Wrapping exhausts

[six]

I need some confidence boost here...

I've recently fitted a Halco style 840cc kit, complete with oil cooler and the location of the oil cooler take-off dictates that I need to wrap the exhausts.

The exhausts were made for me by a friend - 1 3/4" OD stainless, which is somewhat larger bore than standard. I've heard that wrapping the headers can cause an increase in the gas temperature in the ports and I'm worried that the combination of this and the large bore might cause problems with the exhaust valves overheating and burning out the seats.

Does anyone have any experience of anything like this? Any advise is greatly received!!

[skimmer]

My experience is that 1 3/4" is too big even for the displacement you're running. You can do some stop gap measures such as anti reversion cones to help out. Wrapping the pipes keeps the exhaust gas temp up thereby increasing velocity and will probably help you out. Personally I can't see why this would lead to an increase in exhaust port temperature, at least a drastic increase, so if it was me I'd wrap them even though you'll cover that beautiful stainless. I'm sure grizld1 will have some words of enlightenment. good luck, skimmer

[six]

Thanks skimmer!

The pipe size was out of necessity - I needed pipes for an MOT and my mate had some lying around... *cough*. Personally I like the wrapped look.

[cjmahone66]

like skimmer said, the wrap keeps heat in, and higher heat means the exhaust gasses will move faster.

[650leo]

Your pipes are 1 3/4 outside diameter, that will make them about 1 and 5/8 inside. They should be ok. wrapping the pipes is an old trick to improve h/p. By keeping the exhaust hotter ir increaseing the speed of the exhaust gases. Faster moving gases scavange the cylinder better, better scavanging = better cylinder fill = more power. It won't overheat the valves or seats, with better flow it will keep them cooler.