350i Exhaust manifold

[Jas howells]

Just starting to try and get my 350i on the road. Gonna need help with a load of parts I think, but starting with the obvious problems. The exhaust manifolds have a number of cracks and will need replacing. Are the manifolds straight off a Rover V8 or are they TVR made? Any recommendations on sourcing new manifolds? Thanks

[mk1fan]

I got a set of nice stainless ones from ACT with '500' sized headers that I then got ceramic coated before fitting. Don't recall any issues during fitting.

Wendy made 187hp when I got her set up on a rolling road (factory ecu etc..) afterwards. Not that far off the 197bhp that TVR they produced.

[keynsham]

mk1fan said:

I got a set of nice stainless ones from ACT with '500' sized headers that I then got ceramic coated before fitting. Don't recall any issues during fitting.

Wendy made 187hp when I got her set up on a rolling road (factory ecu etc..) afterwards. Not that far off the 197bhp that TVR they produced.

Do the ACT manifolds fit well in between the chassis and gearbox? On my original headers, there is a joint in the pipe on the offside longer pipe to allow the header to be fitted I assume, location shown at red arrow in picture. The issue is that the joint has been made oval to fit between the chassis and gearbox and it is very hard to seal. I see that there is no such joint in the ACT headers?

[mk1fan]

mk1fan said:

Don't recall any issues during fitting.

[Jas howells]

Thanks for the guidance I will look up ACT.

[Wedg1e]

My r/h manifold looks like the one shown but is in one piece all the way to the captive elliptical clamp; it has been squashed in a vice or similar to get it through the chassis/gearbox gap ... as has a spare manifold I bought from another owner a good many years ago, but I don't want to part with it as sooner or later it'll need to end up on my car. The guy who had it made was unimpressed with the squashed bit and had his fabricators make another with an extra kink to go around/over/under the obstruction.

The SD1 manifolds won't fit around/within the TVR chassis.

Depending on where and how badly the OP's manifolds are cracked they could possibly be welded, although the internal soot usually gets pulled into the weld so it's often not pretty. Stainless is also more prone to cracking owing to the heat cycling and vibration.

Edited by Wedg1e on Tuesday 17th March 23:20