This is probably a stupid question, but am I correct in thinking the multi-fuel engines have no glow plugs? If that's true, how do they start as good as they do considering they have no source of pre-heat, save for a manifold heater if equipped. Sorry for the "newbie" question, but it will settle an argument I'm having with a friend.
-
Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!
LDT question
- Thread starter sinister
- Start date
goldneagle
Well-known member
- 4,497
- 989
- 113
- Location
- Slidell, LA
Actually mine has a glow plug setup for real cold weather starting.
ida34
Well-known member
- 4,120
- 33
- 48
- Location
- Dexter, MI
All the military engines had either a preheater manifold heater or either injection. They are only used when the temp gets below 20 degrees Fahrenheit. The engines start without glow plugs because the very high compression creates more heat than the typical light truck diesel. The LDT's have a very high compression compared to other engines. I think the LDT is around 22 to 1 with light truck diesels down around 15 to 1.
ida34
Well-known member
- 4,120
- 33
- 48
- Location
- Dexter, MI
Re: RE: LDT question
The glow plug set up must be aftermarket and it should not be needed until it gets well below freezing. The cucvs need glow plugs to start even when it is 70 F or so.goldneagle said:
- 10,350
- 75
- 48
- Location
- Meadows of Dan, Virginia
Re: RE: LDT question
With good batteries, your MF should start without aids down to about 10°F.
There are other cold start engines, like the Lister engine, which has an adjustable compression ratio, very high up to 40:1 or so, for starting and then 15:1 for running.
Got to appreciate the Multifuel.
You are probably looking at the intake manifold heater igniter (spark plug)....goldneagle said:
With good batteries, your MF should start without aids down to about 10°F.
There are other cold start engines, like the Lister engine, which has an adjustable compression ratio, very high up to 40:1 or so, for starting and then 15:1 for running.
Got to appreciate the Multifuel.
goldneagle
Well-known member
- 4,497
- 989
- 113
- Location
- Slidell, LA
RE: Re: RE: LDT question
Sorry my mistake. I thought the manifold heater igniter was a glow plug. So much for my knowledge of Deuce engines...
Sorry my mistake. I thought the manifold heater igniter was a glow plug. So much for my knowledge of Deuce engines...
- 34,012
- 1,808
- 113
- Location
- GA Mountains
RE: Re: RE: LDT question
Aren't glow plugs generally used on indirect injection engines?
Aren't glow plugs generally used on indirect injection engines?
- 3,021
- 222
- 63
- Location
- eldersburg maryland
RE: Re: RE: LDT question
right kenny, the multi is a direct injection engine and these do not use glow plugs. engines with glow plugs have prechambers that the glow plug and injector are in and are usually more noisey engines having fuel knock.
right kenny, the multi is a direct injection engine and these do not use glow plugs. engines with glow plugs have prechambers that the glow plug and injector are in and are usually more noisey engines having fuel knock.
mangus580
New member
- 6,010
- 282
- 0
- Location
- Western NY
Re: RE: LDT question
Actually, the 6.2 is like 22.5 to 1, and I think Chevy's 6.5 is in the same range. Alot of the guys 'hopping up' their 6.5 will drop the compression to 18 to 1, to be able to achieve higher boost pressures safely. Incidentally, they start harder in the cold when that is done!ida34 said:
- 10,350
- 75
- 48
- Location
- Meadows of Dan, Virginia
RE: Re: RE: LDT question
Four decades later....
Four decades later....
- 8,527
- 2,728
- 113
- Location
- Monrovia, Ca.
Re: RE: Re: RE: LDT question
And I'm STILL amazed that it can burn gas w/o killing it'self!cranetruck said:
- 1,046
- 45
- 48
- Location
- Syracuse, New York
The minimum temp. needed for diesel compression ignition is about 700*C(1300*F). Very cold engines can lose that heat to the cylinder walls, piston crown and chamber. If the loss is high enough the threshold may not be reached. If it isn't the engine cannot start. Aids include glow plugs, ether, block heaters. Each is a different way to solve the problem.
Old engines have a hard time because rings and valves leak . That reduces the actual compression. Batteries have less output at low temp. Engine internal friction is high because the oil is thick. That causes slower cranking speeds. This allows even more time for compression leakage. JimK
- 10,350
- 75
- 48
- Location
- Meadows of Dan, Virginia
The "Arctic kit" addresses all these factors, including heating the batteries to maximize their capacity.