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Have to agree with stevesxm. Having newly adopted "re-torque head" as part of my maintenance routine, I recently had nuts that were corroded on. I could've re-torqued to 100 ft/lbs without any outcome because the corrosion was the resistance, not the actual nut/washer contact with the head. This would be true with any corroded or otherwise binding fastener. You have to level set with a free moving fastener (by loosening it) to assure that your torque measurement is actually the pressure applied from the fastener to the item being torqued.
well thats the standard , isn't it ? whatever engineer specified what ever the preload was going to be didn't just say " 65 lb-ft or .025 stretch " ... he said "65 lb-ft or .o25 stretch using 30 wt motor oil assuming class 2 threads " or something like that. he specified quite clearly how that preload was achieved. so... if you are re torquing that piece of hardware, in order for you to get to what the true spec is ( assuming that is meaningful to you ) then you have to start from " scratch" and the conditions that were called for regardless of what they were. if it was dry then you have to do it dry and if it was oiled then you have to do it oiled and so on. if you don't do this then the preload you are creating is some OTHER number than what was specified regardless of what the torque wrench says. on critical hardware like rod bolts and head bolts and the like doing it any other way is asking for a failure. on oil pan bolts or valve cover bolts , maybe you use a speed handle and say " the hell with it " ... it all comes down to whether you care about doing something correctly or not. its what separates real mechanics from people who ' just work on cars "
 

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well thats the standard , isn't it ? whatever engineer specified what ever the preload was going to be didn't just say " 65 lb-ft or .025 stretch " ... he said "65 lb-ft or .o25 stretch using 30 wt motor oil assuming class 2 threads " or something like that. he specified quite clearly how that preload was achieved. so... if you are re torquing that piece of hardware, in order for you to get to what the true spec is ( assuming that is meaningful to you ) then you have to start from " scratch" and the conditions that were called for regardless of what they were. if it was dry then you have to do it dry and if it was oiled then you have to do it oiled and so on. if you don't do this then the preload you are creating is some OTHER number than what was specified regardless of what the torque wrench says. on critical hardware like rod bolts and head bolts and the like doing it any other way is asking for a failure. on oil pan bolts or valve cover bolts , maybe you use a speed handle and say " the hell with it " ... it all comes down to whether you care about doing something correctly or not. its what separates real mechanics from people who ' just work on cars "
Or you could just follow the Alfa Service Bulletin, which specifically states to "loosen nuts one at a time, oil threads and retorque" to the appropriate values. It sounds like RJ retorques to a higher value than in this service bulletin, but Alfa doesn't seem to assume dry threads during retorque.

 

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Or you could just follow the Alfa Service Bulletin, which specifically states to "loosen nuts one at a time, oil threads and retorque" to the appropriate values. It sounds like RJ retorques to a higher value than in this service bulletin, but Alfa doesn't seem to assume dry threads during retorque.


you always use the method they say because they know what their calculations were based on. i would have no hesitation going to a greater total number because increasing clamp load as long as you stay within the elastic limit of the material is perfectly acceptable technique. the stress/strain curve for any material gives a lot of lattitude for stretch as a function of load. as long as you stay above the minimum amount of stretch that you need for something to be " tight " and below the amount of stretch that causes yield, you can do anything you want.
 

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Yes,JR.....
and you know why they came out with the TSB?
And how many other car makers call out for repeated retourque of their head bolts?
Refer to my earlier post for a hint....
 

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Yes,JR.....
and you know why they came out with the TSB?
And how many other car makers call out for repeated retourque of their head bolts?
Refer to my earlier post for a hint....
It is standard practice for every aluminium headed engine to have a cold retorque after the first heat cycle, or at least I am not aware of any engine that does not have a retorque procedure (even cast iron headed engines).

But yes normally the retorque is only done once.

With my Alfa, I will be retorquing once a year until I know it has settled.
Pete
ps: I am also aware of a customer that did not come back for the retorque on the Alfa Berlina that blew another head gasket ... next time the garage did not let the owner have the car back until the retorque was done, no further issues.
 

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Lubricated with engine oil.

As an engine builder, I've always used Alfa torque specs, without issue, for some 40 years.
 

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on any fastener in any application, automotive or otherwise correct and standard practice is to release the preload and then re-preload. this is to insure that the threaded section is free to rotate without rust or corrosion or any other friction generating circumstance that will cause the torque being applied to be inaccurate. now... if your guy thinks anyone is talking about loosening ALL the head nuts and then retorquing , you have mis informed him and that would be the wrong thing to do. if he is simply cranking on fastners that are already tight and have been that way for any length of time then he is wrong and it doesn't matter how many years he's been doing it... its still wrong. this isn't magic and its not voodoo and it has nothing to do with alfa or ferrari or yugo or mercedes benz. it is standard engineering practice as to how threaded fasteners in ANY application are treated. the ONLY variable is how the factory calls out its torque spec whether done dry or with oil or with moly or any other specific lube whether in lb -st or angular deflection or total stretch... the raw methodology, however, is always the same and anythind done any other way is wrong to some degree. everybody wants to think that everything has to be special or magic or so secret that only the few can know the tricks... and thats nonsense. these are not formula 1 cars and they are not special or different in any meaningful way as to the techniques necessary to work on them properly.
i see your point. makes sense
 

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Hi all,

I have a quick question about the procedure here. I perform cold retorques as outlined here, and follow the alfa workshop manual maintenance procedure except I torque to about 90Nm. I have never however performed a hot retorque after this as the workshop manual doesn't, at least obviously, require it. Is it important to perform the hot retorque and if to what torque value? (2L engine). I ask as I have developed an oil leak below the exhaust manifold at cylinder 4 and hope a torque can fix it.

