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500efi converted to carb and blower cam help

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500efi converted to carb and blower cam help

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Old 10-09-2017, 03:47 PM
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Default 500efi converted to carb and blower cam help

Hey guys so I sold off my complete fuel injection setups from my 500efi motors and putting blowershop billet 250 blowers on with single dominator carbs. Looking at going to a bigger camshaft. Possible along the lines of the crane 651. Any other camshafts that would work well in this setup. Shooting for around 675hp. It's gotta sound nasty so factor that in. I only put about 25hrs on a season. Farming gets in the way. Any help would be great.
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Old 10-09-2017, 06:23 PM
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651 very good proven cam on 540 NA and SC. My first reaction is it might be a tad big on a 502. 741 might be worth looking at and again works extremely well NA and SC.

What heads and exhaust are you running. Also what do you plan to run for boost. Sounds like you have two engines and probably not what you want to here however you might consider getting dual plates and carbs for all around better fuel distribution and power.

741 cam sounds nice but don't let a cams sound dictate your build unless it's going in a muscle car going to the drive in theater on Saturday nights only. Trust me I know what your thinking but...

When u can answer above questions. I personally wouldn't go more than a 741 on that build. That's plenty of cam. That's the beauty of going SC is you don't need a lot of cam and alleviates premature valvetrain issues. Check with mild thunder and maybe he'll let he used in his blown 468's with 420 MB's.

If you don't have blowers and carbs etc you could stroke them and get near same power. Where's the static CR at currently?
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Old 10-09-2017, 07:48 PM
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i agree with getrdunn,crane 168741 would be a good cam choice,an 8.71 with a pair of holley or quickfuel supercharger carbs will produce much better results and be easier to tune.with this much cam a dry exhaust is a must.
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Old 10-09-2017, 08:59 PM
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X3 on the 741 cam
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Old 10-09-2017, 09:07 PM
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Using the factory cmi headers and 088 heads. I may just keep the factory 500efi camshaft. Dollar for dollar at the end of the day the gain from that cam to the 741 shouldn't be a whole lot. And all my valvetrain is currently in mint shape. Thanks for the replies!
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Old 10-09-2017, 09:17 PM
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Tune it horribly and you'll get plenty of lope and blower surge.
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Old 10-09-2017, 10:51 PM
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The 500 efi cam is a nice little upgrade for a 454 / 177 sc.
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Old 10-13-2017, 07:29 PM
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ill have a 250/256 merc unit for sale in the spring
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Old 10-14-2017, 07:49 AM
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Originally Posted by Kichler
Using the factory cmi headers and 088 heads. I may just keep the factory 500efi camshaft. Dollar for dollar at the end of the day the gain from that cam to the 741 shouldn't be a whole lot. And all my valvetrain is currently in mint shape. Thanks for the replies!
You'd better consider stepping up the valve springs at least, now that you'll be "Boosted" just my $.002
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Old 10-20-2017, 04:29 PM
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I am running a 236/245 114 LSA cam in my 468's. The 741 is a 236/244 112 LSA .

Your biggest power killer would be the heads, and the small blower. Buddy had an engine like yours . 509ci with merlin iron heads, 250 B&M blower , cam similar to 5000EFI cam. Made just under 700hp.
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