Aprilia spark plugs

[brian]

A simple question.

I am still struggling to get the Aprilia timed - I am beginning to wonder if the flywheel is actually put on in the right position! - but I thought I would change the plugs as a) they are old and b) all are out so as to see pistons going up and down.
I have NGK B6S at the moment and did not have any particular problems. They are still available for rustic applications (hedgetrimmers etc).
Has developments led to a better option? I know Harry was always keen on NGK!

It looks as if the handbook I have (S2) gives the wrong firing order so confirmation of order for a S1 - and any tips as I would like to get it going for the SPR in June and at my rate of progress this is an unachievable target!!!

Brian

[JohnMillham]

The safest way is to take the rocker cover off and you will be able to easily see which cylinder is meant to be firing, by looking at the position of the valves. Going by numbers is fraught with danger, as Lancia numbered their cylinders in peculiar ways - and not the same for all models. I favour Platinum plugs these days. Since using them on the Lambda, I have experienced no further oiling up of plugs. The Augusta doesn't seem to be very fussy about plugs, but I use Platinum, anyway.
Regards, John

[ColinMarr]

Brian,

I doubt if it’s very complicated to solve. Just take yourself back in time to 1939 and imagine you are the car’s first proud owner. You take it to the smartest garage in Derby to have it fixed. The head mechanic there refers to his pristine copy of The Motor Trader Service Data No 52 on the Aprilia, published in November 1938. (See copies of the first three pages attached). He will quickly see on the first page that the firing order is 1-3-4-2 and then on pages 2 and 3 he will work out the markings on the flywheel to set the distributor. He will do this with great precision and the engine will run very sweetly. And you will visit the garage the next day, pay a modest bill and away you go, as befits a man of your station and with the good taste to own such a fine vehicle. Sadly, the car will shortly be laid up for the duration of WWII and nobody would believe that it might still be on the road in more than 70 years time. Oh lucky man!

Colin

[the.cern]

Colin, that is wonderful!!!!
             
                   Andy

[BlueSky]

Have also been running NGKB6S plugs, recently installed some Bosch W7AC just to see how they go, so far they are excellent. Has anyone devised a method of removing plugs from the head without them getting smothered in oil? I've tried various bits of cloth and paper towel to soak the oil up but there is always too much on the plugs to check their condition.

If you'd like a readable and complete version of the Motor Trader article I've got one on my website http://www.narrywoolan.com.au/lancia-aprilia/aprilia-publications.html, although Colin's copy is wonderful...

Noel

[ColinMarr]

For those who prefer to see a little patination through use (but not by me I am sorry to say) here are scans of the remaining three pages.

Oh yes, and just to mention – there are some original Aprilia plug connectors (not from the same source!) not doing very much on eBay at the moment – see:
http://www.ebay.co.uk/itm/182055641108?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

Colin

[ben]

As Colin mentioned Aprilia firing order is 1342 where the numbers refer to the cylinders and no 1 is nearest the front etc.
 
In their infinite wisdom when the men from Turin wrote the timing instructions for the handbook they chose to use no 2 cylinder as the reference point---I think possibly because it is the one whose plug connector is nearest the distributor----.
Thus when the timing mark on the flywheel is lined up with the 1/3 (?) mark on the bell housing it is actually nos 2 and 3 cylinder's pistons which are at top dead centre.
The numbers on the bell housing and shown in the wiring diagram,(Tav 18 in S1 handbook and Tav 20 in the S2 handbook) refer to the firing order or sequence and are not the cylinder numbers although nos 3 and 4 happen to be the same!!
Thus we can tabulate;

              "Lancia" firing sequence                         1      2      3      4
               Relevant cylinder                                 2      1      3      4
and repeating this cylinder sequence shows it is the same as 1342 but starting at no 2.           

[JohnMillham]

              "Lancia" firing sequence                         1      2      3      4
               Relevant cylinder                                 2      1      3      4
and repeating this cylinder sequence shows it is the same as 1342 but starting at no 2.            
[/quote]

 Lancia liked his firing order to be 1234, so he numbered his cylinders accordingly. Augustas and Lambdas are different again from the Aprilia, with the cylinder furthest from the driver called No. 1 on the Augusta and the cylinder nearest to the driver called No. 1 on the (right hand drive) Lambda. As seen from the top, the firing order is clockwise on the Augusta but anti-clockwise on the Lambda and Aprilia. The distributor rotor arm goes clockwise on all of the engines.  It gets more complicated when Lancia produced the Aurelia, where the distributor cap is almost unbelievable, with connections crossing over from one side to the other. Just so Lancia could keep the firing order 123456, I suspect!
Regards, John  

[ben]

Hi John
         I think you perpetuate the confusion when you say Lancia numbered their cylinders to create a 1234 firing order.
         In the bottom of the Aprilia engine the con rods are clearly stamped 123 and 4 with no1 being at the front and the others following in sequence along the crankshaft. In terms of these numbers the firing order is 1 3 4 2 .
         The numbering of the plug connectors on top of the engine  shown in the handbook wiring diagrams indicate the firing sequence and are best seen as just that rather than seen as redefining the designation of the cylinders.I have to concede however that the instructions for setting the timing in the handbook refer to what is really No 2 cylinder as No 1! In my view the authors of the handbook got confused!!!
         The handbook also states that the cylinder numbers are marked in red on the cam cover.I have never come across an engine thus marked and wonder if anyone else has. and if so are they the true cylinder numbers or the firing order?
                   Ben   

