I did a compression test today after I took my son to school (15 mile drive each way). Car fully warmed up. Battery is 3 months old. Cranked over 15 times. It came out to (cylinders 1-4):
100, 105, 110, 110
after putting some oil in the cylinder:
110, 105, 112, 110

Mods: GSC S2, Perrin Intake, ETS LICP, Perrin DP, MAP O2.
Mods waiting to put on: SpoolinUP COP, FB 70mm TB, IX Turbo, UICP, etc.

Is it rebuild time (110k miles)? Car seems to drive fine. I'm at 360 hp/tq on E85. That's with a massive boost leak at the TB shaft seals. I'm fixing that soon. I also noticed my coolant overflow was overflowing. Bled the cooling system and it seems ok, but keeping an eye on it. Head gasket? WTF is going on?

Also, I always thought when it came time to rebuild then I would have a motor built, but I DD and from what I've read, people with built motors are happy to get 30K miles out of theirs. That would last me a year and a half . I'd like to be at 450+ hp/tq. 2.3 and 2.4L sound good, but I'd like to get another 100K miles.

I plan to DD and maybe AutoX a little this summer. I'm looking for great driveability, low to mid range torque.

What do you all recommend?

 

There's no reason why a properly built "built" motor shouldn't last you. Yes, there is more stress on parts at a higher power level, however, if the clearances in your built motor are good you shouldn't have any problem making it last. I'll have a built 10:1 2.0L up for sale here in a few weeks as I'm changing setups

Good luck with whatever you choose!

 

Thanks! I'm hoping this is true. I'd like to do a built motor built to last 100K. What setup are you going to? I here for DD 2.4 is the way to go.

 

Well, you heard correctly, as I'm going from my 2.0L/35r to a 2.4L/Stock Frame setup.

 

I would definitely go 2.3rr/rpm (i.e. light weight rotating assembly) if you have a good core. If not go with a 2.4.

As far as longevity, it depends on a lot of things. Some motors last 30k miles at 800whp some last 5-10k. Depends on the driver, tune, mods, and a ton of other factors. Being that you aren't going buck wild, I think you would be more than fine.

 

I'd be willing to bet that the test was done incorrectly and/or the gauge is wrong.

 

I was thinking maybe the gauge is bad. It's only a couple of years old and I did a half a dozen tests on other cars. The readings are very low. I would imagine I'd be losing oil or some driveability problems. I'll try another gauge tomorrow.

 

8 or a 9. Change o ring on tester and lube it with a little oil before screwing it in.

 

8

I'll try that. I've seen some gauges slowly leak to a lower indication after the final crank on the engine. I'm guessing that's what's going on here.

 

at least your numbers are consistent. do some hard runs and see if the overflow spits out some coolant. did your car ever overheat?

 

Car never overheated, but while logging I noticed the coolant temp was higher than usual, 205 F after a WOT log. The overflow did overflow, but I have since put a new radiator cap on and it's not overflowing anymore.

From what I learned about this test is that even if the gauge is reading low, they are pretty close from cylinder to cylinder, means that's good.

 

Stock 2005 Evo VIII, 67000 miles, at idle cylinder pressure is 110 psi in two cylinders, 108 in the other two. Runs fine. Hopefully that gives you another baseline. I thought 110 psi was normal?

 

Cool! The car has been driving fine. I got most of the boost leaks taken care of. There is some in the valve cover, but I think it maybe some seals in the valve train.

 

so what can you expect for miles from a 2.3 built motor/head with say 550whp/500tq and good driving not an a hole to the car

 

Plus, a compression test on an aluminum head should be done with the engine cold.