Exhaust Gas Temperature vs Engine Timing

[veggie]

Today I made the necessary adjustment to speed up my Listeroid and increase the kW out of the system for service as an emergency generator instead of a 450 rpm battery charger.

The changes involved...
1] Installing the correct generator pulley for 750 rpm operation.
2] Changing the governor spring to the stock 750 rpm version.
3] Slightly advancing the timing (it was retarded for slow speed operation and knock reduction).

For slow speed operation (450 rpm) I retarded the timing by screwing-in the IP lifter tappet by 1.5 turns.
Today, I backed out the tappet by 3/4 of a turn.
Not back to the factory setting, but just enough to advance the timing and still give significant knock reduction.

My question:
Does a few degrees of timing substantially effect the exhaust gas temperature (EGT) ?
The reason I ask is that after running the engine for an hour at full load (3kw) I noticed the hi temp silicone tape was burned off the first exhaust joint.
This tape has been on for many hours and has never showed any signs of heat stress.
I am trying to figure out which one caused the higher EGT's...

A] The timing retarded by 3/4 of a turn from factory stock ?
B] Or just the fact that I am now pulling 3kw (6hp) from the engine instead of 2kw (4hp) ?

Any ideas ?

http://www.youtube.com/watch?v=Af41jQcBP7M

Oh...and.... what's the normal full load EGT temperature on a Listeroid    anyone bothered to measure that ?

Cheers,
Veggie

[Dualfuel]

Hi Veggie,
Its been my experience that one advances the injector pump timing to lessen knocking. The idea is that the fuel spray has slighty longer to start burning.

I'd bet the reason the sealant is burning off is that you are now burning more fuel.  Whether the fuel is still burning when the exhaust valve is open could have something to do with the timing being retarded. If you advance the timing to 1 or 2 degrees BTDC, you might get most of it to burn before the exhaust valve opens. Regardless, if you are producing an output of 3hp then you are burning at least 50% more fuel then producing 2hp, perhaps more depending on where the bsfc curve lies.

Do you have another thread where you describe setting up the Lister? I have a facsination with them but its strictly arm chair. How many hours have you put on the engine and what is its fuel consumption?
Yours,
BPJ

[veggie]

Dualfuel,

Don't know the fuel consumption, sorry.
Never bothered to check it.
Have a look in the Listeroid section and on the Lister Engine Forum.
Ronmar did some useful testing and documentation and I think it's published on both forums.

veggie

[Westcliffe01]

Can't speak for a diesel, but on my Mercury outboard, the first 50% of throttle advance does nothing more than advancing the distributor, only after that does the linkage start to open the throttle from the idle position.   Also with the new emissions systems on gasoline cars, I know that they retard ignition when cold to flow flaming exhaust gas out the cylinder and into the exhaust to heat the catalyst up faster.

Mechanical injector timing is more complicated because timing and injection volume may be coupled.

Maximum service limit temperature for silicone is 600F, it does not seem hard to imagine you might reach that temperature.  Perhaps you could try to obtain a flex element (bellows) instead of using silicone ?