Technical Is this head salvageable?

[dirkdeman]

Hi!
I bought a 650cc engine with some bits missing on the cheap in order to convert it to a semi-hot 695cc. Basically I only wanted to use the crank case, crankshaft and cylinder head as the rest of it is getting replaced anyway.

When I took of the head I was greeted with this (see attached photo)... Well, I now know why the engine had bits missing!


I have a couple of questions:

• WTH happened here? I've seen faulty head gaskets before, but never this kind of carnage... And I suspect that not all damage (of any!) is caused by a leaking head gasket, there is evidence of mechanical damage too, almost as someone was trying to grind away material with an angle grinder. But why?
• Is this head salvageable, or would I be better off getting a new head? The plan was to skim the head, get bigger valves and smooth out the ports so extensive work is going to be done on the head anyway, no matter if I buy a "new" one or not. But I am curious as to what you think: is this damage repairable?

 

[smart51]

How much of the damage would dissappear if it was skimmed? The head can take a fair bit of material being removed.

 

[Goldnrust]

If a head gasket is blowing badly enough, for long enough, the hot exhaust gasses can actually eat away at the aluminium and burn holes in the head.

I think that is what has happened here, and then it has been welded and repaired. Possibly not to the best standards of you can see grinding marks still!

Welded repairs to aluminium heads are perfectly acceptable when done right. I’m sure an engine shop could weld up the damage and skim the head flat for you. I had similar repairs (though due to corrosion on the water jacket) done to some Daimler v8 heads a couple of years ago.

… but given it will take the shop a few hours work to correct the issue, you might be financially better off just looking for a good secondhand head.

The best bet would be to consult the machine shop you plan to use, as @smart51 says, the damage might just be skimmed off anyway as part of your performance plans.

 

[Toshi 975]

Although slightly ugly in theory with a skim the sealing surface for the head gasket would be restored. If the screw threads in the alloy head are intact and no sheared studs then I would say worth saving as it is one of the later style cylinder heads. I think that Goldnrust has assessed the situation accurately.

 

[the hobbler]

Although slightly ugly in theory with a skim the sealing surface for the head gasket would be restored. If the screw threads in the alloy head are intact and no sheared studs then I would say worth saving as it is one of the later style cylinder heads. I think that Goldnrust has assessed the situation accurately.

I agree with both Toshi and Goldenrust----I would be tempted to have an "engine-shop" skim the head and THEN make an assesment. If taking 60thou (1.5mm) off the head still leaves about 40thou (1mm) in the depth of the relief groove gives you a good 'gasket' surface then you should be OK.The relief groove is about 2.5mm (100thou) deep from new, so measure it first, just in-case it has been skimmed before. As Toshi has pointed out, it is one of the later heads, so worth trying to keep if at all possible. Please let us know the outcome---could be useful to somebody in the future.

 

[dirkdeman]

Thank you all! The head is going to my engine shop this week, I'll update you on the proceedings.

 

[FDNY21]

Thank you all! The head is going to my engine shop this week, I'll update you on the proceedings.

If you did want another head then I have this one for sale:

Classic Fiat 126 Cylinder Head 650cc Engine | eBay

Fiat 126 650cc cylinder head. Untested but removed from low mileage car (1979) and can’t see any major cracks or damage, please see pictures for condition. I’d recommend a good clean up and new seals at the least just as it’s used but as seen it has been well lubricated! Removed off a spare...

www.ebay.co.uk

If it helps you then I'm in Pandino in Italy this weekend or Amsterdam the weekend after! Leaving soon so would need to know shortly to bring it with us though!

 

[dirkdeman]

If you did want another head then I have this one for sale:

Classic Fiat 126 Cylinder Head 650cc Engine | eBay

Fiat 126 650cc cylinder head. Untested but removed from low mileage car (1979) and can’t see any major cracks or damage, please see pictures for condition. I’d recommend a good clean up and new seals at the least just as it’s used but as seen it has been well lubricated! Removed off a spare...

www.ebay.co.uk

If it helps you then I'm in Pandino in Italy this weekend or Amsterdam the weekend after! Leaving soon so would need to know shortly to bring it with us though!

Thanks! But it's already at the machine shop (although it could take a while, he has about 6 months of work lined up).

In any case, something else has popped up in the meantime:

I had the opportunity to snag up a very cheap - yet virtually rustfree - Fiat 126 Prima Serie in Italy! A bit of a last-minute decision, but I couldn't let this one get away. I rented a lorry and my son (he's 13) and I drove to Bari, picked it up and drove back.

