Darren, If you are open, I have a simple crazy idea, YOU could buy Don Johnston's 455ci. Pump Gas DCI Ram Air V engine that makes at least 650hp and has been engineered out and runs and runs well. Check out his video on Youtube, very impressive for sure. That engine could go into your street car very quickly and you can enjoy it!! THEN if you want to build a VERY High End Race engine with DCI Ram Air V heads on it you can go to a professional engine builder and sit down and make a plan that will fulfill your Race Car Goals with reliability.

Darren then you will have fun with BOTH of your Cool cars!!:3gears::3gears::3gears:

Rick, I think our estimate was a bit on the conservative side LOL. 760 HP and climbing on pump gas.


Thank You to everyone that has followed my endeavor and supported me through the long wait. Please stay tuned I think more good things are going to come. Now I need to get the engine in my car and lay down some numbers !!!!!!

Just shipped a set of 500+ cfm DCI RA5 heads to a guy up in Minnesota. I don't think he will be putting the engine together before late fall, but when he doe's get it together. I will let everyone know what the results are. He says he is going to dyno it when done.

nice job Don!

Valve sizes?

2.300 intake, 1.68 exhaust

What a difference ten or twenty years make! Congrats Don!

Those are looking great. Can't wait to see some track results. any approx cam and displacement information? Good luck Kevin

Thanks guy's !!!!! When I look at these heads compared to even my Tiger heads I just cannot believe how big the ports are. 10 years ago we would have all said that there is no way they will make power LOL. The evolution from our beloved factory iron heads that we all had to run for so long, Seems like light years away now. I took a couple of pic's with a factory iron intake gasket over top of my RA5 heads. It's hard to tell in the pic's how big these ports really are, but you will get the idea. Obviously these are not low rpm heads after a race port job, but that's not the intended use of these heads. We know now that the as cast version makes incredible torque on a 455 with pump gas. So now we need to see what these things can do in a big inch high compression high rpm application. I'm doing a set for Danny Estep right now that I'm trying real hard to get completed before Norwalk this year. Time is not on my side, but I will give it my all. Danny is doing everything he can as well to help make this happen and without his help it couldn't be done for this year. As it is we are all going to be burning the midnight oil.

Don,
500 cfm with 2.30" intake valve. What are you seeing on your flow bench? My rough calculations show a Discharge Coefficient of just about 1 at the throat.

Stan

Here a couple more pic's from different angles. I put a factory RA5 intake gasket in the stock location so you can see how much I raised the intake ports too.

I'm not sure that I'm following you Stan. The lift is 1.00" and the throat is 93%.

Don,
@28" water

5/16" valve stem
► (500/((((2.3*.93)/2)^2*pi) - ((.3125/2)^2*pi)))/146 = 0.97381

11/32" valve stem
► (500/((((2.3*.93)/2)^2*pi) - ((.3475/2)^2*pi)))/146 = 0.97886

Which should show an average velocity of 341-343 fps @ the throat.

Stan

I got ya !!!! 5/16" stem 28"

For comparison I took a couple of pic's of a set of Brodix BB2 Big Block Chevy heads I just done for a customer. The Chevy heads flowed 390 cfm @1.00" and 28" with a 2.375" valve and ported. I did not port them and don't know who did. My head is just in the rough in stages in these pic's.

Those heads look sick!

Keep up the good work guys

Was it me? I live in Minnesota. ;)

Could be you, all I need is a check !!!!!