General Performance advice

[UNO-MK1]

1986Uno45S said ''Please let's keep the forum friendly, open minded, informative and on a level playing field.''

Your right , I apologize for my negative comments.

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''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.''


OK , I see your view.

A new engine..
What makes a new design engine ? - that is something open to debate.

Is a new engine one that doesn't share components from a previous engine ?
If so , then considering an OHC 128 engine and one of the same type in an X19 ,. the 1500.
Are they the same engine or not the same.?

They share NOT one common component - does that then make them different motors ?

If the criteria for a new engine means a new block casting then that means that the X19 1500 most definitely a new engine.

The FIRE engine as you correctly said has a cross-flow head and no (or minimal) common components with other engines.

But is that enough to call it a new engine.? - perhaps , perhaps not.


Personally I don't see that the FIRE was so different enough to get excited about.

You said the it was jointly developed with Cit and Pug ..OK.
Again to me that sound more like advertising blab than anything of real substance.
What did Cit and Pug contribute to the design , I don't see anything.--it looks ALL FIAT to me.
the castings look like FIAT , and the engine technically is not really different to what they already had.

It is still a single overhead cam 4 with a belt driven cam , in line valves directly actuated by shim in buckets.
The block (although changed) is still conventional FIAT stuff.
There really is nothing NEW to the design., and certainly nothing modern about it.

And that is what I find most confusing , why would they make a 'NEW' engine that doesn't do anything significantly better than the last version.

Was it for more power ? .well , the power figures don't show that to be so.
Was it for greater MPG ? , again , not much difference between this and the older style engine.
OK , was it so they had the ability to expand and make engines of greater capacity in the future with the same design ? ..No , the 128 series of engines is actually bigger than the FIAT twin cams , as such it could have been stretched to over 1800cc from the same engine easily by increasing the deck height.(and fattening the block for a bigger swinging crank)
PERHAPS , the FIRE was so they could comply easier with emissions due to the head shape....BUT a cross flow head could have been fitted to the 128A series OHC engine easier than starting from scratch.

I think that Cit and Pug wanted a new engine , approached FIAT with a bag of cash and just said that they wanted something different , and FIAT made something different.

(did Cit and Pug ever use a FIRE engine in their cars?)

But I don't think its in any way a better engine.

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''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''

30% less parts ...OK , What parts ?
It still has all of the parts required to make it run, so where are the less parts.? hihi

Actually , the FIRE engine looks like it has more internal parts the the 128 series engine.

I speculate that the '30% less parts' is nothing more than changing from nuts with two washers to a single locking nut that holds things together.

This '30% less ' statement combined with 'weighed 25% less' makes you think that the omitted parts saved that weight....but its not necessarily like that.

Going form a solid crankshaft to a hollow crank could give that weight reduction (almost).
It should be noted that they could have put a hollow crank in the 128 series OHC and claimed the same thing.

I believe that this is all advertising talk and that there wasn't an actually need to go the FIRE way.

Theres no technical reason why they did so. . which could only leave two other reasons.

1. marketing
2. financial.

Marketing , ..everyone likes something NEW , perhaps FIATS PR people said that people were wanting a NEW - something , and not the same old thing , and that was deemed worth the cost of the tool up money.

Financial , maybe this cash (of course it was money related) from Pug/Cit was a good incentive to make something new that wasn't anything really different.

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''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''

OK then , in going forward FIAT went backward.
Maybe thats another thing that they did to give the 30% less weight feature -- by using lower performing parts.

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''And the temperature of the intake air on modern cars is moderated by?''

In modern cars it isn't regulated.
Pre-heating of the intact tract is to prevent a carb from icing up in the venturi.
EFI engines don't have a venturi.

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''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?''

If it was the weather that had the predominant influence on foam production then you wouldn't have asked this question , unless you only drove the 128 engined UNO in summer time.

Assuming that you had equal driving habits and styles , and we know that the car is the same , the only difference is in the engines.

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''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.-- These I have only seen in classic car magazine and classic car shows.''

This is done here regularly.
While it does block cold air from chilling the water in the radiator it is also having another effect.
It blocks air form blowing through the engine bay.

Remember the engine is not just cooled by the cooling system.
The sump which is full of hot oil is cooled by passing air under the car , this drops the oil temp , and in turn the water temp.

Airflow in the engine bay also cools the engine.

