After seeing ( or thought I saw) my temp gauge top out for a moment then switched on fans to get a better reading, I removed the 170F thermostat from my EA81 to see how it went without. This is something I have never done before other than my Vort is currently without.
The 170 was not really affecting the op temp compared with the 182F it had before - vewry little change if any - other than the top out that must have been either eye or electrical trick.
But, when it is a bit cooler or decelerating down mountains the temp can drop to less than 1/4 where half is normal. The last three tank fuls of much the same driving as before - my fuel economy is 10 - 15 % worse off ! My Vort EA82T runs about 5 degrees C cooler without thermostat, and returns consistent 10 l per 100km.
The standard replacement thermostats aftermarket do not have same size bore as genuines do, so i think I will order in a few big bore 170 t stats , or go genuine ,and see if that makes a difference to run temp of the Brumby and its economy - so too the Vortex
thermosta V's no thermostat - economy
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discopotato03
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Triden do high flow thermostats that have the same approximate valve size as a genuine XT4 one . For all round use 82/180 is a good rating . Not sure why an EA81 would try and overheat unless the car had engine or radiator problems . The MY nose supports if anything a better radiator than an L Series does and 81s lower power outputs should equate to less heat output .
I run a twin core L radiator with just the water pump fan and I don't have issues with heat . My rebuilt engine has close to 60,000 on it now rather than an original 3-400K engine with worn rings guides and seals . Blow by and oil burning doesn't do engines any faves particularly if the cooling system is marginal .
You may want to check the water pump on that 81 , at least like everything on an 81 its easy to get at .
A .
I run a twin core L radiator with just the water pump fan and I don't have issues with heat . My rebuilt engine has close to 60,000 on it now rather than an original 3-400K engine with worn rings guides and seals . Blow by and oil burning doesn't do engines any faves particularly if the cooling system is marginal .
You may want to check the water pump on that 81 , at least like everything on an 81 its easy to get at .
A .
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2nd Hand Yank
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Silverbullet
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I couldn't see why running no T/stat would improve economy; it would take your engine many times longer to warm up to operating temp and therefore you'd be running with the choke out constantly. My old engine had the T/stat stuck open but only by 1-2mm and it took about 20 k's at 60-80km/h to warm up. This was when I was at tafe and the choke would pop in when I was just driving into the carpark!
Different engine new T/stat and it warms up to 1/3rd up the gauge in about 5 k's, or 5 minutes.
It would be better IMO to get a T/stat that opens up further, but still closes off completely when the engine is cold.
*edit* Oh and as for economy with the thermo stuck open it got 370k's to a 45L tank (choke open all the time)...Granted that was with the old leaky carb as well but this one hasn't been rebuilt lately either and with a working thermo I get more than 10k per liter in constant stop start traffic.
Different engine new T/stat and it warms up to 1/3rd up the gauge in about 5 k's, or 5 minutes.
It would be better IMO to get a T/stat that opens up further, but still closes off completely when the engine is cold.
*edit* Oh and as for economy with the thermo stuck open it got 370k's to a 45L tank (choke open all the time)...Granted that was with the old leaky carb as well but this one hasn't been rebuilt lately either and with a working thermo I get more than 10k per liter in constant stop start traffic.
Will it ever end!?
-EA81 TWIN CARB!!!!
-L series 5 speed
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-EA81 TWIN CARB!!!!
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steptoe
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when I read that 195F or was it 95C ??? 95C I think, is the most optimum temp to get best fuel economy , start to understand and believe.
I do recall your post 2nd hand,was thinking of it
Sam, forgive me, forgot to say LPG, no choke YEE HAA! just crank and pedal and she starts.
Got a catalogue at hand for Tridon - just a bitch to order and wait for it to come in - so I delay even longer ????
Engine is nice and fresh, 40 thou oversize bores 16/56 cam and LPG ~ 15,000km and i probably shouldn't be revving the tits off it!
Indicated 540km (actual 575) 60.8 litres jumped to 520 km 66 litres .
try getting 66 litres in yer bullet Sam
I do recall your post 2nd hand,was thinking of it
Sam, forgive me, forgot to say LPG, no choke YEE HAA! just crank and pedal and she starts.
Got a catalogue at hand for Tridon - just a bitch to order and wait for it to come in - so I delay even longer ????
Engine is nice and fresh, 40 thou oversize bores 16/56 cam and LPG ~ 15,000km and i probably shouldn't be revving the tits off it!
