Congratulations on your new cylinder head! Anything that's capable of flowing over 500cfm ought to make enough power to start breaking a lot more parts :) Can't wait to see the new most powerful Pontiac head.

Don
Do you think that these would fit under a stock Firebird 400 hood, without having a compromised intake? Before you answer realize I may not be your target customer as I don't need more than say 350 to 370 cfm for my horsepower goal.

Congrats on moving forward with your program Don. All the best towards reaching your goals.

Exciting news. These are the heads I've always wanted.

Very cool.

So about your street heads....are these going to be something that will work on mild to wild? Or are they just geared tward huge CI, max effort type of higher HP street cars?

Ever think about doing an OHC type of deal like the old experimental stuff??!!?? That would get weird!!

An intake that can fit under the stock hood I do believe can be fabricated. It may compromise the heads a little, but I don't think that it will hurt them much( maybe 15-20 HP). The biggest thing I think it will hurt would be torque (maybe 30-35 ft lbs.). Although I think these heads on 412 plus cubes torque is not going to be a concern even compromised a little.

The street version of the head has some features that I designed into the port that improve port speed. So I feel these can be used on what I would consider a conservative street engine say 412 - 467 cubes and still maintain very good street manors. This is going to be a pretty versatile head and can be made to work from mild to wild. I think that it's going to be real interesting when guy's like Jim Robertson, John Marcella, and Calvin Hill among others not to mention myself get their hands on these. I designed allot room for imagination into these heads, and I think these will definitely take us to the next level. I would really like to see someone make 1300 + HP normally aspirated, but I'm putting the cart before the horse. So we will just have to wait and see. I'm sure that we are going to get the nay sayers, but I'm use to that. When I first came out with the Tiger's I had people telling me you can't get 400 cfm from a Pontiac style head. Then they said there is no way they will make 1,000 normally aspirated HP!!!!!

As for overhead cams or exotic one off items. I will leave that up to someone else. I think my audience is already limited enough.



Don Johnston
DCI MOTORSPORTS INC.
330-850-5050 Shop
330-628-3354 cell
Designer of the DCI Tiger Heads and the NEW DCI Ram Air V heads !!!!!!

Can the pushrod be moved over out of the port?

Then its not a V head?Tom

I agree with Tom s, plus the fact that the pushrod geometry would be way out to lunch. Not saying it cannot work. I just don't think that it is a good idea. The race version of my head will have a net csa of 5.2" that's after calculating the amount of area the tube takes up. I know what your thinking though, the pushrod tube is going to disrupt flow.I have considered that, and I have done allot of testing with the tube in the port and think the way I have it designed now. It is not going to be a big factor. There is no doubt it does effect the flow path, but the way I designed the port I have tried to minimize that. After I get them finished I would like to have them flowed on a wet flow bench just to see how well it does work. If needed I will make adjustments to the cores to correct anything that might not look kosher. I have done actual flow testing as well as computer generated models to address this problem, but only actual on engine testing will determine what direction I need to go if any.


Don Johnston
DCI MOTORSPORTS INC.
330-850-5050 Shop
330-628-3354 cell
Designer of the DCI Tiger Heads and the NEW DCI Ram Air V heads !!!!!!

Did you do any CFD work on the pushrod tube, Don?

If not, possibly I could get one of our guys to do a simple model of the diameter (area) of the port, the diameter of the cast in Pushrod Boss, and how much "tail" the boss would need to have proper flow without separation.

Then you could cast the boss/tail to that basic dimension and let the porters do the fine tweaking.

Tom Vaught

I think magic man marcella can handle that.

Jim Robertson made me a 2-4 sheetmetal tunnel ram that would fit under the hood of my 69 firebird.REALLY nice piece.Maybe he has a pic and can post.Tom

Looks great. I'm glad to see there are guys who are into this kind of stuff, but I would be concerned about the head height. As you can see in this picture, trying to clear the valve cover to washer motor will be a problem with a taller head on a Firebird.

Sure would be nice if someone would make a hemi over head cam tunnel port head. That way you could remove the push rod tube all together.

Oh, and if anyone wants to cut up a NOS intake for the crossover, I have one...

;o)

:2cents:

Race cars dont have those issues that we have on our street cars.Tom

Yep. Understood, but if you are going to make a street head, would you not want to be able to stuff it in your engine bay without all the headaches of modifications?

If designed as a street head it would have been copied after the stock head.As a race head it was designed with a straighter shot at the valve making the raised port more desireable.Maybe Don will correct if im wrong.Tom

OR there is always a stock set of V heads!Tom

Understood Gentleman, but why bother making the exterior LOOK like a factory head and go through all the trouble to do so when your objective is to make a better head? Sounds like a conflict in design. I'm all for improving the heads, but if you can't stuff a factory looking head into your factory car, then your market shall be limited to racers for the most part.

I'm just pondering the global picture of the project and wonder if the sacrifices were weighted vs. market sales.