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Discussion Starter #1
Hi guys, Kevin from South Africa here - first time Alfa owner and BB poster! Recently got my first Alfa - a blue 1971 Giulia 1300 Super. It was parked unused for 20 years when I got it.

I have take a few months to replace hoses, fluids, rebuild calipers, tyres, shocks etc and have the car in a reasonable running condition now. I just did a tune up of the Weber's with a "Colortune" and since the sparks were out decided to have a look at the pistons with my cheapie boroscope.

All the NGK BP6ES sparks came out looking similar - blackish/brown. Perhaps running a little rich but no major build up. What is weird is Pistons 1, 2 & 4 look almost spotless (can see the "103" on the top center of the piston head) but Piston #3 has quite a lot of I assume carbon build up.

I have driven the car relatively hard for a bit, no long highway trip yet though. What I am unsure of is why only Piston #3 has the build up? Any thoughts?

Cylinder 1 (2 and 4 look very similar):

1674508


Cylinder 3:
1674509



Out of interest here is the engine bay when I got it:

1674510


And this is it on an early drive (before new tyres etc):

1674511
 

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Do a leak down , will tell you something.
 

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Hi guys, Kevin from South Africa here - first time Alfa owner and BB poster! Recently got my first Alfa - a blue 1971 Giulia 1300 Super. It was parked unused for 20 years when I got it.

I have take a few months to replace hoses, fluids, rebuild calipers, tyres, shocks etc and have the car in a reasonable running condition now. I just did a tune up of the Weber's with a "Colortune" and since the sparks were out decided to have a look at the pistons with my cheapie boroscope.

All the NGK BP6ES sparks came out looking similar - blackish/brown. Perhaps running a little rich but no major build up. What is weird is Pistons 1, 2 & 4 look almost spotless (can see the "103" on the top center of the piston head) but Piston #3 has quite a lot of I assume carbon build up.

I have driven the car relatively hard for a bit, no long highway trip yet though. What I am unsure of is why only Piston #3 has the build up? Any thoughts?

Cylinder 1 (2 and 4 look very similar):

View attachment 1674508

Cylinder 3:
View attachment 1674509


Out of interest here is the engine bay when I got it:

View attachment 1674510

And this is it on an early drive (before new tyres etc):

View attachment 1674511
Looks like some rodents had quite the party...
 

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Discussion Starter #4
So I did a compression test (I don't have equipment for a leak-down test, yet).

I warmed the car to temp, removed fuel and coil, and cranked with WOT. But I stupidly forgot to remove the air filter.

Anyway, these are the results: dry (wet). As mentioned, not discernible difference on spark plugs either, hence my confusion as to why only Piston# has build up on it.

Piston 1 155psi (185psi)
Piston 2 140psi (175psi)
Piston 3 145psi (150psi)
Piston 4 140psi (170psi)

I guess the rings could do with a replacement, I doubt this engine has been opened before.

Here is a pic of the sparks (I have changed to BP7ES now to see if the colder plugs will have an effect) - #2 and #3.
1675011
 
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