I just got my FD back from my mechanic, who did a compression test on proper rotary compression testing equipment. He said everything looks good, but I'd really like to know a little more about where my motor stands. The motor (and the entire car) has 43,000 miles on it and she runs real well, but I'd just like to get an idea of where a healthy engine would be on the chart compared to where mine is and if I've still got a good amount of time on this motor.

Here's the test results:

Thanks in advance!

-Ian

 

Looks like you are pulling mid 6s on what I assume to be the front rotor which is about 95psi roughly, and right around 7 on what I assume is the rear rotor which is about 100 psi. You dont really have anything to worry about. Those are pretty decent numbers and I would consider it still a healthy motor.

 

It would help if you can find the RPM that the cranking was done at, since there is a adjustment factor for it. However this testing tool might automatically apply that when making the plot.

You could try steam cleaning your engine a bit - that can bring up compression sometimes.

Dave

 

Agree on the steam cleaning. Those aren't bad numbers but they aren't stellar either. I believe around the 70 - 80s is really low and almost non-running. Your engine seems to have decent amount of life left in it.

 

For a comparison, here was my original motor at 44.5K miles. I was told these were pretty good numbers.

 

You were told right.
I think they come factory in the 130s or high 120s. I was fortunate enough to have bought mine with a JDM engine rebuilt from the seller (did an awesome job) and the compression was 120-121 and was very even on all faces. I have heard of compression in the 140s in the rare cases but Im not sure how much I really believe that.

 

How do I go about steam cleaning the engine?

 

There are a couple write ups if you search but basically you just run a long vacuum hose from your intake manifold into a jug of distilled water and rev the engine in neutral until the jug is empty. I believe people rev to around 4k and you can use a vacuum Y fitting to use both ports on the uim to supply even water to both rotors. But just search there was recently a thread discussing the amount of water, rpms and vacuum locations recommended, ect.

 

http://www.rotaryresurrection.com/3r...injection.html