I've seen the claims, and frankly, I don't believe they are credible for a street driven 500 cfm carb. For a cross-flow 250:-
There are wild claims that infer 282 hp at 5000 rpm, or what could be around 356 hp @ 5000 rpm from a 250 engine. All from the best 2-bbl Ultraflow manifold, and a 500 Holley an avagas.
In terms of specific power for every rev per minute and cubic inch, there is more power than a V8 Supercar. I mean 7500 revs times 302 cubic inches gives 630 hp. If you reduce the power by the difference in the revs (by 7500/5000), and also by the reduction in the cubes (302/250), then you end up with 348 hp. To get 282 hp, you do need at least 350 hp at the flywheel.
Since a stock carb XE or XF shoves about 100 horses to the pavement, 40 hp extra, with a 500 cfm Holley, would be a 180 hp net engine, up from 131 hp net. I've not seen a street 500 do over 180, but there are plenty of other claims of 350 hp from a 500 cfm #4412.
A7M has seen 302 hp or so on a oval track, but still fairly stock, race 250 x-flow with a 500 2-bbl. Not a streeter, not running on pump gas.
350 hp is technically possible with the big 500 2-bbl in a 350 hp V8 sucking huge vacumm rates at wide open throttle, if this is to be believed.
http://www.einfo-net.com/motorsports/brz/spacers/114-dyno.jpg
So does anyone have any info on 2-bbl Holley power levels?
There are wild claims that infer 282 hp at 5000 rpm, or what could be around 356 hp @ 5000 rpm from a 250 engine. All from the best 2-bbl Ultraflow manifold, and a 500 Holley an avagas.
In terms of specific power for every rev per minute and cubic inch, there is more power than a V8 Supercar. I mean 7500 revs times 302 cubic inches gives 630 hp. If you reduce the power by the difference in the revs (by 7500/5000), and also by the reduction in the cubes (302/250), then you end up with 348 hp. To get 282 hp, you do need at least 350 hp at the flywheel.
Since a stock carb XE or XF shoves about 100 horses to the pavement, 40 hp extra, with a 500 cfm Holley, would be a 180 hp net engine, up from 131 hp net. I've not seen a street 500 do over 180, but there are plenty of other claims of 350 hp from a 500 cfm #4412.
A7M has seen 302 hp or so on a oval track, but still fairly stock, race 250 x-flow with a 500 2-bbl. Not a streeter, not running on pump gas.
350 hp is technically possible with the big 500 2-bbl in a 350 hp V8 sucking huge vacumm rates at wide open throttle, if this is to be believed.
http://www.einfo-net.com/motorsports/brz/spacers/114-dyno.jpg
So does anyone have any info on 2-bbl Holley power levels?
