General Performance advice

[UnoCento:)]

Hey i got a uno cento 1.0 i put a freeflow exhaust on and a cone filter. I had to modify the cone filter to fit the car. But i hav a problem. What do i do with those two extra pipes? I think from the carb...and what else can i do to the engine to give it more power without breaking the bank...thanks
Jason

 

[dave]

you could put its standard exhaust on to get more power, you dont want a free flowing one on a non turbo car

 

[UNO-MK1]

Performance add ons like air filters and low restriction exhaust do very little (if anything) to an otherwise standard engine.

The reason why is 'CFM'.

CFM stands for cubic feet per minute, and its referring to the volume of air that passes through something.

A very small engine , like the UNO 1L has a small exhaust and air filter on them as standard fitment.

However , these parts already have flow capabilities that exceed the volume of air that can flow through an internally unmodified 1.0 L engine.

I would hazard a guess that the standard air filter and exhaust would become a restriction and cost you power ONLY when your exceeding the 70HP mark.

Simply put , an air filter that can pass enough air for a 120hp engine will add ZERO HP when fitted to an engine that can only flow 50HP through the head at operational RPM's.

Any noticed improvement will be placebo affect.


**A 250HP Turbo Ford 4 banger I used to work on only had an exhaust pipe of 50mm.
**My Normally aspirated 128 1100 I used to race that made over 100HP at the wheels had a smaller sized pipe (~40mm)
----------------------------------------------------------------------

To answer your question , you likely will have a fat crankcase breather hose and maybe a smaller vent hose.
To satisfy emission regulations these are connected to the air filter body.


gW

 

[Chas Uno]

Hey i got a uno cento 1.0 i put a freeflow exhaust on and a cone filter. I had to modify the cone filter to fit the car. But i hav a problem. What do i do with those two extra pipes? I think from the carb...

As Uno-Mk1 says, the fat one is the crankcase breather and the small one feeds some of the crankcase fumes from the air filter elbow back into the engine via the carburettor base.

The crankcase breather can be left to vent to atmosphere. Do NOT block it else you can cause a build up of crankcase pressure leading to all sorts of problems.

The smaller pipe needs to be blocked at the air filter elbow end else it will an induction system air leak. This will give you a weak mixture and wreak havoc with the tickover.

and what else can i do to the engine to give it more power without breaking the bank...thanks
Jason

There is no easy fix for extra power. To get extra power from the 999cc FIRE you will have to invest time and money. However, a Punto 75 camshaft can be fitted and will give higher lift and duration though it doesn't have the lobe to run the mechnical fuel pump on carburettor Unos. You can get round this by fitting an electric fuel pump. You may get a 10 - 15% power gain from fitting the Punto 75 cam.

The easiest and cheapest route to more power is to fit a bigger engine. A 1.0 I assume to be the 999cc FIRE engine, in which case go and find a 1242cc engine from a Punto and swap them over. That will give you an instant power and torque boost and you can run it on the original carburettor (it may need re-jetting though). The only modification needed is a spacer for the exhaust manifold to downpipe connection, otherwise it will fit straight in on the 999cc engine mounts and will also hook up with your existing gearbox.

And I'm afraid your 'free flow' exhaust and cone air filter are probably giving you more problems than power. Unless they are specifically designed for the Uno then they will probably have little effect and may even cause a power loss.

Good luck!

 

[UNO-MK1]

The crankcase breather can be left to vent to atmosphere.

While this is commonly only done it should be remembered that venting the crankcase to the atmosphere is usually illegal in most countries and will earn a defect notice and perhaps a fine if found.

A bit of background info on that pipe is perhaps in order.

Fitted to the pistons are the rings.
It is the rings that seal the combustion pressures and keep them in the top half of the engine where they belong.

With an engine in good condition with minimal bore wear and with good rings , the amount of gas (either an ignited or un-ignited fuel air mix) slip past the rings is minimal.

But even in a perfect engine their is some leakage.

To prevent the crankcase from becoming pressurised (which would lead to oil leaks , blown oil seals on the crankshaft etc) they must vent this pressure to a low pressure area -- which is outside the engine.

In the old days , they used to just have a pipe and leave the end open to the atmosphere.,,and again , for a car with a good engine , it wasn't too big a deal.

However , when an engine gets tired , more gas passes by the rings.
This increase the pressure and flow of this 'blow by' gas.

Combine this with crankcase windage (oil whipped up into a mist by the spinning cranksahft) and you have a significant amount of oily , petrol fumed gas being let out into the atmosphere.

This isn't good.
Its flammable , slippery on the road and bad for the air.

So manufacturers decided to reintroduce this 'blowby' back into the intake tract to be consumed by burning in the cylinders.
This is through the big black hose that goes from the crankcase to the air cleaner.

Technically , this reintroduced 'blowby' dilutes the air/fuel mix and reduces power.
Rev heads then think , lets make more power and take away that hose.


The reality is that if your engine is making so much 'blowby' so as to drop power -- then the engine is so screwed that you have already lost most of your power through wear and tear.

