Engine Pre Heating

John T Carroll

Are there any manufacturers of normal Petro/Diesel engines fitting a "Thermos (vacuum) Flask" like the one used in the Prius which keeps a container of water hot and is then circulated around the head/block on a cold start and would surely help with economy/emissions?.

CJhaughey

John T Carroll wrote: »

Are there any manufacturers of normal Petro/Diesel engines fitting a "Thermos (vacuum) Flask" like the one used in the Prius which keeps a container of water hot and is then circulated around the head/block on a cold start and would surely help with economy/emissions?.

Not to my knowledge, there are plenty of aftermarket block heaters available that either sit in one of the frost plug holes or fix to the sump to enable preheating of the engine.

biko

Not that I know of.
There are aftermarket engine heaters you can buy though.

John T Carroll

CJhaughey wrote: »

Not to my knowledge, there are plenty of aftermarket block heaters available that either sit in one of the frost plug holes or fix to the sump to enable preheating of the engine.

biko wrote: »

Not that I know of.
There are aftermarket engine heaters you can buy though.

I have seen those in the UK a good few years ago but I find it a little surprising that no manufacturer has produced a more state of the art one, maybe they don't really achieve much at the end of the day.

CJhaughey

John T Carroll wrote: »

I have seen those in the UK a good few years ago but I find it a little surprising that no manufacturer has produced a more state of the art one, maybe they don't really achieve much at the end of the day.

They work well, but unless its below 0°c most of the time its of little value.
Northern US and Canada use them for vehicles where the oil would thicken up and make it hard to start.
Here most cars in 10 months of the year are starting in 5°c + which isn't a big issue.

John T Carroll

CJhaughey wrote: »

They work well, but unless its below 0°c most of the time its of little value.
Northern US and Canada use them for vehicles where the oil would thicken up and make it hard to start.
Here most cars in 10 months of the year are starting in 5°c + which isn't a big issue.

I wouldnt have thought that it had anything to do with starting issues, especially petrol and the Prius has a fairly standard Petrol engine even if it does use the atkinson cycle but again thats for economy.

CJhaughey

John T Carroll wrote: »

I wouldnt have thought that it had anything to do with starting issues, especially petrol and the Prius has a fairly standard Petrol engine even if it does use the atkinson cycle but again thats for economy.

It may have something to do with occupant comfort, Hybrids are generally driven short distances and if the efficient engine doesn't heat the cabin as fast it may not be very comfortable for the occupants.

Falcon L

I owned a VW Multivan that had a diesel powered engine pre-heater, along with a diesel powered cabin heater, both original manufacturer spec. A bit of a waste on the Costa del Sol I have to admit.

CJhaughey

Just had a look at a schematic, the thermos holds 3 litres of coolant and will keep it warm for up to three days. it fills at 95c but I couldn't see the rate of heatloss at any given ambient temp.
I guess this is probably over half the coolant capacity of the engine.
Having this amount of hot water already in the engine would speed up the warmup of the engine and reduce wear on engine components due to less viscous oil, and possibly provide cabin heating sooner than if there was no heating.
I would assume that it also leads to less emissions as the engine is nearly warm already so a less rich fuel/air mix could be used from a cold start, which if you were running on electric a lot could be a big benefit.

John T Carroll

Falcon L wrote: »

I owned a VW Multivan that had a diesel powered engine pre-heater, along with a diesel powered cabin heater, both original manufacturer spec. A bit of a waste on the Costa del Sol I have to admit.

I saw petrol cabin heaters many years ago in the States on the old air cooled Variants/411s I think. Alot of manufacturers use electric auxiliary heating now on their export models as the alternators are now very powerful.

John T Carroll

CJhaughey wrote: »

Just had a look at a schematic, the thermos holds 3 litres of coolant and will keep it warm for up to three days. it fills at 95c but I couldn't see the rate of heatloss at any given ambient temp.

There are all sorts of posts re the the above if one googles "Prius Coolant Thermo Bottle" (so no cup of tea before I drive off as its not really a thermos flask), all pretty interesting so I wonder will it be become more common?
https://www.youtube.com/watch?v=qjdUr2BD6R4