The Triumph 2000 / 2500 / 2·5 Register Forum

Come to the UK for either the 2000 2.5 National or the Triumph Spares day at Stoneleigh and save on the postage?

Car in bits, manifolds and complete exhaust off. Seemed pointless putting it all back how it was and as postage was actually only £17.50, I rung Witor and ordered one of his 6-3-1s, which arrived today. It's the angle of that front pipe that makes all the difference!

It should be fitted to the car Thursday, so I'll pop along and spend some time getting under Meister Ulli and assistant Tillman's feet while 'we' do it. Nice to have stainless steel though, as both the original and the TR6 jobby were quite rusty, so it will also improve engine bay appearance.

It will need Wrapping or coating as it puts a lot of heat in the bay causing Vapourising.

Lee

Hello Lee,

I have seen quite a few views on line that wrapping an exhaust can lead to problems of cracking etc with the manifold. General consensus I've seen is don't wrap. Ceramic coating appears the answer but at a cost. Perhaps easier to vent the engine bay or introduce extra cool air in?

Alec

Alec wrote:Hello Lee,

I have seen quite a few views on line that wrapping an exhaust can lead to problems of cracking etc with the manifold. General consensus I've seen is don't wrap. Ceramic coating appears the answer but at a cost. Perhaps easier to vent the engine bay or introduce extra cool air in?

Alec

I wrapped a mild steel 6-3-1 and then destroyed it driving through a large puddle - got too hot and went crystalline then shattered.

I don't wrap now - vapourisation isn't such an issue if you run PI - a heat shield stopping radiant heat is the best plan - allows the manifold to stay in the cooling air stream but stop most of the serious heat from hitting the inlets - the hot air isn't the issue - air is good - run the car on a dyno at max torque or power in the evening light to see the issue - extractors will be cherry red (or purple if stainless). Perhaps best shield is 2 x very thin polished stainless with insulating material sandwiched "edit" Just found this https://www.merlinmotorsport.co.uk/p/ci ... aero-cir-s

That's probably ok for standard cars but i'm reving to 6000+ So I've wrapped Mine. The cost for coating is more than the exhaust so in my eyes its sacrificial.

lee

I suppose I'll put it on as it is and then take it easy for a while to see how it goes.

I don't do long journeys much and don't race around either, but I do like the idea of running some kind of tube/pipe(s) from the front or underneath the car to point at the manifold. Also, some kind of metal shield sounds a good idea.

leesellars wrote:That's probably ok for standard cars but i'm reving to 6000+ So I've wrapped Mine. The cost for coating is more than the exhaust so in my eyes its sacrificial.

lee

My 2.5 goes to 6500 and my 2100 to 7300... Sometimes in over 40deg ambient.
To be fair I think stainless copes a bit better than mild steel so your extractor should be fine. Be aware that stopping radiant heat at the engine means the whole exhaust will run A LOT hotter - particularly past the gearbox, speedo cable etc

Hello Christopher,

I have run my P.I. with a 6-3-1 manifold unlagged for ten years or more. I drive it pretty hard on the road and was initially concerned that the starter motor might malfunction due to the extra heat. In practice no problems whatsoever.
Do some research on the web, there are some horror stories out there of problems caused by lagging exhaust manifolds.

Alec

It's all fitted and it looks great and sounds great. As for power difference, there is nothing noticeable below 3k RPM! So far no issues with the extra heat, it runs just as it used to. It got a bit warm when idling for a while, but I have an old electric fan fitted and can manually switch that on if I need to. Pic attached of the rear of the new system. Ground clearance is less now, so I have to watch out on speedbumps.