Author Topic: Mechanical Instruments  (Read 2940 times)

Superarnie Mk2

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« on: January 13, 2013, 18:49:24 »
Here's another one!
   I have bought a set of Smiths Cobra mechanical instruments for my car. The oil and water temp gauges each have a metal 'capillary tube' which extends from the back of the gauge to the engine sensor connection point. Can anyone, particularly those with the Mk 4's, tell me where the oil and water temp capillary tubes pass through the engine bulkhead and where each of them have been fitted into the engine?
   Many thanks
   Gary

Hobo

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« Reply #1 on: January 14, 2013, 11:50:18 »
There is no general answer.
   Engine: Depends on which engine you have build in. Watertemp you can pick up at the intake close to the thermostat. Oiltemp you pick up close to the oilfilter (sandwichplate) or at the remote oilfilter if you have a oilcooler in the front.
   If you have afull set of mechanical instruments there should be oil pressure too.
   
   Bulkhead: Chosse the shortest way from sensor to the instrument.

westcott

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« Reply #2 on: January 15, 2013, 17:39:06 »
Gary, if there is no advice for a more original MK IV path trie the following.The engine and front loom goes through the bulkhead / top-of-footbox into the engine bay. Follow the loom and check the length to the final location with some long single wire to define the needed length.
   
    The intruments should have a long enough capillary tube to follow the loom.
   
   Uwe
Everything should be made as simple as possible, but not simpler!

Superarnie Mk2

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« Reply #3 on: January 15, 2013, 17:57:46 »
Thanks fellas for your help and advice. The capillary tube is over 6 foot long, I will see if it can follow the loom - good idea Uwe!

French Frie

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« Reply #4 on: January 15, 2013, 20:02:14 »
Additional question : can the temp oil bulb  and the pressure pickup be taken on the Tee , near the filter, where the pressure switch and electrical pressure sender are, or is there not enough room and/or inadequate pickup?

westcott

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« Reply #5 on: January 15, 2013, 21:20:13 »
For the pressure port you can use the Tee.
   
   The sender elements for mech temp instruments are very long and close to 1/2 " in diameter fitted into a 5/8 UNF adapter needed for proper installation, normally delivered with the  gauge.
   
   So the best position for a  mech oil temp sender is the sump with the sender mounted in a horizontal position close to the sump bottom. T-sumps with kick outs have more possible mounting positions, even vertical into the kick out top walls.
   A oil temp sender adapter tube fitted into the oil cooler hoses could be a alternative.
Everything should be made as simple as possible, but not simpler!