Negatives of an iron-headed motor?
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From: Lawrenceville, GA
Looking into a new motor for the camaro, and looking at an iron-headed setup. Going with a healthy amount of juice and going to work out the heads, but noticed the motor would be signifigantly cheaper out of a Buick or Impala. Any thoughts on this? Any other conversions or modifications needed to make it work?
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From: Halfway back on the Highway to Hell...again!
There are a few cons to the irons. The Iron heads actually flow better (1st "Vortec" design), they utilize press in studs and the valve seats are smaller. The irons require a bit of machinework to use for high performance. You can get away with Comp 918's on the seat but clearance is VERY close. Too close for me. Screw in studs are a must. And lastly---They weigh a ton.
Any porter will charge more to do a cast head since it eats up more burrs and takes twice as long to cut. I hate porting iron heads. You're better off having a set of aluminums built for such a task, i.e. O-ringed. And you will definately want to use head studs, not bolts, if your "healthy" shot is above 200rw shots.
As for the motor, nothing different except maybe the crank pulley and the accessories. OH, and the style of opti in regards to the timing cover.
Any porter will charge more to do a cast head since it eats up more burrs and takes twice as long to cut. I hate porting iron heads. You're better off having a set of aluminums built for such a task, i.e. O-ringed. And you will definately want to use head studs, not bolts, if your "healthy" shot is above 200rw shots.
As for the motor, nothing different except maybe the crank pulley and the accessories. OH, and the style of opti in regards to the timing cover.
also with iron comes more detanation do to the iron not able to lose heat as fast.you are also limited on the cp level with them..11-1 is max after that race gas is a good idea or a 50/50 mix alum you can go to 12.5-1 depending on your tune up and cam selection before having to go to race gas.
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The iron head motors are 10:1 bone stock and tuned to run 87 octane.
The iron heads can crack if heavily ported, few guys have had it happen after a couple years.
Far as I know the valve seats are actually able to take a bigger valve, but things like the pressed studs needing conversion add cost to using them. Would need to open up the pushrod holes too, really they are fine for mild work but if looking to make serious power the aluminums are the ticket.
For shortblocks though the b-bodies are a great budget friendly source and depending on the car less likely to have been abused as basly as an f-body motor.
The iron heads can crack if heavily ported, few guys have had it happen after a couple years.
Far as I know the valve seats are actually able to take a bigger valve, but things like the pressed studs needing conversion add cost to using them. Would need to open up the pushrod holes too, really they are fine for mild work but if looking to make serious power the aluminums are the ticket.
For shortblocks though the b-bodies are a great budget friendly source and depending on the car less likely to have been abused as basly as an f-body motor.