Picking up a half horsepower by disconnecting the oil vapor tube is nothing compared to the 15 lost HP from engine wear , and certainly not worth the fines from the EPA , or the police defect notices over it.

Some race tracks allow the breather to be vented into an oil catch can bottle and emptied after the race.

I used to burn mine with the black pipe connected to the air filter as standard.

I never noticed any lost power.


gW

 

[randomspeedfreak]

good post thanks

 

[Chas Uno]

While this is commonly only done it should be remembered that venting the crankcase to the atmosphere is usually illegal in most countries and will earn a defect notice and perhaps a fine if found.

That's why you refit it back onto the standard airbox come MOT time

 

[Chas Uno]

I used to burn mine with the black pipe connected to the air filter as standard.

I never noticed any lost power.

I never noticed any power increase, but what I did notice was that the carburettor didn't get emulsified vapour going back into it.

On the FIRE engines the engine breather as you know vents from the camcover to the elbow on the air filter box. There's also a small pipe from this elbow going to the base of the carburettor. I supposed the theory is that the engine breather pipe vents into the elbow and then the vacuum in the small pipe (caused by manifold depression) draws the vapour back into the inlet tract. However, this elbow is also open to the inside of the airbox so any excess vapour also gets drawn into the carburettor venturi.

In cold/ wintery weather (about 6 months of the year in the UK ) and with short journeys all my Uno FIREs would generate a noticeable amount of 'mayonnaise' from the breather. This would spread from the air filter elbow into the air filter housing itself before being drawn into the carburettor. As a result this mayonnaise would end up getting inside the carburettor and cause all sorts of rough running and jet blockages.

Thus in the winter I used to vent the engine breather to atmosphere and block the elbow on the standard air filter housing. In the summer I used to run a boy racer K&N with all the breather pipes detached and blocked. No, it didn't make any extra power but it did look good and sounded gorgeous on open throttle :devil:

However, I would like to add that my 70SX is running a totally standard filter, airbox and breather system

 

[Davren]

That's why you refit it back onto the standard airbox come MOT time

And what do you say to the family of the motor-cyclist who was killed when he/she skidded off because of the film of oil on a wet road?

Dave.

 

[Chas Uno]

And what do you say to the family of the motor-cyclist who was killed when he/she skidded off because of the film of oil on a wet road?

Dave.

The same thing that could have been said to me when I came off my motorbike due to spilt diesel on the road.

Oh, the extended breather pipe fits nicely into an aluminium drinks can to act as a catch tank. Just empty whenever it gets half full. And also remember that many cars/ bikes pre 1980 vented to atmosphere through a breather oil filler cap.

 

[Davren]

Yeah, the difference between a safety feature that was never there and one that has be purposely disabled.

Good to hear you put it into a gurgle can though.

Dave.

 

[UNO-MK1]

--
On the FIRE engines the engine breather as you know vents from the camcover to the elbow on the air filter box. There's also a small pipe from this elbow going to the base of the carburettor.--

--with short journeys all my Uno FIREs would generate a noticeable amount of 'mayonnaise' from the breather. This would spread from the air filter elbow into the air filter housing itself before being drawn into the carburettor. As a result this mayonnaise would end up getting inside the carburettor and cause all sorts of rough running and jet blockages.
--

When the engine is running above idle speed the airflow entering the engine is high enough to draw in the vapor from the large tube.

At idle though , air flow is very low.

This isn't enough to suck the vapor into the engine.
This would lead to a positive pressure building up in the crankcase , which is not wanted.

So what they do is they also use a small pipe connected to the carb (at or just below the throttle plate) or the inlet manifold.

This is a high vacuum point in the intake system and can easily suck the vapor in during idling.

This little tube may or may not have valves attached to it where it connects to the air filter box or the fat pipe - depends on the car.


'Mayo' in the air filter box or on top of the carb indicates one or two things.

1. Worn compression rings....

When rings are worn the air/fuel mix that is compressed slips past the piston into the crankcase.
The compressed air will condense into water , this in turn mixes with the oil in the sump forming a 'mayo milkshake.'
This water'ized oil when heated and whipped up will make its way through the crankcase vent system to the air intake...and thats why you see it.

2. I was joking , there is no 2nd reason -- Your engine was just plain worn out.


gW

 

[Chas Uno]

When the engine is running above idle speed the airflow entering the engine is high enough to draw in the vapor from the large tube.

At idle though , air flow is very low.

This isn't enough to suck the vapor into the engine.
This would lead to a positive pressure building up in the crankcase , which is not wanted.

So what they do is they also use a small pipe connected to the carb (at or just below the throttle plate) or the inlet manifold.

This is a high vacuum point in the intake system and can easily suck the vapor in during idling.

This little tube may or may not have valves attached to it where it connects to the air filter box or the fat pipe - depends on the car.

Nope, just a plain clear plastic tube running from the elbow of the airbox to the carburettor base. No valves or anything. Same system on both my FIRE Unos and all the carburettored FIRE Unos/ Pandas/ Y10's I've seen and worked on.

'Mayo' in the air filter box or on top of the carb indicates one or two things.

