'95 EFI BB Intake Manifold question
Thread Starter
|
Senior User
Joined: Aug 2008
Posts: 253
Likes: 0
From: San Marcos, CA
'95 EFI BB Intake Manifold question
i have an E350 with a 460 BB. i recently installed a BBK dual 61mm throttle body. when i did the install, i noticed the upper manifold was only 50mm. so i took it off and ported it to match the t-body.
when i removed the upper manifold i noticed that it had two runners from the t-body down to the lower manifold. they are SEPERATE from each other - in fact the only points at which there is any common area is for the manifold vacuum port, the egr port, and the air bypass valve - these are no larger than 1/2" each.
here comes my question... is there any advantage to keeping the intakes for each cylinder bank seperate from each other? or is it a disadvantage? why?
thanx in advance
neil
BTW this question has also been posted in the intakes forum...
when i removed the upper manifold i noticed that it had two runners from the t-body down to the lower manifold. they are SEPERATE from each other - in fact the only points at which there is any common area is for the manifold vacuum port, the egr port, and the air bypass valve - these are no larger than 1/2" each.
here comes my question... is there any advantage to keeping the intakes for each cylinder bank seperate from each other? or is it a disadvantage? why?
thanx in advance
neil
BTW this question has also been posted in the intakes forum...
Elder User
Joined: Jun 2004
Posts: 800
Likes: 6
From: Edmonton, Alberta Canada
it is probably the same reason as behind a dual plane manifold, it improves the low end torque and streetability of the engine at the sacrifice of top end power (which on a stock 460 is not the greatest anyways with stock cam).
i have not really looked at an efi manifold, but they probably don't feed individual cyl heads, but divide the cylinders based on firing order. so the runners probably feed 2 cyl on each head.
its all about velocity and keeping the intake velocity at its optimal for torque production.
my theory anyways.
rgds
Mike
i have not really looked at an efi manifold, but they probably don't feed individual cyl heads, but divide the cylinders based on firing order. so the runners probably feed 2 cyl on each head.
its all about velocity and keeping the intake velocity at its optimal for torque production.
my theory anyways.
rgds
Mike
Thread Starter
|
Senior User
Joined: Aug 2008
Posts: 253
Likes: 0
From: San Marcos, CA
thanx mike. i grew up in old english cars so the only time i really ran into v8's were rolls, v8 morgans, mgb-v8s and astons. not a lot of performance intake options so not a lot of background in single plane/dual plane/tunnel ram/etc/etc theory.
runners feeding 2 cyl/head makes excellent sense - will investigate.
also note the 2x61mm t-body has only 50mm inlet openings - t-body then opens up to 61mm at the throttle plates and continues at 61mm up to stock manifold. if i had the cash, i would send out the t-body for boring to make 61mm thru and thru... 460 really liked the BBK, but i don't think full potential is being realized. pretty sure they did it this way for smog and to not force owners to replace complete filter induction system plumbing.
neil
runners feeding 2 cyl/head makes excellent sense - will investigate.
also note the 2x61mm t-body has only 50mm inlet openings - t-body then opens up to 61mm at the throttle plates and continues at 61mm up to stock manifold. if i had the cash, i would send out the t-body for boring to make 61mm thru and thru... 460 really liked the BBK, but i don't think full potential is being realized. pretty sure they did it this way for smog and to not force owners to replace complete filter induction system plumbing.
neil
Freshman User
Joined: Jun 2008
Posts: 35
Likes: 0
I'v been meaning to try a BBK 65mm TB for a Navigator, all the mounts are the same, and the throttle linkage looks like it should work. I posted about doing this a couple months ago, but have since gotten separated from the wife. I did have a Navigator to compare to side by side(now she does).
I think that I should be able to make an '03-'04 Navigator K&N cai work with some extra tubing to eliminate the MAF position. I will still be doing this in the very near future, I just got delayed a little while. I will port matching the intake manifold inlet to the TB as well. I will post results. I have headers to install, and already have a 3.5'' single exhaust.
I think that I should be able to make an '03-'04 Navigator K&N cai work with some extra tubing to eliminate the MAF position. I will still be doing this in the very near future, I just got delayed a little while. I will port matching the intake manifold inlet to the TB as well. I will post results. I have headers to install, and already have a 3.5'' single exhaust.
Thread Starter
|
Senior User
Joined: Aug 2008
Posts: 253
Likes: 0
From: San Marcos, CA
in the vans, the air filter is on the engine centerline and lives above and just in front of the engine just behind the rad. because the element used is also used in 2L pinto motors, i chose to purchase an F350 K&N element. i actually reused the factory induction piping, with some careful cuts of course, and located the new filter where the original battery resided - i used the ambulance tray and relocated it to the pass side. i did use a couple of feet of muffler tubing - hit my muffler guy up for some aluminized exh tubing. fast and easy, doesn't rust and will polish up nicely if you choose to put out the effort. i then sliced into the fenderwell to provide high pressure fresh air from a scoop in the airdam.
neil
neil
Thread
Thread Starter
Forum
Replies
Last Post
neil 95 e350
1968-Present E-Series Van/Cutaway/Chassis
2
Oct 4, 2008 08:50 AM
neil 95 e350
Fuel Injection, Carburetion & Fuel System
1
Sep 20, 2008 01:17 PM
neil 95 e350
1968-Present E-Series Van/Cutaway/Chassis
3
Sep 7, 2008 02:47 PM
neil 95 e350
1968-Present E-Series Van/Cutaway/Chassis
5
Sep 3, 2008 05:48 PM
