How to Lower Compression?
#21
Registered
iTrader: (7)
Be careful.... I think if you get with engine builder and result in some head and intake work and possible timing etc you'll be able to achieve close to your goals. Maybe cam change but your cam seems like it would be within reason if your wanting to stay at or close to 5,500. Cam may be just fine with some head work. You have a nice build there. I'm jealous. Lot of good parts. I just think there's power left on the table. If you can post a cam card it would be interesting to see your timing events.
#22
MiId Thunder - the fact that he isn't putting out much HP with that many cubes tells me he either has real bad heads or a very mild cam.
So with the proper cam I figured he should get it into the HP range he wanted without spending all of the $ on blowers.
I would cam it for at least 6000 RPM because cats like RPM.
So with the proper cam I figured he should get it into the HP range he wanted without spending all of the $ on blowers.
I would cam it for at least 6000 RPM because cats like RPM.
#23
Registered
iTrader: (7)
He's got a nice conservative build that would likely run many trouble free hours. Tinkerer like you mentioned cam would definately help like something in the 260/270-714-714. Existing cam would be fine with the whipple I think anyway. Just depends on what direction he goes. I think once he finds out what he has for head gasket, stock chambers or not, pistons at tdc etc then he can at least see if it's remotely possible to get near 9.0:1. I have a feeling it's gonna be difficult if it's actually 10.5 currently. That's possible an oversite given flat tops and if stock 121 chambers so might get lucky. In my opinion I'd run it hard and spray it til its ready for rebuild then get comp down. Meanwhile NOS it. That alone will probably expedite his future whipple. Lol.
Last edited by getrdunn; 12-05-2017 at 09:39 PM.
#24
Registered
iTrader: (3)
With some chamber porting, and thicker head gaskets , he could be down in the 8.9:1 range. I would have no issues putting a blower on a 9:1 engine, as I have and had no issues doing so.
Compression Ratio Calculator Tools Diamond Racing Pistons
Compression Ratio Calculator Tools Diamond Racing Pistons
#25
Registered
iTrader: (3)
He's got a nice conservative build that would likely run many trouble free hours. Tinkerer like you mentioned cam would definately help like something in the 260/270-714-714. Existing cam would be fine with the whipple I think anyway. Just depends on what direction he goes. I think once he finds out what he has for head gasket, stock chambers or not, pistons at tdc etc then he can at least see if it's remotely possible to get near 9.0:1. I have a feeling it's gonna be difficult if it's actually 10.5 currently. That's possible an oversite given flat tops and if stock 121 chambers so might get lucky. In my opinion I'd run it hard and spray it til its ready for rebuild then get comp down. Meanwhile NOS it. That alone will probably expedite his future whipple. Lol.
#26
I see your mother had obviously dropped you on the coconut much harder than her sister did to me. Leave it be, it's so much more relaxing drinking and listening to the radio than working on things that will break more often and they do break