Compression
10-26-2008, 08:35 AM
#11
Senior Member
RACING JUNKIE
Join Date: Dec 2007
Location: ohio
Posts: 816
bjuice hit the nail on the head, i have heard some guy,s say you can have too much, and under some conditions this may be true, but i don,t see 14-15-1 being close to those conditions. and would be the min.. i would want for a race motor. jmo
10-26-2008, 10:16 AM
#13
Member
JUNIOR BUILDER
Join Date: Feb 2008
Location: Childers Australia
Posts: 98
I was once told something that appears obviously true."there is only one way to make more power,increase cylinder pressure how you do this doesnt matter"obviously the fuel must be able to take it,methanol can & who knows what the upper CR limit is.
10-27-2008, 06:31 PM
#14
Junior Member
SHOW GUEST
Join Date: Dec 2006
Posts: 3
I'm not saying don't raise your compression, but don't expect a 100+ HP gain, by just raising the compression from 12.5-14.5, with no other changes. HP don't come that easy.
My engine program shows a 16 HP gain on a methanol 582" engine making 970 HP, by raising the compression from 12.5/1, to 14.5/1, and it assumes the dome size needed to raise the compression, didn't start hindering flame travel, or causing some other combustion issues.
I think 16HP is more realistic, than 100+.
Randy
My engine program shows a 16 HP gain on a methanol 582" engine making 970 HP, by raising the compression from 12.5/1, to 14.5/1, and it assumes the dome size needed to raise the compression, didn't start hindering flame travel, or causing some other combustion issues.
I think 16HP is more realistic, than 100+.
Randy
10-27-2008, 08:04 PM
#15
Senior Member
SENIOR BUILDER
Join Date: Dec 2005
Posts: 117
methanol compression
there are tables and formulas for calculating how much compression increases power. diminishing returns...
if cylinder pressure is greater before ignition, chances are good it will be greater after ignition..
not sure what maximum compression with methanol is, as long as rich, it will be accomodating..
if cylinder pressure is greater before ignition, chances are good it will be greater after ignition..
not sure what maximum compression with methanol is, as long as rich, it will be accomodating..
12-05-2008, 01:44 PM
#16
Senior Member
RACING JUNKIE
Thread Starter
Join Date: May 2003
Location: Coldwater, MI
Posts: 2,998
Looks like come spring we will get some real #'s on what the compression change is. Motor is going to need new pistons (block was a bit out of round) so I am just making the move to bump compression upto 14.5-15:1
12-08-2008, 07:27 AM
#20
Senior Member
MASTER BUILDER
Join Date: Jul 2006
Posts: 184
You won;t pick up 100, but I would say from expierience, 20-25, maybe 30hp. Which, if you need pistons anyhow, why not. If it was going from 10:1 15:1, you could expect possibly 100hp, but your at the point of diminishing returns. Q-16, will add another 35-40hp over C-16, once tuned properly. Its expensive, and stinks, but definately makes more power.
Frank
Frank