Indicated 540km (actual 575) 60.8 litres jumped to 520 km 66 litres .
try getting 66 litres in yer bullet Sam -
steptoe
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Probably repeating selves from a few years back - found Tridon info on high flow thermostats and explains high flow uses 34mm valve diameter, where they say typical OE will be 29. Others have said before Subaru used larger dia OE, so to fit a standard replacement AM part starts your troubles if this is the case.
An extra 5mm dia allows about 30% more flow.
"High Flow thermostats eliminates any need to use cooler thermostats as a temporary cure for overheating problems as was done in the past"
TT241 is the standard thermostat aftermarket for MY and L Series EA's, and TT2041 is the high flow, 77C >>TT2041-170, 82C >> TT2041-180, 85C >> TT2041-185, 88C TT2041-190
Never in stock, always an order in item
There is also no STANT or DAYCO cross reference numbers for the high flow - looks like it is a Tridon special
An extra 5mm dia allows about 30% more flow.
"High Flow thermostats eliminates any need to use cooler thermostats as a temporary cure for overheating problems as was done in the past"
TT241 is the standard thermostat aftermarket for MY and L Series EA's, and TT2041 is the high flow, 77C >>TT2041-170, 82C >> TT2041-180, 85C >> TT2041-185, 88C TT2041-190
Never in stock, always an order in item
There is also no STANT or DAYCO cross reference numbers for the high flow - looks like it is a Tridon special
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steptoe
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Just rummaged up 10 Subie thermostats - (no wonder I'm short on space!) and measured genuines at 30 and 31mm diam valve - the others range through 24,25 and 26mm. It will be interesting to see if TT2041 can do 34mm as there is not a lot of meat left to go from 30 to 34 on an off set 54 max diameter thermostat
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discopotato03
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Steptoe if you order them they will be a little more expensive at around $20 or were when I last got them . I got a 77C and an 82C to play with and I think the 82 went in first by mistake .
I think the value in them is that the larger valve doesn't have to move as far to regulate temperatures - so its not a smaller valve moving further and chasing itself around in circles . I found that the larger valve ones tend to run at a more uniform temperature which is important when your L Series only uses the first 40% of its temp gauge scale at best .
The important thing with thermostats is that regardless of what temp range they won't stop an inadequate cooling system from overheating . They really only attempt to set the MINIMUM temp because any of them fully open achieves the same thing .
What you will notice easily with a lowish temp thermostat ie 70-77C is that the gauge needle sits lower and if its creeping upwards you can see it very easily on a short changed L gauge .
If fuel economy is the top priority with a healthy engine you would try to run lower viscosity oil for less oil drag and a slightly higher temp water thermostat ie 82-88C . The idea is for the fuel used to vapourise as easily as possible because in big droplet size petrol doesn't burn properly and goes out the exhaust as carbon . Gas will probably be a different story and you'd only ever do that for cost reasons because petrol engines run best on what they were designed to burn .
Actually Coxy tells me fuel density has changed since the mid 1980s so the petrol of today isn't as it used to be even without lead .
If anything the single biggest factor IMO is that a mechanical and manifold pressure referenced distributor can't give best mean torque timing because of its mechanical limitations . Haltech used to do an ignition only computer that worked off I think manifold pressure and revs , possibly TPS too , and they would be a great thing on any engine that had a distributor . They can advance timing right up on part throttle running and cut it back very smartly under load to avoid detonation . I'd love to have had one for my car but they've been off the market for a long time . Everyone wanted fueling and ignition combined computers so the market for them dried up .
Sadly EA81 and 82 heads are a little agricultural and not really set up for todays lean burn engine head temperature control . I know you people don't like Evo Lancer talk here but Mitsy went to more cooling jacket trouble on the MiVec Evo 9 heads so they could run leaner and not have as many hot spots in the chambers - basically could run more advanced timing with leaner mixtures without as many detonation issues . Equals cleaner emissions and better part throttle fuel consumption . The give away was spark plugs with extended threaded sections ("long reach") and smaller diameter thread as well . The result was that the chambers get better cooling around where the spark plug enters and around the exhaust valve seats and ports .
The engine itself doesn't run any cooler anywhere else but the important bits but it makes a significant difference . Timing retarded to prevent detonation retards burning efficiency so the fuel/air being burnt isn't doing as much to drive you down the road as it could . Its the reason why slightly higher octane fuel can at times give you better MPGs but not necessarily better $s per km .