1. Worn compression rings....

When rings are worn the air/fuel mix that is compressed slips past the piston into the crankcase.
The compressed air will condense into water , this in turn mixes with the oil in the sump forming a 'mayo milkshake.'
This water'ized oil when heated and whipped up will make its way through the crankcase vent system to the air intake...and thats why you see it.

2. I was joking , there is no 2nd reason -- Your engine was just plain worn out.

Except when this only occurs in cold weather and with short journeys. Many cars will produce a small amount of mayo in these conditions as the engine doesn't heat up enough to vaporise condensation that can form inside the engine and the 999cc FIRE is no exception. This leads to a small amount of mayo forming within the breather system. The mayo was also ONLY evident under the oil filler cap, along the breather pipe/ flame trap and in the vicinity of the airbox elbow area. Removing the cam cover showed none in the engine and the sump/ engine oil was also clear. This is my experience of two 999cc FIRE Unos, both 1986 models, one bought with 62K miles on the clock and the other with 75K miles on the clock. In 70K miles and 7 years of driving they both only produced a little mayo in the winter months and none in the summer. Thus engine wear was much less a factor when compared with external weather and temperature.

 

[UNO-MK1]

--Thus engine wear was much less a factor when compared with external weather and temperature.

In Finland we have 6 month long winters , with only 2 months a year that you could says is 'warm'.

During these colder months my normal car (Suzuki Swift 150,000kms 1.0L) only gets 3 X 5km two way trips each week.*

*Occasionally I have to use my car for a short trip for work once a week during winter time , this is usually less than a 15km round trip.*

I see no mayo - ever.


gW

 

[Chas Uno]

In Finland we have 6 month long winters , with only 2 months a year that you could says is 'warm'.

During these colder months my normal car (Suzuki Swift 150,000kms 1.0L) only gets 3 X 5km two way trips each week.*

*Occasionally I have to use my car for a short trip for work once a week during winter time , this is usually less than a 15km round trip.*

I see no mayo - ever.

A Suzuki swift is not a Fiat Uno, you're comparing two engines of different eras and designs. My Unos have carburettors and thermospring controlled temperature flaps into the airbox. Your Swift has fuel injection and all manner of sensors to control air intake and engine ECU issues.

A small (as in 'noticeable') amount of mayo is normal around the breathers in older cars, especially in the winter months. Others have also experiences this mayo in Fiat engines as you can see from this thread:

https://www.fiatforum.com/panda-classic/132004-possible-headgasket-panda-bella.html

And also:

"There is one other possible cause for this yellow goop : a blocked scavenger hose. Most engines have a hose which comes off the cam cover and returns to the engine block somewhere via a vacuum line. This is the scavenger hose which scavenges oil vapour and gasses that build up in the cam cover. If it's blocked you can end up with a buildup of condensation inside the cam cover, which can manifest itself as the yellow goop inside the filler cap."

http://www.carbibles.com/engineoil_bible.html


As said above, a small amount of mayo around the filler cap/ breather area/ breather airbox elbow is fine if that is the only place it occurs. My Unos used no coolant and very little oil between changes so the mayo could only be a result of engine gasses condensating in the filler cap/ breather areas. And again, as the symptoms only occured during the damp/ cold months and disappeared come the summer that kind of proves the theory.

And remember this wasn't a one off occurance, this was observed many times from driving two different 999cc Unos over 7 years and 70K miles.

I think it's what they call 'character'

 

[UNO-MK1]

A Suzuki swift is not a Fiat Uno, you're comparing two engines of different eras and designs. My Unos have carburettors and thermospring controlled temperature flaps into the airbox. Your Swift has fuel injection and all manner of sensors to control air intake and engine ECU issues.--
--My Unos used no coolant and very little oil between changes so the mayo could only be a result of engine gasses condensating in the filler cap/ breather areas. And again, as the symptoms only occured during the damp/ cold months and disappeared come the summer that kind of proves the theory.--

''Your Swift has fuel injection and all manner of sensors to control air intake and engine ECU issues''

Totally irrelevant.

Imagining the internal combustion engine minor ignition and fuel systems you will see that it is nothing more than an air pump.
Air comes in one side , pumps around and then goes out the other , rather like an air compressor.

Water in the oil (not talking about cooling system leakages) which leads to the white foam we are talking about comes from leakage past the rings during compression.

ALL engines , even brand new ones don't seal 100% at the rings.
In fact , a very good engine will show about a 10% drop of pressure when using a leak down tester.
A good but used engine may show +20% down.

Often it is more in a tired engine.

The compressed air from the lost 20% goes into the crankcase area and the water vapor from that air mixes with the oil.
Of course , humidity , temperature and driving habits ALL play a role in this.

But the one common factor in ALL engines that produce excessive foam is engine wear.

An engine with bore or ring wear WILL ALWAYS make more condensation foam than an engine in better condition , assuming all other variables are the same.


''and very little oil between changes''
It is the oil control ring that determines oil consumption in an engine , and NOT the compression rings that we are discussing.
An engine can have cracked and broken compression rings and be totally nakered , yet still use no oil.


I guess that a good suggestion would be that if someone lives in such a cold place where they are seeing this foam , they should.

