Fuel density compensator question

[LuckyWolf]

Hi all,
Another newbie question regarding the mechanical side of things,

May sound daft but I recently found out that to run multi fuel deuces you need to have a fuel density compensator and that not all are fitted with them at the factory.....
so thought I’d check with people who know, is this standard fitting?

Second question......
Bonnet / hood numbers, is there a specific reasoning for the numbers on the side of the hood? Or were they just random numbers chosen?

Thank you

 

[cattlerepairman]

No, the "multifuel" capacity is rooted in the engine's design. You do not need the fuel density compensator for that. The FDC measures the viscosity ("thickness") of the fuel and attempts to increase or decrease how much fuel is injected to compensate for the different amount of energy a given volume of that fuel contains.

The engine runs fine on various fuels without the troublesome FDC, but may have a bit more or less power.

As for the numbers, it often is VIN based. Others may chime in.

Sent from my SM-S901W using Tapatalk

 

[HDN]

No, the "multifuel" capacity is rooted in the engine's design. You do not need the fuel density compensator for that. The FDC measures the viscosity ("thickness") of the fuel and attempts to increase or decrease how much fuel is injected to compensate for the different amount of energy a given volume of that fuel contains.

The engine runs fine on various fuels without the troublesome FDC, but may have a bit more or less power.

I think many multifuel owners here have deliberately removed their FDC. I think I've even seen MWO stickers indicating the military removed them. I guess they're pretty problematic (I have no first-hand knowledge of that since I don't have a multifuel truck).

It seems like a neat device to have equipped, so it's a shame it doesn't seem to work well.

 

[SCSG-G4]

FDC is prone to leaking fuel into the engine oil, and not just a little drip either. That dilutes the lubrication of critical engine parts and leads to engine failure if not caught in time. It was one of those 'nice in theory, p---poor in practice' ideas. The concept was that GI's could use a mix of engine lubricating oil and gasoline to get themselves away from a collapsing front line by 50+ miles and thus regroup.

 

[LuckyWolf]

Great,
Thanks for the advice, puts my mind to rest, always best to ask rather than hope and pray

 

[rustystud]

The design of the "Fuel Density Compensator" was a nice bit of engineering, but the actual part had serious designs flaws. Like no seal for the main shaft. So, after years of use the aluminum housing wears out allowing fuel to go into the crankcase.
As far as needing an "FDC" you really just need a "Foot" . Use less throttle or more throttle. Really, that is all it is.