A .
I think the value in them is that the larger valve doesn't have to move as far to regulate temperatures - so its not a smaller valve moving further and chasing itself around in circles . I found that the larger valve ones tend to run at a more uniform temperature which is important when your L Series only uses the first 40% of its temp gauge scale at best .
The important thing with thermostats is that regardless of what temp range they won't stop an inadequate cooling system from overheating . They really only attempt to set the MINIMUM temp because any of them fully open achieves the same thing .
What you will notice easily with a lowish temp thermostat ie 70-77C is that the gauge needle sits lower and if its creeping upwards you can see it very easily on a short changed L gauge .
If fuel economy is the top priority with a healthy engine you would try to run lower viscosity oil for less oil drag and a slightly higher temp water thermostat ie 82-88C . The idea is for the fuel used to vapourise as easily as possible because in big droplet size petrol doesn't burn properly and goes out the exhaust as carbon . Gas will probably be a different story and you'd only ever do that for cost reasons because petrol engines run best on what they were designed to burn .
Actually Coxy tells me fuel density has changed since the mid 1980s so the petrol of today isn't as it used to be even without lead .
If anything the single biggest factor IMO is that a mechanical and manifold pressure referenced distributor can't give best mean torque timing because of its mechanical limitations . Haltech used to do an ignition only computer that worked off I think manifold pressure and revs , possibly TPS too , and they would be a great thing on any engine that had a distributor . They can advance timing right up on part throttle running and cut it back very smartly under load to avoid detonation . I'd love to have had one for my car but they've been off the market for a long time . Everyone wanted fueling and ignition combined computers so the market for them dried up .
Sadly EA81 and 82 heads are a little agricultural and not really set up for todays lean burn engine head temperature control . I know you people don't like Evo Lancer talk here but Mitsy went to more cooling jacket trouble on the MiVec Evo 9 heads so they could run leaner and not have as many hot spots in the chambers - basically could run more advanced timing with leaner mixtures without as many detonation issues . Equals cleaner emissions and better part throttle fuel consumption . The give away was spark plugs with extended threaded sections ("long reach") and smaller diameter thread as well . The result was that the chambers get better cooling around where the spark plug enters and around the exhaust valve seats and ports .
The engine itself doesn't run any cooler anywhere else but the important bits but it makes a significant difference . Timing retarded to prevent detonation retards burning efficiency so the fuel/air being burnt isn't doing as much to drive you down the road as it could . Its the reason why slightly higher octane fuel can at times give you better MPGs but not necessarily better $s per km .
A .
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Gannon
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Actually from what I have read, the latest Subaru engine, the FA20 D4-S direct injection engine for the up-coming Subie BRZ and Toyota FT86, and the FB20 and FB25 have separate water supplies so the head can run at a different temperature to the block. This is for the same reasons as stated above, to enable more efficiency though better fuel atomisation, as well as more ignition timing.discopotato03 wrote: I know you people don't like Evo Lancer talk here but Mitsy went to more cooling jacket trouble on the MiVec Evo 9 heads so they could run leaner and not have as many hot spots in the chambers - basically could run more advanced timing with leaner mixtures without as many detonation issues .
Current rides: 2016 Mitsubishi Triton GLS & 2004 Forester X
Ongoing Project/Toy: 1987 RX Turbo EA82T, Speeduino ECU, Coil-pack ignition, 440cc Injectors, KONI adjustale front struts, Hybrid L Series/ Liberty AWD 5sp
Past rides: 92 L series turbo converted wagon, 83 Leone GL Sedan, 2004 Liberty GT Sedan & 2001 Outback
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Ongoing Project/Toy: 1987 RX Turbo EA82T, Speeduino ECU, Coil-pack ignition, 440cc Injectors, KONI adjustale front struts, Hybrid L Series/ Liberty AWD 5sp
Past rides: 92 L series turbo converted wagon, 83 Leone GL Sedan, 2004 Liberty GT Sedan & 2001 Outback
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steptoe
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oh, another thing I forgot to add - not running any vac advance - got no port to do so on the Mitsu efi throttle body. I'd just like to return to the economy I was getting and the difference of thrree tanks nearly pay for the new $20 thermostat.
Or, it has been a change in the LPG mix and is not going to change with a thermostat ! Just coincidental in the timing perhaps?
