Iron heads
CORE402
01-04-2005, 11:30 PM
I have been reading a lot lately on building SBCs and I have found a conflict from two different authors. One author states "the old days of looking for a set of double hump heads are history." In Lingenfelter's book he states that in the realm of iron heads that he likes the 993, 487, 441, 442 heads. Which to my knowledge are the crappy 76cc heads that have the "smog style" chambers. In another book on building SBCs states that one should avoid heads with these style of combustion chambers like the plague. The author stated that one could lose 20-30lbft of torque throughout the entire RPM range and at 5000rpm that's 15 hp. What do you guys think? Old style with the tighter combustion chambers or the newer castings. NOT THE VORTECS. I know vortecs are better.
Morley
01-05-2005, 02:14 AM
Get a set of L98 heads off of a 350 TPI engine, they are 64cc chambers andwith some port work will do quite nicely. Now if you want to look around and spend a little money, a set of Corvette aluminum l98 heads would do even better, but they have even smaller, 58cc, chambers.
sykotic1
01-05-2005, 01:18 PM
if you're building a serious drag car i have and would always go with iron heads. thats just my prefence, and a lot of the old heds feel the same way.
bigbadbowtie
01-05-2005, 04:45 PM
I have been reading a lot lately on building SBCs and I have found a conflict from two different authors. One author states "the old days of looking for a set of double hump heads are history." In Lingenfelter's book he states that in the realm of iron heads that he likes the 993, 487, 441, 442 heads. Which to my knowledge are the crappy 76cc heads that have the "smog style" chambers. In another book on building SBCs states that one should avoid heads with these style of combustion chambers like the plague. The author stated that one could lose 20-30lbft of torque throughout the entire RPM range and at 5000rpm that's 15 hp. What do you guys think? Old style with the tighter combustion chambers or the newer castings. NOT THE VORTECS. I know vortecs are better.
CORE.. in my opinion what I think the 1st author saying is that there is such a LARGE number of aftermarket/good production heads out there that there is no reason to search for the "Camel Hump" style heads anymore.
The heads you listed in Johns book are indeed SMOG heads.....ok for a driver/tow wagon but not a performer???
I'm with you, its kind of confusing as to what he meant ???????
in my opinion...most any of the aftermarket heads in stock form will outperform the older camel hump heads. Even if you find a set cheap its going to cost you probably more than a new set of heads to have them rebuilt.
CORE.. in my opinion what I think the 1st author saying is that there is such a LARGE number of aftermarket/good production heads out there that there is no reason to search for the "Camel Hump" style heads anymore.
The heads you listed in Johns book are indeed SMOG heads.....ok for a driver/tow wagon but not a performer???
I'm with you, its kind of confusing as to what he meant ???????
in my opinion...most any of the aftermarket heads in stock form will outperform the older camel hump heads. Even if you find a set cheap its going to cost you probably more than a new set of heads to have them rebuilt.
CORE402
01-05-2005, 06:15 PM
I ask this question because in the second book the author stated that, like the new vortec heads, the camel hump heads with their 64cc chamber had better combustion characteristics then the "smog" heads. He even went to state that you can make the smog heads flow really well if you want to but would still have the problem of having the crappy combustion chamber. John Lingenfelter too went to say that a flowbench doesn't tell the whole story. Then again when you visit CHPs website all they use to compare heads is a flowbench. ARGHHHH! Confusing confusing confusing.
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