closed chamber BBC heads are the worth messing with

Old 05-25-2007, 12:11 PM
  #1  
Timmyboy86
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Default closed chamber BBC heads are the worth messing with

i might be buying a .030 over 454 with closed chambered heads on it not sure of the casting number says there 66-67 396 heads oval ports the engine has flat tops the guy that built it thinks that makes a 10:1 motor i tried to correct him it's not even 9:1. if i stroked it to a 496 later on down the road it would make 10 with flat tops but just out of curiosity are closed chambered heads on a BBC worth messing with can the support 650 hp?
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Old 05-26-2007, 12:17 PM
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Timmyboy86
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Default casting ##'S

the casting #'s on the heads are 3917215 "junk from what i heard" the cam has 246 .050 and 576 lift he has quoted me 600+ hp i think he might be trying to feed me a story
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Old 05-26-2007, 12:47 PM
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billhendren
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With that small of a cam and that low of a comp ratio I think he is at least 100 H.P.high on his power estimate.Bill
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Old 05-26-2007, 08:34 PM
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Timmyboy86
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Default wow!

i'd be amazed if it made 400
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Old 05-27-2007, 10:14 AM
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edvancedengines
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Timmy,
I will suggest to forget that head. It is a low performance head for early 396.

Instead look for either the Last casting number digit of 049 or 781 in an oval port open chamber head. You can at times find those at a good deal and with little work and some compression can make a lot of power with them. They were used in some of the 1971 to 1974 Truck and passanger car engines. Even with a mild street engine you can easily get 500 hp with hose. In race trim with bigger valves and minor porting with good cam and higher compression in a 454 style engine you can go over 600 hp with those little heads.

Ed
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Old 05-27-2007, 08:28 PM
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Timmyboy86
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what heads do they use on reman engines do they use the smaller yet penut ports? would a factory roller be the way to go? i know a guy with a dually and a 30-40,000 mile crate in it the hole truck can be bought for 2500.

does anyone have an opinon on the myth a roller cam of the same duration will run no faster than a flat tappet.
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Old 05-28-2007, 07:28 AM
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billhendren
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A roller with the same duration @.050 is actually a much larger cam because the acceleration rate of the valve is far faster.if you graphed both cams and overlayed the graph you would see that at .100/.200/.300 up the ramp the valve with the roller cam would be open much farther increasing the air flow and power.Bill
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