Who Makes Alfetta 4-2-1 Race Headers?

[Martyn]

Would appreciate any advice/experience where to buy race headers for Alfetta either 4-2-1 or 4-1 configuration. Must gather behind engine mount. I've seen & read lots of stuff about 105 setups but it is unsuitable for adaption in a 116 engine bay and floor pan.
Has anyone done the sums on the relationship between the length of the primaries + secondaries to the length of the tail pipe for best torque?

Thanks
Martyn

[Neil Choi]

Martyn

Hugh Harrison at Alfpa Repairs in Bayswater is making them.

Give him a call, 9729 9946

Neil

[Martyn]

Thanks Neil.
I know PACE make headers to.
So that two sources.
Any more in Australia that someone can recommend?
Regards
Martyn

[bonkfrog]

Martyn

I know that Vin Sharp makes good quality stuff, although he's away at the moment.

Bonkfrog

[Martyn]

Bonkfrog
I think you may have spent too much time making tadpoles in the Bigpond!
PACE & Vin Sharpe are one and the same.
Thanks anyway.
Martyn

[MD]

Has anyone done the sums on the relationship between the length of the primaries + secondaries to the length of the tail pipe for best torque?

Martyn,

A general rule of thumb is that the combination 4-2-1 is marginally better toque at lower RPM whereas
4-1 makes marginally more torque at higher rpm so the choice is relative to where you will spend most of your rpm time. Equally, it is more beneficial to use merge collectors to make the transition from one group to the next as opposed to just forming Y junctions.

With respect to the tail pipe, any more than 2.25" OD for a 2 litre* is just more weight. As for it's length, well, the shorter the better for the same reason.

Can't help with fabricators as I make my own. Here's some pics of my previous engine and primaries feeding into a 4>1 collector.

* where the output power is around 180bhp. Beyond that 2.5"OD is rated for 192 and if you are in the extraordinary achievers group of naturally aspirated donks, 2.625" OD will handle 213bhp.