Author Topic: Cylinder Head Dimension  (Read 243 times)

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jones

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Cylinder Head Dimension
« on: September 27, 2018, 11:44:22 AM »
I own a Polish built 126 here in Australia (actually I have two, less said about that the better).

After leaving the poor little thing at the back of the shed for too long, I have recommenced a minor rejuvenation.  To this end, I removed the head, intending to shave some metal for a compression ratio upgrade. 

I am following the advice of the Blitz racing guy that is referenced on this forum,  However, before I hand my head over to my local cylinder head guy I thought I should be sure it hasn't been shaved already - there are indications that it has been off the car before.

So, does anyone know a standard dimension (thickness) for these heads?  Or, is there another way to determine if there has been metal removed?



thanks for your help.
Polski Fiat 126, (2) Alfa Romeos (2)

dikkehemaworst01

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Re: Cylinder Head Dimension
« Reply #1 on: September 29, 2018, 02:06:14 AM »
Do you have the "8" head or the square head from a german build car. They need clean rings and a domed chaimber for the valves.

Do not have the dimentions on me.

But if you need more grunt, buy the head of an aircooled panda 30.
More expensive , but cheaper than getting the head rebuild....


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dikkehemaworst01

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Re: Cylinder Head Dimension
« Reply #2 on: September 29, 2018, 02:10:33 AM »
And get your bum over to the English 126 forum. A world full of friendly people and more knowledge then  you'll ever need...
Learned a lot over there , and i tinker with 126 and derivates for over 20 years now.

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dajwid

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Re: Cylinder Head Dimension
« Reply #3 on: September 29, 2018, 04:56:33 PM »
Good luck finding the Panda head and carb.

Do you have the "8" head or the square head from a german build car. They need clean rings and a domed chaimber for the valves.

Do not have the dimentions on me.

But if you need more grunt, buy the head of an aircooled panda 30.
More expensive , but cheaper than getting the head rebuild....


Verstuurd vanaf mijn SM-G920F met Tapatalk

dikkehemaworst01

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Re: Cylinder Head Dimension
« Reply #4 on: September 29, 2018, 05:20:06 PM »
I have ons,
And on Dutch eBay there 2 more...
Good luck finding the Panda head and carb.

Do you have the "8" head or the square head from a german build car. They need clean rings and a domed chaimber for the valves.

Do not have the dimentions on me.

But if you need more grunt, buy the head of an aircooled panda 30.
More expensive , but cheaper than getting the head rebuild....


Verstuurd vanaf mijn SM-G920F met Tapatalk

Verstuurd vanaf mijn SM-G920F met Tapatalk


Rusty's Uncle

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Re: Cylinder Head Dimension
« Reply #5 on: September 30, 2018, 05:34:27 PM »
I own a Polish built 126 here in Australia (actually I have two, less said about that the better).

After leaving the poor little thing at the back of the shed for too long, I have recommenced a minor rejuvenation.  To this end, I removed the head, intending to shave some metal for a compression ratio upgrade. 

I am following the advice of the Blitz racing guy that is referenced on this forum,  However, before I hand my head over to my local cylinder head guy I thought I should be sure it hasn't been shaved already - there are indications that it has been off the car before.

So, does anyone know a standard dimension (thickness) for these heads?  Or, is there another way to determine if there has been metal removed?
thanks for your help
Just dug out a spare head and put the calipers on it . The thickness looks to be 88.5mm  :)
The gas escape groove ring is 3mm deep.

jones

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Re: Cylinder Head Dimension
« Reply #6 on: October 04, 2018, 11:05:57 AM »
Thanks for your input folks.

Measured my head today - 88.5mm as mentioned above.

If anyone is interested, what I am planning to do skim the head to raise the CR - more or less following the Blitz Racing advice. 

In order to be sure I am on the right track, I measured my combustion chamber volume using a perspex cover and an accurate burette.  This consistently gives a volume of 43 cc.  Doing the maths, this points to a CR of 7.5:1.  Scope for improvement there, depends on how brave I'm feeling when I am presenting the job to the local head shop. 

Tonight's job is to calculate the valve lift so that I can be sure that the head work does not cause piston vs valve events.

I have a Dellorto FZD carb and a decent exhaust.  I am not touching the camshaft or bottom end at this stage.



Polski Fiat 126, (2) Alfa Romeos (2)

Rusty's Uncle

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Re: Cylinder Head Dimension
« Reply #7 on: October 04, 2018, 01:43:03 PM »
Thanks for your input folks.

Measured my head today - 88.5mm as mentioned above.

If anyone is interested, what I am planning to do skim the head to raise the CR - more or less following the Blitz Racing advice

I have a Dellorto FZD carb and a decent exhaust.  I am not touching the camshaft or bottom end at this stage.

If you go for a middle of the road skim then you can also play with different thickness head gaskets for some fine tuning. I have got solid copper ones at 0.5mm up to 1.8mm fibre ones.

jones

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Re: Cylinder Head Dimension
« Reply #8 on: October 07, 2018, 11:58:23 AM »
Thanks - the headgasket advice is appreciated.

This project is for me a learning excerise - I have done a bit of engine work on my other cars (Alfa, Lotus Europa) but this is a first attempt at modifications, the others have been more-or-less standard builds.  The 126 is a cheap and easy platform for learning, and should be fun once its finished.
Polski Fiat 126, (2) Alfa Romeos (2)