cylinder head re-tension

[Morgo]

"click"? indicating wrench please.. for doing actually accurate job.Be it good old Snap-On or more modern digital one.Yeah,millions of engines are built just by hand feel (what you have after done enough work with torq wrench) and run flawlessy.

[user-23911]

Those clicker things have their place but not for this job.

You need to crack them loose first.

[user-23911]

Paint mark on the front of the bolt first.
Crack it loose.
If it's a bit tight still, it has to come out and be lubed.
Retorque to spec and take a note of where the paint mark ends up.
OR retorque using a torquewrench with pointer and scale.......taking note of how much torque it takes to get the paint mark back where it started.
Then repeat with the next bolt.


Then once you've done that a few times........come back and tell us all that they never come loose.
Some people never notice anything, like they walk around with their eyes closed.

[induction apprentice]

Wow! lots of good and bad points of view here. So I might as well add some more. I'll leave it up to the readers to decide which way my comments fall..Lol...

Some engines do need regular re-torquing and some don't. It is not a cut and dry issue. I doubt most V.W. make enough power to need a re-torque ever. Probably a few wood screws would do the trick. On the other hand. A pro modified with a hell fire tune-up would probably benefit from a re-torque every pass. One of the biggest factors is tune up. Detonation will stretch / lift threads, cause the block to pile or raise up around the bolt hole. Also exceed yield strength of fasteners and stretch them. Overheating can effect torque. Arp fasteners threaded into cast iron or aluminum and torqued to ARP's spec can be insufficient and always a problem if the right friction modifier (arp lube) has not been used on the threads and under the head / washer of the bolt or stud. Not always ideal if your threading for example arp bolts into a gen one chevy with wet bolt holes and have to use a sealer in place of the arp lube and on and on....

Torquing a fastener to spec is a poor indication of whether a fastener is tight enough or not. Torque is twist which in the case of a fastener is a result or function of friction not a measurement of wether a fastener is tight enough or in stretch. The purpose of newer torque to yield / torque angle gauges is to remove the error from friction and insure the fastener is installed with sufficient stretch. In my opinion. for most applications they are used in. ARP fastener are to strong. they are no good if they pull the threads out before they reach a point of adequate stretch.

Some head gaskets collapse over time or with abuse. some head bolt landings to settle. some some some yutta yutta. But every case stands on it's own.

Ok. force field is up. I'm ready for return fire.

[Kevin Johnson]

Sovereign_class_deflector_shields.jpg

Way cooler.

[ZEOHSIX]

Motor in the car.....I use a Snap On flex head torque wrench, I have a "clicker" and an electronic Tech Wrench that will vibrate when torque point is achieved....if my Tech Wrench batteries are good....that's what I grab out of my tool box. Realistically if you used quality head gaskets....you probably don't need to worry about retorquing your studs. The backing off and retorquing crowd....maybe on a MLS type gasket but a composite type that has been in use....I wouldn't back off any fastener....and because they are studs and ARP ones....unless you see rust on the nuts I say there is no chance your getting any false readings on just a tightening sequence without going through a backing off of the nuts sequence.

[ZEOHSIX]

Here is the same wrench Snap On sells for less $$$

https://www.amazon.com/Precision-Instru ... PDQJT41KK1

[pamotorman]

on race engine tear downs you should check the torque required to remove the fastener to see if they did loosen

[dwilliams]

I experimented with this a few years ago. A freshly-assembled motor on the stand, properly lubricated and torqued head bolts. Mark bolt heads with felt tip pen. Coming back the next day, some of them took another quarter-turn to come back up to the original torque.

That's just cold gaskets taking a set; no run cycles yet.

It didn't happen with all gaskets, but it was common enough, particularly with engines where only the old-school cardboard-and-fire-ring gaskets were available.

[Brian P]

It wouldn't surprise me one bit that the old school type gaskets could need re-torquing. But this is not dependent on what the cylinder head is made of - it's dependent on how the head gasket is constructed.

Everything that I've dealt with uses a coated steel gasket, whether MLS or single layer. I've never seen one move.

[steve cowan]

hi guys,
some great feedback here thanks for that
i have always used a arp stud kit on all my builds,yes even mild builds
as previously stated it is a worry with early engine blocks with worn threads in the block
a thread chaser is a better option than a tap that tends to cut the thread
yes i like to cycle the head stud nut due to friction
you can feel it when you torque the nut with it galling on the washer
i back the nut off with a breaker bar and re-tension with my warren-brown clicker torque wrench
sometimes you might have to cycle the nut a couple times and reapply moly grease due to friction
i am confident in this day and age that all the gaskets we use are of good quality meaning felpro,MLS etc
and we dont really need to retorque performance cylinder head if the block and cylinder head preparation is up to scratch
but if there is a head gskt issue down the road i think you can tick the box saying we did the initial head gskt deal at the best of our ability
any way keep it coming always interested on others opinions

[MadBill]

If you usually work with the same combination, it's cheap insurance to go through the re-torque routine a few times until you can determine if it's needed and then act accordingly.

Also, my take on thread lube is a slightly different than an earlier post above. For head bolts or studs into water, a sealer is of course necessary. If blind holes with bolts, use whatever lube is specced for the torque. But if you're using studs in blind holes, there is negative value in using moly, etc. on the block threads as, especially if for some reason plain oil was being used on the nuts, it could result in the studs being over-torqued into the bottom of the threads. In some cases you might even want to use something like blue Loctite* to ensure that doesn't happen. *(In which case be sure to torque the nuts before it sets up.)

[induction apprentice]

right. That's why I specified bolts into water holes not studs when referring to sealer vrs friction lube.

[cjperformance]

Also what sealer are you using on the threads into the block? Some sealers are not tolerant of being backed off and reset, then you end up with coolant weeping up the bolt/stud.
In any case if you are retorquing and your stud/bolt go's into coolant then absolutely drain the coolant IMO

[user-23911]

on race engine tear downs you should check the torque required to remove the fastener to see if they did loosen

I do it on every tear down.

That's when they come in broken for a rebuild...anything and everything.
That's how you learn.
Stock bolts.
Aluminium heads have far more problems than cast iron heads.

Think back to old engines like the Hillman imp.( My mate's mum had one back in the 70s, fill it up with water before we go out....it would overheat anyway.......it kept on going until it got wrapped around a power pole)
Pretty much every one of those died due to overheating.
Then there was the Hillman Hunter....the originals had cast iron heads and gave very little trouble.
Then they "upgraded" to aluminium heads and ........????
The best fix was to find a cast iron head.

Now nearly every Jap engine has an Aluminium head.

Subarus are the worst. If they don't die due to detonation and spun bearings, they'll cook themselves to death.