Making them square is a shit ton of work and it’s maybe 10 CFM. There is more to making power than what a flow bench says. CFM is near the bottom of what matters.Krooser wrote: ↑Tue Sep 14, 2021 12:12 am.600 lift before they laid over. If I got those intake ports squared off I have been told they would do 330 cfm.
Had an old friend flow them since the PO didn't remember what they did. He has a pretty honest flow bench (and dyno) and does not sugar coat the numbers to make the customer feel better.
The wonky pushrod angles on the SBM heads cost you a bit of lift but not so much with the W2 heads which have the pushrods moved off center. But I will use 3/8" pushrods to keep as much as I can.
This engine did 575 HP when first built back in '93. Ran about 18 nights and was stored until '07 when it was put into a dirt A mod and was run cold on alky and it ultimately took out two rod bearings, the crank, four pistons three rods and one cylinder. I fixed it and it's ready to be assembled after I do some oiling modifications.
How much HP can this head support?
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Re: How much HP can this head support?
Re: How much HP can this head support?
I kind of feel the flow # allows you to have a target HP that you may hit if all is right. The more cfm the more potential....ClassAct wrote: ↑Tue Sep 14, 2021 12:47 pmMaking them square is a shit ton of work and it’s maybe 10 CFM. There is more to making power than what a flow bench says. CFM is near the bottom of what matters.Krooser wrote: ↑Tue Sep 14, 2021 12:12 am.600 lift before they laid over. If I got those intake ports squared off I have been told they would do 330 cfm.
Had an old friend flow them since the PO didn't remember what they did. He has a pretty honest flow bench (and dyno) and does not sugar coat the numbers to make the customer feel better.
The wonky pushrod angles on the SBM heads cost you a bit of lift but not so much with the W2 heads which have the pushrods moved off center. But I will use 3/8" pushrods to keep as much as I can.
This engine did 575 HP when first built back in '93. Ran about 18 nights and was stored until '07 when it was put into a dirt A mod and was run cold on alky and it ultimately took out two rod bearings, the crank, four pistons three rods and one cylinder. I fixed it and it's ready to be assembled after I do some oiling modifications.
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Re: How much HP can this head support?
Krooser wrote: ↑Tue Sep 14, 2021 1:46 pmI kind of feel the flow # allows you to have a target HP that you may hit if all is right. The more cfm the more potential....ClassAct wrote: ↑Tue Sep 14, 2021 12:47 pmMaking them square is a shit ton of work and it’s maybe 10 CFM. There is more to making power than what a flow bench says. CFM is near the bottom of what matters.Krooser wrote: ↑Tue Sep 14, 2021 12:12 am
.600 lift before they laid over. If I got those intake ports squared off I have been told they would do 330 cfm.
Had an old friend flow them since the PO didn't remember what they did. He has a pretty honest flow bench (and dyno) and does not sugar coat the numbers to make the customer feel better.
The wonky pushrod angles on the SBM heads cost you a bit of lift but not so much with the W2 heads which have the pushrods moved off center. But I will use 3/8" pushrods to keep as much as I can.
This engine did 575 HP when first built back in '93. Ran about 18 nights and was stored until '07 when it was put into a dirt A mod and was run cold on alky and it ultimately took out two rod bearings, the crank, four pistons three rods and one cylinder. I fixed it and it's ready to be assembled after I do some oiling modifications.
I’ve lost flow and made more power many times. That port NEEDS a 2.08 valve. And if the flow never goes over 290 it will still make more power. The flow bench and flow numbers are not the best metric for determining power potential of a given cylinder head.
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Re: How much HP can this head support?
Thats about right for a good mild port job on W2s.
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Re: How much HP can this head support?
I agree with that.ClassAct wrote: ↑Tue Sep 14, 2021 5:51 pm
I’ve lost flow and made more power many times. That port NEEDS a 2.08 valve. And if the flow never goes over 290 it will still make more power. The flow bench and flow numbers are not the best metric for determining power potential of a given cylinder head.
Many of todays racers buy their engines complete and dont have any idea whats inside. But talking to some engine builders I have found they screw SBC's together with "spec" Brodix heads with less flow than my ,W-2's but with cams with way more lift than my two.
My buddy had a .650 lift roller in his small block using those spec heads that flow about 270 iirc. Then the cam guys tell me I need a .555 cam. Confusing info for a senior citizen!!!
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Re: How much HP can this head support?
With a 368 drag race engine on gasoline, just under 13/1 compression our customer made 663 horsepower at 7,800 RPM with a Dominator carb on a Holley intake.
The heads flowed about those exact numbers except they had 2.055" intakes and 1.625" exhausts; cam was 278/286; .645" valve lift.
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Re: How much HP can this head support?
I did a set for Clint, car was featured in Mopar Muscle around 3/19.. It regularly runs 10.4's @ 128 mph and drives it everywhere. Full interior, all steel.
Re: How much HP can this head support?
Was it ever dynoed?SpeierRacingHeads wrote: ↑Wed Sep 15, 2021 4:07 pm I did a set for Clint, car was featured in Mopar Muscle around 3/19.. It regularly runs 10.4's @ 128 mph and drives it everywhere. Full interior, all steel.
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Re: How much HP can this head support?
The cfm could make 400hp or 650hp... there is more to it than just raw flow numbers..
600hp in a 3100lb car should go low 10s.
600hp in a 3100lb car should go low 10s.
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Re: How much HP can this head support?
This is the head Bob Glidden used on the Arrow engine that did so well. A SBM is a 18 degree head to begin with.
I made a post on the FB pro stock of the 70s -80s and it made some Ford peeps mad. This head was light years ahead when it came out. It wasn't Bob Glidden pixie dust only. He had a great piece to use
Gotta ask yourself, what if GM had given an 18 degree shaft rocker head to the public in 1978 ?
I made a post on the FB pro stock of the 70s -80s and it made some Ford peeps mad. This head was light years ahead when it came out. It wasn't Bob Glidden pixie dust only. He had a great piece to use
Gotta ask yourself, what if GM had given an 18 degree shaft rocker head to the public in 1978 ?