Yo Chris
 

Hey man, where ya been? Lisa says hi BTW.

I have some questions for you. I want a nice 500 hp motor for my car. I'd like to get your thoughts on the combo. I was thinking big inches would be nice and I wouldn't have to go so high on the CR. I was going to use a SCAT stroker crank, but see they only go to 4.25. If my math is right, that only gets me about 455 inches or so with the 428 4.13 bore. What stroke are you guys using to get in to the high 400 sizes?

What are your feelings on cams? Solid or hydraulic? What kind of specs?

I'm probably going to use the new Shelby intake. Can it be machined to use the original oil fill tube and use the bolt on breather hose rear plate?

What other advice do you have? CR? Valve size? Etc etc. I would like to see 450-500 at the wheels. If this motor is going to cost a fortune, I want some power in exchange :). I dynoed a real 427 side oiler the other day build with NOS parts to factory specs and it only made 390 at the wheels.

Let me know what you think.

:)

Hi Sal (and Hi Lisa!), other than my four-hour-a-day commute, I've been here makin' it happen.

500 horsepower is easy. The Scat cast steel cranks are a great way to get inexpensive cubes. There really isn't any alternative at anywhere near that price. To get to the big cubes, we use our aluminum block. To get a 428 block suitable for overboring more than usual, you have to go through so many blocks to get one with thick enough walls, that it's (for some people) a big hassle.

The Shelby intake already comes machined for the original "puke tank," (though some pics show it unmachined) but it can't be machined for an original style oil fill: the runner and water neck are in the way. You could machine it anyway and install a fake one, though! ;)

My thoughts? Depends on what you're using it for. If, like most people, you're going to run it on the street and the occasional track event, then if it were me and I were looking for max power, I'd use a hydraulic roller cam and around 10.5:1 CR. I'd keep the cam small enough that we wouldn't need to go too nuts on the valvespring pressures or the rest of the valvetrain. As long as everything was good for 6,200 rpm or a little beyond, I'd be happy.

A flat tappet cam can work very well too, of course, and is a few to several hundred dollars cheaper. We use both solid and hydraulic (mostly hydro), with grinds having duration starting at the mid-240-something degrees intake, mid-250 exhaust. I'd use something a bit bigger for a big-inch motor.

Valve size is an interesting deal. I think you were talking about using the Edelbrocks in our last email convo; I think you can run a pretty high lift cam with those without hitting a 4.130-4.180" bore but I wouldn't know, as we haven't used Edelbrocks yet and the Shelby cylinder head valve spacing is wider, and the diameters are larger (2.25" and 1.75").

What kind of rear end was in the side oiler you dynoed the other day? IRS or solid axle? The IRS'es sap a lot of power over the straight axle ones. Some folks out there have made over 600 to the wheels on IRS though!

Thanks and talk to ya soon,

Chris Weisberg
Carroll Shelby Enterprises
(310) 538-2914

Edit: And yes, since we're all civilized people, I'm talking about Dynojet rwhp #'s, as I know you are too. ;)

Chris, it was the JAG rear (ERA car). His motor was dynoed by the engine builder at 430hp. I usually use 8% drivetrain loss for a manual with a live axle, so I used a 10% guess for the IRS. That gave me 387rwhp. His first pull was 388 :). So he's got exactly 10% drivetrain loss. I still felt 430 hp wasn't a lot for the money spent on the motor. I guess I'll stick with the SCAT setup. I've been told all the power is in the heads. I think I am going to wait and see how the new Blue Thunder heads work, I'm sure they will rock as most of BTs stuff does. I'll probably get the cam setup from you guys and use the specs you suggest. Thanks!

Oh, and is there any kind of "template" available for how you have to cut the Lakewood bellhousing?

Sal,

Yep, most of the power is in the heads and cam. A nice ported aftermarket head is light years ahead of a stock FE head.

I don't see anybody offering a template for trimming the Lakewood scattershield, but you can either order an already-modified scattershield from us, or find pics on the web of where to remove material.


Chris Weisberg
Carroll Shelby Enterprises
(310) 538-2914

Gasholes.com
Forum: Your Car (currently 2nd page of that forum).
Topic: Bellhousing cut/clutch arm

Pictures of the cuts that MAY be required on a scatter shield and the clutch arm.

My ERA does NOT require the bell housing modifications. It does require the clutch arm cut.

The red bell housing is laying on top of the standard plate that would go between the bell housing and the back of the engine. Thus, you can see what would need to be "cut" from a typical scatter shield.

Cut required on the clutch arm.

I believe these pics and modifications are from Kris Kincaid.