quote:Originally posted by ehpantera:
...Using 4V heads, will stuffing the ports be benificial...
Only if you are employing an intake manifold designed for stuffed ports like the Parker Funnel Web. With the strip dominator, no. I personally like a good flowing dual plane manifold for road racing, better pull out of tight corners.
quote:...At what displacement does this become counter productive...
Its necessary & beneficial for any displacement when you are employing the Parker FW. I know of a 427 Clevor using iron heads with stuffers and the Parker Funnel Web making 750 bhp at 7200 rpm. You can bet the heads are ported quite a bit. The iron 4V head is a good head, but not well understood these days. The 4V port is not as big as the entrance would lead you to believe. But if you're going to fill the bottom of the port, that loss in cross-section has to be made up somewhere else. this is stuff you don't normally hear about.
quote:...Is it practicle to regrind the existing crank and use chev rods or should I buy a stroker crank...
Stroker displacements are quoted assuming a 0.030" over bore. 377 = 3.70" stroke, 383 = 3.75" stroke, 393 = 3.85" crank. The 3.75" & 3.85" cranks are available over the counter, the 3.70" crank is an offset-ground oem cast iron crank. I'm not a big fan of stroker kits & street tires. But whatever your plans, the over the counter crank gives you the option of selecting a forged steel version, which I think makes sense in your application. Consider a sportsman crank.
quote:...Cast or Forged...
Since you have a 7000 rpm goal and since you plan to run Open Road Races I say buy the extra insurance and use the forged sportsman crank.
quote:...Billett main caps...
Cleveland caps are not a weak link. I would consider that over kill in your application if the block has four bolt mains. The ProGram caps are used by builders to convert 2 bolt main blocks into 4 bolt mains, they make perfect sense in that application.
Adjusting valve lash in the Pantera engine bay is a bit like laying on a bed of nails. It looks painful but everybody will assume you are a holy man! Hydraulic roller lifters are heavy and pose a challenge to run at higher rpm. To do that with the Z06 'Vette Chevy resorted to titanium valves and bee hive valve springs. Achieving those RPMs will be easier with a solid roller. A solid roller grind with "street lobes" (similar to hydraulic roller lobes) and bushing type tappets can be configured to survive street use and will not require any more adjustment than a hydraulic roller.quote:...I tend to lean towards a hyd. roller cam. Suggestions ...
quote:...I don't see much written about gear driven cams, are there any quiet ones for the Cleveland...
Dunno. They sound cool in someone else's car. But they'd be a pain in the arse to live with. I've never seen a race team run a gear drive, I've always assumed this is because gear drives consume more horsepower than chain drives. I recommend a RollMaster timing chain set.
quote:...Would a 393 hold well considering my RPM requirements...
I'd recommend a 383. I wouldn't go bigger than 3.75" stroke due to rod to stroke ratio and piston speed.
Use a very good set of I beam con-rods, use endurance style racing pistons (stronger than drag pistons, lighter than street pistons), you'll want a lightened crank, a light weight flywheel, a good quality balancer (Romac or ATI) and dynamically balance the reciprocating assembly. Be sure to set the oil system up properly too. The more precise you can build the motor, the more durable it will be. Details like cc'ing each combustion chamber & piston clearance to insure identical compression ratios in each cylinder will stress the motor less and help it survive. Tuning the motor as precisely as possible (i.e. on a dyno) is also a necessity to help the motor stress itself as little as possible and survive hard use.
cowboy from hell