JimV

iTrader: (1)

Thanks Tom! Sorry I couldn't spend more time on the dock, like you, it was busy for me too (thrashing to find a prop). Your chiller set up looks great.

As for the intake ports, yes if it flows a decent amount of air. Most heads need a bowl port and your good to go.
On Check30's 572 twin turbo motor the ports are small enough in volume that it would scare most. It makes a buttload of torque and the motor will still rpm. The intake holes measure 2.1 tall by 1.75 wide and flow in the 385 range. Im sure the efi helps too. Bill will be at Hardy this weekend. He promised me a ride and I'm gonna make sure he sticks to it.

tomcat

Belt driven centrifugals and free floating turbos have very similar boost and HP curves. They come on big time at mid to top range, so you don't need to worry as much about intake flow numbers, but you do need to keep the low end torque.

My experience so far has shown that good heads and mild hydraulic roller cams are the best in the real world. They get the RPM up quickly, then the blower takes over. The blower keeps the torque curve going a lot longer than the cam would suggest. You know this when you see the dyno sheet and the torque peak is only 500 RPM lower than the HP peak.

All you guys building 502/540 keep the compression lower than 9:1. You should see 600 HP and if you use good head gaskets and exhaust valves, you're just a blower away from 1000 HP.

articfriends

iTrader: (1)

jim,your flow #'s on the afr's,were they with a 4.250 cyl adapter or a 4.500? I am on the hunt for the ideal head for my blown 540 this winter,i'm currently running merlin vr's have you flowed any of these?The info iv'e found shows exhaust flow around 200 cfm,i assume it must be holding me back more than anything else. Do you do head work as a business,i don't like to wait 9 months for lapouttre to port heads for me,Smitty

Viper31

Jim have you ever flowed the the Canfield 310cc head?

Strip Poker 388

iTrader: (6)

I thought AFR bought Canfield?

WAGS382

JimV
Thanks for all of your information. If you were buying afr heads for a 502 with a max rpm of 5500 what would be your choice? Jeff

cstraub69@comcast

Wags,
E-mail me at [email protected] I would like to discuss an option.

Chris

JimV

iTrader: (1)

Articfriends All flow numbers are with a 4.600 flow plate. The Dart heads are superior to the VR Merlins by far. 400 cfm @ .700 is doable with the Darts, no way with the Merlins. Also, to get the air flow numbers out of the Merlins you will be into the water jacket. Yes I do heads for a living. BTW I used to work with Rick at Dart years ago

JimV

iTrader: (1)

Wags

That's a tough question to answer without more info about the motor. What compression, exhaust, peak airflow numbers. Generally I will run a cam lift that is at the peak airflow. The duration will vary. Hull design and boat weight is a factor

Nordicflame

iTrader: (4)

JimV worked Canfield Heads, bowl port intake, full port exhaust

.2 150 140
.3 230 181
.4 297 220
.5 342 253
.6 360 275
.65 - 283