Club126UK

Fiat 126 Chat => Tuning & Customising 126 Models => Topic started by: jones on September 27, 2018, 11:44:22 AM

Title: Cylinder Head Dimension
Post by: jones 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.
Title: Re: Cylinder Head Dimension
Post by: dikkehemaworst01 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....
(https://uploads.tapatalk-cdn.com/20180929/023b981d216b9d609eb95e34eb9a86ee.jpg)

Verstuurd vanaf mijn SM-G920F met Tapatalk

Title: Re: Cylinder Head Dimension
Post by: dikkehemaworst01 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.

Verstuurd vanaf mijn SM-G920F met Tapatalk

Title: Re: Cylinder Head Dimension
Post by: dajwid 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....
(https://uploads.tapatalk-cdn.com/20180929/023b981d216b9d609eb95e34eb9a86ee.jpg)

Verstuurd vanaf mijn SM-G920F met Tapatalk
Title: Re: Cylinder Head Dimension
Post by: dikkehemaworst01 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....
(https://uploads.tapatalk-cdn.com/20180929/023b981d216b9d609eb95e34eb9a86ee.jpg)

Verstuurd vanaf mijn SM-G920F met Tapatalk

Verstuurd vanaf mijn SM-G920F met Tapatalk

Title: Re: Cylinder Head Dimension
Post by: Rusty's Uncle 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.
Title: Re: Cylinder Head Dimension
Post by: jones 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.



Title: Re: Cylinder Head Dimension
Post by: Rusty's Uncle 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.
Title: Re: Cylinder Head Dimension
Post by: jones 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.