ICDEDPPL

iTrader: (1)

Maybe just PM the ONE single individual that made the comment? Pretty obvious that no one else agrees so I`m not sure what you`re looking for??
Is it because Bob pushes AFR so you have to make it a point to let everyone know that it`s all good?
Not sure what the point of this thread is. Everyone agrees with you

Black Baja

iTrader: (2)

Brian some of us do appreciate the technical insight from the guys that don't cut corners and do things right. It's a real shame with all the experience and appreciation we all have for marine performance engines we can't have better technical discussions rather than pissing matches and vendor bashing. If your have trouble with something instead of calling it junk why not bring it to the table and see if there is a fitment/ installation issue or whatever. Now don't get me wrong there is some real garbage out there but in the case with this thread I don't see it being the case.

Black Baja

iTrader: (2)

Its not just the case with the AFR stuff. The comment about the AFR exhaust port just kinda pushed it over the edge. AFR knows how to make a head. So does Brodix, Dart, CFE ect. Ect. Many times over I think there are installation / combination issues and someone's product gets blamed for it. Then everyone jumps on the band wagon and b4 you know it you minus well have bought the Chineese stuff and went with that.

mike tkach

iTrader: (3)

is minus well anything like might as well,lol,

Black Baja

iTrader: (2)

Sorry tryin to du 5 things at once

Rookie

iTrader: (4)

I believe this thread started over a 4 year old thread, that was discussing an 8 year old head. And like every great company out there I'm sure they are always updating their product. (Staying stagnant will put you out of business) There is no need to get personal and worked up over internet opinions. We as consumers are fortunate that we have so many options to choose from when making decisions on how to build HP. It's funny we are splitting hairs over, "Do I want to make 643HP or 651HP?"

This is definitely a 1st Word Country problem. Now I'm off to remove some Teflon strips from my blowers. Peace!

mike tkach

iTrader: (3)

no problem,sometime i think one thing and type another.it,s all good.

MILD THUNDER

iTrader: (3)

This morning I was reading this article posted on AFR's website. They did a comparison of several bbc heads, on a 496 stroker. Although the shortblock was untouched, they swapped heads. Something to keep in mind is the compression ratio differences as well.

http://www.airflowresearch.com/artic...t/shootout.php

GM Rect ports with 123cc chamber, roughly 9.8:1
630HP @ 6600
577FTlbs @ 5300

Summit (dart) cast iron 308. 9.9:1
688HP @ 6600
607 @ 5400

Pro comp chinese 369cc 9.8:1
690HP @ 6300
600lbs @ 5500

Trick flow 360cc 9.9:1
691HP @ 6500RPM
603lbs @ 5400RPM

Brodix 332 rovals 10.5:1
705HP @ 6500
624lbs @ 5200

Dart 335 Pro 1 9.9:1
717HP @ 6500RPM
619lbs @ 5600RPM

Edelbrock 355 CNC 11.28:1
723Hp @ 6500RPM
627ft lbs @ 5600RPM

AFR 290/300 Magnum oval 11:1
729HP @ 6500
639FT @ 5400

Its a no brainer, that stepping up to almost any aftermarket head, is where the big gains are found, in comparison to the GM head. The AFR head made the best power in that shootout. I would have liked to see what the 335 Dart head would have done, had it had the same compression ratio. It was down 12hp at peak, and 20ftlbs, but also had a full point less compression.

Even the budget summit racing head, was not a bad head. An as cast iron head, that picked up 58HP over the GM iron head? Pretty sweet.

What else I thought was interesting, was the torque at 3500 in the graphs on the setups.

At 3500RPM,
GM 540 FT lbs (9.8:1)
Dart 335 560 FT lbs (9.9:1)
Brodix 580 Ft lbs (10.5:1)
AFR 570 FT lbs. (11:1)
.

Lots of choices out there for the consumer. Many variables. I don't agree with a one brand is best mindset. Also, cost is a factor. Look at the darts. You have a set of 308 irons that retail for say 1400 a pair bare. Then you have the 335 cnc ported aluminum, for 3200 a pair bare. On this build, there was a difference of 29HP at peak. That gap would probably be even less, on a milder build like say an HP 500 upgrade. Is it worth the extra 1800 bucks for that 29HP? If a twin engine boat, x2=3600 dollars? That might net you 2mph speed gain? I think that 3600 dollars may be spent towards prop work, shorty lowers, better rods, better carbs, or things along those lines.

For the average mercruiser marine upgrade with stock pistons, its kind of a no brainer, that going to a head like the AFR 290, with its smaller chambers, is a great pick. The stock mercs are lacking compression for most performance builds, so bolting a set of those on, not only give you much better airflow, but the gains from bumping the compression as well. Its a win win. Just an article, and just some thoughts on it.

sutphen 30

procomp all the way.

dereknkathy

and that was an AFR OVAL head. it was a rect head comparison and AFR sent them an oval...and won. boy those exhaust ports must really suck!!!! Air Flow Research? i guess they do a little.