Head Temp Sender

[Kevin@ojai.net]

Well, I removed my Oil Temp gauge a while back (sender was leaking, it was the dipstick style). I was thinking of replacing it with a Head Temp gauge. Does any one know if I can a sender that will screw in place of the FI head temp sender?

Oh, here is my poor mans idea of a head temp sender/gauge : Use one of my many existing FI temp senders, and just set one of those cheap ohm meters in between the seats (you all have seen the cheap $10 ones). I guess I would have to run 2 wires to do this from the sender, the wire from the sender -- and a wire from the senders ground (just so the resistance doesn't get too high/(low?) as too cancel out the whole purpose, and accuracy)... Any one know how many ohms=what temp?

Enough about my poor mans gauge idea -- how about a "real" temp sender that I could use with a "real" gauge? Has any one ever seen one of these senders -- any idea where I could get one (AutoZone?)...


thanks,
Kevin

[campbellcj]

You're just looking for an oil temp gauge, no? Why not get the VDO gauge & sender available here at Pelican Parts? It looks "factory" (although it is slightly smaller than the original center-console gauges), and it works. Mounts under a cover plate on the bottom of the engine, towards the firewall end.

Regarding CHT (head temp gauges), I've been told by several 914 racers that they are not that important (unless you have a turbo'd car perhaps), certainly not as much as oil temp & pressure. If you want one temp gauge, definitely go with oil temp before CHT or EGT.

Also FWIW, there have been several threads here and/or on Rennlist recently on similar topics...you may want to search the archives.

Good luck,


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Chris C.
73 914 2.0
70 911E Targa
campbell.chris@gte.net

[This message has been edited by campbellcj (edited 08-05-2001).]

[Jake Raby]

Placing a head temp sensor in the stock location drops actual readings by 40 degrees in our back to back testing with spark plug located senders.

The only place we put sensors is under the plugs..

[Kevin@ojai.net]

Yea, I understand how oil temp. is probably a more important reading, but I have had oil temp gauges on all my Air cooled engines -- never a head temp gauge. So I decided a while back I would like to put a head temp. gauge in its place (especially since my dipstick sender was leaking oil)...

My question was just if any one knows of a sender that will work with a VDO head temp. gauge that threads into where the FI head temp. gauge used to be.

Thanks, for the info on 40deg. cooler with sender location then the plug location. Does this mean you have located some senders that will thread into the FI sender spot?


-Kevin

[Dave at Pelican Parts]

I think what they have done is used the standard "ring" thermocouple, screwed a very very short bolt into the hole where the stock FI's sensor usually goes, and put the thermocouple between the bolt-head (actually a large washer under the bolt-head) and the cylinder head.

I do not know of any sensors that will work with the VDO head temp gauge except for that ring-shaped thermocouple.

The sensor that the FI uses is not a thermocouple at all--it is a Negative Temperature Coefficient thermistor. In other words, a resistor that has lower resistance when hotter and higher resistance when colder. The thermocouple, as I understand it, actually generates a (small) voltage depending on its temperature.

--DD

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Pelican Parts 914 Tech Support

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