Compression test results

[ecc_33]

After numerous drag races and about 28 truck pulls with the stock charger and then about 6-8 pulls with the bigger charger and super diesel fuel regulator. i decided to do a compression test.
I only got to do the left bank today after getting back from the hospital

Test as follows:

piston PSI
1 425
3 415
5 430
7 427

Do you guys think its worth doing the other side if that side was that good?
Does anyone think these numbers are alittle high?

Other things to note: this is a stock long block engine

 

[Stingpuller]

Looks good

I think I should do mine to see. Sounds like your ready for another year. Have you seen the new turbo rules in are class? Give me a call sometime. Thanks Jeff

 

[ecc_33]

Sting ill probly stop in sometime next week if your going to be at the shop.
You are more than welcome to use my compression tester if you want too. Yes i did see the 2.6 turbo rule with the 100mm compressor wheel Sucks i spent 3000 on a turbo that is now to small. Now i think its time for more fuel

For anyone that might be interested in doing this it is Very easy to do

 

[JOHNBOY]

Does your balance rates check even? If you have a low cylinder the rates will usually show it.

 

[bullfrogjohnson]

those look a little high, i have heard the dmax is around 350 or so. I build engines for Cat and a good rule of thumb is not the compression test results its more about the variances in between all the cylinders. as long as you dont have a 50lb variance i would say you are ok.

looks to me like you are good for another season

 

[sweetdiesel]

those numbers look good to me,I would still do the other side
from what ive read it the variances that our the concern as Travis has allready stated

 

[LarryJewell]

Yea, do the other side, just for peace of mind...

 

[ecc_33]

Travis im going to dig up some info to try and see what the actual compression on a stock engine should be. I thought they were kinda high to but this is the kinda test were you cant screw up. Unless my guage is reading wrong which it is brand new.
John if your talking about my injector balance rates then they are damn near perfect.

 

[sweetdiesel]

Eric
mine where 310+- a lil on each cylinder

 

[ecc_33]

right bank test was

2- 440
4- 415
6- 420
8- 420

i think im going to go ahead and do dual cp3's and 45 over nozzles on this engine and about 6-8 pulls into the season i will do another compression test to see how it has held up

 

[sweetdiesel]

Sweet Deal Eric

 

[ecc_33]

First test of the year

right bank test was

2- 440
4- 415
6- 420
8- 420

i think im going to go ahead and do dual cp3's and 45 over nozzles on this engine and about 6-8 pulls into the season i will do another compression test to see how it has held up

I have spent about 3.5 hours on a dyno and have had 3 truck pulls this year with the dual fueler kit installed. I did another compression test today on the right bank and they were exactly the same as before....So im guessing thats really good

 

[LarryJewell]

I have spent about 3.5 hours on a dyno and have had 3 truck pulls this year with the dual fueler kit installed. I did another compression test today on the right bank and they were exactly the same as before....So im guessing thats really good

Awesome

 

[duratothemax]

seems your luck has been better than mine, and I didnt even have dual CP3's.

You are still on borrowed time though. Everyone's luck runs out at some point over ~530-550rwhp on a dmax.

 

[paint94979]

seems your luck has been better than mine, and I didnt even have dual CP3's.

You are still on borrowed time though. Everyone's luck runs out at some point over ~530-550rwhp on a dmax.

agreed but depending how the truck is driven plays a huge roll in how long an engine will last.

 

[Rhall]

I have spent about 3.5 hours on a dyno and have had 3 truck pulls this year with the dual fueler kit installed. I did another compression test today on the right bank and they were exactly the same as before....So im guessing thats really good

Makes me feel a little better seeing your results.

 

[05_LLY]

This is some pretty good info ECC.

What Ar exhaust housing are you runnig and kind of boost numbers are you seeing out of your setup, if you dont mind me asking that is?

 

[Fingers]

The compression you see will depend on the volume of the test gauge. 400 is good.

 

[ecc_33]

IIRC the exhaust housing is a 1.06 and i see 39-42psi

 

[duratothemax]

agreed but depending how the truck is driven plays a huge roll in how long an engine will last.

I honestly drive mine easilly on a smaller tune probably 85% of the time and after 85k miles I still blew it up. I dont drive like a jackass and smoke out every intersection and onramp; Ive only gotten two speeding tickets in 85k miles and other than long trips on the highway I always obey the speed limit. However the times is WAS in fact on the big tune I beat the shit outta it.