hey guys, i recently bought a 4.6 dohc out of a 98 model Mark VIII. However when it was shipped to me it got severly damaged by the shipping company, crack/crush intake manifold, brocken alternator case, brocken throttle body just to name a few . Any way iam after some advice.

The engine is going to be built twin turbo, and i was wondering;

What intake maniforld, aftermarket or standard off another model, would suite these heads and what would you recommand? I've notice the intake on the heads seams differnt to many of the other DOHC head i have seen

Can i do away with the Intake Manifold Runner Control? (i will be running an aftermarket computer)

cheers

 

The only intakes that will fit that engine available in the U.S. are the 96-96 Cobra Manifolds, and the 97-98 Mk VIII manifolds, I don't think there are any aftermarket manifolds for 4V "B" heads. The only other option would be custom fabrication.

You can elimante the IMRC controls, but you will need to keep the plates if you use a Ford Intake Manifold because the injector bungs are in the IRMC. You can uncrew all the plates and remove the rod, and plug the end(s) to make it into a "IMRC Delete Plate".

Actually a stripped set of IMRC plates make a good start to an custom fabricatied manifold because they have the correct port and bolt pattern to match the heads and already have the injector holes which will accept fuel rails made for the production cars. You just need to add some runners going up to a common plenum.

 

I was told if you remove the IMRC, cause the ports are so big and there is no longer any thing to litmit the air flow they get too much air and run rough and lean down low is this true?

I was really looking forward to a nice aftermarket intake manifold but i havent found any to suit the "B" heads yet. Are the B heads any better or worse then the other tyrpes of heads?

 

The only aftermarket intake for B heads is a Hamilton Clarke. I have one on my 98 cobra. It is a great intake, but it does need quite abit of rpm. You can also use a 96-98 Cobra intake and shorten the runners. They don't make the HC intake anymore so you have to look real hard to find one.

JR

 

So can you actually remove the IMRC and the engine still runs alright down low or am i pritty much stuck having to use it?

 

I was about to post about the hamilton-clark intake. I was aware of them though i have never accually seen one before. Or heard of any power numbers with one.

 

Deleting the IMRC's is kind of like changing from a Dual-Plane Manifold to a Single Plane Manifold, it will significantly soften the bottom end, but as long as your cam timing is not too extreme you should be able to tune for it in the fuel injection.

 

yeah well iam hoping the boost iam goining to stick up its ass will bring some more torque down low and i spoke to the boy a sullivan performance and they are bringin out a manifold to suit the b heads hopefully in about 6 months time

 

They have been saying that I think for about 2 years.

 

My intake has supported a bunch of horsepower. 900rwhp thru a 5spd 20lbs of boost and 16* of timing on c16. The HC intake is by far the best intake for b heads if you can find one.

JR

 

I just picked up this same engine. Does anyone have any pics of this intake? I can weld aluminum. So maybe I can build an intake I dont know what to do yet??????????????