Blocking the radiator airflow will have a substantial effect on air flowing through the engine bay and it is THIS that keeps the winter engine temps high. , and NOT from preventing the water from getting too cold.

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''And a small piece of dirt, grit or even dust is enough to block a jet in a carburettor - this is not "excessive".''

My customers would be of the opinion that any foreign body big enough to block a jet and cause incorrect running (or stopping) of the vehicle as being excessive.

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Imagine if FIAT in 1985 had of made a REAL NEW engine.
Say , an all alloy , twin cam engine with 60mpg and enough power to toast the UNO Turbo.

They would have turned the hot hatch market on its ear and taken the customers that eventually bought Civics , Corollas , Golf GTI's and Swift twin cams.

They could have - they are FIAT - instead they decided to make something' new' that is just the same as the old thing and try and convince it is better through marketing.

Personally , I think that is a real P%ss poor show.

gW

 

[alexGS]

Well, all interesting stuff to read. Although this thread is getting very long

I had often wondered why injection systems don't have a warm air intake. I always thought the warm air helped with fuel atomisation as well as preventing icing at the carb venturi. Though I guess when the fuel is going on/near the engine valves, that's going to be plenty warm enough for atomisation!

I didn't know that people still blank off radiator grilles in cold climates. I remember the Zastava 101 (Yugoslavia-built 128) had some sort of blind fitted as standard! But it makes sense that this would make more difference than only the cooling system thermostat by itself.

Meanwhile I am of the view that the FIRE engine is very different to the earlier engine. Yes, they are both four-cylinder OHC engines, but the FIRE is much lighter, has many fewer parts - achieved through things such as the oil pump on the crankshaft nose, camshaft mounted directly in the cylinder head, the distributor on the camshaft (and yes I do remember that very early X1/9s had that too ), the fuel pump on the camshaft, etc.

Basically, it's a neat and simple design. With vertical valves and reduced numbers of castings, it would be cheaper to make, and easier to assemble. It gets its name (Fully Integrated Robotised Engine) from the fact that it was designed for machining and assembly by robots. That was FIAT's focus in the late 70s and 80s. I don't know about Citroen/Peugeot and I wonder if that design-for-robotisation may have been the only association with FIAT, since FIAT owned Comau and other companies in the automation sector.

I get the impression that the earlier Lampredi SOHC (as designed for the 128) was adapted from a pushrod engine design - since the auxiliary shaft was in a similar place to where the camshaft would have been - whereas I believe the FIRE was actually a new clean-sheet design. There are no castings in common between the FIRE and the earlier engines.

The Lampredi engine is much stronger in the bottom end than the FIRE is - wider crankshaft journals, larger counterweights. For that matter it's much stronger in the top end too (five camshaft bearings vs. three) and the casting detail is nice around the cambox and oil feeds. The FIRE is crude in comparison, lots of stress raisers and a bolted-on oil spray bar. However the Lampredi there was an odd weakness in that the cylinder head bolts are not equidistant from the bores. The 1580cc version, and the Turbo versions, have four extra bolts near the spark plugs to address this. I think the 1498cc version had that too (can't quite remember!)

Another ongoing Lampredi engine problem is oil leaks from where the cambox meets the cylinder head - a problem designed-out of the FIRE where there simply isn't a join.

I think the FIRE was designed for good torque - it has a long stroke (almost 70mm from memory). It has been bored out since to get 1242cc. I think that economy and emissions, as well as low cost, have been the main objectives with the FIRE engine.

The Lampredi engine on the other hand started off with that short 55.5mm stroke, so it appears to have been designed more for strength, revs, and power. That's fine too. It lived on into the 90s in the Punto GT and the Punto 90. I think it's heydey was the Uno Turbo in the 80s, of course

FIAT did make a twin-cam 16v version of the FIRE - it went into the Punto Sporting (both Mk1 and Mk2). However, even though I have one, I'm not totally convinced of the merit. Yes, there is 80bhp (85bhp for the Mk1), but I suspect it might be at the expense of torque. The five-cylinder engines, which are a development of the FIRE in themselves, have variable valve timing as a solution to the high-speed-power/low-speed-torque dilemma. My Stilo Abarth's engine was certainly torquey. FIAT had access to that technology a long time ago, as the Alfa Twin-spark engines back in the 80's had variable valve timing. I guess it's all down to how much cost and complexity you want.


