with all of the discussion on tranny coolers lately and the big variance in temps that people are seeing.... I've been thinking.

For those that are measuring temperatures

1) where is your temp sensor mounted? and pictures of speedo drive units would be great

2) has anyone tried using the back up switch location, and does anyone know the thread size/pitch of that spot?

3) I was looking at senders for the small vdo oil temp guages. Would any VDO sender rated fro 300degree's work with the 300 degree guage? Here is a link to the CIP website with multiple 300degree senders for sale:

senders

4) does anyone have before and after temp measurements to show cooler effectiveness? and has anyone tried different sender locations to see if there is a difference in where the measurement comes from (although I would think submerged in oil is good enough)

thanks everyone
brant

Answers are in the multiple and recent threads but I'm taking temps at the speedo drive boss in a plug, and it's a 1/8-28 NPT thread. You could use an 0-ring boss just as well and tap to fit, but my Autometer sending unit was NPT. There's a photo in Post #51 in this thread...

http://www.914world.com/bbs2/index.php?sho...161520&st=0

and more on topic in...

http://www.914world.com/bbs2/index.php?showtopic=177277

I still need the backup sender so I don't know about that location. A sending unit closer to the R&P would be more to my liking, but the speedo plug was just too easy. I'll install another one later but for now and to your question about the delta's. It depends on the size of your cooler, where it's located, does it have a fan, and how much time is your fluid actually in the cooler giving up its BTU's. In my case I'm gonna slow down the pump and measure if I get more or less cooling at a lower flow rate.

Meters have to be matched based on the entire range, lowest to highest, and they have to be either grounded fully at either the lowest or the highest temp in the range... most are fully grounded at the high limit.. you just have to know what your gauge wants to see.

Regardless, you are correct, the sending unit needs to be submerged.

Ron,

any chance you have a picture of that speedo drive plug uninstalled?

I'm trying to guess, or understand how you got NPT to go in there?

is it a large aluminum washer or a solid billet plug, that you can see in the picture....

do you mind describing that further so I can make one?

brant

It's a solid cylinder with a small flange. The picture you see is all I have and it uses the same locating bolt the speedo-drive does to keep it in place. As you can see, the sending unit is offset a little to make sure I didn't drill into the locating bolt hole.

The only difference is that my plug has two o-rings instead of one inside the tailpiece boss, same as the modified speedo housings.

It's aluminum so it's very easy to turn on the smallest of lathes. Just match a speedo drive in dimensions and make a flange so you can get it out easily.

As you can see from the picture in Post #51, it's nothing but drilling a hole into the outer surface and tapping out with a 1/8-28 NPT tap. It's aluminum... takes 5 minutes and most of that is gettin' your tools and puttin 'em up. I do use a drill press unless I don't have one around, but for this you wouldn't really need one in a pinch. Just a vise and the right size drill/tap.