bbc heads
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Re: bbc heads
The 990s will "make more power".
About 90 - 95% of all cars that have ever had them, have gone slower than with something else.
At low RPMs the square ports are all-around worse. Their virtues don't show themselves until very high RPMs, and the RPM where they turn from a net loss to a net gain depends greatly on motor size. At anything less than about 6500 RPM in a 454, they hurt overall performance.
In general, this is one of those things where if you have to ask, you don't need to go there, besides just curiosity. The physics will beat the romantic 60s hot-rodder lore every time.
About 90 - 95% of all cars that have ever had them, have gone slower than with something else.
At low RPMs the square ports are all-around worse. Their virtues don't show themselves until very high RPMs, and the RPM where they turn from a net loss to a net gain depends greatly on motor size. At anything less than about 6500 RPM in a 454, they hurt overall performance.
In general, this is one of those things where if you have to ask, you don't need to go there, besides just curiosity. The physics will beat the romantic 60s hot-rodder lore every time.
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From: loxahatchee fla
Re: bbc heads
http://maliburacing.com/patrick_budd_article.htm
you might find this link above worth reading thru
and Id also point out that there are far better heads available than either of those listed factory big block head castings
TRICKFLOW,BRODIX,AIR FLOW RESEARCH and PROFILER all produce far better heads, any of the better aftermarket heads matched to the correct compression ratio, cam, timing, intake type,and rear gear ratio can easily produce 70-90 hp more than untouched factory castings, and both the factory cast heads and aftermarket heads can be significantly improved with careful port work
you might find this link above worth reading thru
and Id also point out that there are far better heads available than either of those listed factory big block head castings
TRICKFLOW,BRODIX,AIR FLOW RESEARCH and PROFILER all produce far better heads, any of the better aftermarket heads matched to the correct compression ratio, cam, timing, intake type,and rear gear ratio can easily produce 70-90 hp more than untouched factory castings, and both the factory cast heads and aftermarket heads can be significantly improved with careful port work
Last edited by grumpyvette; Nov 30, 2011 at 07:11 AM.
Thread Starter
Junior Member
Joined: Nov 2011
Posts: 4
Likes: 0
Re: bbc heads
The 990s will "make more power".
About 90 - 95% of all cars that have ever had them, have gone slower than with something else.
At low RPMs the square ports are all-around worse. Their virtues don't show themselves until very high RPMs, and the RPM where they turn from a net loss to a net gain depends greatly on motor size. At anything less than about 6500 RPM in a 454, they hurt overall performance.
In general, this is one of those things where if you have to ask, you don't need to go there, besides just curiosity. The physics will beat the romantic 60s hot-rodder lore every time.
About 90 - 95% of all cars that have ever had them, have gone slower than with something else.
At low RPMs the square ports are all-around worse. Their virtues don't show themselves until very high RPMs, and the RPM where they turn from a net loss to a net gain depends greatly on motor size. At anything less than about 6500 RPM in a 454, they hurt overall performance.
In general, this is one of those things where if you have to ask, you don't need to go there, besides just curiosity. The physics will beat the romantic 60s hot-rodder lore every time.
screw square ports... thanx man Thread Starter
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Joined: Nov 2011
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Re: bbc heads
http://maliburacing.com/patrick_budd_article.htm
you might find this link above worth reading thru
and Id also point out that there are far better heads available than either of those listed factory big block head castings
TRICKFLOW,BRODIX,AIR FLOW RESEARCH and PROFILER all produce far better heads, any of the better aftermarket heads matched to the correct compression ratio, cam, timing, intake type,and rear gear ratio can easily produce 70-90 hp more than untouched factory castings, and both the factory cast heads and aftermarket heads can be significantly improved with careful port work
you might find this link above worth reading thru
and Id also point out that there are far better heads available than either of those listed factory big block head castings
TRICKFLOW,BRODIX,AIR FLOW RESEARCH and PROFILER all produce far better heads, any of the better aftermarket heads matched to the correct compression ratio, cam, timing, intake type,and rear gear ratio can easily produce 70-90 hp more than untouched factory castings, and both the factory cast heads and aftermarket heads can be significantly improved with careful port work
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Re: bbc heads
Your 781's are perfect for that. You'll lose power if you try that with 990 heads. The 2.19/1.88 valves with some port work will make a big difference over the stock heads.
My engine uses rectangular port heads but the operating range is 6200-7500+
My engine uses rectangular port heads but the operating range is 6200-7500+
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Re: bbc heads
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