What did Darrin Morgan charge for something like that, Bill? I am wondering how many CFM numbers it takes to gain or make 1-hp??? Does anyone know?

Like I have said previously, if it is for a car race application where saving a pound of weight here and there as well as low as 1-hp, then maybe I can understand these small increases for the time and expense involve for a drag car clocking time in the 1/4 mile....or a circle track car, but I think a boat is a whole different animal and these CNC ports have already filled the gap considerably.

I will admit that I like the ports to be as efficient as possible, and I am sure every little bit helps, and I suppose it depends on how much $$$ a person wants to spend, but where do I draw the line for a pair of hi-zoot offshore engines with supercharging that are already equipped with CNC ported heads that are going in a pleasure boat? Are we splitting hairs here?

You can have two heads that flow identical CFM and have the same port volume. One head makes 50 more horsepower than the other. CFM really means nothing anymore and not the way heads are built/ designed. The reason CFM numbers are posted by manufacturers is because the numbers sell heads. Buy a $10,000 set of billet heads and see if you get flow sheets with them. In the words of Darin Morgan the three things that really matter with a port are: air speed, air speed, air speed.

Irrelevant to this discussion kinda, but good read you guys might like
http://www.enginelabs.com/engine-tec...r-your-engine/

Anything can be improved upon IF someone takes the time and is really skilled, there could be a step backwards too though if someone hacks on something. My 540 made 945 hp blown with 315 afrs, on next refresh did more porting to 502 mag intake, Bob Madera spec'd a bigger cam and Rick Lapouttre who is our very talented local head porter did his mods to my afrs and motor made 1115 hp, what gave it the biggest gain, couldnt tell you. The heads were converted to 2.300 valves when it made 1115 I do know that, Smitty

Replace entirely? No, probably not. Do it faster, more accurately, and with exact repetition? Yes.

Both a blessing and a bane, the skilled craftsman teaches a programmer instead of the next generation

You guys ever wanna know who designed the port (and what the application is for) on a certain CNC'd head ?

It's not like every Casting Company / Cylinder Head Manufacturer has a well known 'go to' cylinder head porter in their arsenault.

Just a question. That's all.

Tell me what you know about the AFR 315's uncle SB . :popcorn: I paid for the very very best ( for my application ) and that's just what I expect to receive . Are we really discussing a tweak that will net 1hp @ 7000rpm . Most of us will only be turning 6000rpm if that . From what I've seen and heard by the brothers that have used these heads in marine applications I believe I'll be well pleased . http://www.airflowresearch.com/performance.php

PS: This post was in no way intended to disrespect Jim V. I believe he has earned the respect of the OSO brotherhood and that is not given freely .

Over achievers for the most part. Unless you want to spend more.

My post was about all cnc heads in general. Something to take in account when buying anyone's CNC head...that's all.

at some point asingle man ported a set of heads,,they worked,,they got cnc'd splashed..