SCJ lift/cfm specs.

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SCJ lift/cfm specs.

Post  72mav on April 12th 2017, 12:02 pm

Hi everyone.
What would be a optimum cfm rate/per lift rate on a Kaase SCJ head, say at 700 lift? Dont want to turn it over 7,200 rpm. Head needs a cleanup and 3 angle valve job. Just want to keep it a minimum massage bolt together deal using the stock valve springs for now. Bore is .080, flattop, 13:1 com, 4.14 stroke.
Thanks.
Al
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Re: SCJ lift/cfm specs.

Post  Lem Evans on April 12th 2017, 3:32 pm

Most of the SCJ stuff I've messed with peaked well before .700" lift.

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Re: SCJ lift/cfm specs.

Post  IDT-572 on April 12th 2017, 3:33 pm

The P-51 has as good of CFM per rate of lift you will find on a conventional head.

Not sure what your after, but that head with a good multi angle vale job and bowl clean up will be very good just like it is and hard to improve upon.

Give us more info on what your wanting to do.
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Re: SCJ lift/cfm specs.

Post  72mav on April 12th 2017, 8:16 pm

Thanks for the replies fellas.
Its for my Maverick. Reason I wanted to stay at 700 lift, was on account of the valve springs. Was just wanting to keep it simple for now. Probably should have bought P-51's.
Keith Fulp went 9.90 on 700 lift @t 4,000lbs. So I figured high 8's should be possible for my cars weight (2,300-2500 lbs.
Looking for some numbers on cfm/ lift that would be optimum using stock valve springs without going hog- wild on then.
Trying to balance things out with velocity/lift cfm's
Thanks. Al
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Re: SCJ lift/cfm specs.

Post  Lem Evans on April 12th 2017, 9:22 pm

72mav wrote:Thanks for the replies fellas.
Its for my Maverick. Reason I wanted to stay at 700 lift, was on account of the valve springs. Was just wanting to keep it simple for now. Probably should have bought P-51's.
Keith Fulp went 9.90 on 700 lift @t 4,000lbs. So I figured high 8's should be possible for my cars weight (2,300-2500 lbs.
Looking for some numbers on cfm/ lift that would be optimum using stock valve springs without going hog- wild on then.
Trying to balance things out with velocity/lift cfm's
Thanks. Al

By 'stock' do you mean the 1243 PAC springs? That come with the SCJB heads these days?


Last edited by Lem Evans on April 12th 2017, 9:23 pm; edited 1 time in total

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Re: SCJ lift/cfm specs.

Post  dfree383 on April 12th 2017, 9:23 pm

Which springs do you have? The roller or flat tappet?
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Re: SCJ lift/cfm specs.

Post  Straubtech on April 13th 2017, 9:56 am

72mav wrote:Hi everyone.
What would be a optimum cfm rate/per lift rate on a Kaase SCJ head, say at 700 lift? Dont want to turn it over 7,200 rpm. Head needs a cleanup and 3 angle valve job. Just want to keep it a minimum massage bolt together deal using the stock valve springs for now. Bore is .080, flattop, 13:1 com, 4.14 stroke.
Thanks.
Al

Piston speed is the "demand" that needs to be satisfied. Based on demand then you can calculate what you need for CFM.

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Re: SCJ lift/cfm specs.

Post  72mav on April 13th 2017, 4:44 pm

Stock roller springs.
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Re: SCJ lift/cfm specs.

Post  72mav on April 13th 2017, 4:55 pm

Straubtech wrote:
72mav wrote:Hi everyone.
What would be a optimum cfm rate/per lift rate on a Kaase SCJ head, say at 700 lift? Dont want to turn it over 7,200 rpm. Head needs a cleanup and 3 angle valve job. Just want to keep it a minimum massage bolt together deal using the stock valve springs for now. Bore is .080, flattop, 13:1 com, 4.14 stroke.
Thanks.
Al

Piston speed is the "demand" that needs to be satisfied.  Based on demand then you can calculate what you need for CFM.

So how do we figure piston speed?
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Re: SCJ lift/cfm specs.

Post  AZFairlane on April 13th 2017, 10:54 pm

http://www.csgnetwork.com/pistonspeedcalc.html

That should work for you.
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