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building a new motor

768 views 4 replies 2 participants last post by  hcmengines 
#1 ·
Hi everyone glad to be a board...
 
#2 ·
building a 383 chevy

i am building a chevy 383 motor. Just picked it up to day. I have a forged crank rods and pistons. the pistons are 8.5 to 1 the heads are 202 160 exhaust 64 cc and 210 runners the cam is 525 lift with 228 dur with a center of 112 hyd. I want to put a weiand 177 on it and the builder says it should be 540 to 550 hp. With what i read i thought it would be around 590 hp at 6 grand am i wrong or right what is your thoughts. thanks chris
the rocker arms are 1.6
 
#3 ·
383

Well first, pistons are most likely 8.5 with 76 cc heads and a .038 gasket.
What are the pistons? forged yes? what brand or part #
The company web site will tell you the comp with a .038 gasket. They may use a different piston to deck hight number like .015 or .005, you need to know these things to be accurate.
The piston will have a cc volume, that with the deck hight, gasket thickness and head cc will give you exact number.
If you call JE tech with these numbers they will tell you what you have.
dish piston with 64 cc is more like 9.5 in most cases.
if you limit the boost to say 5 lbs you will make near 11 to 1 under boost.
A 383 with aluminum heads and 10 to 1 comp will make , without a blower 500 HP and 500 lbs torque.
I recommend a hyd roller cam but there is the money factor.
1.6 rockers will give you a little more torque that 1.5 along with the added lift.
 
#5 ·
8.5

Hi
like i said the piston saying 8.5 means little.
If the combustion chamber size of the heads are 64 cc then you will not have 8.5 to 1
KBs are fine, not my favorite.
Buy desk top dyno program if your going to do engines and you can get the true compression ratio using the pin hieght, deck hieght, gasket thickness and head cc.
you can also get very close HP and Torque numbers.
You will enter exhaust, intake, carb, blower,cam etc. you want to use and then compare with other combos.
Do you want max HP? or Torque?
HP is for going fast, top end, where torque is for smoking tires, snapping you back in the seat, thats the idea, there is a more detailed explanations if you wanted it.
 
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