EVIL_EV0

iTrader: (6)

I recently purchased a new never run 2.0L long block from a reliable EVO guy with receipts to back up the parts list and labor for the build.

The engine came with Wiseco 9.3:1 compression pistons (WIS K597M855) and Kelford 280 intake and 272 exhaust cams (9-177E). They also have the supporting HW such as dual valve springs and titanium retainers.

This weekend I installed the motor and it runs and drives fine but even though it is mated to a BBK full it feels down on power. Prior to this long block the car made 450whp on stock long block and stock cams. Hard to say where it is right now but even at 30psi it feels more like 350whp through the mid range.

I decided to do a compression check and found that each cylinder was about 110 psi and this scared the living crap out of me because my stock motor was 135 on the same gauge. I DID SEARCH and only found conflicting information so I'm hoping you can help me out with some of my concerns.

1. Could these cams be to blame for the lower reading compression numbers?
2. Is the BBK full too small for these cams and thus the reason for lack of grunt?
3. If the above is true and I didn't want to replace the intake cam, what turbo would be best suited for this combo?
4. If the above is not true (FML) what else would cause similar low compression across the board on a brand new top to bottom motor?

Found a pic of the cam specs...

hutch959

iTrader: (18)

is it an evo 9?

i have a 9 with kelford 272s that makes 600hp on e85.
cold compression test on it is around 110 on all 4.

for what its worth....

EVIL_EV0

iTrader: (6)

This is an EVO9 on E85.

Steven

iTrader: (19)

My 2.3 IX with GSC S3 cams tested between 133-137psi on each cylinder. That was after warming the engine.

MRfabolous

iTrader: (17)

evo 9 have lower compression on the compression test because of the intake cam timing even from the factory the read lower your motor is fine boss.

batty200

iTrader: (3)

Big cams make cranking compression lower. I would have a heart attack with those numbers too! However if people who have experience with 9's say it is normal than rock on!

EVIL_EV0

iTrader: (6)

I am feeling a little better about the compression ... thank you soo much for your replies.

Now... what about the other questions? Do these cams need something bigger than an FP RED or should that be plenty to fill the powerband? I don't feel like running the car to 9000 rpm.

Faisalm

They'll be fine with an FP Red. Heck, people are running GSC S3s on stock turbos and FP Greens nowadays and they're not complaining.

enjoiskater7788

iTrader: (2)

Has the car been tuned after with the new cams? Might be why it feels sluggish.

evolve_VIII

iTrader: (11)

If its over 100 and its even across the board, you are good. This may also change after break in when the rings seat depending on how many miles you put on it.

Also, the ring gaps are probably set to a larger gap with forged pistons causing compression to drop a little due to more blow by. Larger cams will also lower compression as stated before.

EVIL_EV0

iTrader: (6)

Pulled the cams and replaced them with stock mivec cams. Compression went up 15psi across the board. Still not exactly where I'd like it to be but significantly better mid range and 10psi more vacuum at idle.

Also ... compression check has to be done when the engine is hot not just warm. PSI difference between a warmed engine and a hot engine is about 10psi. Thanks for all the help!!

evolve_VIII

iTrader: (11)

Your compression should come up after the rings seat. Either way, the results are good. It depends on how the car is driven and not how many miles are put on it before the rings seat. I usually do the first 50 miles of getting into a little boost and then letting it engine brake for a little and repeat.