bclapham
LIFETIME SPONSOR
- Nov 5, 2001
- 4,340
- 0
Hi Guys:
i am reading up on Bells book, and i get the impression that he has little time for the way corrected comp ratios are calculated.
however, from reading Erics book, i see that when he suggests exhaust port changes, he then states that the head should be milled down by the same amount as the port was raised so as to keep the comp ratio the same.
so, what is everyone doing, i assume since Erics book is more recent and he has more experience with jap MX engines that this is the way forward.
so this leads me to further questions.
1. what is the best way to measure exhaust port height?
2. what is the best way to measure deck height?
3. manufacturers often quote two comp ratios, eg PV open and PV closed- since the PV doesnt actually seal against the piston, i assume that the higher comp ratio for PV closed does not figure in to the grand whole scheme of things?
thanks
BC
i am reading up on Bells book, and i get the impression that he has little time for the way corrected comp ratios are calculated.
however, from reading Erics book, i see that when he suggests exhaust port changes, he then states that the head should be milled down by the same amount as the port was raised so as to keep the comp ratio the same.
so, what is everyone doing, i assume since Erics book is more recent and he has more experience with jap MX engines that this is the way forward.
so this leads me to further questions.
1. what is the best way to measure exhaust port height?
2. what is the best way to measure deck height?
3. manufacturers often quote two comp ratios, eg PV open and PV closed- since the PV doesnt actually seal against the piston, i assume that the higher comp ratio for PV closed does not figure in to the grand whole scheme of things?
thanks
BC