Making hp/tq with my low flowing heads (l98)

Yellow73SB

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Mar 24, 2008
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How would I do this. I want to make the most HP and torque that I can but my heads flow around 250 cfm maybe a little more. The compression is around 11.5:1 and I run cam2 (110 octane).

Right now the came has .550 lift and 236* duration. It actually feels pretty good but I'm not sure how it compares to other cars with a known amount of hp.

It ran a 13.01 at 109 with a 3.36 rear gear and it didn't even need to be shifted into third. And this was with 28* of timing(mistake). It really wakes up with 38* of timing.


I think I might get it chassis dyno'd soon. I'll mess with the timing some and turn it up to 38* before the dyno for the next auto-x.

Do you think a different cam would bring more HP/TQ? This one seems to be pretty good.
 
How would I do this. I want to make the most HP and torque that I can but my heads flow around 250 cfm maybe a little more. The compression is around 11.5:1 and I run cam2 (110 octane).

Right now the came has .550 lift and 236* duration. It actually feels pretty good but I'm not sure how it compares to other cars with a known amount of hp.

It ran a 13.01 at 109 with a 3.36 rear gear and it didn't even need to be shifted into third. And this was with 28* of timing(mistake). It really wakes up with 38* of timing.


I think I might get it chassis dyno'd soon. I'll mess with the timing some and turn it up to 38* before the dyno for the next auto-x.

Do you think a different cam would bring more HP/TQ? This one seems to be pretty good.


STILL the same old question, what you want the car to do?? primarily.....
drag queen??, cruiser?? scca handler???

allways compromises... new heads get spendy quick....figger 1500 bux and then they maybe get you a bit quicker....but for drage racing you need better gears....

with that lift, I would think that cam is about 1000 rpm idle speed...
 
If they are unmodified L98 heads they flow less than 200.

250CFM is a good flowing head.
 
They have a good amount of time into them by a very good head guy

As far as new heads go the only time that will happen is if we do a big block. We have a 427 bottom end that we could use.

And the 3.36 was swaped out for a 4.11
 
Going with more lift probably won't get you much since those heads peak by about 0.500" lift. You probably could get more HP with a longer duration cam or you could swap out the stock valves for better ones.

I swapped in Manley "race-flow" valves into a set of L98 heads and picked up ~5-10% flow up to 0.300" lift where the valve is the main restriction (not the port).
 
I have manley valves already

The heads have been gone through by a very very knowledgeable guy

The only reason he took our heads was because he rents from my uncle

He had 18* and sb2.2 stuff in his shop also
 
buy vizards book on cyl. heads, the L98 heads are discussed explicitly there and there are a lot of pics and pointers.
 
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