Abarth 695 pistons barels are 76mm bore and the stroke is 76.0mm.
From Abarth "omologazione" C.S.A.I. HA 26.

RogerNZ said:

Hi Chris, I seem to recall seeing somewhere a picture of an oil pressure sender you had fitted to your car. Can't see it in this thread but am sure it was you? Anyway, as I recall it was a hollow hex that I assume was threaded male at one end for going into the block and female at the other to take the regular switch, and then drilled and tapped to take the sender unit at 90 degrees to the switch. Does that sound right? If so, did you buy the part or make it?
Cheers Roger

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Roger,

Yes it was me and your description is perfect. I got it from Mr Fiat in the US.

I've attached the best photo that I can, taken from below, given all of the bits and pieces that are now in the way. I found that I had to use the correct number of copper gaskets so that when the hexagonal mount was tightened the sender didn't foul on the crankcase.

Chris

Great pics and story. Nice motor!

Hi Chris, I notice you didn't use any sort of base plate or "packer" under your barrels. I ask because when I got my kit from 500 ricambi they also sent two base plates, one about .8mm thick and the other about 1.5mm thick from memory. I sent them an email asking why they were included and they advised that I should be building the engine with about 1mm of headspace over the piston in the barrel at TDC and that the plates would help adjust the barrel height to suit. Fair enough, but I am a little confused that you did not use one, and also that they would provide them in two separate thicknesses. Seems to me the kits should all be the same. Who knows, maybe that's just the manufacturing tolerances on the barrels, or perhaps some cases are slightly different and therefore change barrel height? At any rate, I'm interested to know if you measured head clearance for the pistons in your engine - either the simple test of distance from piston crown to the top of the barrel, or the "squish band" clearance between piston crown and lowest point of the cylinder head?
Cheers Roger

Roger,
The cylinder height should be a minimum of 90.0 +/- 0.015mm from the seating face on the crankcase to the top surface and both of mine were OK with just the thin paper gaskets fitted between the cylinders and the crankcase.
By dial gauge at TDC there was about 0.2mm on each cylinder between piston crown and cylinder top. I assume that some of this was squeezed out when the head was torqued down.
I didn't fit high compression, domed pistons - rather I fitted a thinner head gasket (copper) with standard flat crowned pistons.
Without measuring the volumes of the combustion space at TDC and BDC it's hard to know the exact increase in CR however there are rough guides on the net which take into account the average shape of the combustion space in the head, shape of the crown, bore, stroke, thickness of gasket, cylinder volume at TDC & BDC etc.
I estimated mine to be about 9:1 or thereabouts and it's now covered quite a few hundred kilometers and is running very sweetly. It puts out about 35bhp at ~5500rpm.
Does this answer your question?
Chris

Thanks Chris, there's a huge difference between the 1mm approx suggested to me and your .2mm, I better look more closely at this. I'll let you know how I get on. Your car sounds to be running just fine so I expect I'll end up closer to your measurements.
Cheers Roger

Hi Chris, are you sure your barrels are 90mm? The barrels on my car and on my kit are 80mm. I always thought all 126's had 80mm but maybe not?
Cheers Roger

Yep you are correct - the cylinders are 80mm in height from the crankcase mating surface to the head gasket surface. When I ordered mine, I politely requested that they be matched for height as best possible and they were, though I didn't actually measure the heights, just the difference when fitted.

I've just rechecked the manual and it states - 'the height of the cylinders measured from the seating face to top surface is 3.5433" +/- 0.0006" (90 +/- 0.015mm)' which is where I got the figure from. See attached. Odd - any ideas?

Chris

Hi Chris, that's a page from the 500 manual. It turns out The 500 block is 10mm lower, so 500 barrels are indeed 90mm. I never knew that until this conversation started. All part of the learning curve!
I asked 500 ricambi what they thought of your .2mm piston clearance. They said it was possible but recommended .5 - 1mm was safer.
Cheers Roger

Mine might be a bit tight - maybe I should have used a thin spacer under each cylinder.
I guess the copper head gasket will add about 0.5mm.
If I remember, I'll lift the head in a few months and check for carbon build up etc.
Chris

PS: I didn't know about the height difference either and yeah, it is from the 500 manual.

I'd forgotten about your head gasket. If it is the same copper gasket I ordered from 500 ricambi then you're right, it adds about .5mm. I just measured mine, it was .55mm, so with your .2mm that makes .7 - well within the .5 - 1mm they suggest, and right about where I was thinking of being. Once again you're one step ahead Chris!

RogerNZ said:

Once again you're one step ahead Chris!

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Now and then, I get lucky

I wasn't quite so fortunate with the gearbox though - nothing major, just a lot of f**king hassle .....

Chris

Given that my gearbox is currently entirely apart, and hopefully going back together in the next few weeks (pinion shim willing) is there any advice you may like to offer?!

No specific advice - the correct tools, the correct parts and the correct attitude all help with what is, in essence, a simple job
I was just having one of those days where I was all thumbs.

Chris

We all have those days Chris--it takes a honest man to admit to it--brownie points well earned!

nathanrobo said:

Great! Post...

I'm embarking on a 750cc upgrade to my 600cc Fiat 500 R engine. I hope to do a similar threat once the block comes back from my engineer.

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I was just came across my post from earlier this year and realized that it's taken me around 8 months to get this engine done :_(

My mate Steve helped me to started it and give the DCOE 40's some basic settings... very cool - here's the vid:

http://www.youtube.com/watch?v=npZO2Z_3ubQ&feature=youtu.be

What a beast.
I love the way the spool of solder vibrates its way along the benchtop .....
Chris

Bambino said:

What a beast.
I love the way the spool of solder vibrates its way along the benchtop .....
Chris

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Chris,

Wow that's attention to detail! I had to watch it again to notice that.

The computer I use is in the main room of our house and I watched your video with the sound turned down so as not to disturb my wife while she was watching TV.

With no sound to distract me, the jumping reel was easy to see.

With the sound turned up, what a little barking monster Love the flashes in the exhaust port.

Chris

PS: Also, no oil spraying everywhere with the rocker cover off. This answers a few questions previously posted on the list.

Bambino said:

Have a look here - maybe he's just out of stock.

http://www.mrfiat.com/part.php?item...l and Ignition/Fiat125SIgnitionSwitchNew.html

As to the alternator - it's not hard to wire up. I've attached a diagram.

The old voltage regulator is not required so I stripped the interior and reinstalled it on the rear firewall basically using it as a wire binding post.

Chris

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Do you have to connect the wires to the regulator or can you just leave them loose in the engine bay??