motor is :

gsr block with uspec itr os pistons
b16 head milled .30 with toda b's

1.235
2.232
3.225
4.225

leak down

1. 0%
2. 0%
3. 2%
4. 0%

how are these numbers?





Modified by Reza... at 3:42 AM 9/29/2005

 

Something is bad. your highest compression is your worst leakdown. Did you warm it up? Did you adjust the valves? Are the cylinders round within .0005 thou.? Did you lap the valves?

 

the motor was warm, It has a 1000 miles on it.
what do you mean by lapping the valves?

 

 

bump i would like to know more as well.

 

after a valve job you apply a lapping compund and pull the valve into the seat and turn the valve in a circular motion to complete the seal.

 

does the machine shop typically do this ?

is it to late to perform now ?

 

To lap the valves you would need to take the head off again. If you are going to go through all that trouble I would take the head to the machine shop and have them do the valve seats. That is pretty much the same concept as lapping the valves just having the machine shop do the grind you can be reassured that all the valves are sealing properly.

 

do these numbers look fine to you?
i don't want to go through all that trouble just for 2 %.

 

Did you do the compression test with the ECU fuse pulled?

 

Im not sure.. that has an effect on it?
im asking right now

 

Your leak down numbers are great but how many pund sof pressure did you use. Something is wrong with the compression numbers though. Did you have any chamber work done to the head that could have thrown off the compression number from cylinder to cylinder. I.E. Spot facing.

 

no cylinder work done except for the .30 milling.

maybe the valves tightened up , gonna go through them this weekend.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Reza... &raquo;</TD></TR><TR><TD CLASS="quote">Im not sure.. that has an effect on it?
im asking right now</TD></TR></TABLE>

Yep. You're getting fuel in your cylinders with the ECU fuse in.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LSVT3K 91 C1V1C &raquo;</TD></TR><TR><TD CLASS="quote">Yep. You're getting fuel in your cylinders with the ECU fuse in.</TD></TR></TABLE>

we unplugged all the injectors , same thing?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Reza... &raquo;</TD></TR><TR><TD CLASS="quote">we unplugged all the injectors , same thing?</TD></TR></TABLE>

Yep.. you just made it more difficult for yourself.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LSVT3K 91 C1V1C &raquo;</TD></TR><TR><TD CLASS="quote">Yep.. you just made it more difficult for yourself. </TD></TR></TABLE>


lol

 

up

 

I wouldn't worry about the numbers too much. There is less then a 5% difference between all the cylinders, and your leak down numbers are fine (as long as you used the correct test pressure).

Also the motor is still fairly new, the numbers may change a bit but I wouldn't touch anything unless you are noticing other issues.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bitzbp &raquo;</TD></TR><TR><TD CLASS="quote">I wouldn't worry about the numbers too much. There is less then a 5% difference between all the cylinders, and your leak down numbers are fine (as long as you used the correct test pressure).

Also the motor is still fairly new, the numbers may change a bit but I wouldn't touch anything unless you are noticing other issues. </TD></TR></TABLE>

@ries conducted the test , im sure he used optimal pressure needed for the leak down.



Thanks for the input