New exhaust glowing red! Any ideas???

[Jamie25]

Just finished swapping my old exhaust over for a new stainless version from VW speedshop. Had the engine out in order to sort a few issues: helicoils for a few of the exhaust studs, new clutch, engine and gearbox oil change plus renewed both the crankshaft oil seals and gave the engine a bit of a scrub.

The exhaust bolted on pretty nicely with any real issues. Started up the engine and started to bleed the coolant. Engine was running really rough, which I put down to the timing perhaps being out. The old exhaust leaked badly from at least two of the manifold gaskets where thread had gone in the head, hence the helicoils. I put the bad running down to incorrect timing, possibly due to completely different back pressure due to new exhaust. Thhought I'd bleed the coolant then sort the timing. However I stopped as it was approaching temperature as i noticed the two front manifold pipes glowing bright red and the rear ones just starting to glow!!!! I assume this isn't normal with a stainless system!

Any ideas folks? I'm running lpg which I know runs hotter but surely not that hot! I did have the engine at increased revs to warm it up but only about 2000rpm at a guess, certainly not revving the nads off it.

[Oldiebut goodie]

My old BSA M20 motorbike exhaust would glow red when the manual ignition advance/retard was incorrectly set.(handy for lighting cigarettes). Good chance your ignition timing is still incorrect. Sort that out before anything else and you do some damage.

[Jamie25]

Cheers Oldiebut Goodie. My first thoughts went to timing and in hindsight I should have done that first instead of worrying abouty bleeding it. Always good to get a second opinion though. And hindsight is always 20-20!

Off to wiki to see how the timing should be set on LPG, and then no doubt the alternative fuels section. Cheers

[VWCamperfan]

Stainless exhausts are only about 50% as effective at getting rid of heat compared to the old steel exhausts and so could glow under certain contitions. Timing and mixture do need to be checked though. Overheating like this can also be caused by too lean a fuel mixture.

[Jamie25]

After reading up on the alternative fuels forum I've just realised how important the mixture is when running on LPG. I know how to do the timing but I'm scratching my head after that. I assume that to a certain extent the carb is redundant when running LPG? By that I mean that to tune it I need to set the timing to 5 deg after tdc, then tune with the power and mixture screws on the LPG, although I don't know which is which and which to do first, or indeed how to set them!
It was fitted by gasure a fair few years ago but I'm miles away from them.

[Plasticman]

ran up a big block v8 some years ago nad all 8 lines glowed turned out it was well retarded.
m

[Jamie25]

That's not a very nice thing to say about your engine!

[Plasticman]