Topic: Exhaust system - opinions?

[ACL]

G-HDAE's exhaust (original type) has a stay mounted on a bracket just aft of the point where the #4 cylinder exhaust down-pipe meets the main outlet pipe, the other end of which mounts on the crankcase. I can't really work out what purpose the stay serves - the exhaust system is held on by four sets of big nuts, whereas the stay attaches to the bracket by a single skinny little bolt - hardly adding a great deal of support to the system overall. What it has done is inflict a point of resonance that caused the pipe to crack most of the way round its circumference!!! A quick look at a couple of other Chippys reveals that their stays have been removed (or never fitted).

So while the exhaust is being repaired, I'd like to know what folks out there think the 'support' stay does, and whether we would be best leaving it off altogether.

Thanks for your thoughts,
James

[Nigel Stevens]

James,
A mod exists related to the exhaust pipe bracket. H277. I'm not sure, when you say original type exhaust, if your are refereing to a pre mod H277 system.
Pre H277 there is a bracket welded to the exhaust pipe and the stay is bolted to this. There was apparently cracking around the bracket welds on the exhaust system. My exhaust system was pre H277 and was cracked at this point.
Mod H277 consists in grinding off the bracket ( and presumably welding up any cracks, although it does not say that on the mod sheet) and then replacing the bracket with a strap bent round the pipe and bolted to the stay. The strap is not welded to the pipe and can be positioned to avoid strain when the nut and bolt are tighted.
According to the mod sheet they blamed the cracking on "different tolerances on some installations causing undue strain to be placed on the existing weld clip" with the pre mod bracket.
regards
Nigel

[Duncan]

We still have the stay on G-BDRJ's exhaust, and it currently shows no sign of cracking.  I guess Nigel's point about it being "different tolerances on some installations" bears up the point that some have had Mod H277 embodied, and some have not.

Interesting issue to watch out for on the older exhausts though, especially if replacing them for reasons other than cracking around the problematic bracket!

[ACL]

Thanks for the info.

My exhaust was clearly a pre-mod 277 one as it had the stay bracket welded on. I have sourced a replacement exhaust which has been modified, so hopefully that problem is in the past.

James