compression

[DSMinn0vati0ns]

Quick question, what is the compression for stock internals on the 4g63?

 

[4g63t]

BAM,

Ideal compression on a 6 bolt is 164 psi. Service limit is 121 psi.
Or if you ment the ratio i believe it a 1g is 7:5:1
2g is 8:5:1.

 

[oldman]

BAM,

Ideal compression on a 6 bolt is 164 psi. Service limit is 121 psi.
Or if you ment the ratio i believe it a 1g is 7:5:1
2g is 8:5:1.

http://www.geocities.com/dsmgrrrl/FAQs/compression.htm

1G 7.8 :1
2G 8.5 :1

Make sure the test is done with engine fully warmed up, throttle fully applied and battery fully charged.

 

[GST with PSI]

Compression tests are great, but be careful performing a wet compression test. If too much oil is used it will actually boost compression rather than just help seal the ring surfaces, giving you a false reading. Be sure to use a very small amount of oil and be sure the amounts are equal for each cylinder. If cylinder leakage is suspected and you have access to a leak down tester, I would suggest doing a cylinder leak down test to get a more accurate diagnosis.

I would also keep a battery charger actually attached to the battery while testing and cranking. Any variance in revolution speed during cranking will throw off your test results.