[BMFZZ502]

I am need some advice on picking a new Hyd. Roller for the 502. This will be street driven and will have a 150 N20 plat system.

The engine is at the machine shop getting freshened up.

Block is being decked to zero

New Scat Forged Rods

GM Performance Aluminum Heads flat milled 0.030 to bump comp to 10:1 and pocket porting/valve job.

Honing Cylinders new bearings and new rings

Edlebrock Air Gap

850 DP Black Diamond Quick Fuel Carb.

Note: From what I have read I need to watch out for the lift because of the stock lifters??

Any Suggestions??

[vinniekq2]

didnt like the stock cam?,,,,540?

[BMFZZ502]

Just trying to make more power.

[vinniekq2]

camshaft is a small part of the engine

[hcompton]

Start here with the cams you are thinking about including your stock cam.

On order to reach the numbers your looking for the dcr will need to be spot on for your type of fuel. You will find ypur stock cam had a conservative dcr for street driving. You will need to push the envelope a little further the rpms up higher and the push the compression up.

You will need to get the lift up i am assuming you have big valve heads. If not might as well get that sorted out now.

I will usally look for the max rpm my engine can take and then work on the compression ratio until i can support the desired rpms and still meet my other needs.

http://www.kb-silvolite.com/calc.php?action=comp

[35WINDOW]

I think it all depends on how much hp/tq you are looking for-if those are the stock aluminum GM heads, they were made by Edelbrock (look at their part#60459-the GM head has a 2.25" valve in it, otherwise the same)-

If you are leaving the compression alone (?), and using the GM heads, I think you have a couple of choices:

1. Use the stock GM Cam
2. Use the Cam Edelbrock has designed for this Head (which will dictate new Lifters):

Performance Camshafts, Lifter Kits and Matching Valvetrain from Edelbrock - Cam Card Locator

3. depending on how serious you are, you could contact a custom cam designer (someone like Mike Jones):

HOME

4. buy an "off-the-shelf" cam (which can be hit or miss sometimes, depending on the skill of the selectee)-

I would certainly (at the very least) have the Springs checked (you will probably have to replace them)-

One thing leads to another, and pretty soon you are building a custom engine-watch out! Horsepower is addicting!

[ap72]

Originally Posted by 35WINDOW

I think it all depends on how much hp/tq you are looking for-if those are the stock aluminum GM heads, they were made by Edelbrock (look at their part#60459-the GM head has a 2.25" valve in it, otherwise the same)-

If you are leaving the compression alone (?), and using the GM heads, I think you have a couple of choices:

1. Use the stock GM Cam
2. Use the Cam Edelbrock has designed for this Head (which will dictate new Lifters):

Performance Camshafts, Lifter Kits and Matching Valvetrain from Edelbrock - Cam Card Locator

3. depending on how serious you are, you could contact a custom cam designer (someone like Mike Jones):

HOME

4. buy an "off-the-shelf" cam (which can be hit or miss sometimes, depending on the skill of the selectee)-

I would certainly (at the very least) have the Springs checked (you will probably have to replace them)-

One thing leads to another, and pretty soon you are building a custom engine-watch out! Horsepower is addicting!

Edelbrock doesn't design any cams, they're just reboxed white label cams, many "off the shelf" cams will do better than their stuff.

As for springs, I would assume you'll probably need them and should be considered as part of the cost of a cam swap. There are plenty of good cam guys out there, Mike Jones is good, as is Isky, Lunati, etc. For the relatively little cost difference I would go with a custom spec'd cam over a shelf stock cam. You can't go wrong with Jones, and he'll probably steer you towards PAC springs to go with your cam.

[35WINDOW]

Originally Posted by ap72

Edelbrock doesn't design any cams, they're just reboxed white label cams, many "off the shelf" cams will do better than their stuff.

You are absoluely correct, and I mis-spoke-I should have said the Cam that Edelbrock supplies as part of the "Power Package" for those Heads-I won't disagree that the Edelbrock Cam isn't great (I'm an Isky guy myself), but it is one of the options-

[BMFZZ502]

Thanks for the responses!

The heads are now pocket ported and milled. With the block decked I should be close to 10.3:1 with 0.040 head gasket. Thinking of using Comps XR294HR OR XR288HR Cams.

[vinniekq2]

are those part numbers correct?

[cdminter59]

The XR294HR camshaft is a extreme energy cam and also has another part# for Nitrous use. XR288HR Part# 01-421-8 XR294HR Part# 01-424-8 XR294HR Part# 01-426-8 (Nitrous)