1. Use an engine block heater.
2. Make sure you are fully warmed up before driving.
3. Change your oil more regularly.
4. Don't do short trips. (take a bus)

Following this advice will give better MPG and a longer engine life - guaranteed.


gW

 

[Chas Uno]

''Your Swift has fuel injection and all manner of sensors to control air intake and engine ECU issues''

Totally irrelevant.

I disagree

Whereas the FIRE was a modern design when it was introduced in 1985, much development on newer engines have taken place since. Modern cars are often designed with smaller capacity radiators per engine capacity and more accurately controlled thermostats to enable quicker warm up times. They also have things like solenoid activated emission controls such as charcoal cannisters. Intake temperatures are more precisely controlled and monitored by ECU equipped cars than a simple carburettor'd engine with mechanical distributor as per older Unos.

All engines will have bigger tolerances cold than when hot. Thus if an old engine takes longer to warm up compared with a modern engine there will be an initial period where the tolerances will allow a greater amount of crankcase gasses to pass by the piston rings leading to the formation of mayo in the cam cover and breather system. This also means that on some older engines with less efficient cooling systems they may never reach the optimum running temperature in winter months. This was apparent on both my FIRE Unos in the winter, where neither would reach much over 75 degrees unless sitting in traffic. Both had had their radiators flushed, engine coolant circuit back flushed, new thermostat, 50/ 50 distilled water and coolant and were bled correctly. I do this with all my cars when I first get them. In the summer both would warm up quickly to 80 - 85 degrees and in traffic would hit 90 degrees and have the fan come on. In the summer no mayo was produced. In the winter there was. If by your theory that this mayo was caused by engine wear then this would be expected to have been produced by the engine all year round and not just in winter. This was not evident with either of my Unos.

But the one common factor in ALL engines that produce excessive foam is engine wear.

An engine with bore or ring wear WILL ALWAYS make more condensation foam than an engine in better condition , assuming all other variables are the same.

"Excessive foam" is not the issue. We're talking a small amount in the cam cover breather pipe and the underside of the oil filler cap. This is where the breather pipe connects adjacent to it and then leads to the airbox. There is enough mayo to be noticed inside the airbox itself but ONLY in the vicinity of the elbow and with a small trail in the direction of the carburettor. We're not talking about the whole of the inside of the airbox covered in goop, which would suggest more that the problem was a failed headgasket. Also remember that there was no mayo evident in the sump/ on the dipstick, nor around the camshaft with the cam cover removed - it was only apparent at the breather outlet area near the oil filler cap.

'and very little oil between changes''
It is the oil control ring that determines oil consumption in an engine , and NOT the compression rings that we are discussing.
An engine can have cracked and broken compression rings and be totally nakered , yet still use no oil.

Let me clarify my last Uno's specs, a 1986 45 S with a 999cc FIRE engine.

Approx. 150ml oil consumed every thousand miles.

Coolant level unchanged (and remained uncontaminated) between services.

No visibile smoke from the exhaust.

A clear 'pass' for all its MOT exhaust emission tests.

This is from a car that was 21 years old, with its original engine and 102K miles on the clock. This suggests that though the engine would obviously have some wear it was far from a worn engine.

I guess that a good suggestion would be that if someone lives in such a cold place where they are seeing this foam , they should.

1. Use an engine block heater.
2. Make sure you are fully warmed up before driving.
3. Change your oil more regularly.
4. Don't do short trips. (take a bus)

Following this advice will give better MPG and a longer engine life - guaranteed.


gW

1. Engine block heater - generally not used and largely unavailable in the UK. More common in northern European countries that get very cold winters such as Norway/ Sweden and parts of Germany/ Austria etc. Also to fit such a device to an old car like a Uno wouldn't make economic sense. It would actually be cheaper to change the engine if/ when it wears out as the small 8v FIRE lumps can be picked up for £50 or less. Far cheaper than buying/ installing a pre-heater even taking into account the potential fuel saving.

2. Make sure you are fully warmed up - Older cars will run cooler in winter and many will never reach or maintain the optimum temperature when driving on the open road. The cooling systems over cool the engine. Running a hotter thermostat in winter is an option but only if one were available.

3. Change the oil more regularly - probably the single most important thing that can be done if the car does frequent short journeys.

4. Don't do short trips, take the bus - Sometimes there is little choice but to take car. It takes me 20 minutes to drive to my University campus whereas it would take 90 minutes or more by public transport (including walking 10 - 15 minutes to the station). It's also way cheaper to take the car and the reduced mpg is a drop in the ocean compared with the cost of public transport.

 

[UNO-MK1]

Whereas the FIRE was a modern design when it was introduced in 1985, much development on newer engines have taken place since. Modern cars are often designed with smaller capacity radiators per engine capacity and more accurately controlled thermostats to enable quicker warm up times. They also have things like solenoid activated emission controls such as charcoal cannisters. Intake temperatures are more precisely controlled and monitored by ECU equipped cars than a simple carburettor'd engine with mechanical distributor as per older Unos.

