340 Piston to valve clearance w/RHS heads

dodge freak said

i don't get the logic, you want high flowing heads yet aren't going to spin it past 6,000? A basic rebuild J heads with 2.02 intakes could flow past 6,500 rpm's.

Now the Chevy boy's do run .030 quench, so maybe it be fine but too close for my comfy level. The old Mopar bible claim .060 was min.

Click to expand...

Just because a head can support 6500 rpm doesn't mean that I'm setting everything else up to work best at that rpm level. Good head flow should help everywhere. Like I said, getting the J heads cut with a valve job, spring pockets machined, decks trued, and CC's down far enough to get a true 9.5 to 10:1 compression with a standard gasket, $800 in machine work + springs+retainers+valves...getting awfully close to the price for the RHS heads, and in the end, the J heads would still be inferior.

You get pretty much zero quench effect at 0.060" clearance.

I'm trying to build an engine that has good streetability, hence the lower RPM range.

Not that I use it at a bible, but my planned combo looks damn good in desktop dyno 2000. The extra head flow seems to help everywhere.

This is the results dyno 2000 gave me.

RPM HP TQ
2000 146 384
2500 192 403
3000 241 422
3500 294 441
4000 346 454
4500 390 455
5000 422 443
5500 440 420
6000 430 377
6500 412 332