Technical Dealing with the Summer Heat

[dangfiat]

Hey All,

Another in the long list of dumb questions I'm trying to understand:
1. We have no temp gauge... How do people tell their car is over heating? Truly mystified on this one...

2. Summer Heat: Anyone here from the Southwest or Southeast of the US? Where summer heat can get to multiple 100F days (38c )?

3. How do you deal with the heat? Especially when stuck in traffic? Oil cooler? Just don't drive? Extra fan? Or...... Is it OK to just drive and the little cars handle it?

I'm planning to:
1. Use 20W-50
2. get an aluminum sump (3.5 or 4l?)
3. That is all

Thanks for the help, couldn't find anything in the search on this subject but maybe my search abilities are somewhat suspect

Cheers
Daniel

 

[Desert500]

I drive in Phoenix year round, but I drive less during the summer and tend to take my drives early. I don’t spend too much time sitting in traffic and it’s not a daily driver. I like to plan routes that have the higher likelihood of keeping the car moving along.

-I run Valvoline VR1 20W50.
-I make sure the cooling fins are clean.
-I high temp exhaust wrapped my exhaust.
-I have the exhaust heat shield on and the underside has a layer of gold reflective barrier.
-I run a 123 distributor with exhaust wrap around the body.
I have a 650cc with 28IMB, and have a fuel return running all the way back to the tank to keep cooler fuel circulating.
-I run a large finned oil pan to increase oil capacity.
-I have the underside engine bay windage try installed to make sure I flow air as intended by fiat.

 

[lazylobster]

If you're moving freely then engine temps will not be an issue. It's only if you get stuck in traffic or slow moving and no air flow that it becomes an issue.

However, remember, Italian summers can be just as hot and they sold millions of 500's and plenty were / are used in the Italian heat. In thoery, if your engine oil temp is 100c., and the outside heat is 38C then there is still a 62C differentation and that should provie adequate cooling.

The original oil pan, on stationary movement has airflow directed to it from the engine fan, tin work and it's design. Pretty much all aftermarket alu pans do not.

The only aftermarket oil pan I've seen with inbuilt capability for airflow whilst not moving is from Nanni. But I've no data on how effective this is.

Sump Fiat 500 Fiat 126 light alloy Giannini NANNI with central air crossing way 3,5 liters.

Fiat 500 Sport - Sump Fiat 500 Fiat 126 light alloy Giannini NANNI with central air crossing way 3,5 liters. - Nanni Ricambi Bologna. Ricambi e accessori corsa.

www.fiat500sport.com

So I would leave the original pan on and see how you get on. Fitting an oil temp gauge is easy enough and I would advise doing so.

 

[gordinir8]

If you're moving freely then engine temps will not be an issue. It's only if you get stuck in traffic or slow moving and no air flow that it becomes an issue.

However, remember, Italian summers can be just as hot and they sold millions of 500's and plenty were / are used in the Italian heat. In thoery, if your engine oil temp is 100c., and the outside heat is 38C then there is still a 62C differentation and that should provie adequate cooling.

The original oil pan, on stationary movement has airflow directed to it from the engine fan, tin work and it's design. Pretty much all aftermarket alu pans do not.

The only aftermarket oil pan I've seen with inbuilt capability for airflow whilst not moving is from Nanni. But I've no data on how effective this is.

Sump Fiat 500 Fiat 126 light alloy Giannini NANNI with central air crossing way 3,5 liters.

Fiat 500 Sport - Sump Fiat 500 Fiat 126 light alloy Giannini NANNI with central air crossing way 3,5 liters. - Nanni Ricambi Bologna. Ricambi e accessori corsa.

www.fiat500sport.com

So I would leave the original pan on and see how you get on. Fitting an oil temp gauge is easy enough and I would advise doing so.

