which veg oil temp gauge?

[davidschaffer]

I installed a oil temp gauge after my fphe and before the tee to the heads. I have a V3 and am curious what my oil temp is when the system kicks on in auto mode. The problem with the gauge I got is that it doesn't get up to true temp very quickly. I know that the oil is hotter than the gauge reads but the gauge only moves up a degree every 2 seconds or so. I want a gauge that directly gives me the temp of the oil as it passes the sending sensor, if such a gauge exists. What do yall think. The gauge I have now is a cyberdine digital oil temp gauge. I'd prefer have a non digital.

[muns53]

I use an Autometer GS 1/2 sweep electric guage. It matches the stock panel nicely both day and night. I got it on fleabay for $70-ish and an extra temp sender (get the longer one - there's two versions) that works with the electric 1/2 sweep guages for another $20-ish, I think. I installed a $3 microswitch from Radio Shack that allows me to use the one temp guage to switch between coolant temp and veg oil temp. Pics in my thread about how I upgraded the heat in my V3 system on here.

For the coolant line, you can put it in with a tee (and I also put a ball valve there to shut of heat to the tank). The Autometer temp sender needs a ground, so either ground the valve or thread a slot in the tee for a little screw that you can attach a ground wire to the engine. You already have the veg oil temp in the ideal spot, so a longer probe might help you get a slightly faster reading. Again, the Autometer sender needs a ground, so you can either add a ball valve (stainless would be best on the veg fuel line) or thread a screw into the tee for a ground wire.

FYI, the veg oil temp does rise slower than the coolant temp - especially in the winter when the VO is frozen in the tank to begin with.

[davidschaffer]

Thanks for the info, I'm definitely going to add another sender for the coolant, that's a great idea. When I switch the V3 on, the temp gauge will read whatever the temp is before there is flow, if I switch on when the gauge is at say 90, the gauge starts to go up, but very slowly even though my veg temp is probably closer to 160 +. Yesterday the gauge worked its way up to 177 from around 100 but it was a slow steady climb, maybe 10 miles or so. I had been driving for quite a while on d2 so I knew my veg was as hot as it was going to get before I switched it on. Does your oil temp gauge take awhile before it gives you an accurate reading of your veg when flowing?

[muns53]

The bottom of my temp guage is 100*F. It takes about ~5-6 miles for veg temp to climb up from the bottom reading to 160*F and above. The math makes sense to me and yours doesn't sound that far out of line. In that time, the diesel that was in the fuel line from the last purge cycle has been replaced the veg oil pushing up through the V3 manifold and my FPHE and fuel lines. At 16mpg, that's about 1/4+-ish of a gallon of D2 being burned up - and then the slow reaction of the temp sender, give or take...

FYI, I don't let the V3 switch on at 140*F any more - I wait to switchover manually when my coolant temp is above 160*F. Jay's offering 160*F temp switches now, so once I get that sucker in there, I can go back to operating switchover automatically.

[davidschaffer]

One my set up I have the temp sender about 1 foot after a fphe. So the only d2 left from the purge, that isn't getting heated via coolant, should be in that 1 foot. After that section was burned off I expected to see the gauge jump up significantly. Maybe they only jump in increments of 1.

[muns53]

You still have to push the same volume of fluid up from the V3 through your FPHE to get to your sender. The heat transfer from the coolant to the oil takes a while, especially in the winter. If you have HOH and I have an HIH setup, it's possible I've got a little more heat transfer going on which decreases my heat-up time. I really don't know! There aren't that many of us with V3s that are monitoring temps and even fewer of us with V3s that have an FPHE in there. So, it's hard to really say objectively one way or another. You can but experiment and see! Keep posting your results and sharing your data. I guess the main thing is that you have HOT oil headed to your injectors.