This radiator may just not be as eficient as the other one, even though it has been serviced - might have a few cores blocked off in a repair !
Two stage fan control can't hurt either -aftermarket device for first stage, remaining fan stay as it is with the switch on at 3/4s
Or, it has been a change in the LPG mix and is not going to change with a thermostat ! Just coincidental in the timing perhaps?
This radiator may just not be as eficient as the other one, even though it has been serviced - might have a few cores blocked off in a repair !
Two stage fan control can't hurt either -aftermarket device for first stage, remaining fan stay as it is with the switch on at 3/4s
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discopotato03
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I'm not sure what the gas AFRs are like compared to the petrol ones but a petrol engine would mis vacuum advance . Its designed to advance the firing under light loads (part throttle) when the cylinder filling is not as good and the dynamic or effective compression ratio is lower .
If you run a distributor in mechanical advance mode only then all it can reference off is engine speed so the timing curve will not be engine load sensative .
Early EFI EA82s have a vacuum port close to the throttle plate and I think there's another smaller one ahead to help too . You don't get the same effects if you tap into the inlet manifold itself . Can you use an alternate TB with a similar vacuum port to an EA82 ?
Cheers A .
Actually this reminds me of BMCs old 60s Cooper Ss , they had a mechanical only distributor and were not considered a performance with economy car . Many people put these dizzys in other Minis thinking Cooper S part so must be better . Eventually some went back to or even swallowed their pride and use mechanical and vac advance dizzys on Cooper Ss and actually gained niticable low down squirt and better fuel consumption .
Gannon I'm not really up on the latest Subaru engines but if you have links to the non F86 ones I'd read about them . I can tell from the specs and reviews that the F86 ones going to be another Honda S2000 one without the numbers up high . I'm a little biased away from flat engines nowdays because I think the packaging and extra complexity over an inline four isn't worth having the exhaust ports so far apart . The best thing about them is the inline (north south) layout because you can sort of get at everything on the front of the motor reasonably . I do like that the EA81s are so compact and uncluttered compared to 82s and EJs but they need to be in a light weight car like a Brumby or Hatch . Shame I never had a chance to play with a twin carb EA81S because its probably better than many EA82s and so much simpler . A lot cheaper than my EA82T was in the long run .
If you run a distributor in mechanical advance mode only then all it can reference off is engine speed so the timing curve will not be engine load sensative .
Early EFI EA82s have a vacuum port close to the throttle plate and I think there's another smaller one ahead to help too . You don't get the same effects if you tap into the inlet manifold itself . Can you use an alternate TB with a similar vacuum port to an EA82 ?
Cheers A .
Actually this reminds me of BMCs old 60s Cooper Ss , they had a mechanical only distributor and were not considered a performance with economy car . Many people put these dizzys in other Minis thinking Cooper S part so must be better . Eventually some went back to or even swallowed their pride and use mechanical and vac advance dizzys on Cooper Ss and actually gained niticable low down squirt and better fuel consumption .
Gannon I'm not really up on the latest Subaru engines but if you have links to the non F86 ones I'd read about them . I can tell from the specs and reviews that the F86 ones going to be another Honda S2000 one without the numbers up high . I'm a little biased away from flat engines nowdays because I think the packaging and extra complexity over an inline four isn't worth having the exhaust ports so far apart . The best thing about them is the inline (north south) layout because you can sort of get at everything on the front of the motor reasonably . I do like that the EA81s are so compact and uncluttered compared to 82s and EJs but they need to be in a light weight car like a Brumby or Hatch . Shame I never had a chance to play with a twin carb EA81S because its probably better than many EA82s and so much simpler . A lot cheaper than my EA82T was in the long run .
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steptoe
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This engine can feel a little tardy on take off but can still chirp the tyres, and likely to be the cam and spring tension on the throttle body, not a good match to the pull from the Subie pedal and takes a bit of getting used to. Not worrying about the vac advance as my twins are destined for this engine as soon as they come off the other ute - its got EA82 NA block, turbo heads and cam with mpfi inlet and throttle body to match , a project getting closer just playing with alternator and inlet duct clearance issues 
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steptoe
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Something else I had forgotten is LPG and converter temps, the higher the converter temp the leaner the mix is. The converter is warmed to prevent freezing, by coolant in most cases, some can be hooked up to exhaust - like an old air cooled Vee Dub on LPG
Took a hint from Disco and ordered one at 170 another at 180
Took a hint from Disco and ordered one at 170 another at 180
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discopotato03
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Yes they would need something to stop the water in the air from icing things up . Carburettors and EFI throttlebodies often have water heating to prevent icing in cool humid climates .
