Parts that make you swear

[Yoshimisumi]

Brake shoe springs...


Sent from my iPhone using Tapatalk

[Xylaquin]

The door window trims with the window felt on them ended up in the bin after numerous attempts to fit, these were basically too big between the corner radius's and i found them impossible to rework

I'm with Mark.. The stupid aluminium door glass frame thingy..

That thing is such a pain!

Is it possible? I need to fit new outer frames, as I've had no outer weather strips for ages!

[dadandlad]

Is it possible? I need to fit new outer frames, as I've had no outer weather strips for ages!

The ones I purchased from Axel Gerrstl drove me mad trying to get them to fit, basically they are made wrong and because it is a U section without the correct formers you cannot re bend without them creasing.

I suppose you could try and remove the weatherstrip and attach to your old ones or cut a section out and butt the cut ends together

I ended up refitting my old ones which took me about 20 minutes after 3-4 hours messing with the new ones and throwing them in the bin

Good luck

[Xylaquin]

Yeah...
[youtube]WkgjipGRqhQ[/youtube]

[cider]

Nasty, Did you get a refund

[Xylaquin]

Doubt I have much chance with an ebayer over in Italy after taking a hammer to the thing too. I'll probably just try remove the weather strips and staple them onto my existing ones.

Although one of my existing ones is snapped into 4 pieces 

[1973/126]

 What`s starting to get to me is the quality of the parts more than anything.
 Few photos attached of the incident that happened to us yesterday.
 The drive shaft coupling has done less than 1000 mls. It`s completely had it. The now rusty looking hand brake cable was fitted at the same time as the coupling.
 

 and the quality repair that got us home
 
 

[Rusty's Uncle]

That is pretty awfull but that was a good bit of thinking with those 3 jubilee clips 
Did it get you home?

[dadandlad]

As stated by 1973/126 it is the quality of the parts that really annoys me

Stripped the head off the Bis today and can safely say the gasket kit purchased from Axel Gerstl is the cause of my problem
The head securing nuts had hardly any tension on them caused by what appears to be a gasket gone soggy for want of a better explanation
The head when built was torqued up correctly to the block,my torque wrench is accurate as it was calibrated shortly before doing the job
The engine has run a maximum of one hour and not travelled more than a mile never mind 500

I had noticed with the carb that it appeared to be loose when I came to remove previously tight nuts

The gaskets in the kit are made from a strange black material

Pretty bloody annoyed to say the least

[Gadge]

The exact same thing happened to my old "green" engine, less than 1500 miles done and it blew even with waterless coolant and my best efforts to chase out air locks. I never took the head off to investigate but I suspected that the head nuts had come loose but a soggy gasket would've had the same effect

[dadandlad]

I suspected that the head nuts had come loose but a soggy gasket would've had the same effect

I am certain the nuts do not come loose on there own and have put it down to the gasket material itself.

It seems to keep on compressing once torqued down and the component ends up being loose

[drcdb15]

It's a while since I torqued down a head  but iirc don't you tighten when cold, and then again immediately the engine has warmed up, because the head bolts will naturally expand a fair bit with the temperature. I don't have precise figures to hand, but iirc steel has a cte of about 13 x10e-6 per degree. If a cold head is at 20 degC, and a hot one at 800 degC on the inside, let's say the temperature increase is about 600 C degrees.

How long is the head bolt? I don't know. Let's say it's about 150mm long. That would give an increase in length of 150 x 13 x 10e-6 x 600 mm = 1.17mm.

Again, I'm mentally on the back of a fag packet here, but if the thread pitch of the head bolt is about 1.25mm (which figure I seem to recall Ladislav gave me once for a wheel bolt!) that means the head nuts/bolts would need be tightened roughly a whole turn to get the same torque when the head is hot compared to when it's cold.

If you are only torquing the head when cold, and then assuming the next time you need do it is after 500 miles, then that might explain why the gasket is not sealing.

The "after 500 miles" requirement is to allow for stretching of the head bolts. If you imagine the bolt is tightened when hot, when it cools down again it wants to go back to being 150mm long. But the 'hot' torquing is forcing it to be under the same tension as if it was only 149mm long. Where does that extra mm go? It goes into the tension being applied to the bolt by the relatively incompressible cylinder head.

Like every other material, steel has a degree of stretchability, and after 500 miles the repeated cycling of hot and cold, tension applied (cold) and then relieved (hot) will likely have caused a permanent stretch in the head bolt, hence the need to re-check it is still holding the head on tightly enough to keep the gasket sealing.

All of this is especially important when the head bolts are new. As they age, not only does re-torquing stretch them, but the heat cycling also hardens the metal, making it more brittle and less prone to further stretching.

Now you folks are, I know, very experienced with these engines, so if I am telling you how to suck eggs I apologise - just hoping to help get to the bottom of the problem.

[Xylaquin]

I'm replacing my headgasket with what appears to be a genuine OEM BIS headgasket.

Are you saying the process is fit the gasket, torque it all back together cold then

A) Run the car till warm, then retorque
or
B) Run the car till 500 miles, then retorque
or
C) Both!

[drcdb15]

Well, in my younger days I would have said "C". However, technology moves on, and torquing sequences today are set by engine makers, head bolt/stud makers, and even by the gasket makers - take your pick, they all have specifc recommendations.

My calculations were off the top of my head. On further reflection, the thermal expansion of the bolts is exacerbated, as I said, by them stretching, but is counteracted by the expansion of the cylinder head, which being aluminium probably expands more than the steel bolts - however, this is complex, since a long thin bolt will in practice expand almost entirely longitudinally, whereas a large block like a cylinder head will expand almost isotropically. The figure I used for the steel expansion is the *linear* cte.

Anyway, the net outcome is that some combinations of head/bolt/gasket are designed to be torqued cold, then hot, whilst others should only be done cold.

Then there are TTY bolts, which are meant to be torqued 'half way', as it were, then left to settle for a few hours (to settle after stretching), then torqued again, and maybe even a third time.

You might find this item instructive (or desperately confusing!):

http://www.enginebuildermag.com/2005/07/perfect-engine-sealing-starts-with-proper-head-bolt-use/

If you google 'torque head bolts hot or cold' you will get loads of debate on the subject, but for relevance to classic cars this thread seems typical:
http://www.oldclassiccar.co.uk/forum/phpbb/phpBB2/viewtopic.php?t=10967&sid=15b87ad5becef4c2babc9bdd7717c5dc

Consensus seems to be torquing hot was necessary for iron head engines (shows my age!!), but not advised for alloy heads. What *IS* common to all is that the torque should be checked several times when the head is replaced, to compesnate for stretching of the bolts and compression of the gasket. It seems if you just torque the bolts once during assembly and think "that's it", you will likely have the problems our friends have encountered.

It might be sensible to check the official Fiat factory workshop manual for your model to see what procedure Fiat themselves recommend.

[drcdb15]

Well, I've just checked the Fiat manual on this site for the air-cooled, and all it gives is the sequence and the torque setting. So not a lot of help. It is implied that it is set cold, simply because other operations follow in sequence, and there is no explicit mention of warming the engine before torquing.