All engines will have bigger tolerances cold than when hot. Thus if an old engine takes longer to warm up compared with a modern engine there will be an initial period where the tolerances will allow a greater amount of crankcase gasses to pass by the piston rings leading to the formation of mayo in the cam cover and breather system. This also means that on some older engines with less efficient cooling systems they may never reach the optimum running temperature in winter months. This was apparent on both my FIRE Unos in the winter, where neither would reach much over 75 degrees unless sitting in traffic. Both had had their radiators flushed, engine coolant circuit back flushed, new thermostat, 50/ 50 distilled water and coolant and were bled correctly. I do this with all my cars when I first get them. In the summer both would warm up quickly to 80 - 85 degrees and in traffic would hit 90 degrees and have the fan come on. In the summer no mayo was produced. In the winter there was. If by your theory that this mayo was caused by engine wear then this would be expected to have been produced by the engine all year round and not just in winter. This was not evident with either of my Unos.



"Excessive foam" is not the issue. We're talking a small amount in the cam cover breather pipe and the underside of the oil filler cap. This is where the breather pipe connects adjacent to it and then leads to the airbox. There is enough mayo to be noticed inside the airbox itself but ONLY in the vicinity of the elbow and with a small trail in the direction of the carburettor. We're not talking about the whole of the inside of the airbox covered in goop, which would suggest more that the problem was a failed headgasket. Also remember that there was no mayo evident in the sump/ on the dipstick, nor around the camshaft with the cam cover removed - it was only apparent at the breather outlet area near the oil filler cap.



Let me clarify my last Uno's specs, a 1986 45 S with a 999cc FIRE engine.

Approx. 150ml oil consumed every thousand miles.

Coolant level unchanged (and remained uncontaminated) between services.

No visibile smoke from the exhaust.

A clear 'pass' for all its MOT exhaust emission tests.

This is from a car that was 21 years old, with its original engine and 102K miles on the clock. This suggests that though the engine would obviously have some wear it was far from a worn engine.




1. Engine block heater - generally not used and largely unavailable in the UK. More common in northern European countries that get very cold winters such as Norway/ Sweden and parts of Germany/ Austria etc. Also to fit such a device to an old car like a Uno wouldn't make economic sense. It would actually be cheaper to change the engine if/ when it wears out as the small 8v FIRE lumps can be picked up for £50 or less. Far cheaper than buying/ installing a pre-heater even taking into account the potential fuel saving.

2. Make sure you are fully warmed up - Older cars will run cooler in winter and many will never reach or maintain the optimum temperature when driving on the open road. The cooling systems over cool the engine. Running a hotter thermostat in winter is an option but only if one were available.

3. Change the oil more regularly - probably the single most important thing that can be done if the car does frequent short journeys.

4. Don't do short trips, take the bus - Sometimes there is little choice but to take car. It takes me 20 minutes to drive to my University campus whereas it would take 90 minutes or more by public transport (including walking 10 - 15 minutes to the station). It's also way cheaper to take the car and the reduced mpg is a drop in the ocean compared with the cost of public transport.

You wrote - ''Whereas the FIRE was a modern design when it was introduced in 1985''

Actually the FIRE engine was just a slight revision of the 128 series engine that had been around since '69.
It was the build process that was different.

----------------

''Modern cars are often designed with smaller capacity radiators''

Eh ? . don't think so - bud.
The size of the radiator will be determined by the cooling efficiency of the core and generally , the capacity and application of the engine.

Old cars had large radiators because they used twin row cores with wide spaced fins.
This was cheap.

FIAT's since the late 60's used the fine finned core , which is much more expensive.
The result is a small radiator that can cool like a bigger radiator.

In UNO's they use alloy radiators.
This is another step up again in cooling system design.
The first cars that I saw them on was VW Golfs and Audi Fox's from the mid 80's.

A high efficiency radiator has less of a water volume than an old style rad.
This means that the cooling system as a whole has less water capacity ----that means that any heating change -- up or down , can be responded to faster by the thermostat than if there was more water volume in circulation.

Remember , the thermostat is continually opening and closing depending upon water temperature and it is its job to regulate that , not the radiator.

--------------

''more accurately controlled thermostats to enable quicker warm up times''

Umm , nope.
The FIRE series , and in fact most FIATS (minus pushrod UNO's) use full bypass thermostats.
These thermostats offer the ultimate in water temperature control.
The majority of cars on the road STILL uses single valved flow restriction thermostats.
My Swift has one of these , it cost about 2 pounds.

The FIAT system is MUCH more advanced.

--------------------
''solenoid activated emission controls such as charcoal cannisters''

The emission system has no bearing on water temperature management, and neither add to or detract from performance or MPG.

---------------------

''Intake temperatures are more precisely controlled and monitored by ECU''

Intake temperatures are not ''controlled'' by the ECU.
They will have a water temperature sensor in the intake manifold , this is not for regulating the temp
It is for tell the computer the temperature of the engine and from that it selects the correct ignition timing and fuel maps to suit.

The ECU in no way can increase or decrease water temperature. (maybe turn the fan on)

-------------
'Thus if an old engine takes longer to warm up compared with a modern engine''

If the thermostat is running correctly , warm up times should be no different between older and newer cars.
If I was to wager money , my bet is on a FIAT to get to and operate at temperature faster and more accurately than other engines with a more primitive , £2 thermostat.

