500 (Classic) "Sophia's" Restoration

[Toshi 975]

Thanks guys. Is this the bolts I should replace with?
https://www.ricambio.co.uk/front-main-bearing-bolt-kit-classic-fiat-500-126

And this is the timing chain kit I am thinking of ordering
https://www.ricambio.co.uk/timing-chain-kit-anti-vibration-classic-fiat-500-126

You only need to replace one of the hex head set screws as you have that odd one and the other 3 originals have the Fiat rating stamped on the top. The picture of the Ricambi screws do not show the heads or wether the countersunk screws are Phillips or Allen screw heads.
The timing chain does not seem to have the tensioners like the original as when they turn at the ends you should see signs of the tensioners.

 

[LiteRye]

The timing chain has zero slack when fitted new with new sprockets.
In my experience, it's quite common for the head to seem not very tightly secured when removing. That doesn't necessarily mean it will blow, but in your case there has obviously been blow-by on both cylinders.

The engine has obviously been taken apart previously as there is slight damage to screw heads and at least one of the screws is non-original. I don't think the engine has done a great mileage since then and the head and pistons look like they will clean up well.

I'm sure it will run brilliantly after a bit of tidying up.

Peter, when you say clean up the head and pistons, what method do you recommend?

 

[fiat500]

Peter, when you say clean up the head and pistons, what method do you recommend?

My method is quite primitive and traditional, but has always worked well, but I like to avoid the involvement of professionals or expensive equipment where I can. To remove the bulk of the carbon I use a variety of scraping implements...whatever is to hand. In the past I've used blunt, old chisels and broad screwdrivers and sharp craft-knife blades on flat surfaces. Then I move on to small, relatively soft, rotary, wire brushes at slow speed on an electric drill and stainless steel "wool". In the final stages I use plenty of thin oil such as WD40 as a lubricant to remove all the final traces.

This way, you will end up with a set of mechanically clean components but they won't look too pretty. Many people would take this opportunity to polish internal surfaces and to soda blast or use other more professional methods to clean surfaces up.

Obviously, you need to try to avoid putting any nicks or scrapes into the alloy surfaces, but I find that the metal is more resilient than you might think. If you're leaving the barrels in place, make sure they can't be moved upwards when the engine is turned as you will want the pistons at the top before cleaning; this is shown in the Haynes manual and I would recommend getting hold of a copy before starting.

 

[LiteRye]

Great! Thanks Peter. I’ll give it a try and post the results

 

[the hobbler]

To hold the barrel in place I use 2 short lengths (1 for each barrel) of tubing and a couple of nuts and washers. Very simple and normally the bits for this can be found somewhere in your workshop.

 

[LiteRye]

Cleaned up the pushrod tubes. Got a little creative…took a .75’’ wooden dowel and mounted it up on my lathe and hit it with a metal finishing pad. Pretty happy with the results.

 

[the hobbler]

They look fine Ryan---well done!

 

[LiteRye]

Pulled the pistons today. They look pretty good to me aside from the few scratches. Rings look good too. Any thoughts?

The person who rebuilt the motor last did not put gaskets between the block and barrels unfortunately. Thankfully, the barrels are in good shape.

 

[the hobbler]

The pistons look to be fine, however, I would think that it would be wise to fit new rings.
With regard to the gasket between the crankcase and the barrels, I always use the very thin copper gaskets.

 

[LiteRye]

The pistons look to be fine, however, I would think that it would be wise to fit new rings.
With regard to the gasket between the crankcase and the barrels, I always use the very thin copper gaskets.

Thanks Thomas. Thoughts on these?
https://www.ricambio.co.uk/copper-barrel-base-gasket-classic-fiat-500,-126

 

[The Whitakers]

The pistons look to be fine, however, I would think that it would be wise to fit new rings.
With regard to the gasket between the crankcase and the barrels, I always use the very thin copper gaskets.

I’m with The Hobbler on this, deglaze the barrels though if you do of course ?

 

[the hobbler]

These are the type I always use, but make sure that you get the correct ones for your barrels---these ones you have shown are for '650' barrels

 

[Toshi 975]

Before you rush into new piston rings I would check the ring end gaps against the sizes shown in the manual. If they are hardly worn they can be reused and are already run in to your bores.

 

[fiat500]

Pulled the pistons today. They look pretty good to me aside from the few scratches. Rings look good too. Any thoughts?

The person who rebuilt the motor last did not put gaskets between the block and barrels unfortunately. Thankfully, the barrels are in good shape.

Given that some people don't even use a head-gasket, that shouldn't really be a problem; I think the thin paper gaskets were originally intended simply to bed the metal surfaces rather than as any kind of seal. At the risk of boring regulars, I always come up with this stuff in these circumstances:

https://www.permatex.com/products/g...que-rtv-silicone-gasket-maker-2/?locale=en_us

I've also used it alone, as a sump gasket, for the timing chain/oil-pump cover, on the rubber-rings for the pushrod tubes, where the distributor mates with the block and for all joint surfaces on the gearbox. Over the last 5,000 miles I have had no leaks from any of those interfaces, (but plenty from a couple of FIAT-designed, oil-seal "solutions".)

 

[LiteRye]

Before you rush into new piston rings I would check the ring end gaps against the sizes shown in the manual. If they are hardly worn they can be reused and are already run in to your bores.

Any idea what that measurement is for a 126 650 motor? I’ve got a 500 shop manual.

 

[Toshi 975]

Any idea what that measurement is for a 126 650 motor? I’ve got a 500 shop manual.

Top ring - 0.25 to 0.40mm
Centre. & bottom rings - 0.20 to 0.35mm

 

[JumpJet]

Top ring - 0.25 to 0.40mm
Centre. & bottom rings - 0.20 to 0.35mm

126 Manual

 

[LiteRye]

Awesome! Thanks JumpJet!

 

[F30Msport]

subscribing!

 

[LiteRye]

Sophia came with a spare Dynamo and the one attached to the motor, neither of which work. Can anyone determine if they’re worth rebuilding or am I just better off going the rebuilt route? The first photo shows the very dirty “spare” that was included which appears to be an original Fiat stamped Dynamo. It cleaned up pretty well in the parts washer. The second one was on the motor but not functioning. Any input would be appreciated!