How does all this relate to the original topic? I'm not completely sure I think it was about the cause of mayonnaise. I reckon it is that the engine isn't running hot enough. What I have noticed is that the thermostat fails often (stays open) on the FIRE engine.

With the thermostat open, engine temperature is lucky to exceed 60 degrees under gentle use. For the FIRE it's not a bypass design - just a simple valve that has only one outlet to the top radiator hose, so fortunately it's pretty cheap to replace. Picture of new thermostat attached. Incidentally that is something I reckon the Japanese beat the Europeans for every time - durability of components like thermostats and bearings!

-Alex

 

[Biz]

You two need to "Ciatae" (Is that even a word? lol) Wikipedia! lol

Heres some intresting info though, im at uni right, i meet a young guy who races in the Formula 3 championship but he used to race Renault single seaters
He showed me a picture of the engine....................a 2.0 clio block with a CNC biliet cut Reverse-flow configuration head on it!
Road clios are 16 valve CROSS FLOW heads!
360bhp/***trq!

Now that does that suggest?
Lampredis design is?

 

[UNO-MK1]

Well, all interesting stuff to read. Although this thread is getting very long

Its the never ending story.

--that's going to be plenty warm enough for atomisation!

Atomization ? , Are we breaking fuel down to atoms now ? Don't think so.

I didn't know that people still blank off radiator grilles in cold climates. I remember the Zastava 101 (Yugoslavia-built 128) had some sort of blind fitted as standard! But it makes sense that this would make more difference than only the cooling system thermostat by itself.

If I remember correctly , it was on a mk1 Golf that had flexible flaps at the rear of the radiator.
They would only open when the car was at high speed or if the fan kicked in...I thought that was quite neat at the time.

--but the FIRE is much lighter, has many fewer parts --

If someone can supply me with a good quality exploded diagram or a factory pic's of the insides of the FIRE I probably could count the parts.
It would be interesting to see IF what they say is true.
Personally I think its hogwash.

I get the impression that the earlier Lampredi SOHC (as designed for the 128) was adapted from a pushrod engine design--

The 128 SOHC engine is a single came version of the FIAT DOHC engines.
The DOHC engine started with the 124 as a 1400cc engine.
124's also came with a pushrod engine , and I guess it too was from Lampredi.
It was a good strong engine with no significant weaknesses that did well in motor sport.
No doubt to keep up with Alfa Romeo and their 1750 Berlinas (and that sort of thing) FIAT wanted a twin cam.
The 124 DOHC was sort of based on the pushrod engine in as much as they shared some of the same external parts., but it was an entirely new engine in concept and design.
The DOHC was far more than a twin cam head banged into the top of a pushrod engine (as Lotus did with their BDA series)

After the success of the DOHC engine for a few years , the 128 SOHC came about with the removal of one cam shaft.
This kept a lot of the good strong points of the DOHC but now a small capacity and simple engine.

--However the Lampredi there was an odd weakness in that the cylinder head bolts are not equidistant from the bores. --
Another ongoing Lampredi engine problem is oil leaks from where the cambox meets the cylinder head --

While it is true that the head bolts are not equal distance from the chamber in my experience it never caused any problems.
FIAT used very strong alloy and thick casting for the heads which had to be really overheated badly to get them to warp.
I came across one 128 once that had a warped head (found when the engine was stripped for rebuilding) , and the head gasket still wasn't blown.

The cambox to head joint oil leaks ....well . on the ones that I have seen leaking (really just a weep) was probably caused people removing the box and not using a new gasket when refitting it.

Why would they not use a new gasket ?

A new gasket would not be the same thickness as the old gasket , so if they fitted a new gasket they would have to redo ALL of the tappet shims.

But why would they need the cam box removed ?

In the first or second service from new a head re-torque would be specified.
If the workshop didn't have the correct FIAT tool ,, you cant re-torque 3 nuts that retain the head.
If you take off the cam box you can then access all the bolts and nuts .

In my engines I used non re-torque head gaskets and by smearing a little silicon on your finger tips you can massage it into the paper head to cam box gasket before fitting.

No more oil leaks -- ever.

I think it was about the cause of mayonnaise. I reckon it is that the engine isn't running hot enough. What I have noticed is that the thermostat fails often (stays open) on the FIRE engine.