-----------------
''will allow a greater amount of crankcase gasses to pass by the piston rings''

You clearly do not understand what is going on.
It is a compressed air/fuel mix that slips past the compression rings.
THIS contains a large volume of water vapor , and it is THIS that mixes with the oil in the sump.
It is after this , that it gets reintroduced into the crankcase breather system.

-------------

''This also means that on some older engines with less efficient cooling systems they may never reach the optimum running temperature in winter months.''

A less efficient cooling system would be characterized by LESS cooling, which means a HOTTER engine -- isn't that logical ?

The fact is , is that if someone is experiencing lower than normal water temperatures , after an appropriate warm up time , then it is the thermostat that is the problem , not the radiator.

------------

''This was apparent on both my FIRE Unos in the winter, where neither would reach much over 75''

The opening temperature of most thermostats is in the 70 to 90 degree range.
75 may be the correct temp for the UNO , it might not be,. I don't know.

Consider for arguments sake it IS correct , it should climb to that temp and stay there , not climb and then drop to 50 or lower ,,,,,even in the coldest regions of Siberia. (which I live not too far from)



-------------
''If by your theory that this mayo was caused by engine wear then this would be expected to have been produced by the engine all year round''

Firstly , I don't go by theory - I go by facts.
Secondly in previous posts I did say (perhaps you didn't read it - busy with your ego) that environmental factors do play a role in it , namely temperature and humidity.

Then I said , that an engine that has more wear will have more blow-by ., and present more than the normal foam in the breather system.
And remember, we are talking about such excessive foam that it blocks jets (your words , not mine).

--------------

''"Excessive foam" is not the issue''

You said in post 8 ''As a result this mayonnaise would end up getting inside the carburettor and cause all sorts of rough running and jet blockages.''

So we are not talking about a little residue here.
A little residue around the cam cover breather isn't big enough to block jets and cause rough running - so make up your mind ....are we talking about a little residue , or an excessive build up that is thick enough to cause improper running of the engine...?

---------------


''1. Engine block heater - generally not used and largely unavailable in the UK''

Obviously not a cold country then.

----------------------

''2. Make sure you are fully warmed up - -The cooling systems over cool the engine.''

Not if you have a correct thermostat fitted.

------------------

''4. Don't do short trips, take the bus - Sometimes there is little choice but to take car. It takes me 20 minutes to drive to my University campus''

Ahh. you are still at school ?! , so your saying that when I was building and racing 220kmph+ FIATS , you were still in your pram poo'ing your pants.

Thanks , its all clear now.


gW

 

[Chas Uno]

You wrote - ''Whereas the FIRE was a modern design when it was introduced in 1985''

Actually the FIRE engine was just a slight revision of the 128 series engine that had been around since '69.
It was the build process that was different.

The ohc 128 engine has a totally different layout to the FIRE engine. One is cross flow, the other isn't. There are vitually no shared parts. The FIRE engine was a new design jointly developed with Peugeot/ Citroen. (source - What Car? March 1987). The 128 series engine was not.

The sales blurb for the FIRE engine was that it used something like 30% less parts than the previous ohv design Fiat engine and weighed 25% less . This also reduced weight and reciprocating masses leading to a more efficient and cost effective engine to build, and was done so on a fully automated 'Robotised' production line. (Sources - Fiat Uno sales brochure - 1987 and What Car? - March 1987).

The 128 based engine was discontinued with the mk2 Uno, Tipo and very early 1.6 litre Puntos in the mid 1990's. The FIRE engine is still available today in much evolved form. The two are from totally different families of engines.

''Modern cars are often designed with smaller capacity radiators''

Eh ? . don't think so - bud.
The size of the radiator will be determined by the cooling efficiency of the core and generally , the capacity and application of the engine.

I'm talking in comparison to older designed cars such as those that I grew up with in the 70's and 80's.

Old cars had large radiators because they used twin row cores with wide spaced fins.
This was cheap.

That is true. They were also more commonly made of brass.

FIAT's since the late 60's used the fine finned core , which is much more expensive.
The result is a small radiator that can cool like a bigger radiator.

In UNO's they use alloy radiators.
This is another step up again in cooling system design.
The first cars that I saw them on was VW Golfs and Audi Fox's from the mid 80's.

A high efficiency radiator has less of a water volume than an old style rad.
This means that the cooling system as a whole has less water capacity ----that means that any heating change -- up or down , can be responded to faster by the thermostat than if there was more water volume in circulation.

That was in effect what I was attempting to say, albeit badly. The smaller capacity radiator is used as the system is more efficient, and in particular allows faster warm up times. Forgive me for not being clearer, I've been up since 5.55am working in a cardiac hospital with pre and post surgery patients.

Remember , the thermostat is continually opening and closing depending upon water temperature and it is its job to regulate that , not the radiator.

I am very aware of how a thermostat works. They have a valve operated by a rod that is encased in wax (hence often being called a "wax stat"). Obviously as the wax is heated up by the coolant it expands and opens the valve. If the coolant then becomes too cool the wax will react, shrink and close the valve. Thus the wax will constantly react to whatever temperature the coolant is and attempt maintain the coolant at the set temperature as determined by the design.

