Irockz

iTrader: (1)

Hey all,I have little experiance with these heads,so I thought I'd ask for some thoughts on what I'm doing.
Shortblock:.060 over 350,steel crank,early pink rods,older set of TRW forged slugs,.125 dome.Cam is a Reed custom grind that I got for a song,was actually ground for a dragboat,but I liked the #s.It's a straight pattern .549 lift at the valve,246* duration at .050 lift,106* centerline.It is a balnced assembly,old stuff but all checked out,rods sized,and back in with fresh rings/bearings.Cam is new,as well as the chain/gears.
I bought a set of vortec heads,still 1.94/1.50 valve size,Manley valves,machined with screw in studs/guideplates,pockets opened up for 1.47 springs,I pulled them apart and machine shop magged them and I'm crack free.
My question is,as small as the intake ports are on these,am I stacking apples onto an orange,or can they work?I've used them on mild engines many times,but I don't know what their limits are.I know they are not ideal,but it's a bracket car that I will be spraying a mild shot to for grudge matches,and my end goal is for another bigblock car,so what's everyones thoughts on this combo,topped off with a proffesional products single plane and a 750 quickfuel E 85 carb?Let er' rip,fellas.

Atilla the Fun

Stop right there, older dome pistons will not work with the Vortec combustion chambers. The quench pad extending between the valves will hit the piston dome. If you modify the heads, you get close to water, and lose much of the fast-burn, while if the pistons don't have solid domes, you risk killing them. Even so, you would be around 11:1, and that's just not worthwhile.
vortec heads have great potential, but if you're keeping those pistons, you'll need some old (and crappy) design of heads. Most any decent head will have the extended quench pad, and these chambers all work best with flat-tops, not domes. Domes are obsolete. A better way to get 11:1, if that's what you want, is to stroke it to a 388, and use 64cc aluminum heads.

Irockz

iTrader: (1)

I have plenty of experiance with checking clearences,and I have a mill,so it will be doable.Yes,these are heavy old solid dome pistons.
My question is in regard to how well these heads work at RPMs over 5000 or so.All of the engines I have built using the vortecs were fairly mild,and more of a street engine.What I'm saying is,I have the stuff,I can make it work,how will it perform?

Atilla the Fun

Even with large cams, vortect on 350s are all done around 6000 rpm, if you do cam them big enough to get the HP to peak at 6500, you've given up so much midrange you'll hurt your 1/4 mile times. If you'll mostly be pulling above 2500 rpm, look into a 195cc-200cc head like Dart's Platinum-series.