Failing helicoils - rocker shaft caps - What now?

[lancialulu]

Throw the bolts away and use studs as per Aurelia's Then you are tourquing down on the stud thread!

Amazingly I had forgotten this was part of my repair solution!!!!!

Note I mention Aurelia as they have the M8 fine thread as per Fulvia (at one end or both- which I cant remember!!!!!!!!!!!!!!!!)

Tim

[Peter de Wit]

And you solve the length problem....

[lancialulu]

exact!

[Bart Verbeek]

In a factory where the magic words: [s]arbeit mach....[/s] I mean "Over-engineering is serious business" (in Latin of course) are written above the front gate, the responsable for those bolts (and the neverlasting helicoils) should be still in prison!

[racing]

Solutions of this are alway driven by the cost´s.

This is the reason why Lancia comes 1969 to Fiat.

Andreas

[Bart Verbeek]

That's why it was the slogan for the engineers. Cars nowadays are designed by the enviromental and the financial department in stead of those technical engineers.

BUT, I got my head back (the 302-head it is ) and 5 helicoils were changed. Total cost: 131€. They even gave me new bolts.

Hopefully everything goes according to plan now, so the engine can be mounted in the berlina this weekend.

thumbs up! (tu)

[VAR1016]

Sorry, no time this evening to read all the replies.

At Evolution Engineering we naturally used to come up against this all the time.

I decided that the problem is caused by some sort of crystalline deterioration of the very hard aluminium alloy that was used by Lancia - the material seems to crumble around the Helicoils.

Normally we would use 8 x 1.25 Timeserts, but sometimes the damage would be too bad. What we did then was to order 10 x 1.25 Timeserts for which there would usually be enough good "head" left (!) and then simply screw an 8 x 1.25 Timesert into the larger one.

The one exception I can recall was on the head in my own engine which had a real problem. For this I drilled and tapped the hole to 14 x 2 and the ever wonderful Phil got on his lathe and made me a an 8mm stud with a 14mm end! I fixed the cap with a Nyloc nut. I doubt if it will ever come out!

On the Fanalone I have mentioned elsewhere I had this problem; I was working on the car at a garage in Switzerland near Nyon. Timeserts wouldn't do - or rather I couldn't get the ones I needed. the owner of the garage had friends at Heini Mader's establishment down the road and came back with a wonderful and costly kit with beautiful stainless steel inserts. Sadly I cannot remember what they were called, but the did the job very nicely.

Paul

[VAR1016]

lancialulu Wrote:
-------------------------------------------------------
> Throw the bolts away and use studs as per
> Aurelia's Then you are tourquing down on the stud
> thread!
>
> Amazingly I had forgotten this was part of my
> repair solution!!!!!
>
> Note I mention Aurelia as they have the M8 fine
> thread as per Fulvia (at one end or both- which I
> cant remember!!!!!!!!!!!!!!!!)
>
> Tim

Fine, but you won't be able to remove the exhaust side parts with the engine in the car!

Paul

[lancialulu]

Paul

I wasnt refering to the exhuast ports, only the cam caps.

Tim

[lancialulu]

Paul

I seem to remeber you put one of your heads on my engine (ex Postlethwaite) and one of the studs did fail which is why i had to have it welded back up as the stud came out with a 14mm end to it!! I'll send you the invoice!!!!

Tim