Thermostat removal - possible issues

[Ivan141]

Here is just an interesting tidbit that me and Nohachi found on the inet. It is from a paper originally discussing another engine type, but the used logic should be more or less applicable to the 4A-GE (though, the 4A being a steel lump and the considered engine all aluminium, the 4A should hold up longer).

Quote:Removing the thermostat altogether, as currently practiced by some, is no solution, firstly because engine warm-up becomes protracted, with all the implications for premature engine wear and secondly, because the engine temperature is at the mercy of the pump speed, if engine speed falls, the coolant in the radiator will cool disproportionately, then as soon as engine speed builds and engine temperature with it, the pump speeds to sends a mass of very cold water from the radiator suddenly to the engine. There is no thermostat to even this process out so the engine is repeatedly subjected to thermal shock. Bad for the head, bad for the block, and sooner or later the gasket will go. Fit the thermostat to the coolant output and the extreme temperature gradients that beset the engine when used on the track are significantly mitigated. Modification of this coolant path is something that Lotus should have done with all the K series engines in all their Elise’s, This would have then prevented any gasket failures.

[nmwisima]

I got no thermostat in my gze.
Good thing for the hot Greek summer i 'd say.
Winter, hhmmm, engine take some time to get worm and I consume a bit more fuel, but thats all.

If I could find a possible setup to use I d go for it just at winters

[Ivan141]

I remember you asking a question about that thermostat a while ago...
I still think you should be able to use the ae92 thermostat housing, which is remotely mounted, you just need to figure out how to do the plumbing.
If you'd have read the little article I quoted earlier you should understand that it's not just a bit slower warmup and more fuel consumption, but accelerated engine wear as well. Furthermore your engine should perform better with correct coolant temperatures..

[alimonos]

The old bluetops have it inside the front upper left hose?

[toypower]

The bluetops have them attached at the rear of the waterpump.

For the 4agze I'm searching for a BMW E30 4cyl. thermostat, only
need to adjust it a little bit.

Then I have an inline thermostat for the rubber piping. So that will be an easy job to fit.

[toypower]

Source: http://www.geocities.com/MotorCity/Lane/...valve.html

Only I don't have the 4agze thermostat.

And what I have learned is that you want to have the engine around 85 degrees (celcius). Not any colder or warmer.

[Ivan141]

Warmer is possible...as long as the system pressure is high enough..
I believe porsche once started making engines to work at higher temperatures because it had certain benefits..BTW, that GZE thermostat housing looks the same as the AE92 GTi housing...need I say more?

[The Doctor]

Yesterday, my thermostat broke.

And i can tell you, it sucks to drive without

At temperatures around 0 it wouldn't warm up. Even after 300 kms the radiator was cold.
No heating (so i had to drive with my windows open, to keep the windscreen and rear screen clean)
and with my carb engine: not idling well (stalling everytime the revs drop) and hesitating on the highway.

[nmwisima]

I m not sure how and why, but my heating -interior and front/rear windows- WORK FINE