Friz and Jay:
> <<Mailing List: Sunbeam Tiger Owners
> Back to Index Next MessageDate: 31-Mar-1997 03:39:30
> Subject: Temp Senders
> When putting a new motor in my Mark 1 Tiger one of the other changes
> which I wanted to make was the upgrade to a 4 BBL carb and manifold.
> Since I had COBRA manifold laying around I decided it would be a
> good match to the new cam being used. One of the problems encountered
> however, was the Tiger temp sensor would not fit into the smaller
> sensor hole used on the COBRA intake.
Can't claim knowledge of the COBRA lettered practice, but the original Tiger
temperature sender was mounted on a separate block from the manifold, and used a
straight thread. The thread on most American manifolds is a tapered pipe
and they are incompatible, and of the wrong size (too big) to allow a
There have been uses of massive amounts of teflon tape to "fill-in" the
difference, but I would not recommend it. The original pipe thread hole can be
enlarged with a tapered ream and filled with new aluminum by a good welder with
heli-arc. The taper is to allow the feed lead to reach the bottom of the hole
without contacting the side so it can be filled from the bottom-up. This is old
(dirty) aluminum, so expect some slag during this process. When finished, a new
pilot hole is drilled and the correct thread is cut. I believe it is 5/8 18
straight thread. Double check with a Tiger sender. (Note: not all British
> After having no luck finding a
> suitable adapter for the sensor,
Not strange, considering the thread differences. The OD of the sender is almost
the same as the ID of the hole, and any plug would have no wall in most of the
taper. An adapter that places the new thread above the old would place the
thermal sensing unit too far out of the manifold water flow to give accurate
> Jay Peterson>>>
> I have three questions
> 1) The temp sender hole on the COBRA manifold,is that the same size that is
> common to american cars Ford performance manifolds or was it an oddball size
> from a real Cobra?
Your description that the "COBRA" sender hole was "smaller" than the Tiger
makes me wonder what it was. As stated, the American sender has a larger
pipe thread. If it is indeed smaller, and smaller enough, it might be possible
drill and tap it directly, without welding. See Cobra list.
> 2)You described the placement of the themocouple. I assume that this device
> adjusts the voltage the sensor sends and is somehow wired into the harness.
I believe you are describing the gauge voltage regulator, which also handles the
fuel gauge., and it is under the dash, regulates to 10 volts, and would, if
replaced with another constant voltage, make the fuel gauge inaccurate, and not
fix the non-linearity observable in your reported readings. Some listers have
described a solid-state, and even adjustable, replacement designs, but these
not cure non-linearity.
> 3)Is there a generic temperature sender that can be located in the same
> manner as the thermocouple and completely assume the function of the sender
> and enable the manifold hole to be blocked off? Would this be desirable?
> Thanks for your input
> Tony Frisbey
I am completely confused by that statement. What "thermocouple"? The sentence
obviously distinguishes between the "thermocouple" and the "sender". I can
understand someone calling the sender a "thermocouple" (I believe it is a
thermistor), but then what is this other thing?
Let's assume you may have meant "Is there a sender available, other than the
sender, that will fit in the existing hole pipe thread hole and have accurate
readings. Let's also assume you are talking about the pipe thread typical
manifold, not the one described by Jay as having a 'smaller hole'.
The simple answer is no. The sender, regulator, and gauge are calibrated as a
unit, and a replacement would have to have the same characteristics as the
original. To my knowledge, it does not exist. You can replace your gauge with
American gauge, and use an American sender, but I'm not sure you want that.
A weld-up, retap suggestion was offered, and another solution is to use the
separate original sender block and uses to mount the unit. This normally fed
heater line, I believe, and could be cobbled to do the same. That way you use
pipe thread right angle Ford water take-off to feed the block and heater ( or
carburetor spacer heater). You do need to find a way to support it, and don't
break that extra wire that grounds the sender block, as it is mounted on
I hope this helps.
Steve Laifman < Find out what is most >
B9472289 < important in your life >
< and don't let it get away!>
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