bdy) full works here is the list. thought I would post as we are using a 4G64/63 combo

4G64 Block O-ring & Cement filled(complete)
Arias custom 10.5:1
Manely 88mm crank
Con rods 156mm(steel)
4G63 evo 9 Mivec Head
Fueltech Ft500
Fueltech gear controller(not installed yet)
Competition Clutch Twin disk
Clutch masters flow control valve
Co2 kit
8 1600cc injectors (M1 Fuel)
90mm Wilson throttlebody
Mivec Lock Kit
60mm Tial wastegate
50mm Tial blow-off valve
head work
port n polish
steven performance cams ( 290/290)
PAR dogBox (2.9 first 4.11 final drive) converted to fwd
PTE7175 Gt42
Steven Performance spec turbo manifold front facing
Steven Performance Intake Manifold
Liquid to Air intercooler
D2 drag Suspension
Steven performance custom LCA's (front&back) Kingpin bearings
custom traction bar kit

We have been racing the car, not doing too bad at all. The car has dyno'd at
44psi @ 990hp and covered the 1/4 mile with a best of 9.1@167mph. 60ft@1.57
1/8@6.1.

The issue I would like to discuss is the blow-by. During one pass, we will loose 1 quart of oil maybe a bit more into the oil breather can. The head has 2 -10an breather lines one of the front cover and one on the back cover. you can almost hear like it is having an effect on the engine also, not sounding nice and clean

This is an issue we had previously, so during the tear down inspection before the race, we replaced the piston rings and gapped them tighter. This did not make a difference.

Another mechanic has said, since we have modified the oil pump, there is too much oil in the head which cannot drain fast enough, hence the blow-by through the breather lines. He suggests, that we can put some restrictors in the passage to restrict the amount of pressure coming into the head which would allow the oil to drain.

Has anyone had this issue and if so what did you do to fix. Any suggestions would be greatly appreciated. I will try and post some pictures of the car and dyno graph.

 

Is this installed on your car?

http://kigglyracing.com/all/hla-pres...ersal-fit.html

 

yes we have the kiggly HLA

 

here is an old dyno graph from 2014. having some issues uploading the new one.

 

dyno vid

 

is the pcv system still setup? or is crankcase pressure just vta ? seems like a excessive amount of blowby to lose a whole qt of oil but your engine is also high horsepower which i dont have much experience with.

 

Not sure if anything in this thread will help, but it's worth a shot:

https://www.evolutionm.net/forums/ev...re-issues.html

 

Sounds like an oil draining issue from the head. All of the crankcase pressure has to go from the bottom of the block up through the oil drain back ports in the head then out of the breather hoses. I suggest going with a breather hose off the ballance shaft port on the oil pump cover, if you have balance shaft deleted.

 

https://www.amazon.com/12AN-BALANCE-.../dp/B00IFWNFZW

Once you get ring flutter because of positive crankcase pressure the situation goes into a runaway condition. Also when enough air is going up through the drain back ports in the head, it can prevent oil from draining back to the pan. Are you using ported Pistons ?

 

does it have the valve cover oil baffle removed? if so, put it back on.

 

thanks for the reply guys.

-yes we do have the baffles in place still for the valve cover

the piston rings flutterring are an interesting theory which I can relate to. I do not think the pistons are ported, I did not buy them or install them so I am not 100% sure, and no we do not have he balance shaft delete breather -12an line inplace.

I will talk to the team mentioning these suggestions and see what plan we come up with.

Thanks for your input.