Water Temp Sender for V8 Conversion, To drive the original oil temp gauge |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Water Temp Sender for V8 Conversion, To drive the original oil temp gauge |
DickSteinkamp |
Aug 19 2019, 09:10 AM
Post
#1
|
Senior Member Group: Members Posts: 500 Joined: 27-February 17 From: Bellingham, WA Member No.: 20,876 Region Association: None |
What sender are you non P-motor guys using to use the original oil temp gauge as a water temp gauge? Mine is a Chevy V8 in a 1976 if there is a difference.
I have tried several VDO senders. The closest I can get is their 323-057 (IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-20876-1566227463.1.jpg) It is their 0-150C (0-300F) sender. The problem is that it centers the needle at 75C (165F) so at normal operating temps, the needle is about midway to the right of center. Their 0-120C sender exaggerates this even more. Their 0-200C sender centers the needle, but won't give me much warning if I start to over heat. |
Chi-town |
Aug 19 2019, 11:37 AM
Post
#2
|
Senior Member Group: Members Posts: 850 Joined: 31-August 18 From: Disneyland Member No.: 22,446 Region Association: Southern California |
Use the 0-300 and send the gauge out to be recalibrated to where you want it
|
914forme |
Aug 19 2019, 11:43 AM
Post
#3
|
Times a wastin', get wrenchin'! Group: Members Posts: 3,896 Joined: 24-July 04 From: Dayton, Ohio Member No.: 2,388 Region Association: None |
If your gauge has numbers take it out bench test it, 4 screws hold it in the back, and you can gently move the needle to where it needs to be, then retest it. Get it to where you need it to be, not to hard, it has stops on the low and the high sides.
Move the needle while the gauge is off. Be gentle, as the gauge shaft can be bent ( harder than you might think), but the needle themselves are very light gauge metal, can be mangled with ease if not careful. It is also a good time to repaint the needed if they are sun faded. |
DickSteinkamp |
Aug 19 2019, 02:00 PM
Post
#4
|
Senior Member Group: Members Posts: 500 Joined: 27-February 17 From: Bellingham, WA Member No.: 20,876 Region Association: None |
My gauge doesn't have numbers...
(IMG:http://www.914world.com/bbs2/uploads_offsite/www.2040-parts.com-20876-1566244812.1.jpg) ...but that wouldn't stop me from centering the needle at about 200F. The problem with that is I would probably destroy the gauge. (IMG:style_emoticons/default/sad.gif) The three VDO sending units I've tried seem to be linear but start at 0. I believe the original sending unit for oil temp was probably something like 60-160C (140-320F) with about 110C (230F) as the mid point. The engine would normally run just under the mid point. I'd love to end up with something similar. Maybe something like 130-270F with 200F as the midpoint. I've considered using the stock oil temp sending unit (it would probably be close enough), but I think it might be tough to adapt the metric threads on the sender to the NPT threads on my intake. Has anyone done this? Chi-town...do you know of anyone who recalibrates gauges? |
Chris914n6 |
Aug 19 2019, 02:38 PM
Post
#5
|
Jackstands are my life. Group: Members Posts: 3,321 Joined: 14-March 03 From: Las Vegas, NV Member No.: 431 Region Association: Southwest Region |
Cook the senders at 212f, measure the ohms to find the difference, then add a resister to get close to centered on the gauge.
|
DickSteinkamp |
Aug 19 2019, 03:07 PM
Post
#6
|
Senior Member Group: Members Posts: 500 Joined: 27-February 17 From: Bellingham, WA Member No.: 20,876 Region Association: None |
Cook the senders at 212f, measure the ohms to find the difference, then add a resister to get close to centered on the gauge. Good idea! Thanks!!...but maybe instead of trying to figure out what resistor would do the trick, put a potentiometer in line between the gauge and sending unit and center the needle using the potentiometer when the engine is at operating temp. Does that sound like the same sort of thing? |
Chi-town |
Aug 19 2019, 08:33 PM
Post
#7
|
Senior Member Group: Members Posts: 850 Joined: 31-August 18 From: Disneyland Member No.: 22,446 Region Association: Southern California |
North Hollywood speedometer
Seattle speedometer Palo Alto speedometer |
DickSteinkamp |
Aug 19 2019, 09:09 PM
Post
#8
|
Senior Member Group: Members Posts: 500 Joined: 27-February 17 From: Bellingham, WA Member No.: 20,876 Region Association: None |
In retrospec, I don't think the resistor/potentiometer thing is going to work. That resistance will be there full scale which will prevent the top end of the needle movement from happening.
Thanks Chi-town. I've done a lot of work with Seattle Speedo, but since they (he?) moved to the Spokane area, not the same results. I'll try one of the other two. |
Lo-Fi Version | Time is now: 21st May 2024 - 11:47 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |