TR4A Bell exhaust system

[Jase]

Anyone have any pics of a twin Bell system on their 4A or 4?

Thanks

[Z320]

Bell exhaust on original TR4A cast iron exhaust manifold?

[Jase]

on a stainless manifold which I think is Kestrel?

[Z320]

Sorry, mine is on the original manifold, this is different

[Jase]

Wouldn’t rhe end pipes be the same on the twin exhausts?

[stuart]

FWIW I found the twin pipe exhausts to be noisier than the singles and had a nasty resonance around 2500rpm

Stuart.

[PaulAnderson]

On 12/3/2024 at 11:29 AM, stuart said:

FWIW I found the twin pipe exhausts to be noisier than the singles and had a nasty resonance around 2500rpm

Stuart.

Is that all makes of twin pipe systems Stuart?  I ask because I’ve got a twin pipe exhaust and have a resonance around 60mph, necessitating faster driving for comfort.  I’ve not found the cause to date, but do have the blob fitted on the gearbox.

[stuart]

11 minutes ago, PaulAnderson said:

Is that all makes of twin pipe systems Stuart?  I ask because I’ve got a twin pipe exhaust and have a resonance around 60mph, necessitating faster driving for comfort.  I’ve not found the cause to date, but do have the blob fitted on the gearbox.

It seems to be the cheaper Falcon and TT ones, the blob doesnt make any difference its the actual exhaust design itself. 60mph is the area too. I sold the one I had on mine as it droned and went to the larger bore single pipe/single silencer system and its actually quieter. My blob fell to bits but it seems ok without now.

Stuart.

[trchris]

Hi Jase

when l bought my 4a it had the twin rear pipes and l found the same as Stuart replaced with a phoenix system resonance gone

Chris

[Jase]

2 minutes ago, trchris said:

Hi Jase

when l bought my 4a it had the twin rear pipes and l found the same as Stuart replaced with a phoenix system resonance gone

Chris

I would put up with that all day Chris  love the look of the twins on these cars. Something very 80s about it.

[stuart]

15 hours ago, Jase said:

I would put up with that all day Chris  love the look of the twins on these cars. Something very 80s about it.

It was because of having to put up with it all day (Living where I live its a 3hr run before you hit civilisation) that I changed it. The drone is just at the normal cruising RPM.

Stuart.

[PaulAnderson]

I recalled contributing to a thread on exhausts a while ago and looking back at that post resonance is also mentioned then.  A new exhaust might have to go on the long term but likely never to happen shopping list.

Mine currently is a Double S as sold by London TR Shop. They list a Bell exhaust, which I’d not heard of until this post, but it’s the transverse box type

Edited December 14, 2024 by PaulAnderson

[Z320]

I bought my TR4A IRS with a Bell twin exhaust connected to the original cast iron manifold.

From there two pipes go into a pre-silencer, 

from the pre silencer one big pipe through the frame to a Y to the two silencers.

The former owner had problems to fix both rear silencers with the rubber straps on their brackets.

He cut them shorter and redrilled them - but too short.

It was always difficult to get both pipes to the same height.

I ended with making own brackets.

Ciao, Marco 

Edited December 15, 2024 by Z320

[BlueTR3A-5EKT]

A longer rubber strap from the front mount of the crossways silencer of Triumph TR would have been my fix. Then pierce a new hole in the right place to get the heights nice.

 

 

[tim hunt]

At one point in the '70s I fitted two twin pipe big bore PECO silencers to the 4A for that V12 rear appearance. They sounded great up to a point but there was an awful reverberation period somewhere between 2,500 and 3000 rpm that made motorway cruising in o/d top a real pain on the ear drums. I ditched the system for a Phoenix single pipe. A pleasing note and no nasty reverberation at any engine speed.

[Z320]

I might give some attention next year for vibrations I never noticed before.....

[Jase]

In the process of removing the whole system at the moment so I can change the exhaust back to the manifold.