Hi there, I live in Greece with summer temp going from 38 and up and I'm obsessed with dropping my engine temperature. I know at the same time other owners just driving at hot days and have no problems but i don't think that the hotter the better. First of all a 3.5 lt oil pan will drop your temp about 2-3 C° when you are moving. When little car is stopped at traffic etc temp starts to rising and after you start moving immediately oil temp rises up to 5 degrees Celsius (oil at the oil pan gets hotter because of oil circulation that takes the heat from the head to the oil pan). In a hot day temp is around 105C°, mine runs at about 85-95C° even at highway. Also you have 1 extra liter of oil in your engine and this in not bad. So my recommendation is to go for an oil pan, besides i read that you want to tune your engine so then you will deal with extra heat. If you have Tom's (@the hobbler instructions you can't go wrong) Now if you want a real difference then you have to go for an oil cooler, this can drop your temp as much as 8-10 C° Here is my oil cooler installation post for ref. https://www.fiatforum.com/threads/oil-cooler-installation.462086/

 

[FR85]

I drive in Phoenix year round, but I drive less during the summer and tend to take my drives early. I don’t spend too much time sitting in traffic and it’s not a daily driver. I like to plan routes that have the higher likelihood of keeping the car moving along.

-I run Valvoline VR1 20W50.
-I make sure the cooling fins are clean.
-I high temp exhaust wrapped my exhaust.
-I have the exhaust heat shield on and the underside has a layer of gold reflective barrier.
-I run a 123 distributor with exhaust wrap around the body.
I have a 650cc with 28IMB, and have a fuel return running all the way back to the tank to keep cooler fuel circulating.
-I run a large finned oil pan to increase oil capacity.
-I have the underside engine bay windage try installed to make sure I flow air as intended by fiat.

All good points except for wrapping the exhaust in heat wrap. I think with heat wrap all that heat has to go somewhere, heat by its very nature will rise and therefore end up in the head.
While you have a return for fuel and it's a mod I'm hoping to do in the future, a lot may not have this and it may end up in boiling fuel.
It to me could just cause knock on issues, I could be way off but just thinking about it makes sense to me. Just my two cents, could be way off.

I was concerned about heat then I thought the Italians have warm summers and these little machines handled it and did so quite well those little engines had a great production run and that speaks volumes.

 

[Goldnrust]

Heat wrap is a good idea. The heat that is trapped, rather than radiating into the engine bay, is expelled as hotter exhaust gasses. Heat rising is not relevant as the engine is pumping the gasses through itself actively, not a passive system relying on convection.

The only ‘downside’ of heat wrap is it can in some cases lead to things like cracked exhausts as the metal of the exhaust itself is kept at a higher temperature.

 

[gordinir8]

I can second that heat wrap increases the flow of gases so it is improving power as well. I have touched my right aft fender and then did the same on another 500 with the same engine after a club ride and mine was cooler. (Still impossible to touch for more than a few seconds)

 

[bugsymike]

Also helps reduce engine compartment heat.
Would making the boot lid shut in a "slightly open position " the way VW Beetle owners do help dissipate heat?

 

[FR85]

Heat wrap is a good idea. The heat that is trapped, rather than radiating into the engine bay, is expelled as hotter exhaust gasses. Heat rising is not relevant as the engine is pumping the gasses through itself actively, not a passive system relying on convection.

The only ‘downside’ of heat wrap is it can in some cases lead to things like cracked exhausts as the metal of the exhaust itself is kept at a higher temperature.

My concern is when you turn the car off. There is no more gasses/heat being expelled. The cylinder head is getting hotter with out the aid of air or oil flow.

 

[bugsymike]

I suppose much in the way the advice for turbo charged engines is to give them a few minutes to cool slightly after a hard run before switching off to avoid turbo damage.
Perhaps that would help if after a "fast" run, to dissipate some of the heat. I suspect the original designers of air cooled engines must allow certain tolerances for extra heat etc. Much in the way the piston ring clearances are larger for air cooled compared with water cooled engines.
In the late 1960s we used to race tuned air cooled two strokes that developed much more power than standard and they still had the original fins on the barrels.

 

[FR85]

I suppose much in the way the advice for turbo charged engines is to give them a few minutes to cool slightly after a hard run before switching off to avoid turbo damage.
Perhaps that would help if after a "fast" run, to dissipate some of the heat. I suspect the original designers of air cooled engines must allow certain tolerances for extra heat etc. Much in the way the piston ring clearances are larger for air cooled compared with water cooled engines.
In the late 1960s we used to race tuned air cooled two strokes that developed much more power than standard and they still had the original fins on the barrels.

