OK guys, I am merely a shade tree mechanic, so I could use some help with my engine refresh.

Here is what I have:

GM Marine Crate Engine from 2001. This is the precursor to the ZZ454. It has the GM performance aluminum rectangle port heads. The previous owner changed the cam out for a Comp Cams Extreme Energy 292 cam and the good roller rockers, roller lifters, and pushrods were used. The forged crank, rods, and pistons are all original to the GM Performance engine.

The engine came with a 9.6 to 1 compression ratio, and I beleive it is still that way. Ihave not tried to have it checked.

I don't think the heads were worked over, because there was no receipt in the paperwork for head work. Just the parts that were used in the build.

The car has the 2 1/8" Hooker side pipe headers. I have replaced the Hooker mufflers with the STS baffles.

It originally had a Muncie 4-speed, which I replaced with a TREMEC TKO600 with the 0.64 OD.

The carb was a Holley 850, but I have upgraded to the FAST EZ-EFI system.

The ignition is a MSD billet distributor wit hthe MSD-6AL box with a 6,000 rev limiter. I am considering the programmable box so I can build a cusotm advance curve.

The origial 10-bolt was a 3.42:1 rear gear, but I have upgraded to a "Super10" 3.73:1 and the heavy duty 30 and 31 spline inner and outer axles from Tom's hardened and built by Gary Ramadei.

As you can see, I have really spared no expense when it came to upgrades on the car since I owned it.

This spring, I am pulling out the motor to freshen up the bearings and rings. While doing this, I want to replace the cam with one made for fuel injeciton, that gets me in the power at lower RPM's than the current 2,500. The car screams between 2,500 and 5,500, but I want it to be a little more manageable at 1,800 and pull all the way to 6,000 RPM. I think the main issue I am having is iwth the lobe separation angle. It is currently 110, and I think it needs to be more like 112 or 114 so the O2 sensor in the collector won't freak out at idle and foul the plugs.

I have $500 in gift certificates for Comp Cams that I want to use for a cutom grind cam and new lifters, springs, and retainers. A lit has improved in spring technology in the past 12 years.

I currently have a GM performance L88 intake manifold, but just ordered the Edelbrock Air Gap intake from Summit Racing with my gift card and free shipping.

I believe one of the issues I have to consider when making any modifications to the motor is the large 2 1/8" primarys on the headers and the super long collectors used with the side pipes. Another issue is the low profile L88 intake manifold. A third is the low compression ratio.

The current motor puts out about 330 RWHP and 415 RWTQ, on the dyno (I think this was a little low becaus of fuel starvation. The A/F ration jumped up when the mtoor revved above 5,500 RPM. I have cleaned a lot of trash out of the fueld pump inlet screen and filter. I am considering a fuel cell with a better pick-up. I currently have a new tank wit hthe stock pick-up. I have removed the sock and am using the fuel pump that came with the FAST system.




Now, this is what I want:

A little more HP and TQ at the rear wheels, low enough compression where I can use pump gas, and a good enough valve train to run to 6,500 RPM and still be in the power curve.

I am on a budget, and plan on doing al lthe R&R work myself, but want someone to re-work the heads, help with the cam selection, and valve spring selection. I can use Comp Cams tech line, but I would love to find a machine shop or engine builder in my area that knows what I am looking for and how to get it.

Any suggestions or experience from you guys out there?

 

As far as cam selection, talk to Chris Straub in Tenn


http://www.straubtechnologies.com

Search for him on the Team Chevelle Performance forum

BILL

 

I second the Straub recommendation. He will want to know the flow numbers on the heads, but will cam you perfectly. Actually the flow numbers for those heads should be readily available.

Bill

 

Thanks, guys. I'll give him a call when I get the specs on the motor.

I am starting the tear-down this weekend. I found a local guy that knows big blocks and he is going to mic the block, crank & pistons and help me with the compression ratio. This beats dropping a bunch of money into some good measuring tools.

The only thing he does not have is a flow bench for the heads. If they have not been modified from the original casts, I can get that informaiton from GM Peorformance.

This is what I have planned for the motor:

1. Port match the heads.
2. New valve job with new springs and retainers.
3. New cam better suited for my driving habbits.
4. Maybe new pistons to increase the compression ratio a bit.
5. Check the pushrods, roller lifters and roller rockers for wear. They have about 15,000 miles on them.
6. De-burr the block inside and out.
7. Balance the crank, rods, and pistons.
8. New rings, seals, bearings, and freeze plugs.