reporting and resizing heads- how much hp gain?
12-12-2006, 09:45 PM
#11
Re: reporting and resizing heads- how much hp gain?
Originally Posted by wiggler4490
have now spoke with 3 excellent engine builders and it seems this is a great choice to gain hp for the $, extra 250-300hp will push 7-10mph on my top end, thanks
CMI Big 2 1/8" tubes. All CMI are big .....but in three different sizes.
Last edited by 3600cat; 12-12-2006 at 09:49 PM.
12-13-2006, 08:30 AM
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Re: reporting and resizing heads- how much hp gain?
Originally Posted by JimV
It depends on the head castings and cam. 600 inches is a lot of motor to feed. It's going to need a lot of airflow going in and out. A big mistake a lot of builders make is to install a cnc generic exhaust port on a big inch motor. The best to my knowledge every head manufacturer has numerous choices for volume and valve sizes on the intake side. I don't know of any options on the exhaust side. Keep in mind most of the aftermarket heads were designed for drag racing back when a 500 inch motor was big cubic inches. You have a great start with the big tubes but you will need a high flowing exhaust port to take advantage of them. Crap, I gotta go ill finish later
JIM V
12-13-2006, 09:58 AM
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Re: reporting and resizing heads- how much hp gain?
If these are recent Ron Potter built engines I believe he was using Brodix 3XTRA CNC. I don't know what is done to the heads already, but as JimV said the exhaust can likely use some help, especially on a supercharged engine. If you tear the engines down this far you can find out what cam and see if different cam timing would help. You are only looking for a 10 % increase in power. Don't know about your pricing but doesn't sound like it includes the R&R.
12-13-2006, 01:32 PM
#16
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Re: reporting and resizing heads- how much hp gain?
I find it hard to beleave they can give you 100hp from just porting your head ,knowing that there probaly good to start with.
What does a normal port job cost that would make a HP differance? not by someone/most people just hacking on it making it look pretty.
I know some of the super stock drag racers pay 3000-9000 to do a set of stock heads for that class.
What does a normal port job cost that would make a HP differance? not by someone/most people just hacking on it making it look pretty.
I know some of the super stock drag racers pay 3000-9000 to do a set of stock heads for that class.
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12-13-2006, 07:22 PM
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Re: reporting and resizing heads- how much hp gain?
according to nortech, the 50v takes 30hp/1mph gain, I think the intercooler, porting and 6 lbs boost will get me where I want it at 115mph+.
01-25-2007, 09:57 PM
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Re: reporting and resizing heads- how much hp gain?
01-25-2007, 11:41 PM
#19
Re: reporting and resizing heads- how much hp gain?
rob
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01-26-2007, 01:11 AM
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Re: reporting and resizing heads- how much hp gain?
Wind up the boost, wont it acheive the same thing. 4 pounds is not much. we run 9 with no real worries. Our engine guy did hog the exaust ports on the 512 with a 8-71 and it made a hell of a difference. Not 100HP though. I would definatly work the exaust, not the intake so much and wind the boost and maaybe play with cam timing some. One more thing, do the exaust ports and the NOISE, its glourious! Jas