I'd say they put some wiggle room in there when they were designed and built but these little engines run hot and heat causes problems even with them running so when you take all that cooling via oil and fan away and you have contained that heat within the system......I could be way off, that's just the way what is left of my brain was thinking.
I know a lot of the folks over in the 850 and 850/900 section go heat wrapping due to cooling issues but I cannot help but feel this could be adding to their issues especially seen as the 850s were never kind to their head gaskets.

Debate is open, it would be interesting to see cylinder head temps with and without wrapping after shut down

 

[Goldnrust]

My concern is when you turn the car off. There is no more gasses/heat being expelled. The cylinder head is getting hotter with out the aid of air or oil flow.

Once you switch the engine off, the cylinder head will start to cool. Its the heat of combustion that's making it hotter.

The slightly hotter exhaust gasses will dissipate from the exhaust in a matter of seconds from tuning the engine off. The slightly hotter thin metal exhaust tubes will make little difference to the big chunk of metal of the cylinder head through temperature conduction. What will make a big difference is that the whole engine bay will be much cooler, which will help the cylinder head to cool faster.

 

[FR85]

Once you switch the engine off, the cylinder head will start to cool. Its the heat of combustion that's making it hotter.

The slightly hotter exhaust gasses will dissipate from the exhaust in a matter of seconds from tuning the engine off. The slightly hotter thin metal exhaust tubes will make little difference to the big chunk of metal of the cylinder head through temperature conduction. What will make a big difference is that the whole engine bay will be much cooler, which will help the cylinder head to cool faster.

I understand that it's the fire happening in the pots that makes heat, I know I'm a bit thick and sometimes I show it but I'm not that bad, herself would disagree mind you!!!

I guess you have a point. I seem to remember and I'm not sure if it was on this forum or another that someone with an 850 was having cooling issues, wrapped the exhaust to take heat out off the bay therefore the fan wouldn't be pulling warm air across the block and as soon as he'd switched off the engine the temperature gauge went off the charts. it could have been on FB either. All engines will do this of course but that snippet put me off.

Each to their own!

 

[fiat500]

I understand that it's the fire happening in the pots that makes heat, I know I'm a bit thick and sometimes I show it but I'm not that bad, herself would disagree mind you!!!

I guess you have a point. I seem to remember and I'm not sure if it was on this forum or another that someone with an 850 was having cooling issues, wrapped the exhaust to take heat out off the bay therefore the fan wouldn't be pulling warm air across the block and as soon as he'd switched off the engine the temperature gauge went off the charts. it could have been on FB either. All engines will do this of course but that snippet put me off.

Each to their own!

You're right; when the engine is running, the air that is forced across it and the inducted air that goes through through it then out of the exhaust is taking away heat and thus stabilising the temperature, As soon as you switch off, those heat conveyors also stop, and the temperature of the engine and its surroundings will increase for while.

The tiddly Fiat 500 engine is a massive chunk of metal and has the capacity to store a lot of heat. It doesn't even have the benefit of a water-cooled engine, where it is possible that a limited amount of thermosyphonic action may remove heat from around the cylinders and combustion chambers even when the engine is turned off. Modern cars are proof of the continued temperature rise after turning off; their electric fans can become active without the ignition being on.

If the purpose of an exhaust-wrap is to insulate against heat exiting the pipe early, it follows that the heat will be retained for longer when the engine is switched off.

 

[grubscrew]

Just to add a point, the fuel at the pumps either E10 or E5 as we all know contains this ethanol .
Apparently this can vaporise more readily.
I too am having issues about a hot engine dying after 15 miles . Only on cooling will she restart. It really is a pain.

 

[bugsymike]

Just to add a point, the fuel at the pumps either E10 or E5 as we all know contains this ethanol .
Apparently this can vaporise more readily.
I too am having issues about a hot engine dying after 15 miles . Only on cooling will she restart. It really is a pain.

Didn't I read one Forum 500 member had a fuel return system to aid cooling the fuel?
Some modern cars have what looks like a cooler rad under the car in the fuel system.