Thanks,

Stephen
 

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Hi all,

I have a quick question about the procedure here. I perform cold retorques as outlined here, and follow the alfa workshop manual maintenance procedure except I torque to about 90Nm. I have never however performed a hot retorque after this as the workshop manual doesn't, at least obviously, require it. Is it important to perform the hot retorque and if to what torque value? (2L engine). I ask as I have developed an oil leak below the exhaust manifold at cylinder 4 and hope a torque can fix it.

Thanks,

Stephen

again...standard practice is to retorque any system after it has heat cycled and been stressed a couple or few times. gaskets are not rigid. they compress and cold flow and release preload a bit from brand new so on cast iron heads you re-t hot and on al heads you do it cold. what I would do on every motor was torque during build , start and heat cycle and retorque ( either hot or cold depending on the system ) and then drive it for a day or two and do it again... when the client came back at 500 miles for a break in oil change and inspection I might do it then again as well just as a belts and suspenders thing. in your case you can try to fix the oil leak w/ a retorque but think about it... if the head isn't tight enough to controll oil pressure at 60 psi, what do you think is happening between the cylinders or into the water galleys ?

can't hurt to try but if it works then go buy lottery tickets immediately.
 

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Was educating myself a bit with this thread after wondering if I should re-torque my head. just bought car. 130k miles. all original motor. Just have an accurate wrench, loosen, oil, and re-torque to spec according to pattern shown? Sounds pretty simple. Is this something that may open up a can of worms? lol...
 

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I was looking for the torque values needed for my 89 Quad when I found this thread. Wow - There is a great deal to be said about "we have found from experience". I spent a large portion of my life as an engineer on 1200PSI (975 degree super heat) steam ships. I will keep this really simple - when you heat metal up it does strange things. When you put metal under stress and heat it up - it gets stranger. I had a situation where a shipyard supervisor swore his way was correct and it cost the government almost 6 Million dollars in new repairs. I documented his work - much to my great relief. They have never followed that supervisors instructions since. My bottom line is this - no matter what we all do and accept - we will find the correct way. Some of us are going to have tragic mistakes and by being afraid to talk about it we allow others to make the same mistake. I have learned so much form this BB!


My engine was not re-torqued after a visit to the mechanic four months ago. Could that be why I see a leak at the after end of the engine at the seal? I am willing to bet....
 

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Was educating myself a bit with this thread after wondering if I should re-torque my head. just bought car. 130k miles. all original motor. Just have an accurate wrench, loosen, oil, and re-torque to spec according to pattern shown? Sounds pretty simple. Is this something that may open up a can of worms? lol...
I wouldn't.

Nothing to gain but a lot to lose.
Pete
 

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This is an urban myth.....
Rebuilt my '64 Spider in 1980 and never retourqued the head. Works fine.
I wonder if we are suffering from a miss-communication here?

The workshop manual clearly states that after the first heat cycle they should be left to cool and then the head bolts re-torqued. I bet 101/105guy did this, but I think that what he is referring to is this unnecessary retorquing of heads of perfectly well running engines as some sort of servicing requirement, and yes I have to agree this is bogus.

Once the head gasket has properly seated, retorquing it again and again, and then again is not going to do anything positive but could do something negative and start a leak.

For a short period of time I worked at a little garage that worked on Alfas and the boss had a 105 that he raced. I believe it ran a high compression and he said when he first built that engine he performed many cold retorques after heat cycles but after about 10 (?) cycles he could "feel" that the was nothing further to gain and (I believe) 5 or so seasons/years later the head had never been off and yep no further head retorques.

For example: When I do an oil and filter change on my 156v6, I do not even think of retorquing the head bolts/nuts. Why would I?, the engine has now done 155,000 km's and does not use a drop of water and the only oil it leaks is tiny (from the rear main seal area, and I mean tiny ... would be one little drop a month).

I do know from experience, and I have already mentioned this in this thread, of a Berlina that had a head gasket replaced but the customer did not return for the retorque as requested and the head gasket had to be done again. This time the garage would not give the car back to the owner and instead heat cycled it and then the next day retorqued the head. Never had another issue ...
Pete
ps: Read up about Spitfire maintenance during WWII ... I believe that is where the commonly used statement that "if it aren't broke don't fix it" came from as they discovered more planes failed due to maintenance mistakes than leaving them alone ...
 

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"Remove radiator cap, then squeeze the top radiator hose down with your hand, then reattach the radiator cap while still squeezing the hose. This will provide some vacuum, which can help prevent water exiting the stud passage when you loosen the head nuts."

This is complete nonsense ………… you cannot create sufficient vacuum to overcome the presence of antifreeze by squeezing the radiator hose. I and others tried this decades ago. It does not work! DRAIN the radiator below the level of the head!!!!!! One drop of antifreeze between the aluminum and the gasket and it is going to fail.
 

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Back in the 80s, Fred DiMatteo told me about this pretty slick trick. Many years later, I came across the Alfa TSB linked below.
Knowing a bit about Fred, I'd wager I know who Alfa got the idea from.
 

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