Fuel vaporisation also has an evaporative cooling effect . Multipoint EFI is a dry system where mostly air flows from the throttlebody to the inlet ports . Carburettors and single point EFI , or LPG , have air and fuel flowing throught the inlet manifolds and its more important to make sure the air and fuel is mixed as well as possible to get even cylinder to cylinder fuel air mixtures .
I got rid of my throttlebody heating partly because the water barbs were rotten and partly because generally icing isn't a problem for an EA82/L Series than doesn't know what "too cool" is . Particularly turbocharged ones .
A .
Fuel vaporisation also has an evaporative cooling effect . Multipoint EFI is a dry system where mostly air flows from the throttlebody to the inlet ports . Carburettors and single point EFI , or LPG , have air and fuel flowing throught the inlet manifolds and its more important to make sure the air and fuel is mixed as well as possible to get even cylinder to cylinder fuel air mixtures .
I got rid of my throttlebody heating partly because the water barbs were rotten and partly because generally icing isn't a problem for an EA82/L Series than doesn't know what "too cool" is . Particularly turbocharged ones .
A .
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steptoe
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OK, got me thermostats earlier than expected , retail is $29.99 for a Tridon packaged 'motorad' thermostat. Bloody enormous looking difference in the size of the valve. Got it in and trying out the 170F 82C? unit first to see how things go.
My whole concept of the cooling system is changing, starting to realise I was watching engine temp to see when the fan switch would cut in , when , really I should be watching radiator temp as that is where the manufacturer placed the switch.
Always known the water gets cooled in the radiator, more time sitting there the better, so a thermostat is needed to maintain consistent engine temp and rather a happy consistent is desired, with an efficent radiator to keep it that way.Keeping a just cool rad won't help on the stinking hot days, hot roads or towing, loaded conditions - so a bigger, better radiator not easy to get.
So, just run one fan more often keeping the rad water cool, with thermostat keeping engine happy.
Noted the old 97 at least V6 Camry runs one big fan and it is powered soley by what appears to be the power steering fluid on its way to the cooler up front, so a bit like the old fixed fan on the water pump - always there, always drawing air through radiator, no clutches, no thermostat switches, and speed sensitive.
I understand it may be the vibrations/ resonance of the electric fans running all the time can give people the heebie jeebies.
Anyway, thermostat is in and on trial. next to try is the 180F. Will be a few tanks later to see if my efficiency has returned
My whole concept of the cooling system is changing, starting to realise I was watching engine temp to see when the fan switch would cut in , when , really I should be watching radiator temp as that is where the manufacturer placed the switch.
Always known the water gets cooled in the radiator, more time sitting there the better, so a thermostat is needed to maintain consistent engine temp and rather a happy consistent is desired, with an efficent radiator to keep it that way.Keeping a just cool rad won't help on the stinking hot days, hot roads or towing, loaded conditions - so a bigger, better radiator not easy to get.
So, just run one fan more often keeping the rad water cool, with thermostat keeping engine happy.
Noted the old 97 at least V6 Camry runs one big fan and it is powered soley by what appears to be the power steering fluid on its way to the cooler up front, so a bit like the old fixed fan on the water pump - always there, always drawing air through radiator, no clutches, no thermostat switches, and speed sensitive.
I understand it may be the vibrations/ resonance of the electric fans running all the time can give people the heebie jeebies.
Anyway, thermostat is in and on trial. next to try is the 180F. Will be a few tanks later to see if my efficiency has returned
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steptoe
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Results so far is that with the high flow 170 thermostat is that engine now runs at a few mm below middle when it is cooler, or just on midway when hotter, can also go up a bit more if no fans activated at midway or standstill etc. So, no colder operation, fuel economy is back where expected. And, have noticed SCA stock these high flow in 180 only but at $23.99 instead of the suggested retail of $29.99 from my source !!
I can now see on hotter days the radiator is not coping as well as expected , may need replacing or try a few things as nncoolg suggested TFS 132 or TFS134 the fans switch for the radiator to get the switched fan to come on lower temps!
I can now see on hotter days the radiator is not coping as well as expected , may need replacing or try a few things as nncoolg suggested TFS 132 or TFS134 the fans switch for the radiator to get the switched fan to come on lower temps!