LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Negatives of an iron-headed motor?

Old Nov 26, 2007 | 10:40 PM
  #1  
Out1aw's Avatar
Thread Starter
TECH Addict
iTrader: (1)
 
Joined: Aug 2005
Posts: 2,007
Likes: 0
From: Lawrenceville, GA
Default Negatives of an iron-headed motor?

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?
Reply
Old Nov 27, 2007 | 06:36 AM
  #2  
SAPPER's Avatar
TECH Fanatic
20 Year Member
Liked
Loved
Community Favorite
iTrader: (10)
 
Joined: May 2004
Posts: 1,593
Likes: 267
From: Halfway back on the Highway to Hell...again!
Default

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.
Reply
Old Nov 27, 2007 | 01:13 PM
  #3  
Out1aw's Avatar
Thread Starter
TECH Addict
iTrader: (1)
 
Joined: Aug 2005
Posts: 2,007
Likes: 0
From: Lawrenceville, GA
Default

So is everyone running aluminums in the higher-horsepower applications?
Reply
Old Nov 27, 2007 | 01:22 PM
  #4  
aggiez28's Avatar
TECH Fanatic
iTrader: (19)
 
Joined: Mar 2003
Posts: 1,228
Likes: 0
From: Houston
Default

yup..
Reply
Old Nov 27, 2007 | 02:32 PM
  #5  
suicidal racing's Avatar
TECH Fanatic
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (14)
 
Joined: Sep 2007
Posts: 1,074
Likes: 8
From: Mass
Default

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.
Reply
Old Nov 27, 2007 | 05:06 PM
  #6  
Out1aw's Avatar
Thread Starter
TECH Addict
iTrader: (1)
 
Joined: Aug 2005
Posts: 2,007
Likes: 0
From: Lawrenceville, GA
Default

What about for a 9.5:1 though? ...
Reply
Old Nov 27, 2007 | 05:19 PM
  #7  
suicidal racing's Avatar
TECH Fanatic
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (14)
 
Joined: Sep 2007
Posts: 1,074
Likes: 8
From: Mass
Default

its fine but it will hold heat though in the cc more then aluminum though.
Reply
Old Nov 27, 2007 | 05:27 PM
  #8  
slick1851's Avatar
TECH Junkie
 
Joined: Nov 2003
Posts: 3,265
Likes: 1
From: CHITOWN
Default

i wouldnt run them
Reply
Old Nov 27, 2007 | 05:55 PM
  #9  
96capricemgr's Avatar
11 Second Club
iTrader: (1)
 
Joined: Sep 2004
Posts: 11,975
Likes: 15
Default

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.
Reply


Thread Tools
Search this Thread

All times are GMT -5. The time now is 04:47 PM.