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A7RXY Comp test
Posted: Sat May 02, 2015 3:28 pm
by A7RXY
I meet up today with Tool and Kevin this morning to see if we could get Kevins Elford running for him. I'll let Kevin tell how that all went, but just to start it off as Tool said he would and did get it running.
While there I got Tool to give my car a comp test the result was:
Front 8.5 8.8 8.6 at 235 RPM
Rear 8.2 8.3 8.6 at 236 RPM
So now I'm a very happy bunny .............
PS Tool was good enough to leave Kevin's wheels on his car ........
Dibs
Re: A7RXY Comp test
Posted: Sat May 02, 2015 7:22 pm
by TOOL
Seeing as you're sharing. Your numbers are:
128, 132, 129 psi @ 250rpm front
124, 125, 129 psi @ 250rpm rear
These are good numbers.
Good to meet you. Enjoy putting the diff in (never again lol).
Re: A7RXY Comp test
Posted: Sat May 02, 2015 7:34 pm
by economiser
TOOL wrote:128, 132, 129 psi @ 250rpm front, 124, 125, 129 psi @ 250rpm rear. These are good numbers.
That surprises me. A new ZZ4 crate 5.7L V8 from GM is over 200 psi cranking compression, for comparison. 130 is cause for a re-ring, or a cam swap, if the ring seal is known good.
Re: A7RXY Comp test
Posted: Sat May 02, 2015 8:37 pm
by mc turbo
A7RXY wrote:I meet up today with Tool and Kevin this morning to see if we could get Kevins Elford running for him. I'll let Kevin tell how that all went, but just to start it off as Tool said he would and did get it running.
While there I got Tool to give my car a comp test the result was:
Front 8.5 8.8 8.6 at 235 RPM
Rear 8.2 8.3 8.6 at 236 RPM
So now I'm a very happy bunny .............
PS Tool was good enough to leave Kevin's wheels on his car ........
Dibs
that's excellent results m8 has it had a rebuild recently?
ps, & how was kevins fb?
Re: A7RXY Comp test
Posted: Sat May 02, 2015 8:49 pm
by mc turbo
economiser wrote:TOOL wrote:128, 132, 129 psi @ 250rpm front, 124, 125, 129 psi @ 250rpm rear. These are good numbers.
That surprises me. A new ZZ4 crate 5.7L V8 from GM is over 200 psi cranking compression, for comparison. 130 is cause for a re-ring, or a cam swap, if the ring seal is known good.
mazda list the 12a as having 9.4 bar = 136 psi from new!
Re: A7RXY Comp test
Posted: Sat May 02, 2015 8:50 pm
by Lucky
Great numbers. Anything in the high eights is compression to be proud of
Re: A7RXY Comp test
Posted: Sat May 02, 2015 9:30 pm
by myatt1972
Nice figures, now get some miles done and get them down
Re: A7RXY Comp test
Posted: Sat May 02, 2015 9:39 pm
by A7RXY
myatt1972 wrote:Nice figures, now get some miles done and get them down
Its now got 36,155 on it I might have to put it away for the summer ..................... As I've now worn the paint out on one of the wings I don't want to wear the engine out as well............
Re: A7RXY Comp test
Posted: Sat May 02, 2015 11:25 pm
by economiser
mc turbo wrote:economiser wrote:TOOL wrote:128, 132, 129 psi @ 250rpm front, 124, 125, 129 psi @ 250rpm rear. These are good numbers.
That surprises me. A new ZZ4 crate 5.7L V8 from GM is over 200 psi cranking compression, for comparison. 130 is cause for a re-ring, or a cam swap, if the ring seal is known good.
mazda list the 12a as having 9.4 bar = 136 psi from new!
So, aside from the need for better apex seals, the thing wants boost? ( turbo )
Re: A7RXY Comp test
Posted: Sun May 03, 2015 7:39 am
by ian65
Great numbers Dibs, almost as good as new.
Although the mileage is low these are still old cars so it's nice to have your engines health confirmed and that's only way to do it...i bet you're well pleased
