Head Gasket

[peteracs]

Hi Neil

I bought these from AE Car

https://www.aecar.co.uk/products/cylinder-head-bolt-fiat-lancia-twin-cam

Peter

[Neil-yaj396]

Was a re-torque done after a few hundred miles?  I know it's not in the Haynes or workshop manual afaik, but I recall GC recommending it where a stock gasket (not the later polymer type) is used. I've done a re-torque with plain bolts and it's still going(!), just paint mark the heads, back off 1/4 then re-torque. Must be done when stone cold and follow the original bolt sequence, they will tighten up further.

Guessing the dowel heights were checked so not to bottom out if the head was skimmed?

In SOHC FIAT land, re-torque was always a thing and even when they moved to TTY bolts and astadur polymer gaskets that were supposed to mitigate a re-torque they issued a service letter saying a further 60+30 angle is needed after 600 miles 🤦‍♂️

The head was leaking before the engine was even started. They re-torqued but with no effect.

[Neil-yaj396]

Thanks for the ongoing replies. I bought a set of bolts from Ricambio and a new gasket from Historic Racing Works in Germany.

[rossocorsa]

Was a re-torque done after a few hundred miles?  I know it's not in the Haynes or workshop manual afaik, but I recall GC recommending it where a stock gasket (not the later polymer type) is used. I've done a re-torque with plain bolts and it's still going(!), just paint mark the heads, back off 1/4 then re-torque. Must be done when stone cold and follow the original bolt sequence, they will tighten up further.

Guessing the dowel heights were checked so not to bottom out if the head was skimmed?

In SOHC FIAT land, re-torque was always a thing and even when they moved to TTY bolts and astadur polymer gaskets that were supposed to mitigate a re-torque they issued a service letter saying a further 60+30 angle is needed after 600 miles 🤦‍♂️

On the bulletin that I have it says that with non astadur head gasket but yield type bolts 40nm +90⁰ + 90⁰ then retighten to 70nm after 1000 to 1500 km

[Neil-yaj396]

Hi Neil

I bought these from AE Car

https://www.aecar.co.uk/products/cylinder-head-bolt-fiat-lancia-twin-cam

Peter

Are these 'yeild bolts'? These are the type I bought from BBs and Ricambio. Pretty generic for most Twin Cams I think?

[WestonE]

Hi Neil,

Yes they are.

[Ics19]

Pretty generic for most Twin Cams I think?

I'm sure someone will confirm, but weren't they only standard when the polymer gaskets came into play?

The earlier plain types are like these:
https://www.eurosport-uk.net/shop/index.php?main_page=product_info&cPath=24_46&products_id=766

On the bulletin that I have it says that with non astadur head gasket but yield type bolts 40nm +90⁰ + 90⁰ then retighten to 70nm after 1000 to 1500 km

Thanks, good to know   Were the Lancia bulletins/service letters issued as a collection at any point or do they have to be hunted out singerly?