Running W/O a thermostat revisited....

[Omega Man]

Summer will quickly be upon us. Why do I bring this up again? I was reading SteveJ's thread re: a single carb conversion and he mentioned that in triple digit weather he doesn't run a thermostat. And, as we all know Joedrum never uses a thermostat. Old Girlfriend really feels the extreme changes in the weather here. 20's for a month or two in the winter and 120's with road temps in the 130+'s in the summer.

In the Winter I'm sure the thermostat is needed in my high mileage bike to get to normal running temps. The Summer though makes me wonder. Even though she never overheats and the fan is working, and the gauge rarely gets to high-normal I feel a noticeable change in performance. To the point it gets very unnerving. Should I consider removing the thermostat before Summer really kicks in? Is the function of the thermostat to hold the fluid in the radiator for a specific amount of time to either warm the fluid in Winter or cool the fluid in Summer that critical. Like I stated I'm sure it's needed in winter, but I'm truly wondering more circulation in the Summer would be better.

Does that make any sense?

I would like to hear your opinions, and yes Dan I know already your against this practice, but the guys that do this might have further insight. If you don't run a thermostat in triple digit Summer heat, how does YOUR bike respond exactly? What does your temp gauge tell you? Do you get that sickly performance that my old bike suffers?

~O~

 

[Ansimp]

You can remove the thermostat but you need some sort of restrictor otherwise the coolant flows too quickly through the radiator at highway speeds and you do not get enough heat exchanging. In all reality if your thermostat is operating correctly and you have an overheating problem at speed then you radiator must be partially blocked. Our thermo fans are designed for cooling at low speed ( not much air flow if you are not moving) and I find an override circuit helps in triple digit weather.

 

[slabghost]

I might run with a restrictor plate instead of a thermostat. My reasoning is the flow should be slowed some to allow transfer of heat at the radiator. Poor running at higher temps could possibly come from hot carbs. They might need some adjustment.

 

[dan filipi]

I'm not really against removing the thermostat.
I agree with the last 2 replies. They are what I've been saying all along about removing it.

Mine does act up and get "sluggish" in high temps like that also.
I think it has more to do with the gas being super heated and maybe boiling in the carbs than anything else.

 

[joedrum]

okay this is a rather wide issue ...its like this if you live in high temps and high humidity together you are really pushing the the design ...the cappy gas makes for alot of trap heat in the heads ..

personaly i think the hot spot ...coolant moving to fast is a wise tale when it comes to oldwings ...after yrs of running like this i know they run cooler

ny answer to the restricting is the air flow to radiator and im going to make one hopfully adjustable on the fly or as close to that as possible....

the fan sould be auto and manual for out stop and go slaughter in the highest of heat and sorrounding cars and pavment

tough to what a harley guy on sporter like bike caught in traffic on top of all that heat malting while comforable as can be :hihihi: :help: :mrgreen:

 

[Ansimp]

Hi Joe, Did I read somewhere that you don't use the metal shield between the carbies and the coils? If so you may not be getting the maximum airflow through the radiator. :builder:

 

[joedrum]

yes i do that too all in the same cooling system mod ...i sould have mention that as that is huge part of it the whole deal :mrgreen:

to me its the consistancy of the temp that is huge hugest advantage stuff is more stable and not moving up and down from the temp variation that is the biggest benefit here

 

[mcgovern61]

I have only run in as a high as 110 degree weather, but I use a thermostat and do not experience any sluggishness or operational changes in the summer. I am a big fan (no pun intended) of running the cooling system as designed.

 

[Jungo]

I made the test like 2-3 months ago and seems like it depends on the bike. In my case when I removed the thermo I noticed to main things:
1. In the morning it takes so long to warm up for obvious reasons.
2. When I'm on city and the engine heats up it takes too long to cool down, probably due the inefficiency of heat transfer.

So I decided to keep the thermo, and installed a fan manual switch for my peace of mind.

 

[bigboozer]

The engineer in me says leave it in. Lord knows that the "accountant engineers" get in there an give us many areas where real improvements can be made by upgrading components (suspension comes to mind real fast) but leave it in versus take it out don't see any real advantage to removing a functional thermostat.

One thing I have not checked into is thermostats that opens at a different (lower) temp, are they available? Could see that being an improvement.

 

[OldWrench]

Thermostat’s serve a purpose both summer and winter. Just because the outside temp is 100 plus when you first start an engine you want it to come up to it’s operating temperature as quickly as possible. Sure we feel hot in 100 plus temps but the engine isn’t warm until it is at least 180.

So why do our engines feel sluggish in the heat. The air is less dense and that affects the fuel air mixture. On today’s vehicles we compensate for that with MAP and O2 sensors that help keep the fuel air ratio appropriate for the current barometric pressure.

 

[WindNWing]

I run my thermostat and have no overheating problems. I have no opinion in the debate of in or out.
The one I don't understand is the idea of removing a properly operating thermostat (open and restricting) with a restricter plate.

 

[OldWrench]

On some engines cooling is adversely affected by the thermostat removed and coolant being allowed to free flow. It is argued the coolant moving through the engine too rapidly doesn't allow proper heat dissipation. However from what I have been taught is that the reality is the coolant moves through the radiator too quickly and isn't cooled properly. The radiator dissipates the heat as the coolant moves through the radiator, if it moves too fast the radiator can’t do its job and the coolant returning to the engine entering the engine too hot so it builds greater heat as it passes through the engine and back to the radiator eventually causing an overheating problem.

Several years ago I had a truck come in that had a constant overheating issue. The symptoms were that it would gradually overheat to the point the driver had to shut it down and let it cool down for a while and then continue on.

The thermostat had been removed so it was obviously assumed that couldn't be the problem. We pulled the radiator and had it checked and cleaned, truck came back with same overheating issue. We finally installed a thermostat and that ended the overheating issue.

 

[joedrum]

oldwings are from a time when parts were sized right ...and fit to the job on a wide bases as this was smart engineering ...that died ...now it all about doing it all with nothing ...using every trick in the book to make it work ....when one thread is broken it simply don't work at all ...today it takes high pressure high volume pumps and other things to get a way to small radiator to cool ...so yes when you take a thermostat out of something built so mismatched it will run hotter ...not enough pressure and to much volume flow for a way to small radiator ...so oldwings don't suffer this at all....they do run cooler with thermostat out ...its always one way or the other ...it runs cooler or hotter ...depending on motor and cooling system

 

[Ansimp]

Joe have you ever thought that your water pump may not be moving the volume of water that it should be. In a normal cooling system if you don't run a thermostat/ restrictor at higher rpms the water flows too quickly through the radiator and does not heat exchange effectively leading to the increase in operating temperature.

 

[dan filipi]

Joe has sworn up and down for a long time these engines run better and cooler with the Tstat out.
Mine runs in a good temp zone under good control by the system running as it was designed but until I try it with the stat out I'm not going to say one way or the other which way is is better.

 

[joedrum]

oldwing pumps can hardly be called pumps like car pumps there volume is low ...at high rpm if there is a problem we aint there much to suffer from it ...ive done this to all my wings not just one ...people that have warm up problems with no stat ...really have ignition problems ...its worked for me yrs and yrs is all I can say

 

[Ansimp]

Pleased to hear that this works well for you Joe. In my experience in our climate I have not had a vehicle that has had your success, either a clients or my own.

 

[joedrum]

:doh: :swoon: I give :hihihi: