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Can anyone guess how much horsepower I'll Have?

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Old May 10, 2007 | 06:58 PM
  #1  
stevenb's Avatar
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Joined: Mar 2007
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From: Michigan
Car: 87 camaro
Engine: 357 swap
Transmission: t5
Axle/Gears: 3.42
Can anyone guess how much horsepower I'll Have?

1987 Chevy Camaro Berl.


1978 Carb 350 SB bore .40 over (i think thats about a 357)
Holley 750 Double Pumper Carb
Edelbrock Performer Alum. Intake
World Sportsman 2 Heads with 1.60 int and 2.02 exhaust valves
Alum. Roller Rockers
.40 Flat Top Pistons with 4 valve release
Stock Crank
Stock block
Gear Drive
Edelbrock Fuel Pump
Hooker Shorty Pro Comp Headers
2.5-3" Exhaust (havent put on yet so not sure)
5 speed manual transmission
16lb Flywheel
Stock Clutch

Cam Specs:
DUR @ .50 244(INT) 244(EXH)
VALVE LIFT .510(INT) .510(EXH)
LOBE SEP 107(INT) 109 (EXH)
LASH HOT HYD.

B=16=07

I assume that I either have not given enough detail or it is not possible to just guess or assume what it is going to be. If there is anything else really important I have missed tell me and Ill know what it is. Thanks for you help
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Old May 10, 2007 | 08:19 PM
  #2  
84z28350's Avatar
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Joined: Aug 2005
Posts: 3,004
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From: Yellowknife, NWT, Canada
Car: 84 Z28
Engine: 357
Transmission: TH-350C
Axle/Gears: 3.43
Re: Can anyone guess how much horsepower I'll Have?

should be pumping out numbers somewhere in the high 300s @ the flywheel, maybe low 300s at the wheels.
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Old May 10, 2007 | 08:31 PM
  #3  
stevenb's Avatar
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Joined: Mar 2007
Posts: 270
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From: Michigan
Car: 87 camaro
Engine: 357 swap
Transmission: t5
Axle/Gears: 3.42
Re: Can anyone guess how much horsepower I'll Have?

Thanks for your help...my father is a mech and estimated about 375hp at the wheels. Will it make a huge diff in horsepower if I were to go with a heavier flywheel around 30lbs
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Old May 10, 2007 | 08:59 PM
  #4  
5678TA's Avatar
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Joined: May 2006
Posts: 1,857
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From: Maui, Hawaii
Car: 1984 Trans Am
Engine: broken 385sbc
Transmission: G-Force rebuilt T-5
Axle/Gears: Currie 9" Ford 4.30:1
Re: Can anyone guess how much horsepower I'll Have?

i believe a heavier flywheel will give more torque.. i know its better for launchin on slicks.. so the motor wont bog down from the minimal rotating mass of a 16lbs flywheel.. you know what kind of compression its making?? if its around 10.5:1 then i say 350+rwhp..
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Old May 10, 2007 | 09:58 PM
  #5  
stevenb's Avatar
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Joined: Mar 2007
Posts: 270
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From: Michigan
Car: 87 camaro
Engine: 357 swap
Transmission: t5
Axle/Gears: 3.42
Re: Can anyone guess how much horsepower I'll Have?

9-9.5:1 i think

Well how much will flat top with 4 valve release?
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Old May 10, 2007 | 10:47 PM
  #6  
5678TA's Avatar
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Joined: May 2006
Posts: 1,857
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From: Maui, Hawaii
Car: 1984 Trans Am
Engine: broken 385sbc
Transmission: G-Force rebuilt T-5
Axle/Gears: Currie 9" Ford 4.30:1
Re: Can anyone guess how much horsepower I'll Have?

hmmm.. i'll reclaim my guess to 300+rwhp.. but you never know.. i would say you are around 9-9.5 like you guessed..
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Old May 10, 2007 | 10:52 PM
  #7  
84z28350's Avatar
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Joined: Aug 2005
Posts: 3,004
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From: Yellowknife, NWT, Canada
Car: 84 Z28
Engine: 357
Transmission: TH-350C
Axle/Gears: 3.43
Re: Can anyone guess how much horsepower I'll Have?

You really have to know alot of specs to figure out a compression ratio...

Got the part number on those pistons? or at least know the cc's of its valve releifs?

Whats the cc's of the chambers on those heads?

Which head gasket are you running?

Has the block been decked? if so, how much?



Just a ballpark guess is all you can get without that info. The typical flattop 350 works out to be in the mid to high 9:1s
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Old May 10, 2007 | 11:30 PM
  #8  
rhamm1320's Avatar
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Re: Can anyone guess how much horsepower I'll Have?

Here is the dyno simulations. Looks good, keep in mind these are the flywheel numbers.



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Old May 10, 2007 | 11:31 PM
  #9  
5678TA's Avatar
Supreme Member
 
Joined: May 2006
Posts: 1,857
Likes: 0
From: Maui, Hawaii
Car: 1984 Trans Am
Engine: broken 385sbc
Transmission: G-Force rebuilt T-5
Axle/Gears: Currie 9" Ford 4.30:1
Re: Can anyone guess how much horsepower I'll Have?

ok this is assuming not much has been done to the block besides boring..

stock deck height= piston .025" in the hole
4.03" bore
3.48" stroke
your basic felpro head gasket 4.166"x.041"
i looked on summit for 4valve relief pistons and the largest is 11cc
and assumming the sportsman 2 heads are 64cc

i get 9.140:1 compression.. so this is basically the lowest it should be.. say you have a smaller head gasket, or valve reliefs that are less cc's or a slightly decked block, etc. etc.. it will only get higher.. unless you are using 72cc heads then you are looking at 8.472:1 and up..
----------
wow i guess someone beat me.. hey rhamm1320, do you think you could run my motor through that dyno sim?? all my specs are in my vBGarage

Last edited by 5678TA; May 10, 2007 at 11:33 PM. Reason: Automerged Doublepost
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Old May 11, 2007 | 03:14 PM
  #10  
stevenb's Avatar
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Joined: Mar 2007
Posts: 270
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From: Michigan
Car: 87 camaro
Engine: 357 swap
Transmission: t5
Axle/Gears: 3.42
Re: Can anyone guess how much horsepower I'll Have?

hmmm so around 300 at the wheels....but I mean theres a lot of things that could change that such as with the tuning of my carb right?
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