Quote:
Originally Posted by BlueCoast
Thanks for the advice and suggestions! I'm not certain about the legalities of modifying my car's thermostat here in New Zealand. Beyond a certain threshold, any modifications requires an additional low volume vehicle (LVV) certification and additional inspections atop the annual Warrant of Fitness (WoF) inspections. However, regarding pre warming, I have had my eye on installing an engine block heater. As far as I can tell, this does not require additional certifications and inspections.
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Glad you like the idea.
If the pre heater is a element and pump combo doodat that splices into say the upper hose; then it can simply be removed and an original hose fitted for inspections.
Thermostats are simple melting wax actuated things as explained here:
https://savree.com/en/encyclopedia/engine-thermostat
They simply fit in a housing on the engine side of the top radiator hose and are simple to remove/replace.
In fact in Equatorial Africa thermostats only last until they give trouble or the car runs hot.
They are then removed/omitted and tossed far and you get a dirty look for not having removed it ages ago!
(Ye they don't understand or care for the engine longevity and economy advantages)
The only reason one would want to move the thermostat is that the wax bulb is on the hot/engine side where its difficult to fit a heating element close-by.
Could you post links the the pre heater you have your eye on?
There are a couple of water heaters (with pumps) on the market I see.
They seem to fit into the thinner pipes going to/from the car interior heater radiator in the dashboard.
I don't know that they do much besides make the interior heater work instantly..? It all depends on the cooling circuit for your particular car.
Also; if they are car battery powered rather than wall plugged they just move the load to the car's alternator after startup, negating any economy advantages.
I see you also get fuel powered heaters! WhatTH!??
No time for that research atm.
Edit/Update: (I was just too curious!
)
It seems that the heating circuit for the interior heater-core is on the engine/hot side and bypasses the thermostat/s.
This makes sense as you want your customer's car heater to start working asap!
You can see a whole lot of cooling circuit diagrams here:
https://www.google.com/search?q=car+...M&vssid=mosaic
The hot water for the heater normally comes from the area close to the thermostat.
So lets say one fitted something like this:
https://www.amazon.de/-/en/Auxiliary.../dp/B0BJZZYCWB
There will be some flow of hot water over the thermostat.
So if the pre-heater, which has it's own thermostat switch for the element, (and pump) heats the water to above the opening temperature of the main thermostat; then the main thermostat will open.
However I don't 'see' much flow through the main radiator due to the small pump and flow (if any) will be in the opposite direction to normal.
Be that as it may, there will still be more heat in the cooling system pre startup which should help considerably.
NB that all this revolves around the interior heater being ON:
If not; the water valve in the interior heater's water circuit will be closed and the small pump cavitating. ie: No flow.
I would say that a system like this would be complimentary to a sump heater as there is no water cooling of engine sumps. That's where the oil lies and it too can be heated pre startup.
In fact; it should be pre circulated/pressurized before startup if you want your engine to last..