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Old 06-16-2008, 06:33 PM
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sbc horsepower

I'm starting to put together my sbc 350 and was wondering what kind of horsepower i should get ,it's a 350 40 over flat tops 9.5 comp. i had a set of 458642 heads done 202 160 some minor polishing 76cc , a lunati voodoo cam 213/219@50 .454 .468 lift 1.50 roller rockers a edelbrock duel plane air gap intake and a 650 demon carb , my buddys say it'll be a dog i'm just lookin for a strong running motor in my restored 71 c/10 thanks steve

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Old 06-16-2008, 08:58 PM
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Should be a strong motor....I'm not sure about the flow on the heads.

I'd say you would have a good solid 350hp....

Good luck on it....
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Old 06-16-2008, 09:24 PM
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290 HP at best.
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Old 06-16-2008, 09:43 PM
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You might want to do some calculating on that compression ratio. Many flat top pistons rated at 9.5:1 compression are for 64 cc heads. A 76cc head will drop your compression a lot and you very well could end up with a low compression dog.
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Old 06-16-2008, 10:08 PM
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Hi,
This is what I came up with,
HP277@5250 TQ317@3750
Rich
I didn't add the .040 over, I'll do it again
HP282 @5000 TQ326@3500

Last edited by richard stewart 3rd; 06-16-2008 at 10:15 PM.
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Old 06-17-2008, 01:11 PM
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Quote:
Originally Posted by richard stewart 3rd
Hi,
This is what I came up with,
HP277@5250 TQ317@3750
Rich
I didn't add the .040 over, I'll do it again
HP282 @5000 TQ326@3500

As I said. 290 at best.
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Old 06-17-2008, 01:21 PM
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280 is my estimate. Many people with a similar engine will say it's 350 hp; but they're wrong
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Old 06-17-2008, 02:16 PM
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Its all in the heads. With 76cc's you're not getting a really efficient burn. I'd be a little skeptical about the compression too (lots of times they'll say 9.5:1 and that's not really what you end up with). Last, I think 2.02 valves are a little aggressive for the size cam you have, but they'll work.

The easiest thing you could do would be a head upgrade in the future. Personally I'd go with a 383 or 400, 9.5:1 compression (assuming iron heads) would be great about perfect.

I like your cam or something similar for a larger-cube smallblock truck motor. You'll get a good off-idle dig which would be really nice.

In any case, best of luck!

K
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Old 06-17-2008, 02:35 PM
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2.02s are a bit big for your cam but they'll work.As said.
The Goodwrench motor with the 216/228@050 Crane Powermax made 298Hp through closed 2 1/2" pipe. Thats 7.8:1 compression and 1.94s
Figure with 2.02s and a slightly smaller cam should average about the same but with less lowend due to your bigger valves.

The big valves and lower compression may suck a bit of lowend out but if you have a 3 series gear you should be OK.
As far as the heads they aren't the greatest but for a street driver they should be fine IMO...Acording to the rest of the world though,nobody ever made 300Hp out of a SBC till the creation of aftermarket heads and credit cards BS.
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Old 06-17-2008, 02:38 PM
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I didn't see headers on your list of parts. You need them to make power. Small tube would be best.

That cam is too big if you are running a stock converter and a 3.08 gear. I would drop about 8 degrees of duration if you have a 3.08 gear (typical 71 c10 gear). Trucks are heavy so you need to use a little less cam than a car with the same engine and gears.

However, that cam would run ok with a 3.42-3.55 gear and a 2000 stall. Should run much better than a stock 71 350 truck engine (185hp).
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Old 06-17-2008, 04:00 PM
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thanks

thanks everyone to answer a few of the answers, i have a 700r 4 with overdrive tranny 3.73 rears and i've been thinking of aluminum heads but a little short on cash and credit right now, for some reason my woman had to have heat and a/c instead of a nice 383 stroker ,so i'm doing what i can to get back into the hot rod game. it's been about 15 years since i've been able to afford and have time to do this thanks all . steve
p.s. i thought headers were a givin...

Last edited by hdscooters; 06-17-2008 at 04:01 PM. Reason: heeaders
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Old 06-17-2008, 04:36 PM
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I think it will run just fine. With a 3.73 gear and that ultra low first gear in the 700r, it should be able to get out of it's own way without any problems.
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