Ipgo,
if possible, could we avoid the use of the word 'explosion', as the combustion process in an engine should always be a 'controlled burn' to ensure that peak cylinder pressure occurs between 10* & 20* ATDC?

Here's why I said that EGT and CHT are not always inextricably linked...
"In the initial stages of detonation the EGT will decrease and the CHT will increase."
From: http://www.experimentalaircraft.info/ar ... nation.php

That's an instance when having both CHT and EGT instruments operating would alert the driver ( or pilot) to a potentially disastrous situation, as presumably pinking would not be audible to a race car driver ( or a light aircraft pilot).

ken

True,
also the hotter you can keep the exhaust gas, the faster it will go down those pipes...

ken

[quote="ken"]True,
also the hotter you can keep the exhaust gas, the faster it will go down those pipes...

ken
quote]

A must for a turbo-car. Keeping the exaust gasses as hot as possible when hitting the turbofan....

Thanks for loads of response. I'm aware of CHT and glowing exhausts will be 700°C+. However I'm after a figure, EGT for a standard(ish) 2cv engine.
A good estimation from someone with some experience on this would be perfect.

Thanks!

I can't see that the temp range on a normally aspirated petrol engine would be that much different, I recall the stainless header pipes glowing quite a nice cherry red on my BMW K series bike,when I ran it on full revs whilst stationary ( I did have my reasons) Also from the colours I've had on my Norton Commado's headers,I would suggest the same sort of temps.
However without a thermocouple in the exhaust stream or other method the actual temp would be hard to test. Also I had forgotten to mention the heat wrapping of exhaust is intended to keep the gas temp high to aide faster flow, which in turn pulls the next fuel air mix in faster,hence a more efficient engine,that's it very basically.Good luck with your thermodynamics

Youve had it!
Burning petrol is the same if its being burnt in a Honda Civic, a Rotax Aicraft engine or your 2cv the race car glows its exhaust because its pumping more hot gasses( in a thin stainless exhaust with no cooling going on!) than a 2cv at idle.

id expect if you tested it, a standard engine isn't going to produce any more than 800*C

Also, most of the dual CHT gauges I've seen are set up so that their needles are around horizontal at 'do not exceed' readings, usually 200 *C.
http://www.vwjim.co.uk/ourshop/prod_123 ... Gauge.html
Since the thermocouples are (usually) fitted under the plugs, there should be little or no variation between installations.

However, with EGT instruments, the actual location on the manifold ( i.e. distance from the exhaust valve) will affect the readings obtained.
http://www.aircraftspruce.com/catalog/i ... 2-002C.php
Assuming that the instrument manufacturer's advice is followed regarding location and also that same logic has been used as when designing a CHT display, 'around' 650 *C might be a good guess?

900 *C does seem to be in the 'only for the brave/foolhardy' zone...

ken

So is there an advantage to wrapping the first part of the exhaust manifolds, what about the hotspot tubes should we wrap thoes as well?

Yes there is but only behind the . horspower wise..... so very little, other things like turbotube, better airfilter, good ignition timing, exhaust, proper jettet carburator, valve clearance gives you much more horspower wise....

Yep, all of those...
The possible increase through insulating the exhaust on a road car is probably not worth the time and effort.
Plus the wrapping seems to retain moisture and so tends to cause rapid rusting of the exhaust...

ken