Does turning up fuel or bypassing fuel density compensator effect ability to run UMO?

[dieck]

Ok guys, I've done quite a bit of searching and have not found a definitive answer to my question. I've seen several deuces with bypassed fdc's or fuel turned way up that are also running a high percentage of motor oil. Is this a recipe for early engine failure? Isn't the whole purpose of the conservative tuning and fdc to allow for different fuels to be run reliably? Thoughts? Experiences?

 

[RAYZER]

my fdc is bypassed and i run wmo /diesel 50/50 all the time, the deuce loves it! just did a 1000 round trip to the ga rally running wide open with no issues, if the fuel is turned up you have to watch your exsaust temp with any fuel mix you run.

 

[dittle]

Short answer....NO. The FDC only tries to make the different fuels match power output by adjust fuel flow based on fuel viscosity. The engine itself is multi-fuel capable regardless of what you have done with the IP/FDC.

 

[benand117]

what is the fdc?

 

[benand117]

never mind my answer was in the title of this post.

 

[Hammer]

Actually, I think turning up the fuel DOES affect it.
But for the good. When you turn the fuel up, it starts faster/easier.
I noticed it even more when running the WMO.
Granted, it isn't that big of a deal, and not that big of a difference. But I DID notice it.

 

[dittle]

Might be true Hammer, never tried WMO in my deuce. But I think for what he was asking bypassing the FDC will not negatively effect the ability to burn WMO. In your case it was for the better.

 

[Hammer]

Yeah, not much for negatives on bypassing and/or turning the fuel up.
Btw, turning the fuel up helped one truck start faster on just diesel.

One point where the FDC seemed to hinder things was when running biodiesel. I think Bjorn noticed it was actually compensating the wrong way with that.

As to the OP, the FDC does just like dittle stated. And to accomplish that, the fuel on the IP is in fact turned WAY up (which is what would be needed to run gasoline, which has far fewer BTU's then the heavier fuels like diesel.) All it does is turn the fuel down for more viscous fluids.
Which is why you need to turn the fuel way back down after you remove the FDC!

 

[dieck]

Thanks for the informative posts guys. Seems like I was thinking the FDC protected the motor somehow from thicker fuels. I think I get it now.