Hi, I am looking to get a z28 with an LB9 and 5speed. The engine seems to be runing fine without any hicups and it purrs nice at idle.

I was wondering what PSI of compression should I expect at mile high (denver) as opposed to sea level compression.
Would compression be affected by the altitude??? Just like it affects 1/4 mile times.
Also, it does not look to be leaking anywhere, its just dusty, but other than that it looks really good.

What would you recomend I do to this 150k engine once I get it.

I was thinking Tune-up, possibly injectors, water pump, 180 thermostat, hose replacement...
What else???

 

Compression pressure will be slightly lower. Mostly you want to see them withing 10-15% of each other.

An ignition tune-up, injector cleaning (I'd start with gas tank additive cleaner, no reason to pull them or spend a bunch of money on a machine clean if not indicated), belt & hose replacement, O2 sensor, full fluids change. Leave the thermostat alone. Same with water pump, leave it unless it starts leaking.

 

filters like air and fuel.



I like seafoam in the tank and in the vacuum line. Perhaps some in the crankcase too, with the old oil. Drive it hard to clean out any carbon and move things around. Then change the oil, and your other filters.

 

Where can I get a compression tester???

If you hear this car runing you wont belive that it has 150k. It sounds smooth, no bumpity bump, or slight bump etc. You know how you can hear the motor idle, and slight low and high areas, well with this one its just smooth. I've heard freshly re-built engines and this motor sounds just like it.

So, seafoam in tank, possibly crank case. I've ran some chemtol through my TBI and it cleaned up the slight lifter noise I had. It was awsome. I am defenetly opening up the valve covers and checking for build up. Hopefully the motor is clean.

I am getting it next tuesday, so I can't wait.

Thanks.

 

Compression tester: Harbor Freight, Checker, Autozone, Carquest, NAPA, Pep Boys, Advance Auto, etc.