Engine preheat

[RJ]

Note to purists: a small sniff, right up the air intake, with the filter removed, while cranking, won't put her in the methadone clinic.

Note the key word here:  "A small sniff".  1 - 2 second burst is all that's ususally needed, if it must be used.

Some folk, btw, use WD-40 instead. . .

[Chaz]

Some folk, btw, use WD-40 instead. . .

I have heard that. Anybody know the pros and cons??

Chaz

[Lee Bradley]

I would not want my filter covered with WD-40 but if you're adding it downstream of the filter shouldn't be a problem. Works because the propellant flammable i.e. A-70 HYDROCARBON PROPELLANT (ISOBUTANE & PROPANE) was the WD-40 propellant. The March 1998 MSDS for WD-40 shows that they switched to carbon dioxide as the propellant so it probably doesn't work as well. It still may work as the WD-40 has a FP of 110 degrees F although my most current MSDS shows a FP of 131 degrees F some what higher than diesel. But what we are interested in is autoignition temperature the temperature that the material ignites without a spark or flame. Diesel is 494 degrees F; that is the temperature the combustion chamber to reach by compressing the air for the diesel to ignite. On a cold day, you are trying to get cold air to that temperature, surrounded by cold metal, just by squeezing the air. ETHYL ETHER the main component of starting fluid has an autoignition temperature of 320 degrees F; so you don't have the air quite as hot however because the ether is mixed with the incoming air, it can ignite before the diesel is injected and you have pre-ignition and all the bad things, others have identified, can happen. The engine is going to compress the air and create heat when it is cranking if you stop cranking for a while that hot air in the combustion chamber will warm the metal better than if you keep cranking and pushing more cold air through the engine. So each time you crank and stop the piston and head 'soaks' in a little more heat also more fuel accumulates in the combustion chamber there by raising the compression ratio slightly and therefore more heat when cranking. So when the engine starts, all that unburned fuel turns to vapor (white) and kills most mosquitoes within several hundred yards but some of that diesel is pushed passed the rings and into the crankcase where it dilutes your lube oil. These engines are large pieces of cast iron and when they start cold; one end is very cold and the other end is getting hot fast, never a good thing for large pieces of cast iron. Get a block heater it is a better investment in a long lived engine than just about anything else you can do.

[Chaz]

Thanx Lee!!!!!!!!!! That was a great explaination!!! Even I understood it!!! 


I'm looking to put a block heater on now, but my friend who runs the parts store isn't 100% sure what to get. He said it may be the one that threads into a 1" pipe plug hole in the head. OR, it could be one that bolts on with 4 bolts on the side of the head.

Next question: The plate I think he is talking about has what looks like about a 1" copper tube coming out and going across the back of the bus to what looks to be about a 4" cylinder (it looks a little like an air cylinder from the outside with 4 long bolts holding it together) and then back around the other side to somewhere in the front of the motor. There is also two other hoses that go to the tranny also. But I can't seem to find any other lines. What is that cylinder looking thing for? Does it put heat into the tranny?

Thanx!
   Chaz

[mikeH8H-649]

Chaz that cylinder looking thing is the heat exchanger for the trans,and the block heater I put in last week went into the 1" threaded hole in the front left of the block   Mike

[belfert]

I'm looking to put a block heater on now, but my friend who runs the parts store isn't 100% sure what to get. He said it may be the one that threads into a 1" pipe plug hole in the head. OR, it could be one that bolts on with 4 bolts on the side of the head.

As someone suggested elsewhere, buy the block heater from Luke at US Coach and you'll be sure to get the right one.  It might a little bit more than the parts store, but you won't be draining coolant over and over as you try to find the right one.

Brian Elfert

[mikeH8H-649]

Actually Brian I bought mine from luke and it was $18 cheaper than the truck supply and $23 cheaper than napa even with shipping, that was with shipping   Mike

[RJ]

Luke's Number:

1-888-262-2434

M - F between 9 - 5 Eastern.

Support those who support our crazy hobby!