I have a ZZ502 in a 71, the cam is the stock ZZ502 hydraulic roller.
The intake is the stock ZZ502 , ignition is all MSD Electronic.
I have a Holley 850 double pumper, which i intend to use.

Here are my questions:

1. I will upgrade the cam. What would give me the most grunt down low but not kill driveablility (would prefer hydraulic cam)

2. How do i increase the RPM limit from the current 5800 to 6500 RPM?

3. Intake?

4. Springs?

I'm willing to spend 2000-3000$ on upgrading the engine.

If anyone's got some advice, it'd be appreciated.

 

You have a great basic combo...just needs some tweeking. Short block is fine.

The Edelbrock/GM oval ports can work well. They really respond to some basic cleanup and port work. I'd pull them and have them milled to 100cc...just like Edlebrock does with the EFI/Truck version of those heads. That will get you some compression. Not enough...but better than you have.

Cam is the next biggee. Budget for some new decent lifters. Use Morel brand or Crane...they are most likely to help you get some RPM. Plus they can handle the increased lift that the GM ones can't. You need to think about lift in the mid .600's and some duration. I'm not a hyd roller fan....and it's a fine line with big blocks. The valvetrain is heavy and doesn't like to RPM. Some folks love the beehive springs...but it's only a single spring and if something happens..not much to hold it all together. Either way, plan on some titanium retainers and springs to match cam. Most likely in the 375-400# range over the nose. Seat pressure in the 150# range.....of course it all depends on the cam. There are some cams that make power..but often are noisy. The *gentler* lobes...still big..but as fast opening are more likely to rev. 6500 is edgy territory and will take a good combo. I've seen to Voodoo hyd's spin into the 6200-6400 range. The Crane Marine type cams can RPM well...but may not have the *snap* of the Voodoo's or Comp Xtreme lobes.

Your intake is basically a Performer. Not bad and depending onhood clearance may be best for you.


JIM

 

Thanks, Jim.

What do you think of this For 502 B/B Chevy (Gen V/VI) - 611 hp & 573 ft/lbs. w/ hydraulic roller cam
Performance results obtained on a 502 Gen V shortblock w/ 9.6:1 compression. #2094
POWER PACKAGE TOP-END KIT #2094 611 HP/573 LB-FT OF TORQUE INCLUDES:
Part No. Description
2262 Performer RPM Hydraulic Roller Cam for Late-Model Blocks
77489 (2) Victor Jr. 24° Rectangular Port Cylinder Heads, complete
6997 Timing Cover Gasket and Seal Set
7376 Cylinder Head Gasket Set
2902 Victor Jr. 454-R intake manifold
8564 Intake Manifold Bolt Kit
8554 Cylinder Head Bolt Set

I have a L88 hood.
Would this fit under the hood?

Best regards, TJ.

 

Why to change the heads..if you do and have dollars go AFR CNC 315

 

TJ,

It would help to know what your goal is with the motor to give you better advice. Also it would help to know what transmission you're using - and if it's an automatic, what's the converter stall speed - and what your rear-end gear ratio is.

But if your only goal is to increase your RPM capabilities (much past 6000 RPM), you probably should consider going to a solid roller instead of using a hydraulic roller again. Like Jim said, the valve train is just too heavy to RPM very well. I had real problems with my 427 CI motor above 6200 RPM using a hydraulic roller, and I tried everything (EVERYTHING!) to make it perform better including changing springs numerous times (both rate and style), trying different rocker arm ratios, which also required different push rod lengths, and ran lash loops for every configuration...but nothing made much difference. And in the end a spring broke and it sucked a valve, and well...it just wasn't a good outcome.

As far as the Edelbrock Package you're considering:

HEADS - You have a good set of heads...and personally, I wouldn't change them.

INTAKE - Changing to an Air Gap RPM (+ .775" taller) or a Victor Jr. (+1.45" taller) is required for 6500 RPM. I've had really good luck with both, but prefer the Victor Jr. on bigger cubic inch engines because of better flow at higher RPM. But of course it's taller too. Either way you'll need to measure to see if either manifold will fit.

