head question

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02-18-2008, 09:51 PM

92gt50

1st Gear Member

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Join Date: Jul 2007

Posts: 54

head question

what will make more power having a head with a 58cc combustion chamber and 13 compression ratio or a 72cc combustion chamber with 11 compression ratio. naturally aspired

02-18-2008, 09:53 PM

mjr46

D.R. THE PATHETIC DORK

Join Date: Jun 2007

Location: West Virginia

Posts: 30,863

RE: head question

it all depends on the rest of the build but all things being equal... the 13 to 1 should be

02-18-2008, 09:58 PM

AdderMk2

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Join Date: Dec 2005

Location: Lil' Rhody

Posts: 22,376

RE: head question

higher compression ratio usually nets higher power

also, a motor with 58cc heads with 11:1 compression versus a motor with 72cc heads and 11:1 compression...

the 58cc headed motor would make better power

(figure that one out)

02-18-2008, 10:15 PM

5spd GT

3rd Gear Member

Join Date: Sep 2007

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Posts: 798

RE: head question

The 13:1 will win out.

Dish pistons are SLIGHTLY better at pulling in a bit more air. Just something Nascar used for a few more HP.

02-19-2008, 04:25 AM

greenstreak9205

4th Gear Member

Join Date: May 2006

Location: Waterford, WI

Posts: 1,485

RE: head question

Quote:

ORIGINAL: AdderMk2

higher compression ratio usually nets higher power

also, a motor with 58cc heads with 11:1 compression versus a motor with 72cc heads and 11:1 compression...

the 58cc headed motor would make better power

(figure that one out)

better piston design should make it a bit more correct?

02-19-2008, 09:37 AM

5spd GT

3rd Gear Member

Join Date: Sep 2007

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Posts: 798

RE: head question

There is more volume to be decompressed when the piston is moving downwards while under dynamic conditions (air is incoming).

Compression ratio is simply a static scenario of air.