I've wanted a 126 First Series for a long time, but they just can't be found here and importing a good one from Italy is a process worthy of its own post... So I sort of "settled" for the idea of a 500 (sorry to all the good folks here!!)

So... I might have to head over to the 126-section of this forum. Sadly the 126 section does not seem to be as active as the 500 section, so if you don't mind I'll be around here also, given that most of the technical matters are the same as a 500R anyways.

 

[FDNY21]

Thanks! But it's already at the machine shop (although it could take a while, he has about 6 months of work lined up).

In any case, something else has popped up in the meantime:

View attachment 446657
I had the opportunity to snag up a very cheap - yet virtually rustfree - Fiat 126 Prima Serie in Italy! A bit of a last-minute decision, but I couldn't let this one get away. I rented a lorry and my son (he's 13) and I drove to Bari, picked it up and drove back.

I've wanted a 126 First Series for a long time, but they just can't be found here and importing a good one from Italy is a process worthy of its own post... So I sort of "settled" for the idea of a 500 (sorry to all the good folks here!!)

So... I might have to head over to the 126-section of this forum. Sadly the 126 section does not seem to be as active as the 500 section, so if you don't mind I'll be around here also, given that most of the technical matters are the same as a 500R anyways.

No problem at all! And great to see you bought a 126 Series 1! I don't have a 500, I have a 126 Series 1 as well so I'm just as excited as you to see that! The 126 section here didn't pop off as much as there was a dedicated 126 website but that has "closed" now as well. The active plate for 126s in the UK is the Facebook page "Fiat 126 Group UK".

Here is my UK RHD Series 1! I ought to fix it really...

 

[Toshi 975]

Thanks! But it's already at the machine shop (although it could take a while, he has about 6 months of work lined up).

In any case, something else has popped up in the meantime:

View attachment 446657
I had the opportunity to snag up a very cheap - yet virtually rustfree - Fiat 126 Prima Serie in Italy! A bit of a last-minute decision, but I couldn't let this one get away. I rented a lorry and my son (he's 13) and I drove to Bari, picked it up and drove back.

I've wanted a 126 First Series for a long time, but they just can't be found here and importing a good one from Italy is a process worthy of its own post... So I sort of "settled" for the idea of a 500 (sorry to all the good folks here!!)

So... I might have to head over to the 126-section of this forum. Sadly the 126 section does not seem to be as active as the 500 section, so if you don't mind I'll be around here also, given that most of the technical matters are the same as a 500R anyways.

Interesting it looks like someone has fitted the later black bumpers in place of the chrome.

 

[Toshi 975]

No problem at all! And great to see you bought a 126 Series 1! I don't have a 500, I have a 126 Series 1 as well so I'm just as excited as you to see that! The 126 section here didn't pop off as much as there was a dedicated 126 website but that has "closed" now as well. The active plate for 126s in the UK is the Facebook page "Fiat 126 Group UK".

Here is my UK RHD Series 1! I ought to fix it really...
View attachment 446658

Nice to see the 126s coming forward, I have owned more 126s over the years than 500s and both marks are great. In fact I bought a brand new one in 1989. Also “Fiat 126 Group UK” is definitely the most useful site.

 

[dirkdeman]

Interesting it looks like someone has fitted the later black bumpers in place of the chrome.

You're right! Somewhere in its lifetime it was converted to some sort of 126 personal 4-wannabe:

• Black bumpers instead of the chrome ones
• 126 personal 4 bonnet
• 126 personal 4 interior: seat covers, steering wheel and switch panel

I've already sourced a period-correct Series 1 bonnet: there was only 1 on sale on subito.it and it was right on the way to Bari!

 

[Toshi 975]

You're right! Somewhere in its lifetime it was converted to some sort of 126 personal 4-wannabe:

• Black bumpers instead of the chrome ones
• 126 personal 4 bonnet
• 126 personal 4 interior: seat covers, steering wheel and switch panel

I've already sourced a period-correct Series 1 bonnet: there was only 1 on sale on subito.it and it was right on the way to Bari!

I converted my son’s 126 to black bumpers from chrome thinking that they might be a little safer knowing that he was a new driver and would probably try to tear around even though it was a standard 126 with a noisy exhaust.
The tee shirt dates it.