southern69chevy

I'm building a 350 with 062 vortec casting heads, 1.6 magnum rockers, 230/236 .510/.520 lsa 110 hydraulic roller, beehive springs, hurricane intake with a 750 double pumper and 1 5/8 longtube headers. It's getting backed up by a t56 and is going to be a street/strip brawler. So what do ya think...Could I go with a bigger cam and make a little more power with good torque? Oh and I'm using the stock bottom end so anybody have an idea what the compression is going to be around? I was thinking somewhere between 9-9.5:1

ZONES89RS

iTrader: (25)

Should be about 410ish FWHP with that combo, bigger cam? Nope, not unless you up the cubes to 383. That cam is perfect for those heads, a bit more compression could net 10-20 more HP.

fast01

iTrader: (16)

Aren't the vortecs 462's, not 062? Anyway, I'm thinking your compression is around 9.5-9.6ish, provided the pistons are flat tops with 4 reliefs and power to be around 400 at the flywheel. Is the lift you posted rated with 1.5 rockers or adjusted for the 1.6's? I see a problem with your vortec heads either way though. I'm assuming your using aftermarket beehive springs, but if you haven't had the guides machined, you will have guide to retainer clearance issues. In stock form, the vortecs will only take .480" lift before the retainer hits the guide. Be sure to double check this or you will bend pushrods. If it were me, I'd use a vaccum secondary carb if it's gonna see mostly street time. I actually prefer the Carter or Edelbrock carbs on street engines, but that's my personal preference for ease of tuning. Will you make a little more power with a Holley....maybe, but at the expense of being a pita to tune. The only other thing I would consider is some bigger primaries on the headers. The 1 5/8" will make some great torque, but I think 1 3/4" would work better all around and I agree that your cam choice is a good one, provided you correct the clearance issues you're going to have. Good luck!

southern69chevy

I thought the beehive springs took care of the guide to retainer clearence issue?
I believe the specs for the cam are with 1.5 rockers, so the 1.6's will bump it up some.

ZONES89RS

iTrader: (25)

Yea, the 1.6 will ad about .040 lift.

southern69chevy

Effin A Cotton...hell yea lol. Now about the beehive springs, do they not take care of the guide to retainer clearence issue? I was under the impression that they bolted right up and allowed more lift with no issues or machine work...

fast01

iTrader: (16)

You are right (I did some research), they do....to a point. Here is a piece of an article from Car Craft on the issue.

"Recently we ran across another solution. Comp Cams' new "beehive" or conical valvesprings are similar to those used on GM's Gen II production LS1 and LS6 engines. These springs are wound with an ovate, or oval, wire that creates more room for valve lift before the spring reaches coil-bind. In addition, the smaller beehive design reduces the retainer diameter and weight, which helps the spring do a better job of controlling the valve at high rpm. But perhaps the best news of all is that these springs will bolt right onto a stock Vortec head with no machining required. These springs also increase the amount of available valve lift from 0.450 to 0.550 inch. (The spring can accommodate as much as 0.665-inch lift, but when installed at 1.800-inch height, the retainer-to-seal clearance limits lift to slightly more than 0.550 inch.)"

The problem is, with your 1.6 rockers you valve lift will be .544/.555. You generally want more clearance on the exhaust and you've actually exceeded the max lift at installed height. You could probably play with the installed height a bit, but that's going to affect you seat pressure and IMO your taking these springs too close to the edge with the 1.6's anyway. You may want to consider sticking with 1.5's or do 1.6 on the intake and 1.5 on the exhaust, a very common sbc mod.

southern69chevy

Yea I saw that same write up in carcraft. So you think a 1.6 on the intake and 1.5 on the exhaust should be fine?

fast01

iTrader: (16)

Yeah, if you're determined to use the 1.6's, I'd only use them on the intake. If you've already got the 1.6's in hand, try and find someone else in the market for rockers and have them buy the 1.5's then split the sets between you. Like I said, it's very common to do the 1.6/1.5 thing, so I would think you could find someone willing to go along with you. Otherwise, it sounds like a nice combo you've put together. It should make great torque and be a blast to drive. Just watch out for detonation with cast iron heads at that compression. Good luck!

southern69chevy

Yea its the stock bottom end and I dont plan on bumping the compression up to 10:1 or anything. I might slap a little 100 shot every once in awhile, but nothing to radical.

slvr98camaro

iTrader: (1)

i think that compression ratio is a bit small for that cam

i wouldnt run it with less than 10:1

and 462 heads are the old fuelie camel hump heads, not vortec

fast01

iTrader: (16)

You Sir, are correct. I must have had a brain fart when I first read this post. I saw 062 and my brain automatically told me "that can't be right it's 462". My bad, I stand corrected.