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Old 09-25-2005, 05:56 PM
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picking the right cam for a 383

i am in the process of building my first 383 stroker. any help with choosing the right cam would be a great help.current parts include
350 4 bolt block
performer rpm air gap intake
stroker crank
h beam 5.7 rods
64cc gm heads 2.02 intake 1.60 exhaust
11.5-1 dome top pistons
1.5 roller rockers
750 cfm thunder series carb

I am looking to run a solid lift cam.The car will be run on the street very little. Its basiclly going to be a toy

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Old 09-25-2005, 07:13 PM
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cam selection

What kind of vehicle is this going in ? auto or stick? and what rear gears? This will further help in your selection.
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Old 09-25-2005, 07:30 PM
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1983 z 28 camaro with a 700r4 trans b and m shift kit 2800 stall and 3.73 gears with a posi
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Old 09-25-2005, 07:50 PM
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picking the right cam

Thats a lot of comp for a little bit of stall. But i would recomend comps xs282s but it would be better to go with a 3000-3500 stall. the specs are adv. dur-282/290 dur@.050-244/252 lift-520/540 lsa-110
Hope this helps.
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Old 09-25-2005, 08:24 PM
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Are your heads iron? It sounds to me that you are running a sky high compression ratio. 64cc with domes on a 383 will probably make race gas a necessity. Assuming you have a standard block (decked to .025" clearance), and standard .039" head gasket, and even a conservative 10cc dome, you are looking at around 12.5:1, there's no way in hell that will work. I'd best be looking at changing to flat tops with a 5cc valve relief or even a dish piston to make this a more pump gas compatible engine. The flat tops with 5cc valve reliefs will give you about 10.5:1 CR, about the ragged edge of pump gas compatibility with iron heads (11:1 with aluminum).

Just thought you should know this beforehand.

You cam will be dependent on how well your heads flow and the RPM range you plan on running this engine. We will be able to give you a more suitable cam selection if we know what type of heads you have on this motor. As a guess, I would say something with a 245-250 duration at .050 would make the most power while remaining streetable, considering your higher stall, compression ratio, and rear gears. 383's can take a slightly more radical cam and still behave similar to the benchmark 350 they use when making cam recommendations.
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Old 09-25-2005, 08:46 PM
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Quote:
Originally Posted by Mad Maggot
Are your heads iron? It sounds to me that you are running a sky high compression ratio. 64cc with domes on a 383 will probably make race gas a necessity. Assuming you have a standard block (decked to .025" clearance), and standard .039" head gasket, and even a conservative 10cc dome, you are looking at around 12.5:1, there's no way in hell that will work. I'd best be looking at changing to flat tops with a 5cc valve relief or even a dish piston to make this a more pump gas compatible engine. The flat tops with 5cc valve reliefs will give you about 10.5:1 CR, about the ragged edge of pump gas compatibility with iron heads (11:1 with aluminum).

Just thought you should know this beforehand.

You cam will be dependent on how well your heads flow and the RPM range you plan on running this engine. We will be able to give you a more suitable cam selection if we know what type of heads you have on this motor. As a guess, I would say something with a 245-250 duration at .050 would make the most power while remaining streetable, considering your higher stall, compression ratio, and rear gears. 383's can take a slightly more radical cam and still behave similar to the benchmark 350 they use when making cam recommendations.
That sums it up/..........
Flow test your heads and cam according to the numbers.
keeping in mine of usage (of car)and compression ratio
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Old 09-25-2005, 10:33 PM
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I would run a cam with at least 240o duration @ .050". Get it with as much lift as you can for the given duration. A 110o or a 112o lobe sep. will work well.
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Old 09-26-2005, 06:28 PM
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yes the heads are iron sorry for not giving enough info. also the block is stock and i will run factory head gaskets. the pistons are only a 3.5 cc dome, 11.5 comp ratio w 64cc heads 10.2 with 70cc. Will the smaller dome make a differance? I will run race fuel if i must but the car is just a toy so it will be ok
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Old 09-26-2005, 06:30 PM
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hey 1969 nova thanx for the cam specs sounds good. by any chance do u know the rpm range, i was on comps site but could not find rpm range. also is this a flat tappet cam
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Old 09-26-2005, 08:49 PM
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cam specs

the rpm range is 2400-6800 and its a solid flat tappet. you would see alot more power if you switch to a solid roller like an xr280r. its specs are adv. dur-280/286 dur. @.050-242/248 lift-570/576 lsa-110 rpm range-2500-6500. roller are more pricey but make more power. But if your heads cant keep up it is just a waste of money.
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