Are my heads holding me back????
05-15-2007 | 05:09 PM
#11
Thread Starter
Registered
Joined: Dec 2005
Posts: 390
Likes: 0
From: Mission Viejo, CA
I've had most success porting the intake to a height of 2.1" by 1.750. With a 2.25 intake valve they will flow low/mid 360 cfm. With the small port opening, I dont think the 2.300 is being utilized. I'm a little consern when you say the ex ports have been port matched. Exhaust ports are sensitive in the bowls and the port floors out to the flange. You can hurt airfow if not ported correctly. Overall the heads will work good with some porting.
05-15-2007 | 07:43 PM
#12
Registered
Joined: Sep 2006
Posts: 57
Likes: 0
If you choose to raise the boost, you are sacrificing reliability.
The cam IMO is way too fat in its centerline and you are blowing off your pressure through the duration. Nice cam.. wrong application.
Like JimV said , basically you are needing to open the exhaust ports, now to compensate.... and that compensation is for the cam. IMO
If you want to hear a similiar application , email me at this name on AOL. Would be glad to talk.
The cam IMO is way too fat in its centerline and you are blowing off your pressure through the duration. Nice cam.. wrong application.
Like JimV said , basically you are needing to open the exhaust ports, now to compensate.... and that compensation is for the cam. IMO
If you want to hear a similiar application , email me at this name on AOL. Would be glad to talk.
05-16-2007 | 12:15 AM
#13
Thread Starter
Registered
Joined: Dec 2005
Posts: 390
Likes: 0
From: Mission Viejo, CA
I've had most success porting the intake to a height of 2.1" by 1.750. With a 2.25 intake valve they will flow low/mid 360 cfm. With the small port opening, I dont think the 2.300 is being utilized. I'm a little consern when you say the ex ports have been port matched. Exhaust ports are sensitive in the bowls and the port floors out to the flange. You can hurt airfow if not ported correctly. Overall the heads will work good with some porting.
Last edited by ghittner; 05-16-2007 at 12:18 AM.
05-16-2007 | 07:12 AM
#14
Banned
Joined: Feb 2005
Posts: 1,459
Likes: 1
From: Cleveland, Ohio
Your heads are holding you back a ton!!! With a Supercharged application, a rect. port design is the way to go. I would use a Dart Pro 1 or Brodix BB 2 - plus CNC head on your application with a runner volume of 320. I built a 468 with a B&M 420 with a superchiller same 2 X 750 Holley double pumper with mech. roller camshaft. With 8-9 lbs of boost engine made 875 HP at 6000 RPM. Your camshaft is not "TOO BIG" either. I ran a .672/.672 lift 252/257 @ .050 on a 112 lobe seperation.Degreed cam on a 108 intake centerline.8.75:1 compression ratio, 93 octane fuel . Engine still had power left with timing very conservative. The engine went into a 25' Baja from Michigan. Wild Ride!
Last edited by mrhorsepower1; 05-17-2007 at 06:38 AM.
05-16-2007 | 07:48 AM
#15
Registered
Joined: Nov 2000
Posts: 709
Likes: 2
From: Grand Rapids Mi. U.S.
Yes, grind the material off the roof of the port. This will help but to make it right it needs a good ex port and some chamber work.
Last edited by JimV; 05-16-2007 at 07:53 AM.
05-16-2007 | 10:40 AM
#16
Thread Starter
Registered
Joined: Dec 2005
Posts: 390
Likes: 0
From: Mission Viejo, CA
I thought the Merlins were a good, raised exhaust port and that's why I decided on them for my normally aspirated motor. Is that not the case???
05-16-2007 | 10:41 AM
#17
Thread Starter
Registered
Joined: Dec 2005
Posts: 390
Likes: 0
From: Mission Viejo, CA
Your heads are holding you back a ton!!! With a Supercharged application, a rect. port design is the way to go. I would use a Dart Pro 1 or Brodix BB 2 - plus CNC head on your application with a runner volume of 320. I built a 468 with a B&M 420 with a superchiller same 2 X 750 Holley double pumper with mech. roller camshaft. With 8-9 lbs of boost engine made 875 HP at 6000 RPM. Your camshaft is not "TOO BIG" either. I ran a .672/.672 lift 252/257 @ .050 on a 112 lobe seperation. Engine still had power left with timing very conservative.
05-16-2007 | 07:23 PM
#19
Registered
Joined: Nov 2000
Posts: 709
Likes: 2
From: Grand Rapids Mi. U.S.
05-16-2007 | 08:18 PM
#20
Off the Radar
Joined: May 2001
Posts: 1,097
Likes: 1
From: Cape Coral, FL or Colonial Beach, VA
You have the best input I've seen on heads with some real experts.
The cam is too big, big is not better, a 232/[email protected] on 112 would be max if I was doing it, Maybe a little smaller, but let these guys offer suggestiond with there heads.
LH
