350i Exhaust manifold
Discussion
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
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.
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.
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?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.
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.
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
Many years ago I replaced the manifolds on an 88 350i and an 87 420SEAC three times. The originals and the replacements from Richard Thorpe and ACT all had the squished kink in them. On one set I used a car jack to squeeze it past the chassis. The SEAC had two sets because the exhaust wrap I put on the first set made them glow red hot and they distorted and flaked away (non-stainless). I wouldn't use the wrap again.
adam quantrill said:
Yeah but when you you look at the manifolds?
Most times a few cracks can be welded over and then a small amount of assembly paste smoothed in to fill any pinpricks. MUCH cheaper than replacements (that will crack anyway).
The system that's been on my car since well before I bought it is stainless apart from the mild steel manifolds. In fact, the last 6-8" of each of the manifolds was replaced with a length of stainless as apparently it was considered bad practice to run mild all the way to the olive joint on the silencer inlet. A few years ago the joint between the mild and stainless cracked most of the way around so I had to extract the manifold and reweld it. Luckily it was the easier of the two to remove. I suspected I'd clipped a speed hump or similar as the lowest point of that manifold is lower than the chassis. Both manifolds have had various cracks and holes welded over the last 26 years... my MOT guy used to have a good titter at the 'quality' of the work but he died suddenly a couple of xmases back, his brother who took over tuts and shakes his head instead.Most times a few cracks can be welded over and then a small amount of assembly paste smoothed in to fill any pinpricks. MUCH cheaper than replacements (that will crack anyway).
One of the other drawbacks of stainless is that the silencer can outlive the wadding inside it; I did a piece about ten years ago on my website about cutting it open and repacking it with stainless wire wool... but it made absolutely no difference to the sound level!
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