This is going to be strictly a street car. Weeknights and weekends, very little freeway driving. Anything wrong with this 383 combo in my 1967 Camaro?

350 block, 2-bolt with studs and windage tray.
Scat 9000 cast steel 3.75” crank.
Scat 5.7” I-Beam rods with the cap screws.
Keith Black hypereutectic pistons: KB253, lightweight flat tops, +7cc.
AFR 190cc heads, 74cc chambers.
AFR matching intake, AFR ProFlow.
Compcams, XR282HR, part no. 12-432-8.
Harland Sharpe aluminum roller rockers, 1.5 ratio.

Roughly 450-500 HP and Torque.

With .039 gasket thickness and 4.166 gasket bore and 0 piston to deck clearance, I calculated:
9.74 Static Compression and 7.7 Dynamic Compression and .039 Quench.

TH350, but I might spend some more to get the 200r4.
2200-2400 stall converter.
12-bolt posi with 3.31 gears (original).
15x8 rims, with 255/60R15 tires, 27”.

What do you guys think for a street car? Should I change this to 6.0” rods? 1.6 ratio rockers? 1.6/1.5 combo? Different Cam? Newer Eaton posi unit and newer axles?

Thanks, guys.

Should go with a bit more gear. (373)
I'd spend some money on porting the heads if you want 500+HP (get 300+cfm, and open then up a bit)
And dont forget a good fuel & exhaust system. It should be good for some 11s easy if you can get it to hook.

i shouldn't port the heads. THe AFR 's are very good heads, the best !
with the 195 AFR, you'll build up torque. I 'd go with the XE274 instead of the bigger cam. SO you'll get max power in the 5500 range. and 500 lb of torque . and 450 HP
It all depend on what you want. if you want less torque/more HP, go with the bigger cam, even the bigger 210 cc heads... but i wouldn't.

Otherwise, i 'd use 1.6 roller rockers.

Oh yes ... If torque is what matter for you, the 3.31 gears is the best.
If you want more RPM/less torque (bigger cam and bigger heads cc) go with higher gears.

Question 1: Why would you port and already CNC ported head? If your going to spend the money on porting, find a different aluminum head and have somone port them.
Question 2: Why go with the smaller cam? The 383 will make plenty of torque no matter how you build it, and who cares if you have to spin it to 6200 or so.

Id go with the 6" rod if you havent bought parts. And remember there are more companies out there than "comp" Also checkout the Brodix RR200, its a new head of theres i just bought some for my 350.

Yeah, no need to port those AFR heads. I tried looking for those Brodix heads, but there was no info on their website.

So I would want to use the 6.0" rods, because they will make my engine rev a little higher and it puts less pressure on the walls?

Not really because they rev higher but because it increases piston dwell. With a 5.7 rod your piston dwells at TDC about 1-2 degrees, with a 6.0 rod it sits there for 9-10 degrees. This is somthing of alot of debate and youll hear different sides to it.

Originally posted by Novaguy73:
Not really because they rev higher but because it increases piston dwell. With a 5.7 rod your piston dwells at TDC about 1-2 degrees, with a 6.0 rod it sits there for 9-10 degrees. This is somthing of alot of debate and youll hear different sides to it. There's not really any debate to this, it's a geometry problem. The 5.7 and 6.0 rods stay at TDC for exactly the same time. If you consider the difference between piston positions at 15° from TDC, the difference is .0011", probably less than your machining tolerances for the deck. At 30°, the difference is .0039", at 90° it's .016", not very much difference at all.

Oneofakind....im simply quoting Smokey Yunick from his power secrets book, who in my opinion probably forgot more than any 5 of us ever knew, not saying that you dont know anything but i gotta go with the legend on this one.

Neofaguy,
I didn't say anything about power production or who has forgotten a lot, just that the difference in rod length doesn't make much difference in piston position near the top of the stroke. Whether you are Smokey Yunick or a Local Yokal, the calculations will come out the same.

Don't bother porting the heads.

5.7" rods are fine. .3" just isn't enough difference to worry about on a street engine.

Everything looks real good to me. You could get away with just a hair more converter, like 2500. Same with the gear but 3.31 is a decent ratio for what you are building IMO.

What would putting 1.6 rockers in do for this street engine? How come some people use 1.6 intake and 1.5 exhaust?

i thnk you'll gain something with the 1.6 roller rockers, bith intake and exhaust.

I think the 6" rod is better. i read an article, i 'll try to find it again to show to you. It statre that because of the geometry with the smaller 5.7 rod you get more stress on the rod (the angle it makes with the piston dell is wider -sorry my english vocabulary men :confused: ) but anyway it is a angle issue between the piston and the conneting rod. Also because of that increased angle, the power the piston have when getting down isn't so well given to the rod.

i guess it is that ... I think.

Marc

http://www.rustpuppy.org/rodstudy.htm