CAM - An RPM cam wouldn't be a bad choice. But if it was me, I'd call Comp Cams 'CAM HELP Line' (800.999.0853), tell them what you have and what you want to accomplish...and just ask for their recommendation. They're great and they can do more for you than anyone on here. They'll be able to tell you what your maximum lift can be with the current heads/pistons, so you won't have any interference issues. And you can ask them to recommend a set of springs, retainers and locks at the same time if they don't think the current ones will work.

CARBURETOR - I don't think 850 CFM will be enough, but you can try it and always get a bigger carb later if you don't like how it performs. Ideally, if you know someone with a 900-950 CFM, ask if you can borrow it and see how the new combo responds before spending the additional money. But based on what I know so far I think a 950 CFM unit is in your future.

Anyway, that's my $.02.

Good Luck.

...Jerry

 

That package doesn't do that much for me. *IF* I was going to change heads.....and it's not entirely necessary.....I'd do as mentioned and go for some AFR's...or at the least some Brodix Race Rites. The Edelbrock cams are not the strongest. They work...but leave a lot of performance on the table.

The Vic Jr will likely require a little work to fit. They have a *flat* carb flange..whereas intakes like the Strip Dominator from Holley are angled similar to stock. You can do some milling on intake and make it work...and the Vic JR IS one of the best out there. The RPM Air Gap will do well also....what it makes on the bottom it will give up on the top. But if you insist on HR cam..then it will be fine because you won't be revving too high.

JIM

 

Could you please describe a little more about the ..."little work to fit.?"
Also, what on the intake needs milling?

Thanks

 

You will need to mill the carb pad at an angle to lower the front part of the carb similar to how stock intakes do to clear the hood. The best way is to weld the bolt holes up and drill and tap new holes on the *new* angle. Not hard to do for a machine shop.

Otherwise all is good. Several folks here have done it. Ck with Mark....ML67...he did the one on his 540 to fit under the C-2 hood.

You don't even want to know how I got a Super Victor under my hood!


JIM

 

Yeah, getting a tall intake to fit under a stock hood is a pain. And of course cutting the intake down defetes a good portion of the purpose of using a high(er)-rise intake manifold in the first place. (That's what they make tall hoods for ) It all comes down to how much pain you're willing to endure to go fast.

 

Thanks

 

I'd like to see the answer also, don't think anyone did. Will the Victor Jr. 454-R fit under an L88 hood? The Victor carb flange is 5.9 inches above the manifold base. Or what about the Air Gap it's flange is 4.45 inchs at the distrib end and 6.0 inches at the front of the engine. Anyone have any experience with either manifolds under a L88 hood? Also, I think I read some place that there's a version of an L88 hood made that's higher than stock, anyone got some info on that? Thanks!!!

 

No, a stock Vic jr. will not fit under an L88 hood unless the pad is milled with the back to front slope. The best single plane to use under an L88 hood is a Holley 300-5 Strip Dominator. It has the correct slope. I am using one with my L88 hood. A modified Vic jr. is a better intake though.

Bill

 

Ditto what '69ttop502 said...

You can use an OLD style Weiand Team G, a Holley Strip Dominator, most of the dual planes, the old C-396,C-400, C-427 and C-454 Edelbrocks, an old Tarantula or Torker (sideways carb).

The Vic Jr's and most of the newer race style intakes have the carb pad flat and not angled as stock type intakes do and don't fit.


Jim

 

Thanks for the above info. BTW I had a Tarantula on my L88 clone engine and the Tarantula was a perfect fit with the L88 hood and air box. I was impressed with the power the engine had.

 

I have aftermarket L-88 hood in a 1973 and the intake is World Products single plane and it fits...

And 850cfm is good until some 650hp, when tunes and choke tower etc stripped...may steel litte power like 10-15hp compared to 1000cfm but thats not bad

 

Thanks for all good answers, I have now ordered Edelbrook top end kit.
Hopefully it will work, I will post some pictures of the results when I'm finished.

Trond

 

I have to share some updates with you, guys. I have just installed my Edelbrock top end kit. And I have been on dyno, it produced 605 hp.
I'm very happy with that, I have installed a serpentine system.
What do you think, guys? I want to add some pictures when it's finished.

 

Hi! Is thar hp at the wheels?
And did you have to modify the front crossmember to get the serpentine pulley system to fit if any??

 

Which top-end kit did you go with? Did you get the one you were originally looking at?

 

hp at the wheels?


yes and the hp at the crank.

TJ