Lancia Motor Club

I understand the very early inlets had exhaust heating.  Both types I have seem to connect to the same ports in the head with water heating.  Anyone tell me when each was used, pros, cons, gotchas.

Both have drain taps - the round type also has a take off of some sort on the top of an inlet passage.  Did Aprilias ever have a vacuum guage or a vacuum windscreen wiper?

Photos to follow...

David

Photos per above.

David

I think the difference is that the smaller square type was on the first series 1350cc car and the larger round type on the second series 1500cc car.  I had the later round one on my 1350cc car with a large Zenith carb and it was the fastest Aprilia I had driven, better than a car with a big carb but only the small manifold. Ade.

I've a large and complicated looking Zenith VN and an adaptor plate to get me going but am concerned that its post war (I don't know for sure...) and the VSCC won't like it.  The next idea is a downdraught SU as its such a known quantity to get bits to set up just-so.

Any idea what that vacuum take off is for?

David

The vacuum take off could have been for a windscreen washer. Such washers were popular years ago.

The more rounded manifold (still fitted to the head in your photo) is more familiar as on a late Series 1 car.  I agree with Ade – best used with a big Zenith or better still a big Weber. I have never ever seen an Aprilia fitted with an SU! Did SU ever do a downdraft version?

There may have been a coolant duct through the manifold, but I don’t think any Aprilia had an EXHAUST heated manifold!

I suspect the connector fitting you have is for a vacuum econo-meter or as John says, for a screen-washer.

The photo below shows the early Aprilia from Italy that did the Sliding Pillar rally in 2006. It looks to have an early ‘square section’ manifold with the standard small Zenith carb. (Had I known David was going to ask all these questions, I would have taken more photos!) Note the very elegant cam actuated hand throttle linkage. What a fantastic car!

(Only I can’t post the photo because the bloody uploader is full again – s*d it!)

Colin

One of my Viva cuttings said the very first cars had exhaust heating - maybe only prototypes that iced on the top of a mountain and they tumbled down the nearest ravine in disgust.  When I see it next I'll quote the referance.

Sounding like "square" is small and early - the academic debate as to quite when they made the change - for my purposes it sounds like its the one to use.  Also sounds like the tapping is not original, but might be handy to drive a vacuum wiper motor I have in hand.  Useless - but light and simple - and wipers can be quite a wee project in themselves as I learnt with the Aurelia and am struggling with on the Midget. 

The question this throws up is how much the 1500 and 1350 engines have in common.  Looking in LaLancia its 72 bore x 83 stroke for 1352cc against 74.61 x 85 => 1486cc.   

My engine numbers:

MOT97 *1383*, MOT97 *1637*, MOT97 *5* which is the dirty one - I struggle to believe it was 5th off the line...  Is that a code for "replacement spare" or something?   

David

Am I confused (don't all shout at once),

 but what is the purpose of the heating/cooling facility in the manifold. Is it to try and cool the charge on the way to the combustion chamber (to enhance in some respect the combustion process) or is it to warm the manifold as the engine heats up.Neither seems practical to me in terms of actually making a difference.Cold starting and icing of the carb will not be helped in the first few miles if the water jacket is still cool and conversely the small channels I see won't really cool the inlet manifold very much in my view when the whole thing is at running temperature.

I even less see the relationship in terms of preventing carb icing and I thought that didn't exist anyway in the good old days? (I understood this results from the use of modern petrol which is "thinner" and has different characteristics to older fuels;)
answers on a postcard please ...

Depends if your talking about a water heated manifold or not, my experiences of water heated manifolds is that the actual amount of coolant concerned is minimal, & as it is coming directly off the cylinder head & block water jacket, as soon as the engine is running it starts warming up quite quickly to aid mixing the fuel & air. try putting your fingers on a water heated manifold after a couple of minutes.
Thinking back to my old Vauxhall days the intake manifold was mounted siamese fashion directly above the exhaust manifold, with a thermostatically(coiled spring) controlled flap that directed the exhaust gases to the underside of the inlet manifold, which warmed things up pretty rapidly! downside was when the spring weaked it rattled like buggery :o
As for carb icing, it's always been around! certainly in my personal experience since my motoring days started back in the 1950's. 

I measured up and both the same size for carb, all ports, and bolt holes.

The water passageways on the "round" inlet are SOLID with what looks like a soot and lime mixture.  Am knibbling away with a dental probe and have a satisfying pile of dirt to show for it for all still a way to go to clear it fully.

David

I have to say I share Scarpia’s doubts about the wisdom of pumping coolant through the inlet manifold, but it seems to be common practice. I think my Aprilia’s late type manifold had passages for water, and the Fulvia’s thermostat housing is surely located where it is to warm the inlet tract.

