383 port size for a truck

[grumpyvette]

What is your take on running a 200cc runner head on a 383 sbc, daily driven truck application. I might occasionally spin it to 5500 and never take it to the track.

I feel a 170-180 cc head would would give me more low speed torque where I spend most of my time. Its just the fact that I found a really good price on some EQ 200cc heads new in the box.

Thanks

I will assume this will use a dual plane intake or fuel injection as a single plane manifold would never be used on an engine that rarely sees north of 5000rpm,I generally use 195cc-215cc heads building a 383, the choice would depend on the cam,compression and intended operational power band,the cam, compression ratio and intake manifold used will all have a greater effect that the port size,and all the factors are easily calculated but I can assure you Id select the 200cc heads well before a 170-180cc even on that application on a 383, unless the cam has 215 @ .050 duration and .500 lift or less and under 9:1 compression, and something like a 2.57:1-3.08:1 rear gear

viewtopic.php?f=52&t=333

GOOD 6" CONNECTING RODS FOR A 383 SBC
http://m.summitracing.com/parts/sca-26000716

viewtopic.php?f=52&t=8460

http://www.rbracing-rsr.com/runnertorquecalc.html

http://www.northernautoparts.com/part/ek-ek1097alb

http://www.wallaceracing.com/max-rpm2.php

http://www.wallaceracing.com/chokepoint.php

 

[grumpyvette]

Nice graphs! I always appreciate your reply. The build is in the planning stage. I have a nice 1pc seal block. Plans are KB 18cc dish pistons. Have decks cut to achieve .038-.042 piston to head. Target CR is 9.6:1. Looking at a hydraulic roller from Bullet that is 266/266 214/214 110 LSA .494 lift at valve with 1.52 rockers. Yes, a dual plane Performer RPM. Using Pat kellys DCR calculator puts me at dead on 8.0

TH350,3.08 gears,28" tall tires

most of the parts selection choices youll make will also be effected by other choices, as does limits on your budget,so if the cam , or intake or headers you select do not have the lift and duration, or flow rates to allow the ports in a killer cylinder head to reach full flow potential youll never get the heads to operate at near their upper potential power levels. with those specs, your quoting, Id personally still select the 200cc heads, you mentioned if your getting a bargain price as you mentioned. but a really good 180-190cc head would be compatible, and as long as you don,t intend to exceed 5000rpm an option, but considering the fact that most cheaper heads don,t flow near the upper flow capacity of the better designs, like the AFR 180cc heads , http://www.airflowresearch.com/index.php?cPath=24_25

notice the 180AFR heads have much better exhaust flow numbers and the aluminum heads by AFR would both weigh less and be easier to repair when damaged plus have less tendency to get into detonation with crappy fuel octane levels
you might want to read this comparison dyno showing what good heads are worth to a build and why the 200cc eq or the 180cc AFR heads will work better than the stock chevy heads
http://www.airflowresearch.com/articles ... 5/A-P1.htm

heres those 200cc EQ heads

Id say sticking to the 200cc ports is the smarter move,here,and the route Id go, without a seconds hesitation, unless your willing to spend the bucks to get the AFR 180cc heads which would marginally outperform the EQ heads in YOUR application, but considering the cost difference those EQ 200 cc heads seem like the way to go here, as you certainly won,t see a easily measurable loss of power in the rpm range your talking about any where but on a dyno


but to be fair here, Ill point out that if your going to spend the cash you have options and the larger 195cc heads from AFR would easily out perform ether option
http://www.airflowresearch.com/index.php?cPath=24_29

AND that one of the better VALUES is the BRODIX 200CC aluminum heads, which respond well to minor port clean-up and provide good power and torque over a mid rpm power band in a 383-406, while costing noticeably less than the AFR heads
http://www.jegs.com/i/Brodix/158/102100 ... ProductId=