SBC Horsepower estimate

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wilson1970
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SBC Horsepower estimate

Post by wilson1970 » Sun Aug 13, 2017 5:43 pm

What could I expect for power levels with ths combo? 355 SBC zero deck, 10.5 compression, .597 lift 236/242@.050. Hydraulic roller, Sportman 11 heads with some port work, stud girdle, Rpm Air Gap intake, 750 HP carb. Thanks for info.

redliner
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Re: SBC Horsepower estimate

Post by redliner » Sun Aug 13, 2017 5:45 pm

400h.p.

wilson1970
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Re: SBC Horsepower estimate

Post by wilson1970 » Sun Aug 13, 2017 5:52 pm

Would a rev kit help in this application.

redliner
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Re: SBC Horsepower estimate

Post by redliner » Sun Aug 13, 2017 8:21 pm

A rev kit will not increase performance but does help keep roller tappets on the cam....

wilson1970
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Re: SBC Horsepower estimate

Post by wilson1970 » Sun Aug 13, 2017 8:46 pm

I was hoping for 450. Regardless it should be a decent little street engine.

Frankshaft
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Re: SBC Horsepower estimate

Post by Frankshaft » Sun Aug 13, 2017 9:27 pm

I would guesstimate 440hp, and 435 ft/lbs. Its possible you will make 450hp

lefty o
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Re: SBC Horsepower estimate

Post by lefty o » Sun Aug 13, 2017 10:06 pm

id say 425-450, needs a bit more duration to really get numbers. a lot depends on exactly what "some port work" is.

wilson1970
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Re: SBC Horsepower estimate

Post by wilson1970 » Mon Aug 14, 2017 6:41 am

We kept duration a little conservative. Wanting to use A/C and power brakes. 2004r and keep stall around 3000 with 3.73 gear.

mag2555
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Re: SBC Horsepower estimate

Post by mag2555 » Mon Aug 14, 2017 6:48 am

Those out of the box heads flow 240 something Intake cfm @.600" lift, I figure you will average about 220 cfm which could let you make 450 hp tops , but you should make no less the 420hp if you get a good tune into the motor.

The wild card here is the port work, if by bowl porting you net say 250 cfm@ .600" then you should have 450 hp to play with under your right foot!

wilson1970
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Re: SBC Horsepower estimate

Post by wilson1970 » Mon Aug 14, 2017 7:15 am

I know they arent stellar by any means. I bought these heads 20 years ago and at the time best that I could afford.
Had a .557 lift .256/.264@.050 flat tappet in it before. 9" converter with 4.10 gear. It ran really strong. Back in the day.

lefty o
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Re: SBC Horsepower estimate

Post by lefty o » Mon Aug 14, 2017 10:07 am

wilson1970 wrote:I know they arent stellar by any means. I bought these heads 20 years ago and at the time best that I could afford.
Had a .557 lift .256/.264@.050 flat tappet in it before. 9" converter with 4.10 gear. It ran really strong. Back in the day.
those heads make darned good power on a street 350 with some porting. they were, and are a good head for the money. time may have passed them by some, but they make power.

Frankshaft
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Re: SBC Horsepower estimate

Post by Frankshaft » Mon Aug 14, 2017 10:22 am

World Sportsman 2's. The Rodney Dangerfield of cylinder heads, they get no respect. They can make big power, I made over 700 with them in 1999. They can and do make power. They also make more power than their flow numbers would suggest, as cast, or mildly modified. I remember reading an article in one of the magazines back around that time, late 90's, early 2000, that world had made like 600,000 pairs of them, back then. They can't be that terrible. I also read back about then, edelbrock made 1800 heads per day. That was then, now, only one could imagine.

wilson1970
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Re: SBC Horsepower estimate

Post by wilson1970 » Mon Aug 14, 2017 10:58 am

Nice to hear a few words of encouragement. Excited on getting the thing back together over the winter and in the car.
Those are crazy numbers on the amount of heads that were made.

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Re: SBC Horsepower estimate

Post by wilson1970 » Mon Aug 14, 2017 11:58 am

Has anyone else built a similar combination with the Sporman 11 heads? Happy with the results?

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Re: SBC Horsepower estimate

Post by 6.50camaro » Mon Aug 14, 2017 6:14 pm

I known you asked for builds with the same heads. I had similar built 350 but with as cast 205cc Brownfield heads that flowed close to what the Sportsmen II heads do without a little work. Stock 4" bore 3.50 ,stroke cola crank, 6.125 rods ,Icon forged pistons 11 to 1 comp., edelbrock rollin thunder hyd. roller cam 234°/238° @.050 .538 in .549 ex w/1. 5 rockers but I used 1.65 in 1.6 ex rockers giving .592 in. and . 586 ex at the valve edelbrock performer rpm air gap intake, 750 Holley DP w/ aftermarket HP body . 1-3/4 " headers , 2-1/2" X pipe exhaust , Pypes 2-1/2" M-80 mufflers turn downs in front rear axle . Th 400 transmission 3600-3800 stall 10" converter, 4.56 gears , Hoosier QuickTime Pro DOT slicks. Thru the mufflers I got into 7. 50's in the 1/8th@around 92 mph w /1.70 60', before I pulled that motor at the end of the year. 72 camaro, cal Trac bars w/ landrum parabolic mono leaf spring in back. moroso trick springs up front koni shocks all round 3250lbs at the line. Hope this is what you are looking for .This is my first post on ST . Dan

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