[larryfrank20]

I am finishing my rebuild of a 2L engine from my 1978 spider, and have read and re-read many posts of the torque procedure for the cylinder head.
Re-torque after one heat cycle. Re-torque cold. Never re-torque cold. Re-torque at 50 miles. Re-torque at 100 miles, at 500 miles.......all very confusing.
At least I think the initial torque values should be 63-65 ft-lbs.
What is the standard schedule for torquing a new rebuild of a 2L engine.

Thanks
Larry Frank

 

[Seliquella]

I posted what I gathered from all the info from various sources in another topic, see quote below regarding a TS 2.0 8V. Not sure if this is the general agreed and accepted procedure though, but nobody rejected it so far .

No, I am planning on using the EFIgnition 46 and using 2x Beru coil pack.

EFIgnition 46 Engine Management System

EFIgnition is een vrij programmeerbaar motormanagement systeem waarmee de injectie en ontsteking van vrijwel iedere motor aangestuurd kan worden.

www.efignition.nl

Any ideas about torquing the MaxSpeedingrods, i.e. stretch 0,0055-0,0060" method vs Torque 45lbs-ft for the ARP2000.
I unfortunately do not have the have stretch measuring tool...

What is the general consensus about torquing of:
Head bolts: 60lbs-ft cold&greased, then after first warm-up 65lbs-ft hot and after 1000miles released re-greased and re-torqued to 70lbs-ft one by one (75lbs-ft for race engines).
Main bearing caps: 36lbs-ft, with oil or should one use Loctite 243 (medium strength)?
Flywheel bolts: 83lbs-ft, with oil or should one use Loctite 243 (medium strength)?
Pal nuts for windage tray on main bearing caps: 8-9.4lbs-ft with oil

The very helpful Centerline torque chart is not clear about the different models, maybe because it is more US model (V6) oriented. The 2.0 8v motor of the Alfa 75 was also delivered in the 164 and 155 early models (pre-Fiat 16V engines), and the table mentions "164 all".

 

[andylarry]

Alfa factory "engine overhaul manual for Spider 2.0" publication number pa8777 states:
Cold 63-65 ft. lbs. and then again by 1200 miles cold 63-65.

 

[Seliquella]

Head Torque for Rebuilt 2L Engine Storage

 

[goats]

I use 68-70 ft/lbs. Based partly on RJ advice, and partly on the notion that back in the day with a needle-type torque gauge, +/- 15% was the standard, putting 70 at the top end of the spec. But to each her own.

 

[DPeterson3]

A couple of things to add - from working on things, including Alfas, for over 50 years.

Buy a largish bottle of ARP thread lube. It is really nasty if you get it on you, so keep rags handy. You WILL get it on you. I found a good deal on Amazon.
Use only a bending beam, or gauge type, or gauge+vibration torque wrench. Click type wrenches will introduce significant error in your results, almost always on the low side of your target. You do NOT want to stop holding pressure on the torque wrench when the click first does it's thing. That's why you don't want to use a click type. Particularly with a good lubricant like ARP, the nut/bolt is likely to continue rotating beyond when you first achieve the stated torque value. With old threads and/or poor lubricant, your click type will announce "success" far short of the real value you want to achieve.

It is my opinion this is why people often recommend a higher value than what Alfa published. It is to help you achieve the real target rather than being fooled by your wrench.

This is particularly important on aluminum structures with long studs. Just like an Alfa engine.

 

[goats]

 

[alfaparticle]

I took a couple of Harbor Freight clicker torque wrenches to work and checked them against a calibrated electronic gauge and they were surprisingly accurate above about 20% of maximum. I practiced getting the best accuracy and as Don wrote it was by holding and not pulling anymore when I heard the click. My readings agree with his that the actual torque was always a little below the indication on the torque wrench. I have a paper chart for indicated vs actual torque and it results in me setting the wrench around 2 ft-lb higher than the spec.
For my last engine build Jim Steck advised me to lube the washers and threads with camshaft break in lube and torque to 65 ft-lb cold.

 

[75Tickspark]

Torqued all my 8v TS heads in stages to 90 Nm (66 ft lb) and never touched them again. Never had a problem. No cold/hot torque after xxx km.

Type of torque wrench really does not matter for this. A clean, lubricated thread vs rusty thread has so much more influence that the accuracy difference between torque wrenches pales in comparison.
Don't overthink it, if the parts are in good order and you use quality gaskets any of the above methods works just fine.

 

[andylarry]

Perhaps there are "better" ways to do it. I have been using the same Snap-On click type 1/2" drive torque wrench for 35-40 years. I used to get it "calibrated" every year when I was wrenching full time. Now, not so much. I have replaced dozens and dozens and dozens of Alfa head gaskets, and refurbished the same amount of Alfa engines (as well as many other imports and domestics). I clean and lube the threads, I use the factory recommended torque specs, and retorque in 500-1000 miles. Not one of my rebuilds has ever needed to come apart because of a leaking head gasket, to my knowledge. I am very careful to slowly pull and hold every stroke as evenly as possible for each fastener.

 

[DPeterson3]

Maybe this will be my last try, then I give up.

The “accuracy” of the wrench is almost irrelevant to achieving the desired result. It is the procedure that matters. Your click wrench could be +/- 0%, and you’ll still end up NOT achieving the design tension. Note that word.. “tension”, not “torque”. Words matter.

A click type is simply not suited for high torque, CRITICAL fasteners. Once above about 25 ft-lbs, friction becomes the dominant variable, along with rough threads. To reliably hit your target tension, technique is the biggest variable.

