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Hi-flow thermostat Subaru
tweety - April 25th, 2012 at 09:35 PM

Tweety's radiator (alfa) is now front mounted and sits lower than the engine. The ea81, according to the digital temp guage was slow to fall in temp after the 82 degree thermostat opened.

The installation of a hi-flow thermostat (Tridon TT2041-180 from super cheap $24) was carried out and a cold start showed that the temp fell much quicker after the thermostat opened.

Might help owners to circulate coolant quicker as to prevent excess heated coolant in the manifold.

I dont drill holes in my thermostats either, a common practice but I dont agree with the idea.

http://i804.photobucket.com/albums/yy330/eaglefree/IMG_0008-5.jpg

http://i804.photobucket.com/albums/yy330/eaglefree/IMG_0006-4.jpg


ElusiveStranger - April 28th, 2012 at 12:38 PM

I'm glad it works for you.

What temp does it open?

"I dont drill holes in my thermostats either, a common practice but I dont agree with the idea."
Nor do some of we, in fact, it's a despicable act *shudders*

Circulating coolant quicker....well the delta T on the rad is proportional, swings and roundabouts.


ian.mezz - April 28th, 2012 at 01:51 PM

A thermostat is to bring engine up to operating temp quicker. doesnt help cooling .:blush: once it opens the temp still goes up.


tweety - April 28th, 2012 at 02:51 PM

A good debate here. The ea81 wasnt designed to have its radiator 2 metres from the engine and lower that it. While the water pump has the ability to pump the coolant around the circuit if there is restriction of the coolant and that flow slows then we have an issue.

It has been suggested to me that the hi-flow thermostats available from say Tridon are similar to the standard ea81 stat from Subaru. I wouldnt know either way. But if this is the case then the common thermostats on the market should be labelled "SLOW FLOW". If you get my meaning.

I have two 12 inch thermo fans on the Alfa radiator. An expansion bottle at the highest point of the coolant system. The digital temp switch combo incorporates a fan switch easily adjustable for the fans to kick in. This is mounted in a unit after the thermostat in the rubber hose. I also ahve a Hudson Instruments sender switch in the original sender location next to the stat. This sender switch has a rating of 95 degrees C. It is connected to a truck reversing alarm.

So, the SLOW FLOW stat which is 82 degrees opens but the flow is slow enough that cooled coolant takes too long to make its way from the radiator back to the engine (we are talking at idle here say in traffic or start up in the morning). Hence the coolant heats up quicker in the engine and sets off the truck alarm. This was when the fans cut in at 88 degrees. Rev the engine and no problem- 30 seconds alter all cool. Fans go off at 81 degrees as set.

Then replace the stat with the Tridon hi-flow. Truck alarm does not go off. It is clear when the stat opens as the S/steel pipes heat up, coolant circulates quicker and hence the digital temp gauge doesnt even get up to 88 degrees. About 83 before it goes down again to about 78. Subsequently the truck alarm doesnt go on at all meaning the coolant temp at the manifold doesnt get near 95 degrees.

As I ride off the temperature gauge stabilises at around 80 degrees whereas with the slow flow stat it would hover around 84 and at idle in traffic of course, it goes up to 88 pretty quick because that flow is more restricted. Whereas now in traffic the temp takes a looong time to reach 88.

Many words to explain but the hi-flow does have an positive effect on the cooling system efficiency IN THIS CASE I stress. Those stats with smaller openings are a bit like the lap band surgery of cooling systems but ok for standard engines in standard cars.


ian.mezz - April 28th, 2012 at 05:26 PM

i think you running to cool 102 sounds better,
a car should never over heat in winter, thats when the thermostat works best to keep motor hot.
a car will run hotter in summer if its already a 36deg day. the temp is allowed to go up . just look at a older ford falcon and check out the normal range in the temp gauge.


1303Steve - April 28th, 2012 at 05:49 PM

Hi

Am I reading this correctly, are you letting the trike sit around and warm up before riding off?

Steve


tweety - April 28th, 2012 at 10:18 PM

1303steve. In winter here in the foothills of the mountains I warm it up using my throttle lock only long enough for the heater to work as it supplies the large windscreen with a bit of warm air to keep it from misting up. I have a 12V hairdryer I will adapt for this purpose soon.

I know where you are coming from and commonly in warmer days just ride off immediately taking it easy for a few kms or so.

I dont tend to explain every facet of my threads with my trike. The reason is simple- many things about it is unique and each problem has its quirks. EG when I carried out the conversion I went days wondering why it wouldnt start. It would turn over but not fire. Subaru and VW forums were no help. Then it hit me...the kills switch was off! started first go!!. No wonder car forums couldnt help me...how many cars have a M/cyucle kill switch?

So in this case, allowing it to idle is for the sole purpose of ensuring the engine is running ok. etc.

What I suggest is for water cooled converters if they have an issue with poorer than ideal coolant circulation that it is an avenue to pursue- the higher flow thermostat.


ElusiveStranger - April 29th, 2012 at 04:12 AM

Umm, I don't agree with your logic on the 'stat, but as I said "if it works for you".
My rad is underslung, approx 5' from the motor and running a stock 'stat.

The best way to warm an engine up is to use it. It needs to be under load.
Lose the screen in the winter and wear a thicker jacket or get a car :lol: ;)


tweety - April 29th, 2012 at 06:11 PM

Had many people tell me "you might as well have a car"

If you ever get to Australia Elusive stranger I'll give you a ride on Tweety....nothing like a plain car.


ElusiveStranger - April 29th, 2012 at 11:10 PM

Quote:
Originally posted by tweety
Had many people tell me "you might as well have a car"

If you ever get to Australia Elusive stranger I'll give you a ride on Tweety....nothing like a plain car.


:cool:


GeorgeL - May 2nd, 2012 at 09:02 AM

Before fiddling with the thermostat, is the coolant bypass functioning properly? That's what tells the thermostat to open. No bypass means that the thermostat only sees coolant that has flowed all the way to the radiator and back.


tweety - May 2nd, 2012 at 08:13 PM

new bypass hoses recently renewed. blew through them and all ok. the engine runs beaut how it is now. just with the common lower flow thermostat the flow rate is such that when idling it takes too long for the coolant to make its way around the circuit. it isnt a problem now.

I'm just preventing an issue in the summer when it would be idling in traffic. I think if people have and issue with a remote radiator the hi flow stat could be looked at.

tony