cooling

[peterm]

Beating a dead horse once again, changed fan clutch, replace water pump, recored radiator, water wetter etc etc still to no avail on a warm day i need the put the heat on when stopped for any period of time to prevent a migration over the red.  Does anyone have a source for supplemental electric fans i could have installed?

[glennard]

Timing, tune-up, fan shroud, idling rich,

[jeffc280sl]

There is precious little space available in front of the radiator for an electric fan. With the A/C condensor out I have installed an electric fan which works helps marginally at best.  I don't think the fan I chose will fit with the condensor in place.

MB sells a bypass kit which routes water from the rear of the head via the TTS outlet back into the radiator.  This is an option for you.  It is expensive but so is a head gasket.  

Last summer I installed tee fittings in the heater hose lines running to and from the heater core.  These tee fittings are connected by a section of heater hose effectively routing super hot water from the head bypassing the heater core (when the valve is closed) and back to the radiator.  When the heat lever in the car is moved to the heat setting hot water is routed through the heater core as before.  The heater still works fine for me with this setup. Basically this setup does the same thing as you do when you use the heat setting in the summer to circulate water through the heater core.  The difference is that you do not route the heat through an already hot cabin.  My engine temperature is maintained between 180 and 200 degrees or so.  My only concern is with the engine temperature in the winter and if it is high enough to reach an efficient operating temperature.  I don't drive it in the winter so I have not looked into this.  Maybe some other folks can add their thoughts about this.

Jeff C.
1970 280SL 4-speed

[Klaus]

A long and interesting discussion (in German language) can be found at
http://www.pagodentreff.de/diskussionsforum/t2741-kuehler-hochleistungsnetz-erfahrungen.html.
Summary:
Several owners in Germany have installed electric fans into their Pagodas and report excellent results (but it does not regularly get as hot in Germany as e.g. in the southern US). They use Spal fans, diameter 382 mm, depth 52 or 63 mm available, both seem to fit, installation behind the radiator (fan must be suction fan). This fan is available e.g. from http://www.jaycorptech.com/. Owners report 5-6 hp performance increase (visco fan deleted) and smoother engine running.

Klaus
1969 280 SL

[jeffc280sl]

I have for a long time considered the idea proposed by Klaus.  Glad to hear it works well in Germany.  Now that I have the bypass as an option I may try the electric puller fan setup and eliminate the motor driven fan.

Jeff C.
1970 280SL 4-speed

[jeffc280sl]

The Spal fans are available from $69 to $142 and 1300 cfm to 2470 cfm respectively.  Make sure you have a proper sized alternator.  They draw 8.5 to 22 amps.



Jeff C.
1970 280SL 4-speed

[hands_aus]

Peter,
Have you checked that there are no air pockets in the cooling system?

I was told that all you have to do is fill the system plus the expansion tank to the very brink then start the car and let it warm up until normal operating temperature.
When the thermostat opens, if there is an air pocket the water will push it out and the expansion tank will self level.

Do you have a rubber hose on the expansion tank overflow pipe?

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[mbzse]

quote:Originally posted by hands_aus

Have you checked that there are no air pockets in the cooling system? ../...all you have to do is fill the system plus the expansion tank to the very brink then start the car and let it warm up until normal operating temperature.
When the thermostat opens, if there is an air pocket the water will push it out and the expansion tank will self level

A useful practice for our cars is to park the car slightly uphill when running the engine for warm-up. This will aid the "burp" which relieves the trapped air, and also ensure that all of the air will come out

/Hans in Sweden

[ted280sl]

Peter,
  Some of our cars have a bleeding bolot on top of the thermostat. While the car is running you can carefully unscrew the bolt and let the air out. I do not believe that this is the reason for your overheating but, id does not cost anything to try it.
Good luck,
Ted 1969 280SL

[Ben]

quote:A useful practice for our cars is to park the car slightly uphill when running the engine for warm-up. This will aid the "burp" which relieves the trapped air, and also ensure that all of the air will come out

.........surely one would need to park in such a way as to ensure the expansion tank is the highest point. Parking nose in the air will see air bubbles in the rad no ?

Regards,
Ben in Ireland.
'64 230SL 4sp.