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Cam specs? whats duration at.050??

Old 08-16-2013, 05:24 AM
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Default Cam specs? whats duration at.050??

My custom ground cam only has the advertised duration engraved, I do not have the cam card....

trying to see what duration it is....


I do know...

ground 114LCA
Says advertised duration 302/310
lift is .578

its erson.... cannot find what duration is @.050

how do I find that out??
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Old 08-16-2013, 05:44 AM
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Depends where the advertised duration is measured at. .006, .004, etc

Do you have the valve IO/IC EO/EC numbers?

Last edited by MILD THUNDER; 08-16-2013 at 05:47 AM.
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Old 08-16-2013, 06:06 AM
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Might be something like 242/248* @ .050 or in that range. Im guessing these were in those scarab engines?
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Old 08-16-2013, 06:12 AM
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Yes that's the only thing I don't know... My buddy had a engine builder that I would have shot hence the reason I build my own stuff but this was a deal so I grabbed the boat....

I know he built them very conservative using small cams for the CI... I plan to change things in a couple years or if I hurt one and rebuild... These can make 675-700 hp easily...

Right now they are [email protected] [email protected]

Hp is 597-598 from 5100-5400 then drops off...

Tq peaks 4200 but still hold [email protected] so 5200 is about what I wanna prop at also
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Old 08-16-2013, 06:13 AM
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Originally Posted by MILD THUNDER View Post
Depends where the advertised duration is measured at. .006, .004, etc

Do you have the valve IO/IC EO/EC numbers?
I don't only info is what's engraved on back of cam
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Old 08-16-2013, 06:31 AM
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Put a degree wheel, dial indicator and pointer on it.
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Old 08-16-2013, 06:33 AM
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Originally Posted by lil red View Post
Put a degree wheel, dial indicator and pointer on it.
A little late now lol engines are in boat haha

I was just curious to see what they are...
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Old 08-16-2013, 08:00 AM
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Full Force,

The cam is a derivative of the shelf cam:

E120207

RH-302-2

234/242 @ .050"

.340"/.340" Lobe

Ground on a 114 Lobe sep

Attached is the cam card for theat cam on a 112 sep, measured with a 1.72 rocker ratio.

Bob
Attached Files
File Type: pdf
120207.pdf (80.8 KB, 152 views)
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Old 08-16-2013, 08:03 AM
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Originally Posted by rmbuilder View Post
Full Force,

The cam is a derivative of the shelf cam:

E120207

RH-302-2

234/242 @ .050"

.340"/.340" Lobe

Ground on a 114 Lobe sep

Attached is the cam card for theat cam on a 112 sep, measured with a 1.72 rocker ratio.

Bob
So it's close to that? What's the 310 for on the back? Any idea? This cam seems small for 547ci aluminum head engines 320cc runners I think I have that info at home
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Old 08-16-2013, 08:22 AM
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Yours is identical to the catalog cam sheet posted, with the exception of yours is ground on a 114 lobe separation angle, and the catalog cam has been ground on a 112 LSA. Duration, lift etc. is all the same.

the 302/310 designates the seat, or measured duration. I posted the catalog cam to give you a look at the lobe architecture.

"Hp is 597-598 from 5100-5400 then drops off..."

That is typical of that duration for that displacement, power will plateau, dropping off due to pumping losses.

Bob
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