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Author Topic:   SBC Iron head shopping, need input
#28
Member
posted February 06, 2002 10:09 AM
FWIW - I like GM's L31 Vortec head on my 6" rod 355. Makes good, solid power even with IMCA's 350cfm carb rule.

In my opinion, cam selection is CRITICAL with any under-carbed motor, such as mine. How big of a carb can you use?

[This message has been edited by istock59 (edited February 06, 2002).]

sdhnc29
Member
posted February 06, 2002 10:27 PM
If your looking at aftermarket heads , the Dart Iron Eagle will be dollar for dollar , your best investment .

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


#28
Member
posted February 07, 2002 12:11 AM
Alky engines like big intake runners !! So I'd use the 230cc Iron Eagles ! With out dyno testing the Victor copy , I'd be scared to try one , there is too much that could be wrong it , and Alky is very sensitive to distribution . Your best would be the 2925 Super Victor . Other than the Dart/Wilson , I think it's the best on the market right now , and I'm not a big fan of Edelbrock components .

As for cam selection , I need to know a little more about you car , track size , and operation RPM range . As with most alky grinds , you will most likely end up with a custom ground cam . Most book cams have too large of split in duration for alky . Let me know some answers to my questions , and I'll give you some numbers to look for .

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


#28
Member
posted February 07, 2002 03:59 PM
I forgot to ask what size engine your running , this head cold is killing me!!! Also , do you want to use a roller or a flat tappet cam ??

With the Iron Eagles on a 355ci , you should look for a cam that is around 258 int/260 ex @ .050" , provided your running a decent compression ratio . The key to alky is exhaust duration . Alky is an extremely slow burning fuel (much slower than gas), and most book type cams will have too much split in duration between intake and exhaust(i.e. , gas type cam) . We found years ago that if you close up the duration when using alky , you will pick up a ton of torque !! This is due to the fact that your keeping the exhaust valve closed longer , thus allowing your slow burning alcohol to complete it's burn cycle . If you pop the exhaust valve too soon .... then you end up blowing all your torque (unburned fuel) out of your exhaust pipes !! A book cam will work for you , but a custom cam with the duration closed up will vastly improve your torque over a book cam ! Most cam grinders will laugh at you when you tell them what you want , most will refuse to grind this type of cam as well . I'll be happy to email some cam specs to you , so you can have something to go by when ordering your cam . I'd suggest using Dave Crower (this is who I use )for your custom cam , he will grind what you want . He also has some book cams that are very close to what you might need . Let me know , and I'll email some spec's to you , I might even be able to give you a few custom grind numbers that we used years ago in California .

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


dirtracers
Member
posted February 14, 2002 08:10 PM
nevermind

[This message has been edited by dirtracers (edited February 14, 2002).]

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