Dave,
Could you post the Street Dominator and the DP4B torque and HP curves?
Thanks,
Ron

Excellent info dave. Thanks for posting this. I'll be running a Performer on my 400 due to low hood clearnace...doesn't look like it gives up that much to an RPM (with your combo). That's good to know!

Cool. I agree on why the 6bbl did well. Small engine, decently low peaks. I'm curious tho. It seems that all these are a little softer than I would expect from the parts listed. How mu ch fussing was needed to dial them all in? Which one had the best BSFC at peak tq, and what was that number? I like these tests, but sometimes you just uncover a whole bunch more questions. thanks for making us think!

Here are just a few data points. Also, a reminder that this thing had STOCK heads. I think the heads were the restriction, therefore the manifolds did not make drastic changes; except for the really bad ones, the different intakes just wiggled the numbers around by 5-10 hp or shifted them to the low rpm (dual plane) or high rpm (single plane). I'm pretty certain there will be more difference between the intakes once some better heads are on the engine. I find that out at the end of the month.

Street Dominator
3,000: 381, 217
4,000: 449, 342
6,000: 395, 452

Torker
3,000: 395, 225
4,000: 455, 356
6,000: 397, 454

Perf RPM
3,000: 408, 233
4,000: 457, 348
6,000: 392, 448

DP4B
3,000: 419, 239
4,000: 454, 346
6,000: 387, 442

Performer
3,000: 418, 238
4,000: 452, 344
6,000: 382, 436

Six Pack
3,000: 413, 236
4,000: 459, 350
6,000: 391, 447

From the looks of that the DP4B & Torker look pretty darn good considering you can pick one up off ebay for less than $75. Thanks DF

The real test will be when you get some better heads and a bigger cam. With the weak point being the intake, then the big differences between all of them will come out.

This is still great data, shows you don't have to spend money on aluminum heads and still make good numbers for a street car.

Another side question, is about 450hp the limit for stock heads on a 440 as well, with a similar build?

These same heads on Dulcich's 440 made 470 on a differnt dyno. Virtually every 906 head I've ever tested has been limited to 450-470.

The intakes will totally rank differently with a real cam and heads. I think you'll see the RPM get way better then the Performer, the Victor way better than the Torker, etc.

DF

Here is the article I did for Mopar Muscle back in 2005. This was a low deck stroker motor (470 inches) that made 550 at the crank and 475 at the rear tires. The Performer RPM was much better than the Victor 383 for street driving and on the dyno they were very close. The Victor made a little more on the top end but gave up a bunch of torque at the bottom. Since you'll be running headers you might see the Victor make some more power. I was running a MP .528 cam so if your next dyno test uses a bigger cam then the single planes might pull ahead a bit more.

http://www.compcams.com/Community/Articles/Details.asp?ID=2004264609

You used an Edelbrock carb both on the dyno and on the street? IMO those tend not to like huge plenum volume because they are signal sensitive. That shows less on the dyno than in part-throttle loading on the street. Holleys are the same, but seem to be more easily band-aided.

I bet that Wilson 2-inch tepered combo spacer really worked on the RPM. I usually find them to add some top end without hurting power anywhere. Then sometimes they don't work at all. Carb spacers are voodoo.

Yep, I used both a 800 AVS and the 800 AFB carb. They both worked okay but we might have been leaving a little on the table. My issue with the Eddy carbs is that the guys at Edelbrock won't provide any aftermarket parts for the carbs so they can't be "tweaked". Without a supply of throttle bodies, venturi clusters, etc. you're limited in what can be done to the carb. If you run out of pump shot for instance you're out of luck.

The Performer RPM liked the carb spacer. The more carb spacer we gave it the better in terms of top end power but the big spacer did cause a bit of a bog. With a Holley DP carb the bog might be covered up but the Edelbrock carb is limited on the pump shot.

Well, I didnt realize they were stock heads...lol. I know I read it. I just didnt recall it when it mattered . On the averages, I was thinking the tq average should be fairly close to peak value anyway, given the range of the test values. Meaning they wouldnt have had real peaky results and they'd exibit fairly flat tq curves. Maybe my thinking is off on that too. I'd like to see some back to back stuff if you're bored. A nice one would be the Holley/Edelbrock/Demon/someone's custom shop version carbs on a street type 4.25 stroke BB. Or 2.08 vs 2.14/2.18 valved iron heads with the same level of porting on a small bore (383) wedge.

Well if you're talking to me I'll say that I don't intend to ever do another Mopar article with cast iron heads. The last one I did was the 383 stroker article for Mopar Muscle. The Eddy heads picked up about 50 hp over a set of non-professionally ported 906 heads.

After that dyno test I sold the heads and I also sold all of my core heads. So I don't even have any cast iron heads in my shop anymore and I don't intend to ever buy any or work on any again. Breathing cast iron dust just isn't any fun for me!

http://www.moparmusclemagazine.com/techarticles/mopp_0605_mopar_performance_383_stroker_engine

What's amazing is that you saw 500 hp with iron heads. We haven't gotten that from 906s even with bigger engines that have larger cams. Perhaps that pocket porting was better than you thought.

Andy, I was talking more to Dave. I agree using aluminum makes the most sense today. But the vast majority of guys building these things are still using iron. Some with the understanding that they will not end up keeping them on there. And there's some misinformation regarding even their use on some setups due to advances in cylinder head understanding. (like Dwayne's...) I sympathize with you. But reality is there's still thousands more sets of iron being re-used than there are aluminum at this point. And many of the readers of the mags are the guys who will run iron first for budget reasons.

Thing is, by the time you buy some 906s, clean them; mag 'em; mill them; install new guides, valves, and seats; get a valve job; and enlarge the seats, you're halfway to a new set of aluminum heads.

I think I had $1200 in my last set of 906 heads (the ones we used on that 383 stroker motor) after doing all the work. That includes buying new valves, springs, retainers, locks, guides, seals plus doing all the machine work and the bowl hogging. Porting would've been even more.

The Eddy heads are a lot cheaper than a comparable flowing 906 head.

Holley Street Dominator