All other things being equal (which they never are!) you might expect it to be best to cool the inlet so as to get the maximum amount (mass) of air + fuel into the cylinder. But, once the engine is up to temperature, I can only imagine that it’s heating rather than cooling that takes place. Perhaps this warming of the inlet is to counter any tendency for icing-up.

Icing-up can be a real problem. I had this with a Fiat Uno, which unknown to me was missing its flap-valve in the air box designed to take warm air from the exhaust manifold. The result was an occasional ice encrusted carburettor, which stopped everything, most notably on warm humid summer days – all very distressing. I have never encountered this problem with any other car.

Colin

A turbo gets very hot - red hot - a note on the Phoenix Car Company page (engine woes with the car pictured inside the front cover of Viva Lancia each and every month) says 1090 degrees celcius.  On top of heat soak there is also the problem of air getting hot as its compressed.  Wrapping the exhaust and heat sheilds and having the correct spec intercooler and getting the cold air intake and who knows what else right are "details" that will make the differance between a championship winner and a car that does a couple of laps between repaints.

http://www.phoenixcarcompany.co.uk/latest_news.html

By contrast ambiant air temperature over 40 degrees is considered "hot".  What sort of temperature would an Aprilia's water run at?   I'd think the 70-90 range.   The exhaust will be more than warm but it is over the other side of a tall and wide block.  Maybe Scarpia can fix a max/min thermometer under his bonnet and enlighten us as to the range he sees.  In a normally aspirated engine there's also the issue of wind chill.   For a 1350cc Aprilia engine with a 32mm choke at 3000rpm I make it a 93mph breeze through the carb.  Hand out the window at 90mph and its chilly.

For sure if the carb is too hot vapourisation becomes the problem...

As discussed on another thread "cool fuel" can be a benefit...

For sure there's a small gain for getting cold air from infront of the radiator...

Then again a "clever" cold air intake system might be restrictive and sap more power than it gives back.  I remember a write up on a Fulvia in I think Classics Monthly were such a system fell off and they found it went much better.

David

Let’s not get carried away by ‘wind chill’ and ‘hand out of the window at 90mph’. An engine drawing air through an otherwise dry carburettor will not chill the carb – it might even heat it up a tiny bit. The chilling effect comes from the vaporisation of the fuel. This change of state from liquid to vapour requires energy in the form of heat to be absorbed from the surroundings – just like the refrigerant in a fridge. It is this localised cooling around the venturi that can cause condensation and freezing of water vapour in the air that is drawn into the carb, and hence icing up.

I can’t remember anyone having icing-up problems with an Aprilia. Also I suspect that the water-ways into the inlet manifold were well and truly crudded-up many years ago and there wasn’t much warmth from that source.

At risk of another diversion… Remember that the Aprilia was designed to run on very low octane fuel. Modern higher octane fuels burn more slowly. An example that I know from a few years ago, was an Aprilia engine, running on what was probably 4 star, with the exhaust manifold glowing dull red because the exhaust valves were opening on still-burning fuel. I don’t suppose the exhaust valves liked this very much. How do Aprilia runners cope with this nowadays?

Colin

spot on Colin.
and the characteristics of modern fuel enhances this evaporation I understood. This is why I thought this was a recent phenomenon but Brian suggests it exists a long time already.To visualise it better think of a camping gas bottle that forms ice on the outside on a summers day.I have had this on holiday in spain at 35 degrees with thick white ice forming due to this cooling effect.

The octane argument becomes complicated but ironically octane retards ignition so "high" octane actually burns later as Colin correctly points out. Sounds the wrong way around of course.Incidentally , lead was introduced to perform the same retarding function and they only discovered later the protective qualities for the valve seats.

Anyone help on this one:  "The question this throws up is how much the 1500 and 1350 engines have in common"

As for wind chill try this experiment: breath out - open lips - open teeth about 5mm - breath in quickly.  My teeth get very chilly.  How does that differ from air through a carb?   Am not saying its the whole story, but its a factor.

With the round manifold I dug as deep as I could.  Brushing I knocked out a plug the oposite side from the head but so far, for a fair bit of scraping, the blind hole goes nowhere.   Under the remains of the carb gasget is a date stamp 1940something and I think its 1945.   The square one is stamped 1939 on the side.

Am finding the variety of stampings facinating - no idea what they are or mean but an intreaging variety.

David

The teeth get chilly due to evaporation of the moisture on them.

an old trick for cooling items when camping was to place them under a flower pot, pour water on the
outside and wait. as the water evaporates the air inside the flower pot cools rapidly

it's science Jim, but not as we know it.................

even the gamma has a small section under the carb which is heated by the water sytem.
Geoff

Next time I'm camping I'll know where to put the G&T.

