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Old 07-27-2016, 10:48 AM
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I'm looking into stroking my 502 to 540ci with forged internals, Lower the CR to approx 7.5-8 :1 and add a 871 Blower on top !!!!
Im looking for 750 to 800 HP motor
Im using my dart iron eagle heads and cam is a 525efi cam
I cruise alot at 3500 RPM and when I go full throttle its only for a couple minutes
Here are my questions ....
Can I run on 89 octane with 5 to 6 psi of boost ????
If yes what CR would I need to run 89 octane ???
Twin 750 carbs or 850s ????
Is 800 Hp possible ?????
I dont plan on spinning the motor past 5400 RPM !!!!!!!!!
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Old 07-27-2016, 01:48 PM
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i'm no expert but what i've seen in builds in person, I know that what you are looking for on that build/ compression a 540 around 5-6psi you do need to run 93. also would have to go bigger fuel to get closer to 800 im thinking. and if you aren't running past 5400 I doubt you'll see that number id say closer to 700-720hp at 5400rpm if you were to spin 6000 I would say you'd be closer to 750-800.
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Old 07-27-2016, 05:02 PM
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Have a 509 with 8-71, two Demon 850's, Underdriven to 6+ or 7 lbs of boost. Would have to look at dyno sheet, but was about 830 HP. Only ran 94+ fuel
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Last edited by Gordo; 07-27-2016 at 05:06 PM.
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Old 07-27-2016, 05:22 PM
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Looking for 750-800HP? No problem.

Icdedppl's 540's made really close to 900hp, on two different dynos. Dart iron eagles, 10-71 blower, 8lbs boost on dyno. Crane 139651 camshaft. At 5500rpm, it was making about 840ish. Nothing exotic, iron heads, shelf pistons, shelf cam, shelf carbs, etc.

750-800 is very doable with your combo, even with the smaller cam and 871. Actually, you can do it with the 509 combo.

Go with the 850 carbs.

Last edited by MILD THUNDER; 07-27-2016 at 05:25 PM.
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Old 07-28-2016, 05:34 AM
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Thanks Guys I appritiate the info
Here in Malta at the Marina we only have 89 octane unfortunately
I think ill be better of and more reliable with a 9:1 CR big cube N/A motor to run 89 safely like a 598 or 632 and make impressive torque without spinning the motor past 5400 rpm
Not sure what road to take .....
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Old 07-28-2016, 05:37 AM
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Plus since I raised my Engine 3 inches to raise the X, I dont have any room left in my 29 scarab !!!!! I checked yesterday and the Air cleaner is a half inch below the hatch so the blower with carbs on top will be extremly high so I cant go much higher and I hate scoops
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