General Fiat 500D Engine 1962

[Franko500]

I have just dropped my engine casing off to someone who thinks they can weld it

Will have to wait and see if its successful.


Also taken my pistons, head and barrels to an engine shop.
£58 per barrel.
I took one of my 126 crankshafts of which he said looks fine & will just need a polish. The D crank had already been ground twice and I couldn't even get the main bearing back on the journal. So decided it had seen the end of its life.
Head he will clean and reseat the valves.
He reckons all these heads had hardened seats since original manufacturer due to them being alloy heads. Therefore they will run perfectly ok on unleaded.


Hope to have it all back in a couple of weeks.

 

[Franko500]

I mentioned previously that there are a number of differences on the 500D engine and that the flywheels are different to the L & 126 models.
So today amongst other things I thought I would do some measurements.
Number of teeth x width of teeth:
500D 104 x 13.5mm
500L 123 x 13mm
126 123 x 9mm


Thickness of Flywheel:
500D 19mm
500L 19mm
126 25mm


Clutch plate:
500D Diameter 139mm, 6 splines
L-126 Diameter 155mm, 20 splines


The D should be fitted with the earlier clutch diaphragm but has clearly been fitted with a later more modern equivalent.
Apart from being rather dirty I think it will be salvageable should I go the original route. Although I am tempted to fit the 500L flywheel and then I can use the later clutch plate which has 20 splines.
I am figuring that they found the larger clutch plate and greater number of splines made the clutch a lot smoother. Also the additional teeth made the starter a lot smoother as well. I would need to change the cog on the starter to match. I know this is not "original spec" but as I am looking at fitting the later gearbox as well to improve gear change it would be daft not to change to the later type. after all its internal components that cant be seen and would improve its driveability.
I can only imagine that fitted the heavier flywheel to the 650 engine to help the balance of the engine.

 

[fiat500]

There can't be many people with a collection of flywheels like that Sean...it will be a good nudge to memory when you're still messing with these things in your 90's and you're trying to patch things together from memory.
That D is definitely more of a vintage car than our "F"s and "D"s and I would love to "feel" the difference.
I think your idea of using the later type of flywheel/clutch assembly is good, but do you think that balance will be OK. I get the impression that flywheels were balanced to match the engine or perhaps even balanced as an assembly.
So many people seem to report that wobbly engines are normal but I don't think it has to be that way.

 

[Franko500]

There can't be many people with a collection of flywheels like that Sean...it will be a good nudge to memory when you're still messing with these things in your 90's and you're trying to patch things together from memory.
That D is definitely more of a vintage car than our "F"s and "D"s and I would love to "feel" the difference.
I think your idea of using the later type of flywheel/clutch assembly is good, but do you think that balance will be OK. I get the impression that flywheels were balanced to match the engine or perhaps even balanced as an assembly.
So many people seem to report that wobbly engines are normal but I don't think it has to be that way.

To be honest Peter I haven't found any evidence of balancing on the flywheels. There are no extra holes drilled to reduce the weight at certain areas - that is the usual way of balancing. Both engines had been apart before so I cant say for sure if they were fitted correctly before.
My 650 engine, I never checked the position. just bolted it on and it runs lovely.

 

[Bigvtwin996]

That D is definitely more of a vintage car than our "F"s and "D"s and I would love to "feel" the difference.
.

I'm just waiting for him to finish this "Youngtimer car" so I can give him something more difficult to work on..... I may have found everything by then.....

 

[fiat500]

I'm just waiting for him to finish this "Youngtimer car" so I can give him something more difficult to work on..... I may have found everything by then.....

I challenge you to find something that Sean will find to be difficult.
( as long as you're in charge of the rare parts sourcing).

 

[Bigvtwin996]

I challenge you to find something that Sean will find to be difficult.

Ohhhhh I think I can............. Sean is only just touching on difficult to find......
here is the first challenge then.. NOS Cream hard plastic sun-visors (not the Bianchina ones...)

 

[fiat500]

Ohhhhh I think I can............. Sean is only just touching on difficult to find......
here is the first challenge then.. NOS Cream hard plastic sun-visors (not the Bianchina ones...)

Mr. Big....you're forgetting..that's your area of expertise.

 

[IanEmery]

I mentioned previously that there are a number of differences on the 500D engine and that the flywheels are different to the L & 126 models.
So today amongst other things I thought I would do some measurements.
Number of teeth x width of teeth:
500D 104 x 13.5mm
500L 123 x 13mm
126 123 x 9mm


Thickness of Flywheel:
500D 19mm
500L 19mm
126 25mm


Clutch plate:
500D Diameter 139mm, 6 splines
L-126 Diameter 155mm, 20 splines


The D should be fitted with the earlier clutch diaphragm but has clearly been fitted with a later more modern equivalent.
Apart from being rather dirty I think it will be salvageable should I go the original route. Although I am tempted to fit the 500L flywheel and then I can use the later clutch plate which has 20 splines.
I am figuring that they found the larger clutch plate and greater number of splines made the clutch a lot smoother. Also the additional teeth made the starter a lot smoother as well. I would need to change the cog on the starter to match. I know this is not "original spec" but as I am looking at fitting the later gearbox as well to improve gear change it would be daft not to change to the later type. after all its internal components that cant be seen and would improve its driveability.
I can only imagine that fitted the heavier flywheel to the 650 engine to help the balance of the engine.