''more accurately controlled thermostats to enable quicker warm up times''

Umm , nope.
The FIRE series , and in fact most FIATS (minus pushrod UNO's) use full bypass thermostats.
These thermostats offer the ultimate in water temperature control.
The majority of cars on the road STILL uses single valved flow restriction thermostats.
My Swift has one of these , it cost about 2 pounds.

The FIAT system is MUCH more advanced.

By "full bypass" are you talking about a junction off the thermostat housing that allows coolant to bypass the thermostat via a seperate pipe? If so that doesn't apply to the FIRE thermostat, which has a large singular pipe that takes coolant straight back to the radiator.

''solenoid activated emission controls such as charcoal cannisters''

The emission system has no bearing on water temperature management, and neither add to or detract from performance or MPG.

My point was that modern cars have far more tightly controlled emission systems compared with the system fitted on a FIRE Uno. I didn't say that this affected temperature management.

''Intake temperatures are more precisely controlled and monitored by ECU''

Intake temperatures are not ''controlled'' by the ECU.
They will have a water temperature sensor in the intake manifold , this is not for regulating the temp
It is for tell the computer the temperature of the engine and from that it selects the correct ignition timing and fuel maps to suit.

The ECU in no way can increase or decrease water temperature. (maybe turn the fan on)

And the temperature of the intake air on modern cars is moderated by? Older cars, such as Uno FIREs, used a similar system to the wax thermostat to operate an airbox flap. This directed either a hot air feed from the exhaust manifold or cold air feed from an air intake away from the engine depending on ambient temperature.

'Thus if an old engine takes longer to warm up compared with a modern engine''

If the thermostat is running correctly , warm up times should be no different between older and newer cars.
If I was to wager money , my bet is on a FIAT to get to and operate at temperature faster and more accurately than other engines with a more primitive , £2 thermostat.

Please read the threads in here and in the Panda section and you will see this is very common occurance with winter driving and the older FIRE engines. Design and theory are one thing, on the road experience can be another entirely.

''will allow a greater amount of crankcase gasses to pass by the piston rings''

You clearly do not understand what is going on.
It is a compressed air/fuel mix that slips past the compression rings.
THIS contains a large volume of water vapor , and it is THIS that mixes with the oil in the sump.
It is after this , that it gets reintroduced into the crankcase breather system.

:bang: Again I apologise. I wrote the above after getting home from an early shift on a hospital ward. The mayo is caused by water vapor that enters the engine via the intake system. Hence the slower warm up times/ cooler running engine will allow a greater amount of intake gasses to pass by the piston rings into the crankcase during this period when compared with an engine that warms up quicker.

''This also means that on some older engines with less efficient cooling systems they may never reach the optimum running temperature in winter months.''

A less efficient cooling system would be characterized by LESS cooling, which means a HOTTER engine -- isn't that logical ?

No, by efficient I mean a cooling system that MAINTAINS the correct coolant temperature. An engine cooling system needs to allow the coolant to reach operating temperature quickly as well as cool it when it gets too hot. A system that overcools is NOT efficient for the operation of the engine and will increase both emissions and fuel consumption.

The fact is , is that if someone is experiencing lower than normal water temperatures , after an appropriate warm up time , then it is the thermostat that is the problem , not the radiator.

Can you explain then why both my FIRE Unos, both fitted with new thermostats (one genuine FIAT) experienced over cooling in winter? Yet my Uno 70SX fitted with the 1301cc engine (128 based) suffers from this trait far less?

''This was apparent on both my FIRE Unos in the winter, where neither would reach much over 75''

The opening temperature of most thermostats is in the 70 to 90 degree range.
75 may be the correct temp for the UNO , it might not be,. I don't know.

Consider for arguments sake it IS correct , it should climb to that temp and stay there , not climb and then drop to 50 or lower ,,,,,even in the coldest regions of Siberia. (which I live not too far from)

The 999cc thermostat begins to open at 85 to 90 degrees and is fully open at 100 degrees. The radiator fan kicks in at approx. 90 degrees. In winter the engines would heat up to 80 - 90 degrees if sitting in traffic but once moving again they would drop to the 70 - 80 degree range. Thus when my FIRE Unos ran over winter at these lower temperatures, with new thermostats and coolant and in brisk moving traffic then that can only be down to overcooling.

For what it's worth I also remember the days when people would put pieces of tin foil over their radiators in the winter to try and get the car to warm up quicker. In fact, some motor factors used to sell universal radiator covers such was prevelance of older cars suffering from overcooling. Some very old cars actually had a radiator 'blind' that could be drawn in front of the radiator to reduce the passage of air through the radiator and thus reducing its cooling efficiency. These I have only seen in classic car magazine and classic car shows.

I've long been an advocate for preventative maintenance and keeping the cooling system in good shape. However, in the 70's and 80's it was considered normal for cars to run much cooler in the winter (and for its occupants to freeze inside due to the heaters that didn't). Today I doubt if cars are any better maintained, most probably the opposite, but this trend is not generally repeated and can only be down to better engine and cooling system designs.