David

The pedantic answer to David’s question about the differences between 1500 and 1350 Aprilia engines is that apart from the dimensions, the larger engine produces more torque at lower revs.

The visible differences between the two, apart from the numbers, include - the later engines have:

•   A spring clip cover over the flywheel inspection aperture.
•   A larger diameter fitting for the bottom water connector at the front of the block.
•   At the top centre of the rocker cover a cast-in fitting for a bracing strut fitted to the top of the radiator. (Note that most early cars the rocker cover would have been drilled to take a bolted through fitting.)
•   The exhaust flange is angled to allow the pipe to clear the later modified engine mountings.
•   The rounded inlet manifold was a feature of the larger engine, but may also have been fitted to later 1350 engines too.


I am sure ‘La Lancia’ will have details of the differences in BHP.

Most engine parts were stamped ‘Lancia’ and in my experience mostly with the date of either 1939 or 1947.

I’ll carry on drawing air through my teeth… ‘Wind chill’ is the cooling/ chilling effect of air flow over a warm surface – the faster the flow the more rapid the heat loss. This is just what you feel when you step out into the cold on a windy day. This is simply heat transfer by thermal conduction. In a dry carburettor in the absence of fuel (or water) there will be no temperature differences and hence no cooling or heating due to air flow. As somebody said earlier, it is vaporisation/ evaporation of the fuel (change of state from liquid to gas) to gives rise to localised cooling – just like in a fridge or as in Geoff’s examples.

Colin

In general do parts from post war engines fit the prewar?

David

I think a safe working assumption is that all the bits that are unique to the larger 1486 cc engine are the block and all that’s in it. The sump may be the same overall size as the smaller 1352 cc engine, but may not be interchangeable because of the oil pump and its drive in the sump, which might be different. The heads and valve gear are certainly interchangeable.

But it may not be as simple as pre versus post-war. I think some 2nd Series cars with the larger engine were made in 1939.

Colin   

Geoff. On the Gamma, the bit that heats the water under the carb  ,is it called the head gasket? ;D ;D

That's as bad as the post I rec'd telling me   Amy Winehouse was awarded 5 Gammas

Here is the photo that I wanted to accompany my post of 18 February. It’s such a perfect engine bay that it’s worth showing it, even if the carb details are mostly obscured.

Colin

Lovely photo Colin!!

I'm looking at the top hose now, and then the rigid pipe for the 90deg bend.  I can remember you saying how such short hoses were possible due to the radiator being mounted to the engine not the car.  Just this weekend I got my hands on an Aprilia radiator, dynamo, and the most beautiful fan/pulley.  I understand there are three and two blade types, mine is a two blade. What I've yet to fathom, or source, is a water pump.   I've decided now I'd rather go to the trouble of restoring an Aprilia pump than mounting something else.

Meanwhile here's another manifold variation - does the brace from the radiator to rocker cover make this a "late" engine?   Its interesting to compare with Scarpias setup - and the various Barchettas.

http://web.mac.com/geoffreyg/Cars/Aprilia.html#14

The site is mostly about the restoration of his SII Aurelia (he got it running just this month) but lots more Lancia interest besides.

In this weekend's bundle was a downdraught SU with an adaptor to an Aprilia manifold - VSCC approved and as easy as anything else to refurbish and setup.   A nice "getting started" solution.  It looks the part on the "round" manifold but yet to see how well it clears the rocker box cover - photos to follow when I empty the camera.

In time I'll make up a little gallery of Aprilia carb and manifold variations...

David

The manifold "scrubbed up nice".   This picture also shows that vacuum take off. 

David

A couple of intake manifold novelties. 

The setup was first with a blower over the foot box with the shaft drive over the head and curved intake pipe to a standard inlet.  It was then revised to mount above the red manifold with the carb on top with a direct drive.   Said to improve the torque considerably but it burnt through exhaust valves too often to be usable on a road car.   I understand the blower and special pulley are long gone.

David

I've also learnt that a first series crank will fit a late series block - and that a late series block will bore out to take 78mm B20 pistons.

David

And here, perhaps just for the delight of Scarpia and David Laver, is a photo of something special.

A delight for sure!!

That looks the same as the "Nardi twin carb set up on cabriolet" on the American site I gave a link to above.  The American one isn't painted, but shows the throttle link, fuel lines, and air filters.

Where's your picture from?   Is it crackle black?   As a general question - when did Lancia move from gloss black to crackle under the bonnet?

