Intake Manifold port size question..
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,387
Likes: 2
From: Meriden CT
Intake Manifold port size question..
Hi!
Long time since I've been around the forum. Life has kept me very busy and the vette parked for long periods. Sad, but there's no intention of ever selling my baby so she can rest easy.
My wife bought me a killer Christmas gift this year... FAST XFI 2.0 fully sequential fuel injection conversion kit. Today I started digging in to the 383 and pulled off the Edelbrock performer RPM intake. The ports on the stock cast heads match up fairly well with the old intake... but the ports on the EFI intake are much larger. Measurements as follows:
Heads
1.14" X 1.97"
New intake
1.24 X 2.28
I'd like to do my best at port matching and also do some polishing of the runners of the new intake. These measurements threw me for a loop today. What do I do in this situation to ensure proper airflow without removing the heads? What do I do for gaskets? The old setup had Fel-Pro 90314-1 gaskets.
Any help is appreciated..
Thanks
JoeRags
Long time since I've been around the forum. Life has kept me very busy and the vette parked for long periods. Sad, but there's no intention of ever selling my baby so she can rest easy.
My wife bought me a killer Christmas gift this year... FAST XFI 2.0 fully sequential fuel injection conversion kit. Today I started digging in to the 383 and pulled off the Edelbrock performer RPM intake. The ports on the stock cast heads match up fairly well with the old intake... but the ports on the EFI intake are much larger. Measurements as follows:
Heads
1.14" X 1.97"
New intake
1.24 X 2.28
I'd like to do my best at port matching and also do some polishing of the runners of the new intake. These measurements threw me for a loop today. What do I do in this situation to ensure proper airflow without removing the heads? What do I do for gaskets? The old setup had Fel-Pro 90314-1 gaskets.
Any help is appreciated..
Thanks
JoeRags
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
This is easy. Tell the wife you have to have some new heads to match up with the 383 and intake. They are well matched but the stock heads are a mismatch. No problem! 
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,387
Likes: 2
From: Meriden CT
She figured me out long ago.. I could probably justify the new heads - but I worry about the repercussions. "honey, my bracelet broke. You know that nice diamond one I like?". 
Gary, thanks for the idea, but I would just assume weld it to add material. Not too keen on the idea of epoxy in the runners.
Sigh... New intake or new heads...
Gary, thanks for the idea, but I would just assume weld it to add material. Not too keen on the idea of epoxy in the runners.
Sigh... New intake or new heads...
Melting Slicks
Joined: Mar 2008
Posts: 2,666
Likes: 289
From: Spring Park MN
She figured me out long ago.. I could probably justify the new heads - but I worry about the repercussions. "honey, my bracelet broke. You know that nice diamond one I like?".
Gary, thanks for the idea, but I would just assume weld it to add material. Not too keen on the idea of epoxy in the runners.
Sigh... New intake or new heads...
Gary, thanks for the idea, but I would just assume weld it to add material. Not too keen on the idea of epoxy in the runners.
Sigh... New intake or new heads...
I think myself, I would wait until I could replace the heads to put the new manifold on. It would be much more rewarding in power output to go along with the great FI drivability!
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Bolt it on as is with the gasket the intake requires. You won't lose much. Your better off going bigger to smaller than the other way. The ledge is tiny. your talking 1/10th of an inch /2 and 3/10 of an inch / 2. No big deal. I have done a square port intake on oval port heads with a lot more difference than this with no perceived issues.
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,387
Likes: 2
From: Meriden CT
That's what I'm beginning to think.. Problem is, I have no idea where to start with all the options out there. I guess first step is to get my cam specs... Motor paperwork has been MIA for a while now.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Don't radius the head, and don't waste time polishing the intake runners.
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Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,387
Likes: 2
From: Meriden CT
Bolt it on as is with the gasket the intake requires. You won't lose much. Your better off going bigger to smaller than the other way. The ledge is tiny. your talking 1/10th of an inch /2 and 3/10 of an inch / 2. No big deal. I have done a square port intake on oval port heads with a lot more difference than this with no perceived issues.