I have a scan of a Polish owners manual for the 126p. I was looking at the recommendations for fluids, as well as engine adjustments and discovered that the maximum advance for the 650cc engines is not 18 degrees at 3000 rpm as I thought (like the 500), but rather 21 degrees (+/- 2 degrees) at 4000 rpm. Point gap is shown as 0.5mm.
This information can be found on page 47 under "Zaplon" (Ignition).
I have attached all of the Technical pages.
John

What years does this info refer to?

On P.51 benzyny E94
On P.52 Etylina 94
On P.56 E74, E78, plus mention of different carb. versions.

I suspect that the above refers to fuel types? available in Poland and might explain the different max. advance of ignition timing compared with specs for other Euro countries.

Al.

So first thing is, Google Translate is your friend for all things Italian or Polish. https://translate.google.com/

The section on pg. 51 you refer to is giving fuel consumption at 70 and 90 kph.
"Control fuel consumption at a constant speed under the conditions set by the PN-80 / S-04000 with gasoline E94 is"
I assume PN-80/S-04000 is some European or Polish standard. The unit dm2 is 1 liter.
On page 52, Etylina 94 is the same as E94 which is the European or Polish octane rating. That entry shows the fuel capacity in liters.
Octane ratings in Europe are different than the USA. A European octane rating of 94 is 90 in the USA.
On page 56 "wersje specjalne" translates to Special Versions. It appears to be a lower horsepower engine than the standard unit. Unlike the rest of Europe, Poland had some very low octane gas available, like E74 and E78. I expect vehicles delivered in Poland could be purchased or tuned to run on this cheap gasoline, hence the lower power output and different carbs listed on page 56.
I'll let you translate the rest!
This owners manual has a publication date of 1988. So it would be very late production. My Polish built 650 engine was built in 1987-88 and is different from earlier 650 engines in that it is wasted spark ignition (but still with a distributor with no cap), re-profiled camshaft for economy and torque output, 8.0/1 compression ratio, and hardened valve seats for unleaded gasoline.
John

This is still puzzling me. Regardless of whether a specification can be found stating 18 or 21 or any other number of degrees of centrifugal advance on either the 499 or 652 engine, I keep dithering over whether or not this is a cumulative measurement....ie. is it added to the 10 degrees of static advance to make 28 in total.
It was the 123 ignition system that started me thinking this as their specification sheet shows that their standard setting is 28 degrees at 3000rpm. Some time ago they replied to my query stating effectively that it was cumulative despite the fact that most discussions here talk about 18 degrees, and the graphs in all of the books make it look that way too.
I checked the spark plugs today and although the engine could not be running better, the plugs appear to be running hot...something I've never seen before.
Obviously there is a huge difference betwen 18 and 28 degrees. I checked it with the strobe and it looks like I must have originally decided to go with 28. I have never had a Fiat 500 engine that started better than this one, it never pinks or sounds to be under stress. It's one of those "ain't broke-don't fix it" moments. But I don't want to ruin the engine.
Any ideas?

Peter very interesting observation from the 123 guys, can you remind me what is the 10 degrees static advance that you are referring to?
Perhaps this explains why nobody can achieve a good setting using a timing gun.
You will make me mess with advance again!!
Thomas

With the standard distributor you adjust the points to be just opening when the engine is 10 BTDC.If it's in good condition, the mechanical advance inside the distributor will rotate the points. At around 3000 RPM the spark will now be firing at 28 BTDC. So with a strobe, 28 is the figure you should be setup to look for.

I reset the engine according to the specification above. To get the correct positions on the pulley for the 10 degrees and 28 degrees markings I measured 13mm and 38mm respectively on a piece of masking-tape and stuck this on the circumference and made white marks using Tippex.
I strobed the engine at high revs first and adjusted the distributor so that the 28 degree mark aligned with the timing-case arrow.

[ame]https://youtu.be/N2eones3uCE[/ame]

I repeated this at tickover to find that the 10 degree mark settled into place, which was nice.

[ame]https://youtu.be/-o1LMOGd5FI[/ame]

If it had had been wrong I wouldn't have re-adjusted as the accuracy of the dynamic timing is more important.
Now I have a very smooth tickover and good acceleration.

gordinir8 said:

Peter very interesting observation from the 123 guys, can you remind me what is the 10 degrees static advance that you are referring to?
Perhaps this explains why nobody can achieve a good setting using a timing gun.
You will make me mess with advance again!!
Thomas

Click to expand...

