compression ratio on 95 7.3???

[harley1rocker]

i heard it was over 400 but i saw a engine today with a consistant 350 on all 8 cylinders and it was a new(rebuilt) moter,whats the consensus? i do say ol'chap will you be haveing a totty with me tonight??? i guess ill go back to my roots and post like a freakin scholar since people cant read anything without correct punctuation and grammer...freaks

[AD5GB]

IIRC 400-425 is Ford's spec. 350 is a bit low but if the rings haven't yet seated (you said it was recently rebuilt) that would be expected. It takes a little while too. That being the case the uniformity is the big thing and the pressure will come up when the rings get seated. The compression ratio is 17.5:1.

[harley1rocker]

kay,thanx dude.i meant to update this today,we did a compression test on one that has 305,000 miles today and all 8 cylinders were consistant and in the area of 350,

[AD5GB]

Originally Posted by harley1rocker

kay,thanx dude.i meant to update this today,we did a compression test on one that has 305,000 miles today and all 8 cylinders were consistant and in the area of 350,

I guess if it starts easily and runs good, then "let her go"! The consistency is the important thing.

[bucwheat]

I was told at one time and can't remember where that the compression was 30 to 1 on these trucks.

[AD5GB]

Originally Posted by bucwheat

I was told at one time and can't remember where that the compression was 30 to 1 on these trucks.

Just a little more than half of that. Check out this article: Ford's Power Stroke Diesel History - Diesel Tech - Diesel Power Magazine

[ridiculously_necessary]

the 6.5's run soemthing like 22.5:1 or there abouts. a popular rebuild mod is 18:1. i would imagine the 22:1 certainly helps cold starts though!

[ryandamo]

yea my buddys got an old 6.5 and a 6.2 and hell fry the head gaskets if his boost gets to high

[ridiculously_necessary]

Originally Posted by ryandamo

yea my buddys got an old 6.5 and a 6.2 and hell fry the head gaskets if his boost gets to high

yeah stock is about 7 psi max borderline mod is about 12. the guys who put in 18:1's generally run up to 18.

[dereku]

wow those good old useless GM motors