Re: A pop quiz on some engine tests

[Orin Eman <orin@wolfenet.com>]

> Subject - a 200TQ, built in 5/88, w/a virgin engine.

> Bentley sez compression should be 123psi to 144psi for a brand new MC
> engine (my guess is that the lower value is for my single knock MC
> w/compression ratio 7.6:1 and the higher value is for a late dual knock
> MC w/compression ratio 8.4:1 ).

Hmmm.  5k Bentley says 116 to 159.5 new, 94.3 wear limit.  The range is
what they expect it to fall in, doesn't have anything to do with
older/newer MC.

Wear limit is 92psi, max delta between
> the cylinders should be no more than 44psi.

Same.  I think it's the delta that matters the most as long
as you are above the wear limit.

> Actual test values before the head removal=>
> Compression:
> #1 - 120psi
> #2 - 122psi
> #3 - 115psi
> #4 - 118psi
> #5 - 115psi
> (not bad for a 10y/o car!)

Nope, but my '86 5kCSQ with 165k miles is > 130 on all cylinders!
(WOT, all plugs out, engine warm, coil lead grounded etc..)
My old UrQ had readings like yours, though with some in the 90s just
before it went in for a valve job... 

Orin.