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Discussion Starter #1
can anyone do a desktop dyno for me? i have a 383 stroker cast iron crank, hypereutectic flat top pistons, 882 heads (64cc,1.94 intake), 268 xtreme energy cam, performer intake, holley 750 carb, crane hi6 ignition system. all this in an '81 monte carlo, 700r4, 8.5inch 3.73 posi, B&M ratchet shifter. is this a good setup? should i change anything that wouldn't cost a great deal, or should this combo create significant power? any info would be very much appreciated. thanx
 

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Everything looks good to me. Watch the compression ratio though - My input has the deck height on the block cut 0.025". With this and 383 inches and 64cc heads - Compression Ratio is over 11:1

Also I ran with a Mallory ignition, will not make a power difference from what you have - I just didn't take time to add it to my database.



 

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Discussion Starter #3
Thanks for the input, RHamm1320. About the compression ratio, I ran these same heads on my 350, would they give a higher ratio on the 383? On the 350 I was able to run on 87 octane. How do I decrease compression without changing heads? Thicker gaskets? What type? How thick? Will throttle response be flat at top end with this combo, and should I try to increase horsepower? Thanks for your time and help.
 

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I think your combo looks great. As for the compression ratio, the extra cubes of the 383 over the 350 will definately increase the ratio.

Best bet is to cc your heads and manually calculate. There are alot of assumptions with the dyno simulators (true deck height of the block after machining, valve relief cc's, etc). The best the computer can do is let you know you are getting into a 'range' that you better check closer.

You can definately get a thicker head gasket. I had to do this on my last engine for piston to head clearence (I had zero deck, piston top came exactly level with deck). Still best bet is do the measuring before spending any $$ though.
 

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Discussion Starter #5
could you possibly show me the results with these specs:
engine-383
block-4-bolt mains
crank-stock 400 ground to 350 specs
rods-stock 5.7inch
pistons-TRW hypereutectic flat top
cam-268 xtreme energy comp cam
rockers-stock GM
heads-441 casting (73cc/1.94/1.50)?
intake-edelbrock performer
carb-holley 750 single pump, vacuum secondary
exhaust-flowmaster 3 chamber, headers
ignition-crane hi6
timing-initial 12deg/total 34deg
driver weight-190
car weight-3400

thanks for your time and help.
 
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