Honda CRX Forum banner
1 - 2 of 2 Posts

·
Registered
Joined
·
2,040 Posts
Discussion Starter · #1 ·
So I've been reading bit about engine builds becasue I'm starting to think about rebuilding my chevy small black 350. I've stumbed across a lot of good info that i'm trying to carry over to my honda.

We've all folllowed the saga of Downest as he attempted to go super high compression using pm7/p29 pistons in an a6 block with a y8 head and stock cam. This combination yeilds somewhere near ~12.6:1 static compression ratio using an oem honda head gasket. I began to wonder about the feasibility of running super high compression in my motor witht he proper cam and tune after having read his sad story.

I do not have the specs for lobe seperation and valve opening and closing times for the stock cam but I do for a stage 2 and stage 3 crower cam.

Here is a table of static and dynamic compression ratios with two different piston sets and two different camshafts:

Head Piston Camshaft Static CR Dynamic CR

A6 PM6 Stage 2 9.1:1 8.32:1
A6 PM6 Stage 3 9.1:1 8.11:1

A6 PM7 Stage 2 11.1:1 10.12:1
A6 PM7 Stage 3 11.1:1 9.87:1

Y8 PM6 Stage 2 10.3:1 9.40:1
Y8 PM6 Stage 3 10.3:1 9.16:1

Y8 PM7 Stage 2 12.6:1 11.48:1
Y8 PM7 Stage 3 12.6:1 11.18:1

I ran the numbers in excel myself for the static compression ratios. I was feeling lazy and used http://www.wallaceracing.com/dynamic-cr.php to run the dynamic compression ratios.

Not almost all of these numbers suprise me. Why you ask? Well based on all I know from what I've research in blueprinting my small block 350ci chevy motor dynamic compression ratios beyond about 8.5:1 are impossible to get to run on pump gas. So this leads me to believe that there is either somehting i'm missing or the calculations are simply wrong. Does anyone else have experience blueprinting motors, or honda motors?
 
1 - 2 of 2 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top