So I tested this theory; firstly by wiping the cobwebs of the 123 distributor and refitting it.
I thought that because this unit electronically advances the ignition to the optimal advance that you have selected, it followed that by using the strobe I could easily work out if the maximum advance was 18 degrees, as most often quoted, or 10 + 18 =28 degrees.
I measured 28 degrees.
Conclusions: If you set a standard distributor at 10 degrees static timing and the distributor is working properly, your engine will work as designed and even if you don't test it you can be confident that it will be at around 28 degrees at 3000 rpm.
Similarly with the 123, if it is set with the green LED coming on at exactly TDC then the timing will be at 10 degrees when starting and at low revs moving up to 28 degrees at 3000 and above.
The problem is that if you use a strobe to dynamically set either type of distributor at 18 degrees BTDC at 3000rpm, then your engine will be 10 degrees retarded at all speeds and may be difficult to start and will lack power.
If you wish to use a timing-light you should set the advance to at at least 28 degrees BTDC at around 3000 rpm. If it can't achieve that or ends up widely adrift of 10 degrees at idle then you have a faulty distributor. I measured 38mm clockwise from the TDC timing-mark around the pulley to make my 28 degree mark.
I have a strong suspicion that the well-meaning advice to use a stroboscope for most accurate timing has been detrimental to my engine in the past and might explain quite a number of other badly running engines whoich have cropped up around here.

fiat500 said:

I thought that because this unit electronically advances the ignition to the optimal advance that you have selected, it followed that by using the strobe I could easily work out if the maximum advance was 18 degrees, as most often quoted, or 10 + 18 =28 degrees.
I measured 28 degrees.
Conclusions: If you set a standard distributor at 10 degrees static timing and the distributor is working properly, your engine will work as designed and even if you don't test it you can be confident that it will be at around 28 degrees at 3000 rpm.

Click to expand...

Interesting observations, you confirm my conclusions that 18 degrees is not realistic and i have achieve better results at around 24-26 degrees ''estimated with my eye''
I will make a mark at 28 degrees and give it a try when i have the time.

gordinir8 said:

I will make a mark at 28 degrees and give it a try when i have the time.

Click to expand...

Since then I have done about 130km with the 123 set exactly at 28 degrees. It's definitely very smooth and probably exactly as it should be. But there is a slight lack of perkiness compared to the standard distributor which was maybe a bit more advanced. There are also some settings on it for 32 degrees and I am going to ask the company which makes the 123 exactly what those settings are all about.

Hold on, just noticed that the discussion concern the 650 Engine, are those also applied at 500 engines? Peter can you ask the 123 guys what they are recommend for the 500 next time you will contact them?
Thomas

Thomas, the printed information they supply shows that the timings apply to both engines. The only difference are a couple of settings that are for versions of the 594cc engine. The company that manufactures them are very reluctant to talk to the public and tell you to speak to your supplier. But I will try hard to get the information about the "curves".

Thomas gordinir8, I'm pretty sure that I'm not going to get a reply from 123 about the distributor but my little crusade about 28 degrees has had its final confirmation.
I was surprised to see on eBay, the correct Fiat tool for setting the static timing or for using a timing light to get the advance......and look at the number written on it.

Fiat 500 Timing Plate by Peter Thompson, on Flickr

Yeap you are right. Actually i was looking for that tool, Is this still on sale?, Can you send me the auction number?

By the way check this "adjustable" timing disc.
https://www.blocklayer.com/degree-wheel.aspx

gordinir8 said:

By the way check this "adjustable" timing disc.
https://www.blocklayer.com/degree-wheel.aspx

Click to expand...

That looks very interesting and I will bookmark to check it out later. Would that be used for setting the position of the camshaft sprocket when fitting a non-standard camshaft?

It made me look at the valve timing specifications in the manual and that reveals a whole other can of worms. There are at least two different factory camshafts available for the 650 with distributor (Haynes). The 594 camshaft is different and maybe the same as the 499? Most suppliers list one type of standard camshaft as suitable for all engines in the range.

The FIAT timing tool was won by one lucky and stupid bidder:bang: who can't stop collecting all things Fiat 500.
But when it is delivered to me I can make a life-sized paper-rubbing of it for you as I don't think it would be difficult to make one once you had the pattern.

I really like to have this original tool in my toolbox, I have search in the past with no success for it. At list it is in good hands so I definitely need an exact copy of It, maybe a scan so I can fabricate one out of aluminium. I will also make a timing disc. All I need is a 650 motor!

Valve-timing discs can be obtained from a number of camshaft manufacturers at a very reasonable cost---much easier and more accurate (and much more cost effective) than trying to make one. Both 'KENT' and 'PIPER' cams can supply them for about £10 plus carriage.

I know that I am labouring this point, but I tried the timing quadrant tool today and it was a revelation,
It is a very snug fit on the nuts of the timing-chain cover. Even though I had "accurately" measured the pulley to get 28 degrees advance by using the usual method, I still had a few more degrees to add by twisting the distributor. I found that, unlike the 110F type distributor which has a better friction fit, the body on the 126 engine is easily forced around by the momentum of the engine even when you think the clamping nut is half-tight for adjustment purposes; I lost my setting a couple of times as the distributor turned back clockwise at high speed.:bang:

MAL_8434 by Peter Thompson, on Flickr

You need to remember to remove the tool afterwards:bang:. Luckily my test drive was only a few hundred metres but I can't see why a diminished version of this timing indicator couldn't have been fitted to the engine design.
So now I am completely sure that I have the maximum recommended advance I can maybe start to experiment by pushing it a little further .:shakehead:
There's no doubt that the engine is as smooth and quiet as I can ever remember it being.