vortec heads on carb engine

[dusty82]

hey guys, i just picked up set of vortec heads for my 383, got them for right price, question is do i need to have them machined? im going to be running a 507/510 lift cam, ive been told yes i need to machine for anything over .450? and ive been told no just run proper springs for cam? whats the real deal for them?

[JoshTheCanadian]

for the amount of lift you have.

http://www.summitracing.com/search/Department/Tools-Shop-Equipment/Brand/COMP-Cams/Part-Type/Valve-Spring-Seat-Cutters/?Ns=Rank|Asc

Do it yourself with one of these comp tools.

I ran new comp springs with .480 lift and im fine.

[Stroked385]

Yes they need to be machined for that lift.
www.chevyhiperformance.com/howto/97458/index.html

[dusty82]

right now im running same cam as you josh the xe268, so your saying i can just flip my springs from old heads to vortecs and im set? my cam swap im gonna do with xe284 with 507/510 wont be for while but for time bein i can run them as is with spring i run now?

[randeez]

vortec heads don't have the clearance from the valve seat to the retainer.
so you need to either:
run the comp cams beehive springs(26915 or 26918) AND their retainers (787) which will cost you about $240ish when i got mine
or
get the valve seats machined down or you can buy the tool to diy

[dusty82]

ok makes sense now, next question is i run 1.6 crane roller rockers fully rollerized, i do i need taller valve covers then stock ones?

[randeez]

with 1.6rrs you'll want to open up the pushrod holes in the heads- you may not NEED to do this..but better to do with heads off, instead of putting them on then realizing you need to

and i'd imagine most 1.6s you'll need taller valve covers over .500 lift

[04SilveradoMykk]

The rockers need to be self aligning, vortecs don't have pushrod guide plates unless you pull each stud and machine for screw in studs (which would be recommended anyways, screw in studs... not guideplates). You would also need to make sure the rockers are narrow body to clear the valve cover hold down bolts. Most aftermarket self aligning rockers use polylocks and would need tall valve covers

[dusty82]

yes thats what the plan is i think is get them all machined, possible hogging out for 202 valves, but defently screw in studs, ill look for set of tall valve covers as well, my rockers should work aswell..

[JoshTheCanadian]

im using the these springs with comp retainers and locks, no problems

http://cgi.ebay.ca/Comp-Cams-981-16-Valve-Springs-Set-Of-16-SBC-350-Z28_W0QQitemZ220600213944QQcmdZViewItemQQptZMotors _Car_Truck_Parts_Accessories?hash=item335ccc21b8

[randeez]

you're right at .480 with that cam(in sig) and 1.5rockers

also with that being said, from what i've read vortecs don't like much more then .500 lift in either case, flow starts falling off

[dusty82]

is my new cam too big for these head?

[randeez]

should be fine ..if not stick shift ,just stall pretty high and gears would be a good idea

[dusty82]

mines got a nv3500 5spd manual haha

[dusty82]

last question guys, tmw will be head swap day i as posted before i thought i had the xe268 cam in my 383 right now, i was wrong its just a rv cam, can i run heads straight up or do i need to flip springs from heads i run now?

[04SilveradoMykk]

last question guys, tmw will be head swap day i as posted before i thought i had the xe268 cam in my 383 right now, i was wrong its just a rv cam, can i run heads straight up or do i need to flip springs from heads i run now?

I really couldn't imagine an "RV' cam pushing the lift limits of stock vortecs. But specs would be nice.

[dusty82]

i wish i had specs, when i pulled timing set today to look for part number it didn't have anything must be on other end of cam, my builder that picked it dosn't remember seein engine was built 2 years ago now, but told me its nothing special just an RV cam, melling as far as he new, he said lift wasnt very high from what he could remember, my 1.6 rockers made most of lift he told me, so im thinkin maybe .470ish maybe.. sry mykk thats best i can do with out pulling it right out

[dusty82]

my rpm range starts at about 1500-5500 if that helps

[maxkroll]

i built a 355 for my dad with vortec heads and thought id be okay cuze the cam is only a RV cam with a .210 duration and .440 intake and exhaust lift,stock 1.5 rockers, had the motor still on the stand adjusting the valves and went to turn it over and the springs "tinged" and also bent some push rods.. this is crane cams energy i believe part # 100042.some where i read they don't take as much as everybody thinks, this proved that article right

[woody80z28]

My heads are machined for my lift, but I've heard good things about the beehive springs.

[04SilveradoMykk]

i built a 355 for my dad with vortec heads and thought id be okay cuze the cam is only a RV cam with a .210 duration and .440 intake and exhaust lift,stock 1.5 rockers, had the motor still on the stand adjusting the valves and went to turn it over and the springs "tinged" and also bent some push rods..

How many turns past zero lash did you go with the hydraulic lifters?

[xch3no2]

Maxkroll: Hmm I would say most of us are thinking that ain't right.
Dusty: You want to top the guides & lengthen the pushrod slots, that just makes sense. If not now likely in future upgrades.
Woody: Just think what that Beretta would do with the Camaro's engine...I got some parts,.. luv frame is just right (currently retired), I've already run it to 10.teens on 355 cubes.

[woody80z28]

Maxkroll: Hmm I would say most of us are thinking that ain't right.
Dusty: You want to top the guides & lengthen the pushrod slots, that just makes sense. If not now likely in future upgrades.
Woody: Just think what that Beretta would do with the Camaro's engine...I got some parts,.. luv frame is just right (currently retired), I've already run it to 10.teens on 355 cubes.
I thought about building a tube-chassis RWD with my last Beretta...just didnt have the place to do it.