Tighting cylinder head

[Seamus]

Just a quicky to see how folk do this

Read lots of bits, some just torque in increments and others torque to the value, release and retorque.

What is the consensus here?

Thanks

Seamus

[Bitsa (Ralph Wright - RIP)]

Hi Seamus.
I have always followed the book start off with a T bar by hand, then by torque wrench, leave it for 5 Min's then with the torque wrench re check them.Never had any problems like oil leaks done it like this since the 70s.
Hope this helps you with your survey.
All the best
Bitsa

[ST1100]

Any recommendations about the 'old ways' of checking the torque after 1000km/600miles?

[Bitsa (Ralph Wright - RIP)]

Hi ST1100.

I do not remember ever re torquing head bolts after a settling down time,as with the 750 its engine out again job.One would assume if all OK after 1000k why bother with removal etc.I do recall with the old cars it was done as technology was not so good then.Interesting to hear what others think.
Regards
Bitsa

[Bryanj]

I don't remember any of the Japanese having a re-torque procedure in the manuals

[Seamus]

I seem to recall reading somewhere (US site?) that heads were torqued up, left for a while and loosened, then retorqued. Seems an odd practice!!

Just wondered if i anyone else did this. perhaps repeat this thread on the other site.

Cheers for the input

[Spitfire]

Seems a bit strange to me, I always hand tighten the bolts then torque them down as per the diagram and that's it.

Cheers

Den

[the-chauffeur]

I've had varying degrees of success with tightening head bolts for a number of reasons.  The 750 isn't too bad, but the smaller capacity bikes (350's in particular) don't seem to hold their torque all that well after rebuild and shakedown runs - and I've found they need re-torquing.

Before you do yours up, check out the post I put in the Tricks and Tips section dealing with head gaskets and the dowels that fit between the cylinders and the head.  If you did a dry run without the head gasket in place and found the faces sit flat together, you should be fine.  I'd followed the fiche and it turned out to be a bad move.  It might just save you a lot of work in future - especially if you haven't got any way of getting the head off once the engine's back in the frame.

As for the torquing process, there's advice all over the place . . . and you'll probably get as many answers as the numbers of people you ask.  Hondaman recommends torquing to something like 75%, then 90% then 100% over a period of hours - I guess that's the let the gaskets crush and settle - and you may find that the cylinder studs have stretched a bit, which can make life slightly more complicated.  But I've also heard of torquing up, leaving the engine to sit then undoing and re-torquing one nut at a time.  Having done that with my 350's, I invariably find they torque better after an undo/redo (although they've got heavy duty studs so they can take the additional pressure).

The only other thing to mention is that if you use any kind of locking compound, don't overdo it with the tightening - before it sets the compound acts as a lubricant and so will give different/false torque readings.

[Seamus]

Thanks for the thoughts,

I had read the Chaufferr's post with interest. I will measure the space, but the head had not leaked before, so I suspect that it is OK. I have a new Honda head gasket on order and at that price, I want to get it right. Ape studs fitted as well so I can apply a bit more torque to the head.
I suspect I will torque up in increments, leave for a couple of hours and retighten to see if anything happens. The frame is standard, so an engine removal for a leak.
Once the bits turn up I can start.

[the-chauffeur]

Seamus

If you've got the engine out of the frame and not assembled the top end yet, my advice - other than saving yourself all sorts of heartache later by fitting a frame kit (unless you're dealing with a sandcast) - is to do everything you can to prevent leaks in the top end.  It took me about three engine-out attempts to get this bit right, but that stopped being a problem after I'd fitted the frame kit.  For me, the process involved all the usual steps - sealing the rubber pucks under the cam towers, and torquing everything up/down right.  I made sure I used Honda seals/o-rings, especially the tiny ones under the cam tower ends, 'cos I've had trouble with aftermarket ones in the past.

But it also involved replacing the four bolts that hold the cam towers in place (#3 in this diagram) with a spare set of studs (#21 in this diagram) - and coating the bottom ends in threadlock to stop leaks out of the front of the cylinder head.  It's not mandatory, but apart from preventing little weep type leaks (the far left and right bolt holes open just above the spark plugs) it saves the repeated insertion and removal of the bolts, which can eat away the cylinder head aluminium. - all I have to do now is drop the cam towers and clamps in place and hold them down with nuts.  Either way, use threadlock or a small amount of silicone on those studs/bolts.

While you've got everything out, dry fit the cam cover to the head with the locator dowels in place (but without the gasket), again to make sure the faces sit flat.  Same goes for the sidecovers - I know this stuff sounds obvious, but for some reason the dowels in mine made the sidecovers and the cam cover sit away from the various case edges.  Again,  I'm not convinced the fiche is right in some places.

Good job with the APE studs - an excellent investment.  Just remember to fit sealing washers under the nuts (that goes for the crankshaft bolts in the underside of the bottom end, too).

[Seamus]

Thanks for the advice. All of it good and will be taken into account when I get my head back, (new guides fitted, reamed to size and seats recut) new rings just gone on, so will be ready to fit pistons and block later.
All seals and gaskets from the cylinder base upwards replaced with genuine Honda stuff.

Fingers crossed now as I would like to have the bike back on the road for Wednesday as there is a local classic car/bike show that I like to go to.

Cheers all