For sure that is also related.
If you can keep the oil hot enough it will evaporate any water out of it. , a faulty , or wrong thermostat will definitely increase the mayo.


gW

 

[alexGS]

You two need to "Ciatae" (Is that even a word? lol) Wikipedia! lol

I couldn't find that word in Wikipedia and consequently I have no idea what you mean

Anyway - UnoMK1 - sorry about my use of the word 'atomisation', which tends to crop up with spray painting as well. The meaning is not to break into atoms, but instead to disperse as a fine mist. I'm sure you knew this, but the word is confusing as you pointed out

Oh, and I have those crows-foot spanners. I thought you needed them for all five nuts along the back edge Like you, I've seen a lot of these engines. The first cylinder head I took off was 20 years ago in my Dad's garage. It had to come off because the cambelt had broken early for some reason.

I much prefer the bolts of later engines (FIAT switched to stretch bolts in 1980, no re-torque required), as the earlier studs would corrode into the head. When I was 15 a friend and I used the front-end loader of a tractor to try and lift the head off one engine, which lifted the 128 off the ground instead. To fix the coolant leak into the No.2 bore, we decided to change the engine instead of just the head gasket. We hooked the loader to the body and lifted it off the engine, and five hours later we were driving off with a mighty 1290cc from a rusty Coupe that had sat in a paddock for five years. I don't remember us changing the oil but as a bonus, the clutch was replaced with a slightly-less-rusty spare.

Remember how the early thermostat housing - complex bypass beast that it was, with removable element - used to disappear into a powdery mess and most of it would come off with the hoses. We crafted an emergency repair using polyester body filler (bog) which lasted for years! I suspect that a lot of engines from that era didn't receive the proper antifreeze/coolant mix that they needed (nobody thought they needed antifreeze in NZ), hence the seizing on the head studs. And probably the corrosion that would have caused the head gasket failure in the first place.

If anyone's still reading this and wondering what all this reminiscing is possibly EVER going to achieve, well, take it from me that it's worth keeping engine coolant in good condition, with antifreeze, changing every two years. It avoids a chain of problems that, while quite fun for teenage country bumpkins to solve, would be annoying and expensive for anyone else.

-Alex

 

[UNO-MK1]

--sorry about my use of the word 'atomisation', which tends to crop up with spray painting as well. The meaning is not to break into atoms, but instead to disperse as a fine mist.--

Oh Darn I was hoping that my UNO was a atom splitter in disguise.

--FIAT switched to stretch bolts in 1980, no re-torque required, as the earlier studs would corrode into the head. When I was 15 a friend and I used the front-end loader of a tractor to try and lift the head--

On another 128 engine that came my way for rebuilding it too had the head stud corrosion problem so bad that the head wouldn't come off.

What we did was weld the nuts to the studs , and then use an air gun to unscrew the studs.
In time all came out and the head was removed.

The solution is to coat those studs with Loctite Anti-Seize all the way up to the nut.
An engine that I rebuilt 10 years previously that I did the Anti-seize on came in for some more head work , and this head slid straight off , no problems at all.

Remember how the early thermostat housing - complex bypass beast that it was, with removable element - used to disappear into a powdery mess and most of it would come off with the hoses. ---

Yeup ., those old housing were pretty bad.
I think they were only used on 128s before '71 and replacement was the sealed unit which lasted a lot longer.

I suspect that a lot of engines from that era didn't receive the proper antifreeze/coolant mix that they needed (nobody thought they needed antifreeze in NZ), hence the seizing on the head studs. And probably the corrosion that would have caused the head gasket failure in the first place.

Antifreeze/coolant is nothing much more than an alcohol that doesn't attack rubber.
As it doesn't have the acidic or alkaline properties that water has , corrosion in reduced.
The alcohol raise the liquids boiling point and also drops the point at which it will freeze.

In my normal cars in OZ I used rain water and a small can of Castrol corrosion inhibitor.
I never had head corrosion problems or head gasket failures.

Here in Finland we have to run 100% alcohol anti freeze so our engines don't turn into ice blocks.

In the 128 series of engines the head bolts and studs shafts aren't through a water passage , so the corrosion found on them isn't from water ,, well , not engine water.(rain water could go down the bolt from the top , but thats very small and unlikely to cause any corrosion)

This corrosion is likely from current passing through the bolts shafts to the alloy head.
These dissimilar metals react to each other (and the air) to cause the corrosion.

Coating these parts in Anti-Seize (which IS electrically conductive) takes the air out of the picture and drops the electrical resistance to zero.

No more corrosion then.

gW