[Poll] Fan Shroud Flaps and Thermostat

[cunning plan]

After learning in more depth about the fan shroud flaps and thermostat, I realised that my engine never had them! :shock:

I took my engine apart a couple of years ago, where it then sat in boxes and the missing thermostat and flaps were not something I noted at the time. :?

So, I have read a bit about the thermostat and flaps and there seems to be two trails of thought:

1. You need them, VW designed them in for a reason. Your engine will wear faster due to the inefficient cooling system and you will get less MPG.

2. You do not need them, Air Cooled engines warm up very quickly without the need for the thermostat and flaps to speed up the correct / even warming of the engine.

Now, I agree with point 1 and I would just find a set and install them. However, trying to find a set of flaps is very difficult, especially at a 'reasonable' price.

So that then got me thinking about point 2. Perhaps at the factory the thermostat and flaps were the solution to improve the cooling system as they were what was cost effective at the time, but now we have a range of options for upgraded oil cooling with external coolers, electric fans and external filters etc.

It seems odd that we can buy almost every part of a bus brand new, made by aftermarket companies, yet only the Brazilian thermostat is available to buy new from the thermostat and flaps setup, the flaps seem to be super rare.

So, with many people not using the flaps at all and perhaps the new modern oil-cooling techniques negating the need to have the thermostat and flap setup at all, have the aftermarket companies have looked at the tooling required to reproduce the flaps, then looked at the demand and decided that it was not worth it?

oke:

:sign0009:

 

[Clem]

VW didn’t fit them for the lolz. Even with no thermostat they are best in place for the air deflection.

 

[ozziedog]

Slightly different point of view perhaps, I’m agreeing with most of what’s said above and if you only run your motor in the summer, then most of the above points are indeed valid. A quick warm up and off you go. In the winter or on very cold mornings and evenings it may be a totally different ball game , as in the motor may not get warm enough or even up to operating temperature without stat and flaps so the motor might be wearing at an extremely unacceptable rate in cool conditions the whole time it’s running. Mrs Ozziedog tells me that’s it’s an incredible feat of engineering when the heaters are chucking out more heat than you can deal with in the hot weather but Luke warm if anything in the cold weather without flaps and stat and when it’s freezing,you’ll at best get a draught to the screen if you are very very lucky. So that tells me the motor is cool runnings when colder. Imagine how much harder it is for the motor to warm up if it has any extra coolers, or how much harder if there is more oil to warm up,

Ozziedog,,,,,,,,great topic to run with (or warm to) :mrgreen:

 

[Clem]

I dont think an engine will disasteraously explode/implode without thermo/flaps, but over sufficient time, I expect there would be a difference in wear rates of components. Possibly not an issue for the light use that many buses get, and the higher incidence of rebuilds that occur for performance gains that were not anticipated when these engines were designed.

The flaps direct the cooling air where its most needed during the warm up period and then focus its direction at optimum running temps - removal of the flaps means just a random load of air flying about - not a disaster, but not as designed. Same principal with the heat exchangers, not only do they provide heat but they also take heat away from the engine in a way that j-tubes cannot.

I get the logic regarding poor heating in the winter but I'm sure that's more to do with the heat loss over the distance from engine to dash, through leaky unlagged pipes outside rather than real ambient temperatures. Run an engine for five minutes in the deepest winter and there is still no way you want to rest your face on the exhaust :lol:

 

[atafonso]

I dont think an engine will disasteraously explode/implode without thermo/flaps, but over sufficient time, I expect there would be a difference in wear rates of components. Possibly not an issue for the light use that many buses get, and the higher incidence of rebuilds that occur for performance gains that were not anticipated when these engines were designed.

The flaps direct the cooling air where its most needed during the warm up period and then focus its direction at optimum running temps - removal of the flaps means just a random load of air flying about - not a disaster, but not as designed. Same principal with the heat exchangers, not only do they provide heat but they also take heat away from the engine in a way that j-tubes cannot.

I get the logic regarding poor heating in the winter but I'm sure that's more to do with the heat loss over the distance from engine to dash, through leaky unlagged pipes outside rather than real ambient temperatures. Run an engine for five minutes in the deepest winter and there is still no way you want to rest your face on the exhaust :lol:

Extremely spot on
Abel

 

[cunning plan]

Thanks guys, fairly conclusive poll results!