I'm not too worried about burning a piston as I have been running with it disconnected for near 20 years. I don't remember what I set the timing at but the setup instructions came with settings with or without VOES. I need to find that instruction sheet though. It's in all my "stuff" somewhere.

 

Yeah he probably had something else going on there too for that to happen.

 

Not connected...just eliminates the "timing retard" ability.
Running with the Hose disconnected is probably gonna burn a Piston.

 

From my manual, It appears that 1980 was the first year of electronic ignition that incorporated electronic advance with no VOES. The Softail of that year was the first with the VOES switch. These two systems appear to be the same except for VOES. I noticed that advance timing is set at 2000rpm with no VOES and at 1300-1500 with VOES. THe system w/o VOES was on the Shovelhead. VOES was added when the EVO engine was in stalled in the Softail models. THis kinda brings me back to my original question. Is VOES needed for the Shovelhead? Looks like Harley Davidson didn't think it was needed. Or was it somthing they just discovered during R&D of the Evolution engine and just didn't consider for Shovelheads since they were on the way out



?

 

Needed??? No...As you say...HD didn't "find it" till later..Many a Shovel runnin around without VOES.
But, Much like other "improvements" it may be worth looking into. Remember that the MoCo took compression away from the shovelhead, and leaned the carburerion wayyy out [giving the Keihin Carb a very bad name] in the efforts to meet EPA standards!
If you give your Shovelhead a dose of Compression, and let some gas thru that Keihin carb, you may find something called Pre-Ignition [spark knock] especially due to the inefficiencies of the Combustion chamber.
A VOES will allow a More Aggressive advance curve, and higher compression, while helping to avoid Pre-ignition...
Bottom line...If ya leave yer Shovel Motor at least close to stock...You probably won't gain a thing with a VOES!!

 

my 80 FLT is electronics in the cone, but no VOES at the petcock. I've thought about adding it, think of it as an anti-knock update that simply wasn't an option offered in 1980.

 

Hmmm...Making me feel bad that I use so Damn many words to get to where you already Are at!!!

 

but your explaination was much more through and informative. And the pictures helped. With my motor being still all stock and low compression, perhaps I wouldn't benefit as much as I thought. I could maybe run a lower (ie cheaper) octane gas?

 

Two things...I only own one shovelhead that needs more octane than Regular...1] know that over octane is detrimental to performance, and...a waste of $$
2] Even A Relatively mild Shovel, [or ironhead, as they are both Hemi's]
can benefit from a bit more timing Lead [more advance]. A VOES will allow you to put more timing in than recommended, and not ping under load, because it takes some timing out!!
Not a huge benefit, but it is beneficial.

 

I run the Regular no ethanol gas from the station near my house along with the stock Keihin carb. The motor was rebuilt, from what the previous owner said, by a highly respected builder in Dayton, Ohio about a year before I bought it at 23k miles. I have 68k on the clock, but the clock didn't work for lots of miles. I'm guessing it's at about 75k now. As good as it runs, I believe I will leave well enough alone and keep on just as things are. Sometimes it's good not to fix something that ain't broke. That temptation always seems to be there though! Thanks all for the conversation and good information.