[JohnMillham]

Hi John
         I think you perpetuate the confusion when you say Lancia numbered their cylinders to create a 1234 firing order.
         In the bottom of the Aprilia engine the con rods are clearly stamped 123 and 4 with no1 being at the front and the others following in sequence along the crankshaft. In terms of these numbers the firing order is 1 3 4 2 .
         The numbering of the plug connectors on top of the engine  shown in the handbook wiring diagrams indicate the firing sequence and are best seen as just that rather than seen as redefining the designation of the cylinders.I have to concede however that the instructions for setting the timing in the handbook refer to what is really No 2 cylinder as No 1! In my view the authors of the handbook got confused!!!
         The handbook also states that the cylinder numbers are marked in red on the cam cover.I have never come across an engine thus marked and wonder if anyone else has. and if so are they the true cylinder numbers or the firing order?
                   Ben   

You might well be correct Ben, but I suspect someone put the rods down the wrong holes! The cylinder numbers are marked on the heads of an Aurelia - and they agree with my theory.
Regards, John

[ColinMarr]

All of which goes to show how wise was the head mechanic at the English garage in 1939. Having been schooled on English cars from Alvis to Wolselely, when he read that the firing order should be 1-3-4-2, he unhesitatingly read the number sequence from front to back. None of this fancy foreign nonsense for him!

Colin

[ben]

Hi John
          This debate could run and run!
          According to Peter Renou in the most recent edition of the Australian Lancia Newsletter the Aurelia handbook has conventional cylinder numbering from front to back and a firing order of 1-4-3-6-5-2. Thus the numbers you refer to on the cylinder heads are the firing order for the cylinders and not the cylinder numbers.They are there to tell you where the plug leads connect to as the corresponding numbers are marked on the distributor cap.Fortunately for this engine they start the sequence at No1 so that bit is less confusing than the Aprilia  but as you say any ideas of simplicity are quickly blown away by the design of the distributor cap with its internal cross-overs.Peter suggests this has more to do with achieving a neat layout of the plug leads than anything else and I have to agree with him as it does not achieve any other purpose!
          I think on my first Aurelia (bought and sold as a crash victim) I naively assumed that the rotor fed the sparks out of the distributor in a circular sequence which is why I could never get it to run properly.
          I hope all these musings have not left Brian even more confused.

          Perhaps to put the lid on it we can get Dilambda Man to tell us what the arrangements are on Modestines narrow Vee 8 ?   

[brian]

After my lie-down followed by a stiff G&T I am ready to try to get my head around this!
In the S2 handbook I quote Page 58 "Rotate crankshaft.. until flywheel tooth with "0" corresponds to A/A [sic and NB!] shown on edge of the spyhole and the valves of No 2 cylinder (the first to ignite) are both closed".

The mark 1/3 is used apparently for valve timing (Page 42).

This from memory is not the same on Augusta where the 1/3 is used for ignition timing.

Thus the front cylinder (No2) should be firing at this point with with second (No1), third (No3)  and fourth (No4) following in sequence to the back (i.e. what anybody else would call 1,2,3 and 4). The Lancia numbering of both cylinders and firing order is clear on page 57.

So do I use the A/A or 1/3?

Isn't it interesting that the simplest of questions seem to generate the most complicated of answers - I found it so in Medicine too.
Brian

PS I will stick to my NGK B6S plugs as cheap and work!

[JohnMillham]

Sorry to have confused you, Brian. It all makes sense to me, but I'm obviously not very good at explaining it! You are correct in thinking the ignition timing uses the A/A mark, which is a few degrees before the top dead centre of the firing cylinder. The Augusta is the same as the Aprilia in this respect. Note that the firing cylinder is No. 1 or No. 3. (The second or third cylinder from the front of the engine.) Obviously the valves of the firing cylinder will both be closed, while the opposite cylinder's valves will both be very slightly open. That's why it's safest to take the rocker cover off and look at the position of the valves, particularly if the distributor has been removed from the engine and it's not obvious which cylinder is on the appropriate stroke.
I hope that helps.
By the way, the Lambda flywheel only fits in one position, unlike some of the others, but the 1/3 and 2/4 marks are surely referring to the cylinders, not the firing order.
Regards, John

[GG]

On the Aurelia then -

 the cylinders are 1,3,5 on the left, and 2,4,6 on the right.  But there was a second series of numbers from the cap. There was a reason, but it is some distance from us now.

It all starts at the distributor cap, and is easily misunderstood. The caps and their lead are visually arranged (e.g. aesthetic) so that the plug wires plug in in a good looking way. That makes it hard to know how the sequence is working inside the cap.

So what Marelli did (very likely with Lancia input) was to mark the caps with the firing sequence as it occurs within the cap, not the engine. This runs counter to common experience, where we prefer the engine sequence on the cap, so we can simply plug in the right wires into the right spots. They assumed the user would go an extra step and figure out the connections themselves.

It's odd, even frustrating, but, like most Lancia solutions, not without intent. It was probably it was a bit of overthink by an ambitious underling.