Club 80-90 Forums

Why do some folks lag exhaust pipes with asbestos?
I have seen it on custom bikes too and on those I think it looks very odd

Either to protect things nearby or as a performance mod. By keeping the heat in the exhaust gases, there is a small increase in gas velocities in the primaries.
A friend of mine fully lagged the exhaust in his street-legal Jag mk2 racer and found several bhp for nothing, might have been in double figures on a 260 bhp engine.
Also the paint on the floor doesnt burn but the tailpipe gases are at 200 deg C....

ghost123uk wrote:Why do some folks lag exhaust pipes with asbestos?
I have seen it on custom bikes too and on those I think it looks very odd

Sometimes on the bikes John it's used as a heat shield on the link pipes - was actually thinking of doing that on my SP as they get bl00dy hot and it doesn't help there being a radiator on each side as well generating even more heat. When your in hot weather with your old power ranger gear on can get a bit warm up the old trouser leg

ghost123uk wrote:Why do some folks lag exhaust pipes with asbestos?
I have seen it on custom bikes too and on those I think it looks very odd

Not so much performance for me, more a way of reducing engine bay temp in standing traffic. Juries out at the moment as to whether it works or not. Oh and not asbestos (would never touch it for obvious reasons) they are made from basalt rock I think.

Love my Kawasaki can. Wouldn't go back to an OE box now - they're stupid money. With baffles in good order you just get a quiet rumble. Floor it in 3rd though and it sounds like a Ferrari

Yesterday some lager-swilling schoolboy passed me in traffic with a an exhaust that sounded like he was red-lining it on a track - he was doing just 20mph. Laughable. At least my engine is actually doing what it sounds like its doing.

Just fitting a 900 suzuki box to my 1.6 td nice alloy box which can be fitted using original exhaust fittings (three bolt) original plan was to put it in normal position but now think cutting pipe back and sticking on left of engine bay facing back. Pics when its done also stuck a k&n type air filter in the box on the left and a breather catch pot. Already noticing that the turbo spins up faster and can actually feel a push (if not a kick).

You wouldn't think a cheap bike can would actually be an improvement over stock exhaust - particularly when it wasn't designed for an engine like this, but it can work rather well. The slight downside (perhaps) is you sometimes find the reasonant frequency of some cans is somewhere you don't want it to be - ie at 30mph which through town is mostly the speed you drive at and can create a somewhat uncomfortable drone until you speed up or slow down.

Its a 'mod' in insurance terms but not exactly a game changer. I can't see it being a reason to refuse to pay out anyway. They might take a dim view of alloys not rated for the job - they tend to make a beeline for wheels and tyres.

Cheers for the info on the exhaust Nic (unable to PM a response to your message). Going to try & get my mate to fabricate a slight turn on the exit.

Ralph, once I eventually get this done I'll post up some pics.

Cool. Well worth doing. Not everyone (particularly if you're bringing up a child on your own as I am) can find the cash for, or justify a full stainless system. Besides which, time is sometimes a factor - like just days to pass an MOT with a holed silencer or rotted tailpipe. Its also one of those fun challenges that can work out well.

Exactly mate - its a challenge & something slightly different to the norm which is what I like

So I had an exhaust delivered and attempted to fit it today. So far I have snapped 3, and rounded 2 nuts of the 6. Got 1 off though. How do I go about sorting out the snapped ones, can I drill the, out and just replace with new bolts? What a bummer! Not sure what to do now.

Any help would be great.

Cheers
Josh

PlusGas all the 5 studs. Get some grips on the studs left and try to work them back and forth. The ones that are snapped too close to head, drill them out. If no joy, you're taking the heads off-carefully, try leave the piston shells on though, and pillar drill the studs out of the heads. You may need some heli-coils once you have re-tapped the holes.

https://www.youtube.com/watch?v=66ATKL4G04M" onclick="window.open(this.href);return false;

If not, https://www.youtube.com/watch?v=fjlnqlWDbfo" onclick="window.open(this.href);return false;
I bought a set - best thing in my toolkit.

DoubleOSeven wrote: If no joy, you're taking the heads off-carefully, try leave the piston shells on though

Always work hot. Beg/borrow/misappropriate a propane lamp and warm the heads up, it helps to release them from the barrels.
Then locally heat up each boss and try to get the stud moving if there is anything left to grab.

PS if you have pulled the heads then you may as well draw the barrels up (in turn, dont pop the rings) and renew the bottom seals. Assuming that the top seal grooves aren't pitted...