David

Colin,
what is the story behind this photo? Is it an old picture or is the setup still in your possession.

and by the way, is anyone clever enough to explain the relation between the engine breathing and this sort of twin carb provision. It's all very well with these bolt on extras but do we think the characteristics of the various manifolds were designed specifically for the Aprilia.? Generally the more air you can get through the engine the more power but I always wonder what other aspects I should tune to get the best out of it.I guess a rolling road is the way to go.?

Am alternative to a rolling road is road testing with an exhaust gas analyser.  I've also heard that exhaust gas temperature is enough information on its own but requires a manifold with tappings up close to the head.   That reminds me - I've got the article "Aprilia Bananas" here from Norman Wilson - who would like a scan...?

Anyone out there "in the trade" know what exhaust gas analyser or temperature instruments are suitable and how to interpret (and act on) the readings?  If not I'll be catching up with someone mid May who does instrumented on-road testing and can report back after.  He takes a scraper on his test drives to fine tune SU needle profiles, he rubs a bit off the side as it doesn't have to be symetrical then measures it up after.

Otherwise its soot colour and plug readings...  Graham Bell's Four Stroke Performance Tuning is my favorite, the Vizard A-Series tuning bible is a good general book for all its title and focus is the A-series engine.

http://www.amazon.co.uk/Four-stroke-Performance-Tuning-Practical-Guide/dp/1844253147/ref=sr_1_1?ie=UTF8&s=books&qid=1208296535&sr=8-1

http://www.amazon.co.uk/Tuning-Engine-Definitive-Performance-Economy/dp/1859606202/ref=sr_1_1?ie=UTF8&s=books&qid=1208296659&sr=8-1

David

This is a nice intro:-

http://www.airfuelmeter.com/english/lsu4_en_sensor.htm

Here's two examples of the sort of gear for on road testing...  I think BWE used to have a very early version of this stuff with the electronics is a suitcase size thingy.

http://www.turbobits.co.uk/acatalog/Innovate_LM-1_wideband_air_fuel_ratio_gauge.html

http://www.aempower.com/ViewCategory.aspx?CategoryID=67

http://trigger-wheels.com/store/index1.html

http://www.innovatemotorsports.com/products/lm1.php

To me its like doing your own welding - once you've got the gear you can spend what would be a commercially insane amount of time fiddling about to get it how YOU want.   I'd love to have one...

David

This is nice - very compact, will interface to a laptop, and got the exhaust gas temp as well.  To improve on this would take a "proper" logger with water temp and throttle posn etc or a "proper" garage "six gas" jobbie.

http://www.driftworks.com/catalog/products/vems-wideband-o2-monitor-with-optional-egt-sensor.html

Perhaps the one downside is needing to put the tappings into the exhaust system.   Yet to find the "lance up the tail pipe" system.   I'll give up soon and "phone a friend" for the answer!!

David

With regard to the photo of the twin-carb set up. I am really sorry to say it’s not mine and sadly, neither is the car that it came from! It’s a photo I took ten days ago of some parts that belong to a friend who is not a LMC member (nor a member of any other club, come to that!) and I am not free to say who he is.

But it is Nardi and probably the same as fitted to the car on the US website that David referred to. The black-crackle finish looks original.

In response to Scarpias’s question, I think the exhaust provision for the standard Aprilia must have been generous, so that improvements to the inlet could yield benefits to power output. And I guess this Nardi set up would have paid off without any other mods. I ran my car with a standard exhaust manifold and the power increments by upping from small-Zenith to big-Zenith to bid-Weber were evident. Yes, I would love to do it all again.

Colin

Saw the guy over the weekend at VSCC Wiscombe - breaking the class record as it happens. 

He uses AEM with bosch sensors.   The sensors are VERY fragile, do not drop even from an inch.  The exhaust lance is something he made up himself.  All his regulars have got a boss welded somewhere into the exhaust system.  It doesn't need to be close to the manifold - a foot in from the tail pipe is fine.   The response even with a sensor way back there is fine.

http://www.aem-power.co.uk/aem_uego.htm

He's considered adding an exhaust gas sensor and a knock sensor but is getting the job done just on air-fuel.  He sees no value in data logging - he tests, adjusts, tests, adjusts etc.  A customer of his was there and said it was a night and day improvement having been setup correctly - ticks over sweetly, very happy on a light throttle, and lots of torque right through the range.   I can remember our MG Midget when we first got it - it felt like a racing car all top end and coughs and splutters and pops but only made 75bhp.  For being set up correctly it ticks over so slow I think its about to stall, drives like a normal car, and makes 75bhp.

David

His other advice was to get a new setup looked at before driving it - he's seen plenty of engines damaged by bore wash with the mixture set up very rich for power and to be on the safe side.  Its not just lean mixtures that do damage.

Looking at the drift-works unit again it has an input for RPM and also for a throttle position sensor.

David