Had compression test done on the 454 in my 72. Here are the results:

1 -- 135
2 -- 125 <low?
3 -- 135
4 -- 140
5 -- 135
6 -- 140
7 -- 145
8 -- 140

Engine was tested basically cold. It's *supposed* to have 10:1 forged TRW pistons. Has a mild street cam, don't have the details handy...

Is the #2 reading cause for real concern?

I don't have the money to tear it down now, so I'll just ride it for a while. Will look under the valve covers to see if anything is wrong.

Any tips? I'm running 15-40 Pennzoil...

Thanks!

Good oil choice BTW. Do the test HOT and see what the numbers are. The variance should decrease and you should see better numbers. But the variance you have now is just OK. 135-ish seems quite low for anything attempting to produce power though.Bet it has a wide center cam ( 114 lsa ). I'd check it hot.

[This message has been edited by 427L88 (edited 01-14-2003).]

If the compression ratio is really around 10:1 combined with a mild cam, I would think it should be a bit higher than what you are seeing. With the engine hot, it would increase some, but I'm not sure how much.

My 454 has a true 10:1 cr (calculated with the cc of the dome and comb. chamber, deck height, gasket thickness) with a fairly aggressive cam (248 deg @ 0.050") and a "warm" engine (120 degF) averaged out at 190psi.

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Darren
1971 Chevelle
454/4spd/4.30/N2O