Pan Exaust question

[George Greer]

Another seemingly id10t quesion.

Why is it on most of the exaust ports on the heads for pans buggered up?

Lack of attention to mounting's coming loose...mishandling? Design of the exaust system?

Just about every head that I have seen has several degrees of damage to the exaust ports.

Just curious.

George

[jdpan]

Mostly due to loose clamps and years of vibration.

[Panshovevo]

Probably the difference in the expansion rate between the aluminum head and the steel exhaust pipe is a contributing factor.

Regards,
John

[Billpan58]

Running drag pipes years ago that went outside frame w/o squash pipe, pipe would hit when you cornered, if you werent careful. mine decided to fall off near chicago,returning from the west coast[early 80's]. lucky for me a truck repair shop was able to tack it back on so i could get to central mich. area. had it rewelded,still runing it.

[pusher]

junky exhaust spigot design (look at the shovel exhaust port design that followed this one)
chopper guys not properly bolting the custom exhaust system in place creating stress on the spigots
over torquing the clamps, vibrations
dumping the bike
probably was easier to get your hands on a good oem head back in 60/70s

[Bigincher]

Like 'pusher' says, over-torquing the clamps can contribute to the problem. I've actually crushed the spigot a little when using those hot-shot aftermarket 'aircraft-style' clamps. You have to be careful with those.
Lately, I use a little of the red RTV silicon as a sealer-- let it cure, trim off the excess that goo's out, and all is well.
Other than that, all the above reasons are valid........

[George Greer]

Thanks all.

George