I'm new to this forum and I am currently in the process of having my first high performance motor rebuilt. I purchased a 1971 camaro with a 400 this summer. The motor ran but had bad rings and valve seals so it is currently at engine builders torned down. I'm new to this so sorry in advance if i'm hacking some of the specs and terms.

Here's the specs:

1971 Camaro Standard with a vinyl top- Split bumber (someone removed the full front bumper and installed the split).

the motor was a 409 sb and had all parts below but was 14:1 compression and had a solid roller cam that was apparently so agressive the powerband was 4,500-8,500 rpm.

HONED- 400 Bow Tie small block bored 40 over- 409 sb
Eagle Forged crankshaft
6" Rods
NEW-Keith Black Forged Pistons- 10.5:1
NEW-Competiton Cams Hydraulic Roller-I believe a .3 duration- .6 lift
NEW Roller lifters
FRESHENED- Brodix 11X Aluminum Spread Bore Heads-Spread Port Exhasut
I was told these heads are usually used on late model dirt track and drag cars so they aren't the most ideal for street use do to the high rpm power range. Meaning I needed to have a large cam to get all the power out of them.
Weiand Team G Intake
MSD Ignition
NEW 850 Holley DBL Pumper

Headman Spread Port Long tube Headers- 1" 7/8"- 3 1/2 collector
Flowmaster 3" exhaust down spouts before the axle

Turbo 350- we suspect the stall is 3,500-4,000

12 Bolt Moser rearend posi- 4:11

He is thinking somewhere between 540-575 hp and around 600lb feet of torque on 92 octane.

I would be curious to your feedback on if my engine builder is going in the right direction?? He was referred to me by a close friend who knows him very well. Thanks for your help!

 

This is a race car? based on those specs your going to have no street manors. Your going to go from runs like crap to ludacris speed with almost nothing in between. My biggest worry would be the heads and the stall your going to need. Maybe this guy has build motors like this before? Circle track cars start from a roll most a designed with a very small power band. We used to use 6400-7200 RPM. That is where we dynoed the motor, that was all we cared about. Coming out of the corner and the end of the straight away.

Maybe this guy has all the bugs worked out of this setup but on paper I would not be impressed I am sure the motor will Dyno real nice.

 

This is a weekend cruiser and I'll bring to the strip for fun. But almost all street.

I was told with the 11x heads won't have much for low end power and the higher stall will be very necessary he said it will be a 3,500-7k power band. I already had the heads and to save money (looks to be about 1,500 for comparable heads) to just use the ones I have. Was that a bad call? Should i sell the heads and buy different aluminum heads?

Do you think the cam is extreme?

 

Have you ever driven a car that needs to be over 5K just to run good? Are you really trying to build a 550hp based on throwing together parts you have and hoping they work? To design a engine you need a Plan. To say if I put these parts together what will I have is a beginners mistake. building a race engine is easy compaired to building a fast street engine. You need to decide on what you want from the car and then talk an engine builder about those goals. You do not want to guess. You would need to know how the heads flow in order to pick the best cam. Of course you need to decide where you want your power also. If the Cam does not match the heads the car will not run great and any RPM but if the heads are to large the air charge will be to slow until you hit high RPMs. This why there are so many steps or varition in after market heads. You need to design everything at once.

If you are looking for over 500 streetable HP you really should look at fuel injection or even a LSx type motor. It really is up to you and what your think is streetable. I have seen a dozen time, guy think they know what they want they buy all the high end racing parts only to redo the motor within 2 years to make it more street friendly. My friends are older now and fighting with a car trying to get it to pull out smoothly or have all kinds of problem cause you get caught in a 2 hour traffic jam is not fun.

 

Thanks for the advice.The engine builder works on a lot of drag and dirt track motors. And he thinks the motor came right out of a dirt track car with over 600hp and we are trying to tame for the street. This is likely something I will put in the car and sell mid summer. I bought it for a steal of a deal.

He told me that he has been talking with Comp Cam for a realistic cam street/strip cam for this setup (I may be way off on the cam) and we may need to change out the stall (we don't know what converter is in it). He told me it is not the ideal set up but will still run hard with rough street manners. I appreciate your insight, thanks!

 

When I use to build circle track motor we just built the same motor comfiguration each time. We where hitting 540-550 HP 20 year ago. I had access to "used parts" I never got any. The block/crank would have been the most usable cause it was a classic 383 design but block damage was the main reason for swapping out motors so there was never spare blocks around. I would never tried to street any of the other parts.

Sell your heads and get a nice matched set Heads/cam I am sure Comp Cams or any other good cam manufacture can recommend nice setup at or near 500 HP that will be lower RPM friendly which in turn will make a much more drivable car. Heck with that bottom end setup you could build a very tame 400 HP motor and go nuts on the exhaust and add a 200 shot for track runs.

 

Okay I this is the cam we will be using:
Comp Cams #249-01-426-8
Xtreme Energy™ XR294HR Hydraulic Roller Camshaft
Lift: .540"/.560"
Duration: 294/300
RPM Range: 2800-6400

Anybody have experience running this cam??? I spoke with my engine builder and he said this will be totally streetable with this cam. It's aggresive but will still idle fine.