"E" Gas Coupe Build

[Bob Drury]

  Tony and Rex, Maybe I am confused on your tank heaters, but I know that mine look exactly like standard Hot Water Heater Elements.
  If in fact they are, they will burn up if not immersed in liquid, beleive me I know (H2O ones anyway).
  Just curious on this and hope you guys can straighten me out.........  Thanx, Bob

[maguromic]

Bob, If you are using an "element style" heater it can cook your oil and cause oil breakdown (the chart below shows the three main ways oil breakdowns) with the most common being oxidation.  Even though there are a few factors that contribute to this, the most critical is temperature.  That's why you want a covering to minimize the effect.

I use Watlow, Firerod cartridge heaters with a Watlow 93 controller http://www.watlow.com/products/heaters/firerod-cartridge-heaters.cfm These have the heating coil covered in insulation as not to contact the sheath which is made out of Incoloy 800.  One thing to keep in mind, which ever set up your using is to size it properly.  You can do this by using the watt density formula.

Watt Density = W / (Π x D x HL)
W = wattage
II = pi (3.14)
D = diameter
HL = Heated Length

I think this is the correct formula. Some of you engineers on here would know better than I would.   I know when we use to road race we would always take oil samples after each session and look at it under a microscope to see how the oil was behaving.  Tony

From Machinery Lubrication


Watlow 93 Controller

[Bob Drury]

  Thanx Tony, now I have one more thing to worry about!
                                 :-P :-P :|           Bob

[maguromic]

Let me clarify it a bit, watt density means  the heat flow rate or surface loading. It is the number of watts per square inch of heated surface area.  The controller is used to set the temperature as not to over cook the oil.  I am making a box up with three of the controllers that is external with leads to the three systems I am running which is part of our starting procedure.  Tony

[manta22]

Let me clarify it a bit, watt density means  the heat flow rate or surface loading. It is the number of watts per square inch of heated surface area.  The controller is used to set the temperature as not to over cook the oil.  I am making a box up with three of the controllers that is external with leads to the three systems I am running which is part of our starting procedure.  Tony

That is exactly right-- watt density is all important. That's why the rod heating elements are not a good idea-- to prevent burning the oil with those heaters, the heat input needs to be low so it takes a long time to heat a whole dry sump tank. The best heater is a patch style made by Watlow Electric, Minco, etc. they distribute the heat over a very wide area so no one spot gets hot enough to burn the oil. These types of heaters attach to the outside of the tank with a high temperature adhesive-- some are even stick-on types. The heater element is nichrome wire or thin-film nichrome sandwiched between silicone rubber or Kapton film. The last time I checked they were available in a wide range of sizes, wattages, and voltage ranges.

Regards, Neil  Tucson, AZ

[Saltfever]

Or you could put a mini drysump pump on the tank to circulate the oil during the warm up time. That way no oil would dwell on the heating element. Note, I'm not specifing the kind of device to circulate the oil. Isn't it fun to add even more complexity! 

Even with Neil's idea, there is very little convection to "stir" the oil and I found heating  is still quite localized. That is why it is good to drive the pump with a hand drill every once in a while to stir things up.

[Tman]

Let me clarify it a bit, watt density means  the heat flow rate or surface loading. It is the number of watts per square inch of heated surface area.  The controller is used to set the temperature as not to over cook the oil.  I am making a box up with three of the controllers that is external with leads to the three systems I am running which is part of our starting procedure.  Tony

That is exactly right-- watt density is all important. That's why the rod heating elements are not a good idea-- to prevent burning the oil with those heaters, the heat input needs to be low so it takes a long time to heat a whole dry sump tank. The best heater is a patch style made by Watlow Electric, Minco, etc. they distribute the heat over a very wide area so no one spot gets hot enough to burn the oil. These types of heaters attach to the outside of the tank with a high temperature adhesive-- some are even stick-on types. The heater element is nichrome wire or thin-film nichrome sandwiched between silicone rubber or Kapton film. The last time I checked they were available in a wide range of sizes, wattages, and voltage ranges.

Regards, Neil  Tucson, AZ

I sell 3 sizes of those external heaters and am looking at incorporating one into our car at some point.

Thanks for the input "guys that know more than me" I learn something here every day.

[manta22]

We ran a Watlow Electric patch heater on the dry sump tank of Bob's McLaren M8C; it took overnight for the oil to come up to temperature. Of course you could heat it up in a big container on a stove and pour the oil into the tank if you're in a hurry. Not recommended, though.

Regards, Neil  Tucson, AZ

[Saltfever]

Yeah, Neil, I agree and like the pads the best. But you just made my point. The lack of convection makes for that long warm-up time. Introducing some turbulence greatly reduces the warm-up time.

[maguromic]

Or you could put a mini drysump pump on the tank to circulate the oil during the warm up time. That way no oil would dwell on the heating element. Note, I'm not specifing the kind of device to circulate the oil. Isn't it fun to add even more complexity! 

We will circulate the oil with the electric pumps every so often on the trans/rear, and on the main tank we also have a pump (its a single stage version of what used for the trans/rear). I will post a picture of it later today. Tony

[maguromic]

This is my circulation pump for the main tank,  its a single stage pump with a .200 gear. I am still trying to figure a way to cycle all three automatically while in warm up mode without someone having to toggle the switches every 5 minutes. Tony

[Kiwi Paul]

Hmm.....Toggle Switch Circulation Technician? As a current Tech Inspector, I may almost qualify for that position. Perhaps I can apply? There are some on here who wouldn`t grant me, or any Orange Hatted human, even an application form, let alone an interview.....

[38flattie]

Tony, I love that electric oil sump idea-I've got the ele ctric mptor, and I'm going to build a similar on for the tranny and rear end, using a 4 stage pump to handle both jobs. Thanks!

[Tman]

Hmm.....Toggle Switch Circulation Technician? As a current Tech Inspector, I may almost qualify for that position. Perhaps I can apply? There are some on here who wouldn`t grant me, or any Orange Hatted human, even an application form, let alone an interview.....

Funny Paul! But wouldn't it be more like 3 orange hats looking at said toggle switches, one disputing the length of the switch, one disputing the placement and one wanting to see the specs of the switches?!

I jest

[Dynoroom]

That ^^^^^ was funny, really.....