Sean, From what I can find out from my books it looks as though, for a '62 D post chassis 842001, you have the correct clutch cover but with an earlier plate? Obviously you are controlled by the number of splines on the input shaft but I read that a car of that age should have a 20 spline imput? Another case of using hold over parts perhaps, or maybe the gearbox is from an earlier car? Although I think this unlikely Ahhhh I have a NOS clutch plate which is marked as being for a '62-'65 D and clearly has 20 splines on it!

I wonder if the car was built with the smaller/older components and as your engine has been modified, 540cc plus sport camshaft, perhaps it was felt that the earlier coil spring clutch might have been a weak link and so the diaphragm cover was used as an upgrade? The plate would have had to be retained as it matches the gearbox input. My point, long winded though it is, is if you're going to use the later gearbox maybe the flywheel you have on the engine will take the larger, later clutch plate?

 

[IanEmery]

That D is definitely more of a vintage car than our "F"s and "D"s and I would love to "feel" the difference.

Peter, I had a '72 L prior to getting "into" the D and I can tell you the clutch is much sharper feeling as though it's missing the rotational shock springs in the clutch plate, which of course is exactly as it is. Makes pull aways a little interesting sometimes especially on the hills I'm sure you would be quite at home after driving your old Austin:worship:

Other than that you only thing I really notice is the lower top to the windscreen, 6'0"

East Anglia is a long way but you're welcome to a test drive!!

 

[fiat500]

East Anglia is a long way but you're welcome to a test drive!!

You'll regret saying that Ian. I recently made contact with a very long-lost, good, old friend from my college days who first sparked my interest in cars by driving me up the A1 from Peterborough to York in a 1938 Morris 8. He's still mad on cars and after working hard all his life he now has some real gems in his collection. He lives in Suffolk so my summer plans might involve me being diverted away from Europe and down into deepest, darkest England!

 

[IanEmery]

You'll regret saying that Ian. I recently made contact with a very long-lost, good, old friend from my college days who first sparked my interest in cars by driving me up the A1 from Peterborough to York in a 1938 Morris 8. He's still mad on cars and after working hard all his life he now has some real gems in his collection. He lives in Suffolk so my summer plans might involve me being diverted away from Europe and down into deepest, darkest England!

Anytime you like, but just remember Ds don't go out in the rain

 

[Toshi 975]

The interchangeability of parts from the two cylinder Fiat engines never ceases to amaze me. I recently bought some big end shells from a local motor factor and they were marked as being suitable for 1957 to 2012 engines. The same would apply to crankshaft & main bearings. The gearbox bell housing from. 126 water cooled Bis will fit a Giardiniera and facilitate a larger clutch. I had an '89 126 Bis that we had from new. It decided to throw the clutch when just outside the first year warranty. It was a Sunday and I needed the car running the next day. Had a rummage in my shed and found a reasonable clutch plate on an old 500D engine. It fitted and ran quite successfully for some time

 

[Toshi 975]

I am just in the process of rebuilding a gearbox so the components are fresh in my mind. It occurred to me that you could probably change the coarse spline input shaft for the later one with the fine spline. Had a look at my 500 workshop manual and these diagrams are 500N & 500D

 

[Toshi 975]

500n

 

[Franko500]

I think you are correct about the change ability of these parts.
Mine clearly has the early flywheel, clutch plate and gearbox shaft and can only think it has been fitted with an after market diaphragm as it fits the flywheel & clutch.
The clutch plate is smaller than the later one, as is the surface area on the flywheel.
So the only way to upgrade to the later clutch is to fit the later 20 spline shafts, later flywheel & clutch assembly. As long as it all fits within the bell housing then it should provide a smoother clutch than the original.

 

[Franko500]

I picked my crankcase up from the welders today. I was pleased to see it welded okay.
Damian you were right there was another crack

. When he started welding it he noticed some oil residue bubbling from a small crack a little further round so he welded that as well. After a fair bit of filing, grinding, sanding, drilling and tapping holes out, it came out quite well. The bearing housing fits really nicely now. I had to do a little extra sanding as there were a few tight spots where the housing goes in. I think it was like this before as it was a bugger to removed the bearing housing originally. Possibly part of the cause of the cracks as it was too tight a fit. Anyway, all looks good so I can get the crankcase down to the engine shop Monday for a good clean as I think I should get them to remove the oil gallery plugs and make sure everything is clean ready for the rebuild.

 

[IanEmery]

Some very nice work.

Inspirational :worship:

Glad you were able to save it.

 

[fiat500]

Sean, did you smooth off all that welding off yourself? It's a brilliant result...I would really have struggled with that.

 

[Franko500]

Sean, did you smooth off all that welding off yourself? It's a brilliant result...I would really have struggled with that.

One of the things my Dad first taught me in engineering was how to use a file. However now days we have air grinders, rotary sanders to play with as well. I was rather chuffed with the finished result?