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Iron heads
- Thread starter longshot
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HaxbySpeed
New member
A customer's 509 -Merlin "Grumpy's" 7.5lbs boost no problems. There was a real sharp eyebrow between the valve seats in the chamber that looked like it might create a hot spot that I smoothed out, and put bronze guides in them.
You can use them, but you do give up one of the absolute least-expensive ways to make power. First off, unless you have $2000 worth of hand porting done on the heads, they're not going to flow like a good out-of-the-box aluminum head. Second, the intake/exhaust flow ratios are not as ideal as many aluminum heads when used in blowe applications- you need alot of exhaust flow relative to the intake. lastly, the inherent thermal abilities of the aluminum allow you to get away with a bit more boost and a bit more timing. You could see 100 to 150 hp on a mildly blown 540 simply by bolting on a set of heads. AFR 315CNC's are about $3 grand. Where else can you find 150 hp for that kind of money?
Tomas Wallin
Charter Member
509 with GM 088 heads, IC and 8PSI boost
The combustion chambers are made a bit bigger (120cc) and very smooth.
The combustion chambers are made a bit bigger (120cc) and very smooth.
mbam
Sponsor / Charter Member
Chris I agree and would not go that route with iron again if looking for big power.
Did it back in 93 or so. CFE did the porting, 1000 HP, 89 octane, Merlin heads.
http://www.go-fast.com/36_cigarette.htm
At that power level controlling the heat in the head was a real problem. Went through 500 gals of fuel on the dyno figuring out how to keep a head gasket in it. Revised water flow, passages drilled between the cylinders, and the pressurized cooling finaly did it. Would still flash to steam behond the exhaust valve if you shut down quickly after running hard (had my idiot switches there).
Did it back in 93 or so. CFE did the porting, 1000 HP, 89 octane, Merlin heads.
http://www.go-fast.com/36_cigarette.htm
At that power level controlling the heat in the head was a real problem. Went through 500 gals of fuel on the dyno figuring out how to keep a head gasket in it. Revised water flow, passages drilled between the cylinders, and the pressurized cooling finaly did it. Would still flash to steam behond the exhaust valve if you shut down quickly after running hard (had my idiot switches there).
runninhotracing
Charter Member
Dart 496 / 600 hp 6 lbs boost no worries mate
ITS A SKATER NATION !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
ITS A SKATER NATION !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Geronimo36
Charter Member
Merlin 345's, 580", 7lbs, 830 hp and no worries... 93 oct. only for me..not taking any chances.
I'd probably make near 900 with Alum. heads though!
I'd probably make near 900 with Alum. heads though!
CNC
New member
Dart CI heads, w/M-4 procharger, 12lbs boost 1078 hp on 93 pump gas no problems
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