''If by your theory that this mayo was caused by engine wear then this would be expected to have been produced by the engine all year round''

Firstly , I don't go by theory - I go by facts.
Secondly in previous posts I did say (perhaps you didn't read it - busy with your ego)

Excuse me, in no way have I resorted to any personal insults whilst responding to your threads. That comment was totally uncalled for.

that environmental factors do play a role in it , namely temperature and humidity.

You didn't mention this when you first brought up the matter. You stated this:

'Mayo' in the air filter box or on top of the carb indicates one or two things.

1. Worn compression rings....

When rings are worn the air/fuel mix that is compressed slips past the piston into the crankcase.
The compressed air will condense into water , this in turn mixes with the oil in the sump forming a 'mayo milkshake.'
This water'ized oil when heated and whipped up will make its way through the crankcase vent system to the air intake...and thats why you see it.

2. I was joking , there is no 2nd reason -- Your engine was just plain worn out.

It was also you who brought up the "excessive foam" remark whereas I stated "noticeable" as in an amount of mayo that could be clearly seen but was far from excessive. As such I was putting across that my engine producing this amount of mayo was unlikely to be caused by excessive engine wear.

Then I said , that an engine that has more wear will have more blow-by ., and present more than the normal foam in the breather system.
And remember, we are talking about such excessive foam that it blocks jets (your words , not mine).

And a small piece of dirt, grit or even dust is enough to block a jet in a carburettor - this is not "excessive". A small amount of mayo from the airbox elbow can be enough to disturb the delicate balance of the carburettor internals if it gets into the carburettor venturi. This is more so as the mayo will contain water droplets, and water mixing with the fuel can cause jets to block. As I'm sure you know this is also why water in the fuel can be so problematic.

''"Excessive foam" is not the issue''

You said in post 8 ''As a result this mayonnaise would end up getting inside the carburettor and cause all sorts of rough running and jet blockages.''

So we are not talking about a little residue here.
A little residue around the cam cover breather isn't big enough to block jets and cause rough running - so make up your mind ....are we talking about a little residue , or an excessive build up that is thick enough to cause improper running of the engine...?

See comment above, and this is what I posted:

In cold/ wintery weather (about 6 months of the year in the UK ) and with short journeys all my Uno FIREs would generate a noticeable amount of 'mayonnaise' from the breather. This would spread from the air filter elbow into the air filter housing itself before being drawn into the carburettor. As a result this mayonnaise would end up getting inside the carburettor and cause all sorts of rough running and jet blockages.

After noticing this a few times I redirected the breather pipe from the airbox and the carburettor no longer suffered rough running in the winter months.

''1. Engine block heater - generally not used and largely unavailable in the UK''

Obviously not a cold country then.

Compared with Norway, Sweden, Finland etc., no. But a country that gets very damp, chilly and carries a large amount of ambient moisture in the air during the winter months.

''2. Make sure you are fully warmed up - -The cooling systems over cool the engine.''

Not if you have a correct thermostat fitted.

You are assuming that all cars have perfectly designed cooling systems from new and are run in a perfect environment. And can I ask you - have you ever owned a carburettored FIRE engined Uno? Do you have experience of their characteristics over both summer and winter months? If you haven't then you're basing your statements on theory rather than on the road experience, which as in any scientific study can differ.

''4. Don't do short trips, take the bus - Sometimes there is little choice but to take car. It takes me 20 minutes to drive to my University campus''

Ahh. you are still at school ?! , so your saying that when I was building and racing 220kmph+ FIATS , you were still in your pram poo'ing your pants.

Thanks , its all clear now.

gW

That's very sarcastic and egotistical of you, and that's twice in one post that you've made an insult towards me. You are also, very wrongly, presuming my age. I am 39 years old and attending University to retrain for a new career as a healthcare professional. I've also been owning/ driving/ riding/ maintaining/ building cars and motorbikes since 1986. I may not be a professional mechanic but I have read enough books/ magazines/ workshop manuals to a have a grasp of most of the fundamentals of the internal combustion engine. I also have a wealth of experience with working and driving with many cars and motorbikes, especially FIRE based Unos as a number of forumers on here will attest to.

You are obviously very, very knowledgeable, and I respect most of what you have had to say in your posts. However, I don't necessarily agree with everything you've stated and that is why I have answered the points raised. This is the point of having an open forum for members to discuss any issues relating to their vehicles, share knowledge and engage in healthy debate. Obviously the person that thinks they know it all is the person that stops learning, so I am always open to debate and don't expect everything I say to be right. I do, however, try to be as factual as possible and to give advice to the best of my knowledge and experiences.

As such you do have the right to point out when I state incorrect or debateable points just as I can with you. But you don't have the right to insult or demean me, nor make assumptions about me and my knowledge just because I disagree and put forward contrasting points, experiences and theories to those from you.

Please let's keep the forum friendly, open minded, informative and on a level playing field. Thank you.

 

[Biz]

Wow the qouting is mad! lol

But seriously, UnoCento..............get a Turbo

Power problem solved