Cam Selection

[Boosted Baron]

I'm getting the final pieces together for my 2.5 build and was wondering what cam you guys would recommend. Here's a rundown of the setup.

2.5 CB .020 over

forged bottom end

ported big valve 782 head
Lift
.100 78
.200 132
.300 168
.400 194
.500 211
.600 216
.650 216
.700 216
.750 216

port matched intake, 52mm TB, TBI header, Turbonetics TO4E Super 50 .63 A/R Stage 3 wheel, supporting fuel mods, SDS engine management.

The motor is going in a gutted Omni with an A 413 trans. I was thinking about one of Steve M.'s cams, but not sure. Also, what RPMs would you guys think this would be running at?

[cordes]

With the proper valve train mods, it should be able to spin pretty high. I know of a couple of guys on the board that have heads which flow that much, and they are going past 7K. I think they are both running taft S3 cams.

That thing should scream when you get it all together.

[John B]

What gearing and how much boost?

[Boosted Baron]

Boost will be 28-30 psi.

Gearing and convertor are still up in the air. Any input on those would be appreciated too. I'm just trying to get everything working together before I go out and buy this stuff.

[Frank]

I'm getting the final pieces together for my 2.5 build and was wondering what cam you guys would recommend. Here's a rundown of the setup.

2.5 CB .020 over

forged bottom end

ported big valve 782 head
Lift
.100 78
.200 132
.300 168
.400 194
.500 211
.600 216
.650 216
.700 216
.750 216

port matched intake, 52mm TB, TBI header, Turbonetics TO4E Super 50 .63 A/R Stage 3 wheel, supporting fuel mods, SDS engine management.

The motor is going in a gutted Omni with an A 413 trans. I was thinking about one of Steve M.'s cams, but not sure. Also, what RPMs would you guys think this would be running at?

Steve Menegon CAM in a heart beat.

[John B]

OK, Frank's vote is in! I say it depends on whether you are going to "grunt" off the line or "buzz" out of the gate. At high boost (like you will use) there's reason to recommend a cam with tighter timing. On the other hand, with the stage 3 wheel you are going to need to turn up some RPMs to use the sweet spot for that turbo. If we had more gearing choices available it would be a lot easier to decide.

[Frank]

With a head like that, factoring in the StageIII wheel wont be much of a player. that is a good setup with tall gearing 413 in an Omni... good combo. I think you will need the tallest gearing and tires you need. You will probably run out of turbo just past 25-27psi. Of course your HP will be nearing 400whp. Not bad.

[glhs875]

I've been finding out that as more and more flow is achieved from the 8V head and combo, that good power in fairly high rpm's (7000+) can be made even with stock cams. I never did really find out at what rpm the S3 cam would actually pull to. I was running into valve float at 7400 to 7600rpm with that cam. I'm upgrading the springs and going with titanium retainers for the next go around. With a little more work I think I will have a screamer. After I get the valvetrain issues sorted out, I want to play with intake runner length and plenum volume. I'm running a highly ported 2 piece w/ 52mm TB now. When it comes to shooting for more R's, the cross sectional area of the ports is just as important as flow. Air only likes to move so fast.

[GLHSKEN]

You will need to pay attention to the springs with a Steve M cam.. you could run into coil bind. Lift is that high. Exhaust is .53x