i tune the car, its not making any power more than 570 to the wheels.

any thing more than 16psi is a waste.

power is dropping from 5500 RPM

i checkd the timing, and the cold lash for the rockers its normal

then, i did a compression test.

it was really reallllllly bad

1 = 95

2 = 91

3 = 91

4 = 85

5 = 91

6 = 91

the engine temperture is normal, but its overheating

the overflow tank is allways full with dirt

ill start all over again and rebuild the engine


im not sure how this is happend, bad luck with my darton sleeves.

N E way, i just like to share with u guys

 

sounds like the rings didnt seat properly if this is a freshly built motor.

 

Damn, those numbers are really bad. Anyway, good luck on your next build.

 

not really.

the short block is built by built z motors.

the engine is overheating, but the sensor is showing normal temperture.

 

i hope so

 

Fairly consistent numbers though, so the problem is uniform. Describe what you did exactly for your compression test.

 

first, i run the car for 6 minz to reach normal temperture.

then

fuel pump fuse is removed, injectors discconected, coils are removed.

throttle is open.

cancking 4 to 6 times.

and thats it. i used a compression test guage.

this is one of the runs, no need to tune more than that its a waste.

 

what should the compression be at

 

Do a leakdown. I think your numbers are way too consistent for such low numbers.

Then also do a compression and crank 5 times and then 10 times and see what you get.

Compression with 9 to 1 pistons should be around 150ish on this engine.

Lastly, pull your engine apart if the numbers are bad and check the deck heights on the mating surface to the heads and then on the mating surface on the sleeves and see if there is a difference. Good luck with everything.

 

should remove spark plugs as well

 

good luck getting it repaired. Seems like everyone with big turbo kits are having alot of problems lately.

 

+1 those numbers are way too close. Try a different gauge, then a leakdown as suggested.

 

a leakdown test will tell you exactly your problem.....

its not a headgasket/mating surface issue since all the numbers are uniform.

 

Can you consistently reproduce that dyno chart? If so, I again don't think it is an engine problem - but rather something else (such as tuning etc)

 

how does that explain the compression numbers?

 

Hal is saying if the dyno can be reproduced consistantly, then they low compression issue could an issue with the gauge being used, or the method

 

Quick and easy way to see if its block related. Take a few drops of trans fluid, squirt it in before connecting the gauge, then crank again. If the #'s shoot up, your issue is in the block. If the #'s stay the same, the issue is in the heads

 

It doesn't.. I am curious to know if that motor let go at 5750rpm on that dyno pull causing the drop in power and poor compression numbers (still weird they are so consistent), or if it will consistently draw that same curve producing over 500tq and something strange in high rpm. If it can keep doing the same exact curve it leads me to believe there is something else going on.

 

I watched a guy do a compression test on a car with two different gauges being broken. Then the third one ended up being correct.


Also, some people will argue how many times you are supposed to let the engine turn over during the test, as long as you are consistent across the board then you can find a weak cylinder.

 

Did you buy the Long Block or just a short block? Who did the timing of cams?