Fiat cylinder head bolts - Ribe socket tool

[stefan89]

hi

can any one answer me a quick question, just in the process of taking my cyclinder head off, what size of Ribe tool is it for a 16v 2.0 Fiat engine. M13?

[Guy Croft]

M12

GC

[stefan89]

thank you GC

[Balidey]

Is the Fiat 2 litre 8 valve also an M12 ribe?

The online auction page we are not allowed to name on here seems to suggest its M13, but we all know how reliable that information can be.

Thanks,
Steve

[stefan89]

The 16v is definately the M12 because I took it off last night! Those sites don't seem to be all that reliable - I nearly got an M13.


edited by GC

[Guy Croft]

At a guess I'd say Fiat introduced Ribe on 8V and 16V engines post 8V Integrale on, around 1986. No idea why. Stop 'DIY' maybe?? They coincided with the introduction of the marvellous Goetze Astadur thermosetting polymer head gaskets that did not require retightening.

The Ribe type bolts (also known as torque-twist or stretch/yield bolts) can be used in place of the old hex head type (which where either waisted a la Strada 130TC, 105TC, Delta and Volumex) or plain shank (131/Beta type) and can actually be torqued-up in a conventional manner rather than torque + angle which is how the manual states. The torque-twist sequence puts a high load on the block threads and it's imperative to have a good lubrication regime. How you tighten them depends entirely on the gasket type. You cannot retorque a bolt that has been done-up via a torque-twist regime.
I have not been able to buy the early plain shank bolts for some years, but can still get Ribe (8 and 16V).

The attached GC 'How to' explains (I hope) everything you need to know about tightening and lubrication etc. on Fiat TC units.

GC

[stefan89]

Can you use the same cylinder head bolts that you have taken out, some one told me that they are more prone to snap?

[Guy Croft]

Yes,

Ribe - for instance - can (according to OE manual) be reused (I think) 4 times, but irrespective of that I would not persaonlly re-use an OE bolt more than twice. GC 12.9 grade can be re-used easily 4-6 times and I have done so.

a lot depends on the age of the bolts, I would never - for example - reuse original bolts from an old 131 2 liter (hex, plain shank) on a build and I would not re-use Ribe unless they had personally be fitted BY ME and never touched since.

GC

[Rik]

Guy,

Last night I set about stripping my 1991 16v Thema Turbo engine down in preparation for my Beta Block conversion. I was expecting to find 'Ribe' head bolts but was instead confronted with the following bolts as pictured...

Lancia Thema Turbo 16v Head Bolt

Thema_Turbo_Head_Bolt.JPG (381.09 KiB) Viewed 13353 times

Unfortunately I don't have a tool that fits them, my Ford Pinto head bolt socket is the same head pattern but too big... could you tell me what the correct tool is called/what size it is? and where I may get one from?

Many Thanks, Rik

[Guy Croft]

I don't know is the short answer, sorry. If you go to Halfords they will be able to match it form their Facom range I guess,

GC

[Julian]

Just a small word of warning - if they sell the same tool at different prices you should seriously consider the more expensive one(s). Some of the head bolt tools (including the official Fiat tools) don't last very long. We had a problem a couple of years back where we were going through (on average) one of the head bolt tools per engine stripdown. The problem was specific to the 16v FIRE engine and we haven't done one in quite a while now.

[Rik]

So are these the bolts you would expect to find on this engine? 2.0Ltr 16v Turbo... they have Fiat stamped into the head of the bolts, but it just seems strange. I have three Fiat/Lancia twin cams in my garage, all from a similar era and each needing a different tool for the head bolts....

Rik

[Evodelta]

Rik,

The type of tool needed for the bolt in your pic is 'Spline'.

Martin.

[Rik]

Thanks Martin,

would you know what size spline it is? I have 2 spline drives already (the two needed for Ford Pinto engines) unfortunately their sizes are not marked but one of them I measured at 8mm which is too small and the other I measured at 10mm and its too big! but try finding someone who sells a 9mm spline socket....

I was measuring across the diameter from the tips of the splines, not sure if thats the correct way to measure them though... so hopefully I'm wrong and its 10mm but before I go buying a set (no set includes a 9mm) I could do with clarification as they are not cheap...

I'd still like to know however, if these are the correct bolts for my engine?

thank you, Rik

[Guy Croft]

Whethr they are an OE fitment or not I don't know, I haven't seen spline-type used on F/L engines but then I haven't seen every engine.

All head bolts are 10.9 grade or higher and if they fit the washers without the underhead rad fouling and have the righ thread engagement in the block (min 2 x thread diameter, 20mm) and don't 'bottom-out' in the blcok there is no reason whey they cannot be used.

That said I am not a great fan of re-using OE type (of any origin) production bolts - even if some manuals say you can. That is because of the metal loss that occurs on the threads on assy and strip and you just don't know how many times they have been used before..

GC