Brad Perry

Thanks klaw. I can't seem to finad any BBC head that is any more that 290cc port volume. It seems the indexes are screwed up (or I am).

klaw

Come on Brad I found one that is 292cc (Just Kidding)
You are correct In the big volune catagories there are none above 290 (292)
I will keep looking

blown1500

Klaw, Brad, where are you looking? If you want intake port volumes over 290, look at almost any aftermarket source and you will find up to 400+. But be conservative on a boat, you'll be glad you did!!

HyperBaja

Head flow.....my buddy had a motor makinf 450hp, desktop dyno was off 200 hp. Im guessing he didnt enter something correct.

blown1500

HyperBaja, the Dyno 2000 has been pretty good for me. We use it to get close on a combination, then go to another program that takes a l o n g time to det up. The info you give the Dyno 2000 program must be correct in each instance and some of the things you must enter require practice to understand. I read the whole manual and all instructions at least twice before I got decent results. I know some very good engine builders who use this program!!

Brad Perry

Blown 1500,

The topic at the point that you chimed in was concerning finding head flow files for dyno 2k, not heads in the material sense. I already have them. I'm helping out a buddy with his 502 and dyno 2k...............

Ratchet

I actually inputted all the information from an engine (11:1 572)we dynoed.................. We did not have the exact head flow data, but used the mfrs numbers listed.

The engine made 932 hp @ 7000, and 739 ft lb @ 5600. If I recall correctly, the program predicted around 940-950 hp (I would say possibly because of the head flow numbers), and 750-760 ft lb of torque, but what was interesting was that the peaks were at the predicted RPMs. Even on the dyno. when we changed the cam timing, it only varied the peaks by 100-200 rpms.

In any case, once you get a baseline where you'd like to be, you can get an idea if you're going in the right direction when you make changes.

Just our expereince.................

Blown1500,

What exhaust combo do you use (on the program) cause this changes alot ? For instance, I seem to see that using small tube headers with mufflers to simulate exhaust manifolds, such as stainless marine.

bago Baja

Brad,
I e-mailed chevyhiperformance a few weeks ago and told them that their indexes were screwed up. The info on the big block high volume intake port heads is missing. They told me the site had recently been re-designed and they were still working out some bugs.
Tom

Brad Perry

They never even responed to my e-mail....better luck with yours. Maybe we'll have it in a while.

blown1500

Brad Perry, if you call the mans. they will usually give you the numbers.
Ratchet, I use the stock manifolds and mufflers for stock Mercruiser, HP manifolds with mufflers for Mercruiser with elbow, and approximate the tubing size for the headers used. Wet exhaust is like mufflers. Hope this helps. Remember, the 2000 is a good tool for changes, just close for absolute numbers.