compression test results from 394/2000

[91vr4394]

130 130 145 130 /ubbthreads/images/graemlins/uhh.gif

 

[Nartanian]

Low compression... Now you can crank the boost some. /ubbthreads/images/graemlins/grin.gif

 

[Muskrat]

Do a leakdown test. My guess would be valve seals, but that's based on almost nothing.

Need more info.

 

[Barnes]

Valve seals do nothing to help compression. /ubbthreads/images/graemlins/confused.gif

 

[91vr4394]

time to build a nice setup

 

[Launch]

What is the problem? ...still completely within serviceable limits....
Shep ran almost 190mph with a motor that ran 65ish cold /ubbthreads/images/graemlins/smile.gif

In what way did the gauge needle move? Steady, 90+ on the first try? Did you try a veeery small amount of oil to test the rings?
Stock Mitsu shortblocks arnt given the respect they have earned

 

[91vr4394]

Actually there arn't any problems just wanted to test it.And yes it went straight to 90+ not sure exactly where but they were all above 90 on the 1st crank..I didn't try a little bit of oil

 

[Launch]

... The cyl with low compression should be tested cold first;
-add oil (teaspoon or 2), re-do comp test: Does comp increase?
Repeat the same test with engine fully warm.
Report back to us /ubbthreads/images/graemlins/smile.gif

 

[turbowop]

I wouldn't worry about those results unless you were gonna try to break some records.

 

[alansupra94]

I thought you were suppose to test a motor after it warmed up?

Thats at least what I was taught.

 

[mikus]

just to put it out there, are you sure this gauge is good? Teh last one I bought read about 25% under straight out the box - freaked me out on first use.

Unfortunately it was 6M after buying, so there goes $$ boo

 

[91vr4394]

I'll get a new gauge and try..I will let you guys know the results..The car runs great.No smoke.It's got a brand new head was like that when I got it..I dont know why they never changed rings or anything..I would have.

 

[Rausch]

Quoting turbowop:
I wouldn't worry about those results unless you were gonna try to break some records.

+ this- Those #s are fine. A little low, but all close enough to each other not to be an issue.

And you can test it warm or cold- Cold is obviously easier, but your #s will be a bit lower than they would warm. In any case, you have a good idea of where you are with either.

Quote:
It's got a brand new head was like that when I got it..I dont know why they never changed rings or anything..I would have.

- Rebuilding the cylinder head and rebuilding the bock are two different animals. It's not a matter of just throwing rings in the thing. MAtter of fact- That alone probably would not net dramatic results... /ubbthreads/images/graemlins/wink.gif

 

[turbowop]

Also, I don't remember if it makes a difference or not, but in addition to doing this test at full operating temp, the accelerator pedal should be floored during cranking as well to allow air into the motor.

 

[Nartanian]

Quoting turbowop:
I wouldn't worry about those results unless you were gonna try to break some records.



Yup. My cousins 1g has 130 across the board and it's kicking just fine without any issues.