Cooling

[welleyes]

We have a cooling problem with a Series 1 Aprilia. We note several mentions of overcooling in previous posts, such as...

“I have been running with the shutters open and even on the hottest days I have not been able to reach 130 degrees F which is the minimum start-point registered on my carefully concealed (new) water temp gauge. ”
and
 “With a new radiator, my car runs pretty cool and only got up to temperature in town with the shutters shut, needing them opened only in a traffic jam (in winter).”
and
“Like most of the older models the Aprilia is a little "overcooled" in the radiator department and in anything other than warm weather can take quite some time to reach operating temperature with all the mechanical disadvantage that this implies.”
and
“The Aprilia was originally provided with
1)thermostatically opened radiator shutters (opening automatically by a wax filled piston and lever assembly)
2) a basic engine thermostat situated in a housing between radiator and block.
3) a cooling fan driven from an engine pulley.”

Unfortunately, we have no shutters or associated mechanism and no thermostat. Where would the thermostat housing be? Was it between radiator and head? There does not appear to be room at the bottom of the rad. How was the piping plumbed in at the other end? We are confused!

We thought we would understand more when we found, “All that remained was to design the housing within the original dimensions and source a suitable and replaceable modern thermostat to do the job.With an outlet to the heater unit (also an add on of course ) and a take off for the water gauge,  the housing (which needs to remain slim to fit next to the block) was in danger of getting crowded and demanded careful consideration.
   "The original thermostat was much smaller in diameter than modern car equivalents but a readily available alternative that fits and works perfectly is from a kawasaki motorcycle ( KLR 600) part number 49054-1053.
   "The thermostat housing can be seen in the photo's added below.The first two photo's show the unit and in the last photo you can just see it in position when mounted on the block. The lower take off is to the heater, the upper for the temp gauge. Now I have as much driver information as in any modern vehicle and a great deal more control.Which is just how it should be... “

A picture is worth a thousand words. But, sadly, the above was followed by, “[attachment deleted by admin]”

We cannot find a thermostat or housing in the Instruzione e catalogo pezzi di ricambio. Can somebody enlighten us? Better still, if anyone has the makings of the shutters and their associated trappings .….

Stuart Tallack p.p. Andy Tallack

[davidwheeler]

There never was a thermostat in the hose.   The wax filled thermostat sits in the RH side of the top tank and operates the shutters through a bell crank the which I have never had but the thermostat does not seem to move anyway.  I operate my shutters with a Bowden cable and a bicycle lever thingy.  The engine never gets hot in the winter and barely hot in the height of summer (the curse of the new radiator!).

I have a spare set of shutters though not the panel in which they fit but this is basically a sheet of steel.    Probably the easiest and most efficient thing to do is to make a housing and fit a modern thermostat in the top hose.   However, if you really want to go original I may be persuaded...

David

[BlueSky]

As David says first series cars just the one thermostat, the wax type fitted in the radiator. Second series Aprilias have two thermostats, the standard wax one in the top rhs of the radiator plus another in the top radiator hose, see the attached TAV of a second series radiator. You can get reproduction 2nd series thermostat housings from Italy, I hate to think what the cost might be though.

I put this story on my web site a few years back regarding my radiator and cooling experiences.
http://www.narrywoolan.com.au/home/The_radiator_saga.html

I have shutters and a working wax thermostat. Since the above the only cooling issue I’ve had is getting the engine hot enough on cold days, she struggles to get above 60 deg C. On warm days in traffic and steep mountain climbs she sits comfortably around 70 - 75 deg C.

However if you have an overheating problem I would be looking at the radiator first to see if any of the tubes are blocked, then take the water pump off and check the internal channels fixed in the bottom radiator tank are there, if not the water cannot circulate correctly. Next the water pump, they can corrode horribly, and I found mine was missing the spacer at the end of the impeller (p/n 38-4041), which meant it wasn’t engaging with the pulley. Also the slot in the copper tang, the part with the left hand thread that the fan screws on to, (p/n 38-4060) can wear which also means the impeller isn’t turning.

New water pumps are available also in Italy, again at a price! Many owners have fitted a normal thermostat like the motor cycle one mentioned, maybe they can come forward with their experiences.

Oops, re read your post and realise your problem is not overheating, please disregard the above!

Noel

[lancialulu]

Noel is right re second thermostat as I have one fitted as well and have same cooling experiences (ie it never gets hot). I would say it is not so much in the top hose but in a housing in the top steel pipe from rad to head.

[ben]

In my experience it doesn't seem to matter that the engine runs cool. I suppose if you have tuned it up and want to go racing it might be a different story!
 Is your car misbehaving in some way that you attribute to it being too cool?
In my view it is nice to know you have some capacity in hand for when that really hot day comes along and you get stuck in traffic!
I cannot remember my car ever boiling. I installed a gauge for a time but don't remember what readings it gave and I ditched it again as it looked untidy and the capiliary tube got in the way under the bonnet!

[welleyes]

Thanks to everyone. We are mulling over all the information.


The Tallacks

[Scarpia]

the posts regarding the thermostaat and reproduced housing/kawazaki unit (now without photo's) is one of mine.
i'll see if i can find the original photo's once more.

[welleyes]

Scarpia, thanks. Photos would be much appreciated.
Ben, we agree that overcooling is better than overheating but before it warms up to an acceptable temperature, from home we have to negotiate several main road roundabouts and junctions. Fiddling with the choke and hand throttle as well as accelerator takes away the pleasure for the first few miles.  Other cruder cars in the garage cope better.

Andy and Stuart

[Scarpia]

in the summer you scarcely need the choke and in the winter also not for long (with mine). I do have manually operated shutters which i leave closed (most of the time in the winter).is you mixture ok?
aftermarket blinds used to be available , maybe you can adapt something (vertical roller blind inside like on asturas ?) or use a radiator cover in the winter.Running to cool is not really a good idea long term.  the provision of a second series style (and location) thermostaat is the best solution, you are otherwise trying to heat up a much larger volume of coolant in the start up.It's not by accident that this mod was introduced .hot engine= better economy , performance and longevity.

[Scarpia]

here the photo's of the new thermostaat housing and position on the block.Took me a while to find them again (on the old computer). shame they were removed in the first place.description in my original post back at the dawn of (forum) time.....

[davidwheeler]

Was that all carved from the solid or do I detect parts from a plumbers' merchant?
Where did you connect in the other side of the heater?
David

[davidwheeler]

Just read Narry Woolan's radiator saga.  Mine was rebuilt perfectly and rapidly by   http://www.vintagecarradiatorcompany.co.uk/  cost about a grand.

[simonandjuliet]

It appears that there are 2 take-offs - do I take it that one is for temp gauge and the other for the heater system ?? Would be interested to see the original thread to explain your mods. I have the thermostat housing but it has been repaired several times so keen to see a mod tthat includes the temp gauge - not too worried about the heater !

Anyone done aircon on an Aprilia ........

[JohnMillham]

Where does the water return from the heater to the engine (or radiator)? I completely disconnect the heater on my Augusta for the summer and have given up using a thermostat while the heater is disconnected.
 Regards, John

[Scarpia]

see my original post "temperature regulation in aprilias" march 2007 (tab 8 below).
2 take offs, heater and temp sender unit connection.no plumbing parts in a 100 miles.....

John,the other heater connection is on the outlet connection from the top of the radiator that connects radiator to the top of the thermostat housing (with rubber connections inbetween). the heater take of is  just in the bend. see photo.