Quote:
Originally Posted by Jay S
If you were pumping 190 to 195 with the past combo, I think it would have been wise to get the 85 cc KRE D ports. The 74 is going to be pushing things with only a very small gain in power.
Location, temp, and elevation makes a big difference. The engine ran before and has a baseline to go off of, I don’t know why the builder decided it is wise to push the compression that much higher. I am a high compression guy, more than most, but I would not have went with the 74 cc versions, 85 cc would have been a better choice. After you try the 74s report back here and tell us how it’s working.  |
Jay,
not sure what the last motor was ,the 190-195 will be the
new set up as per the "cranking pressure calc" I'll know for sure in a week or so.
SO getting back to the original question.
" 11.4:1 "
i did a lot of reading and some math to figure out what the 2 big Pontiac shops and my builder were trying to tell me. ( tried to use a forum and take the easy way out)
has anyone looked at the cam card?
with the intake closing @ .050 73 ABDC she will not start make pressure until late in the compression stoke so it needs a higher compression to take up the slack in the low to midrange area...NOW lets just hold are key boards.....
I may not have worded this right or at all but you know were I'm going with it.
here is a good read for those of us who feel the need to read it.
wish I found it a few days ago I hate math.
https://www.motortrend.com/how-to/81...e-compression/
as for the cast parts this set up is not to far past the last set up ,would a nice shiny forged rolling assembly be better maybe so but i do not foresee a problem with the power I'm making.
ok gentlemen have at it.