If the FDC leaks fuel into the engine...

[davey8943]

Russ,

I am not sure how to answer your first question. I don't think either (too thick or too thin fluid) would endanger your engine, but your engine performance would likely suffer (one of the more senior members can probably answer better...)

I would imagine you can replace the seals in the FDC; but "making engine oil" is probably the only way you would know something was off.

My engine started making oil, so step one was to bypass the FDC ... It is a really simple task, that required a couple of pipe plugs and some poly tubing. I don't plan on hooking it back up, the truck has been burning WMO like a champ!

Kelley's Island looks to be a long way from Laurel IN (Site of the SS Haspin Rally), but the more SS guys that make it the funner it will be!

Dave

 

[JasonS]

The real "Multi-fuel" part is the design of the combustion chamber, piston top and injector. The FDC would only very the maximum amount of fuel delivered depending on fuel type to help keep the power output of the engine at the rated spec.

There is ONE thing which allows the engine to burn varioius fuels and that is the compression ratio.

 

[russ132]

I am certainly scoping Haspin out. I have nice a stockpile of oil.

 

[gimpyrobb]

Russ, we can show and explain it all at Findlay.

 

[LowTech]

If the FDC is bypassed do you still adjust the delivery rate the same way, on the base of it?

 

[davey8943]

If you bypass the FDC it "defaults" to high flow.

My truck may be slightly smokier when cold, but it runs and drives the same overall.

Some have suggested that IF you bypass the FDC, you should keep an eye on your EGTs with a pyrometer (more fuel = higher exhaust temps).

I honestly think a good salesman was involved with getting the FDCs added to these trucks...

Dave

 

[gimpyrobb]

The FDC was added to get the same power out of the motor when different fuels were used.

When using diesel, it is mosty closed. When using gasoline it is mostly open. All your fuels have different BTU ratings. The higher the rating, the more power you can get out of the motor. The FDC's job was to keep power out put the same across man fuels. It is not needed and can fail adding fuel to your cranckcase oil. You cannot replace some seals to lessen the chance of leakage because there isn't one. Two pieces of metal have a tight enough clearance to keep fuel out of the oil. When that clearance is worn away, you get trouble.

Yes, if your truck runs fine now and you bypass the FDC, you will probably have to play with the fuel settings, but IMHO its worth it considering the alternative.

 

[LowTech]

So you DO still adjust it the same way?

 

[Floridianson]

So you DO still adjust it the same way?

Correct still adjust with the twin nuts main fuel. When the FDC is by passed you should check boost at 1600 and 2200 rpm. They should in theroy should be higher. The droop /1600 rpm would be the one you might want to reduce as your just waisting fuel. The high end might be fine and not need a pyro but as allway they are a good thing to have. I would bypass FDC check boost at 2200 and shoot for 12lb. If you not there or close adjust twin nuts. Then when you get the high end set to where you would like it then adjust droop to 4 to 5 lb. Then go have fun.
Do this with clean new diesel then run the mixes.

 

[timb1956]

what does fdc stand for and where is it located?

 

[timb1956]

never mind found it in previos post sorry

 

[gimpyrobb]

Fuel Density Compensator

It is behind the IP's hydraulic head(the thing that has the injector lines coming out of it.)
It is toward the firewall from the hydraulic head.

 

[SEAFIRE]

When we first got our 1968 A2 W/W it had a non-turbo engine, the oil level seemed to "rise" after each use, it took us a bit to figure out it was diesel in the oil, we bypassed the FDC and the problem stopped. We also had help from this forum.

That engine since crapped out and he have a brand new LDT engine with a "D" turbo that was already bypassed out of the crate.