Finished cooling system refurb.

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rich112
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Finished cooling system refurb.

Post by rich112 »

20210809_143244 (Medium).jpg
Added a header tank, plumbed the outlet into the lower rad hose, inlet to where the old filler was (top hose of rad).

Also fitted a thermostat was there wasn't one at all!

Got electric temp gauge fitted on hot side of thermostat to check what's going on, as the original temp gauge was on the cold side (which now there is a thermostat, really is the cold side!)

All went together OK, no leaks!

Took a while for trapped air to come out.

Seems to run OK, but I am noticing quite rapid changes in the electric temp gauge. It's a very cheap one, and I didn't calibrate it, but it will jump from about 85-90C up to 100-110C and sit there. The rad temp stays pretty steady at about 70C. This seems to coincide with engine RPM and not time.

The electric temp gauge sender is in the inlet manifold, so maybe this is measuring steam from time to time?

No sign of boiling over.

I also noticed that when reading over 100C, if you turn off the engine, the temp gauge drops almost immediately back to 85-90C. I was wondering if the cheap gauge can't handle varying supply voltage?

I might pop the sender out and test it on the stove to see if it's close to reality. I can run it off a bench PSU and ramp the supply up and down too...



rich112
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Re: Finished cooling system refurb.

Post by rich112 »

Turns out £10 gauges off ebay are cr@p, who'da thought it!

Gauge reads correct 85C when ignition goes on and when you start the motor (hot). As soon as the alternator kicks in, which for some reason only happens when the revs get up high enough, the battery voltage jumps from 11v to 13.8v and the temp gauge jumps to 110C!

I guess these gauges do need a stabilised 10v supply voltage after all!

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