 

[alfaparticle]

A click type is simply not suited for high torque, CRITICAL fasteners

The Nuclear Regulatory Commission does not agree with that. Valves on Uranium Hexafluoride cylinders are torqued to around 250 ft-lb with giant clicker wrenches that are on a high frequency calibration cycle. Doing it any other way is a federal offence and you are likely to have an interview with an FBI agent if you get caught violating the procedure.
I knew a guy who got a suspended jail sentence for willfully violating a procedure about measurement of differential pressure across HEPA filters. You cross the feds at your peril.

 

[DPeterson3]

The Nuclear Regulatory Commission does not agree with that. Valves on Uranium Hexafluoride cylinders are torqued to around 250 ft-lb with giant clicker wrenches that are on a high frequency calibration cycle. Doing it any other way is a federal offence and you are likely to have an interview with an FBI agent if you get caught violating the procedure.
I knew a guy who got a suspended jail sentence for willfully violating a procedure about measurement of differential pressure across HEPA filters. You cross the feds at your peril.

Do you actually believe this extreme case is a valid point in contradiction to what I have attempted to explain in simple terms? If you do, please carry on with whatever you wish, resolutely resisting useful knowledge that might help you someday.

 

[4sfed]

The Nuclear Regulatory Commission does not agree with that. Valves on Uranium Hexafluoride cylinders are torqued to around 250 ft-lb with giant clicker wrenches that are on a high frequency calibration cycle. Doing it any other way is a federal offence and you are likely to have an interview with an FBI agent if you get caught violating the procedure.
I knew a guy who got a suspended jail sentence for willfully violating a procedure about measurement of differential pressure across HEPA filters. You cross the feds at your peril.

Tongue firmly planted in cheek . . . just because the Government says it's the right way, doesn't mean it's the best way. However, Ferrari uses click-type torque wrenches to assemble F1 engines.

I add an additional step to the Alfa procedure using the ARP lubricant on the studs and bottom of the nuts. The washers must not turn. The nuts are all torqued to 30 lb-ft, then double-checked. The center ones will certainly move on the second round because the gasket compresses as additional nuts are tightened. Once all nuts are evenly tightened to 30 lb-ft, a reference mark is made on each nut, all pointing in the same direction . . . usually toward the front of the engine. The torque sequence is completed normally and when finished I expect all reference marks to point in the same direction. (The rear nuts tend to move a little farther because they have less area to clamp.) With too little rotation, damaged / dirty threads or poor lubrication is suspected. Too much rotation could mean a failing stud or could be caused by a washer that has rotated.

With the ARP lubricant, the difference between static and dynamic friction is minimal and the nuts are just retorqued at the appropriate interval . . . they are not removed . . . still paying attention to the angle of rotation.

 

[DPeterson3]

The complete study on the best tensioning technique(s) is a multi-page treatise. I keep trying to simplify it here, but my impression is that people dedicated to their expensive wrenches just can’t let go of the fixation, so come up with obtuse rationalizations for what is “best”.

“best” is the procedure that reliably establishes the designer’s intended tension.

Jim Steck’s technique above at least encompasses the idea that tension is more related to rotation than to simply an indicated torque value.

I find it eyebrow raising when people just say “Alfa was wrong in setting their torque values for cylinder heads”. Maybe people are blaming the wrong thing.

 

[alfettaparts2]

I’ll trust an aircraft mechanic over a motor mechanic any day 😁

 

[yvesmontreal]

Once above about 25 ft-lbs, friction becomes the dominant variable, along with rough threads. To reliably hit your target tension, technique is the biggest variable.

It is a lot easier to achieve reliably a torque spec which is given for a lubricated fastener than for a dry one. How dry is dry? New fasteners are often coated with some rust protection which is a lubricant and is sometimes hard to clean off. We've seen mildly rusted threads where rust dust acted as a dry lubricant. And above all, don't lubricate a thread if you have a dry torque spec. You'll end up with way too much tension - maybe 20 to 30%?

But I see your point about how careful you have to be when using a click wrench. I used to attend club track days, and I noticed one guy who retorqued his wheel nuts between each nut. He would go "click-click-click" on each nut. I wonder how much torque would have been required to move these nuts by the end of the day.

 

[divotandtralee]

It seems "fear of failure" can be all-consuming and over-thinking can lead to night sweats. I always used a clicker (Craftsman) wrench, the Shankle manual, motor oil lube and and a graduated step-up method starting at 30 psi in two to three cadences. Most errors I have witnessed are rooted in the fact that that the ranges are defined by type of engine ..750 engines use as much as 50% less torque than a 2L and on down the line of 101-1300, 1600, 1750..... That's where I think most people get in trouble. The other thing is consistency .. use the same methods on the same engine(s) for subsequent re-torques and stick to it.. Just my 2 cents.

 

[alfaparticle]

Tongue firmly planted in cheek . . . just because the Government says it's the right way, doesn't mean it's the best way

The consequences of a failed valve fitting on a UF6 cylinder are such that there is a federal rule dealing with the fitting of them. Want to make the world news - accidentally release the contents of a UF6 cylinder, preferably in a foreign customer country or while being transported through a town center..

 

[goats]

I agree with both Don and Ed , and RIck, and all here -- many things can be true at the same time. I also think everyone here somewhat agrees with the golf great Lee Trevino when he famously said -- 'It ain't the arrow, its the Indian." (which with his heritage he had every right to say INHO). Use the tool you like that is reasonably suited for the job, lube the threads, pick a reasonable value, and be consistent. Cheers!