I thought this was interesting.

[big-phil]

After my car was sputtering at 10 to 12 pounds of boost, I started doing everything I could think of to fix it.

 

But this was interesting: my car has 169,000 miles (thats alot! for anyone who was wondering)

 

I did a compression test--in the book for a 1978 164-178 psi is acceptable.

With 169,000 miles my compression was no less than 170 in any cylinder, the average was 175psi....WOW!! What a motor those little Datsun people buit.

 

And now that I fixed it (for now) and I am boosting strong to 15 pounds, I think I'll go back to the body work that I started before I found that $150 turbo motor.

[EZ-E]

Its no worrie, I have 200k on mine, and it is a turbo motor, only thing ever really done to it was to have the head and block trued for the HKS metal HG and it still has 150 across the board.

[proxlamus©]

i hate you guys..

 

my 130,000 mile N47 only has 135psi across the board! *crying*

[Guest bastaad525]

i hate you guys..

 

my 130' date='000 mile N47 only has 135psi across the board! *crying*[/quote']

 

 

all compression gauges are not created equal.

 

I bought one from Auto Zone... I don't even remember the brand... bright orange colored packaging... tested my motor after the rebuild after like 6000 miles on it, and got 130ish psi on all cylinders. Then I took it to my friends house, he had a Snap On compression tester, and his registered ~160psi on all cylinders.

 

That's why it's better not to look at the exact numbers (unless the motor is old and you think it's really worn), but more important to look at how they vary from one cyl to the next.