Help! Aussie Exhaust Manifold

[Anonymous]

I purchased an aussie head complete with intake and exhaust manifolds on ebay last year and now have assembled my engine and have run into a problem. The manifold supplied, in additon to the header I had, do not seal against the aussie head. There is a 3/8" gap atop the center exhaust port (the manifold extends beyond the head surface). The head appears to be a '71 casting and I believe the exhaust manifold is a 76. The casting numbers on the manifold I believe are aussie as they definately are not US. Do I have mixed parts? Are the manifolds year specfic and how do I remidy my problem? Not that it should matter, but this is installed in a '68 Mustang. Any input is appreciated. :x

 

[addo]

Dan, all 2V motors came with a set of headers from the factory. (We call them extractors here.)

The "quick and dirty" fix is to load up the top of your cast manifold with weld, and resurface. The other fix is good quality headers. I personally would recommend Pacemakers but you may be constrained by budget.

With a 200 in a '68 engine bay almost any brand headers will work, but try to avoid ones that crowd the starter.

Avoid the port divider.

Regards, Adam.

 

[Anonymous]

Thanks Adam. I did installed a port divider on the US head on my brothers Bronco and did notice that the US head had the grooves for the port divider to interlock into and the Aussie head does not. Is this the reason for not using one as it would create turbulance from the ribbing?
Dan

 

[addo]

Dan, this is a touchy subject! Ford substantially repatterned the head when they made the 2V. Considering that they specified headers with every car sold (remember even the K-code Mustang came with cast shorties!) they obviously considered performance an important attribute.

It would have been a piece of cake to recreate the centre exhaust ports for independent runners and draw the choke heat from a tube welded to the headers. Yet they did not. To me, that says it's of negligible value to this head and normal applications.

I know of one 2V head that was cracked about the time of installing the port divider. Probably from excess force - but why risk it? Aussies who believe separate ports are a must, used to weld a "fin" to the flange face on their headers. You make it to fit the ports with just a touch of clearance (say 1/16" - 1/32") and then weld to the flange. Recheck afterwards to avoid any binding or stresses.

Regards, Adam.

 

[250mav]

sorry to butt in but would an aussie extractor fit a domestic U.S. 250?

 

[addo]

Like the ones for sale? Possibly. Location of the starter motor is different on the US 250 (it's lower), that is something of an issue.