860GT head nut wrench and torque setting

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rjk40
750 GT
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860GT head nut wrench and torque setting

Post by rjk40 »

1. Are the 4 nuts holding down the head 16mm? Wrenchwise, 5/8" is close, but a bit sloppy.

2. Any tricks on how to lash up a torque wrench on a spanner? There's no way to get a socket in the nut, so if anyone has a "creative" approach to share,
I will be most thankful. (According to my old Haynes manual, the head nut torque range should be 24.6-31.1 ft lbs.).

Regards,
RJK40
900tlc
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Re: 860GT head nut wrench and torque setting

Post by 900tlc »

I got a 16mm spanner ,and cut it short about 25mm long, then drilled and tapped an M8 hole in the shank which was cut.Take an M8 bolt and using some 638 Loctite, fix the bolt in to the previous tapped hole and screw the bolt up to its head. level off the excess thread , pean over for good measure and there you go, one Ducati head nut torque tool.
Remember to reduce the torque value , due to increasing the length with the tool, the main thing is , you have an even torque on the head,good luck.
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abmartin
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Re: 860GT head nut wrench and torque setting

Post by abmartin »

The tool I've used for years is a 16 mm open/closed-ended wrench with a socket welded to the middle appropriate to the size of the torque wrench. I seem to recall that the factory tool uses a similar set-up. Works well although you may have to shave down the sides of the wrench to access the cylinder head nuts properly.

Bruce
1979 900SS
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Craig in France
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Re: 860GT head nut wrench and torque setting

Post by Craig in France »

rjk40 wrote:Are the 4 nuts holding down the head 16mm? <snip> According to my old Haynes manual, the head nut torque range should be 24.6-31.1 ft lbs.
The answer to both these questions is in the FACTORY workshop manual, RJK40 :-D . Keep that Haynes manual for its photos, but don't use it for anything important ...

I quote (page 113):

"5) Tighten the nuts with a 16mm polygon wrench, at a torque of 4Kgm."

Notes:
a) polygon wrench =spanner
b) 4Kgm = 39 Nm = 29lb/ft.

HTH

Craig
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Craig in France
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Re: 860GT head nut wrench and torque setting

Post by Craig in France »

abmartin wrote:The tool I've used for years is a 16 mm open/closed-ended wrench with a socket welded to the middle appropriate to the size of the torque wrench.
And as sold by (amongst others, I'm sure ...) Andy Jones at Mdina.

Image

Go:
http://www.mdinaitalia.co.uk/cgi-bin/co ... &key=TOOL1
machten
MHR / S2
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Re: 860GT head nut wrench and torque setting

Post by machten »

I got one of these that used to be sold by a Queensland gentleman.

Image

He made quite a selection of good Ducati tools for singles and twins. Haven't seem them around for a few years, but his stuff was excellent and I have no idea how he made them at the price.

Image

Kev
rjk40
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Re: 860GT head nut wrench and torque setting

Post by rjk40 »

Thanks kindly to all; I really appreciate the info. Now if I can persuade the nuts to let go after heat gun heating and many apps of easing oil,
I will be in great shape.

I take your point about the Haynes manual. I got bitten once when a torque spec was listed in foot pounds and should have been in inch pounds; it cost me a
destroyed engine pan gasket , no fun to replace in situ.

Regards,
Richard (rjk40)
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Craig in France
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Re: 860GT head nut wrench and torque setting

Post by Craig in France »

machten wrote:I got one of these that used to be sold by a Queensland gentleman.
(Hopefully I'll never need one, but ....) Ooh - that looks nice :mrgreen: .
machten wrote:He made quite a selection of good Ducati tools for singles and twins.
Not this fella by any chance, Kev?
http://www.ebay.com/usr/discusprinlo

(Off-topic here, but ...) The one tool I sometimes think I should get is a crankshaft turning tool - you know, just for easing the engine up to TDC when checking valve clearances. But they seem quite rare - neither Steve ...
EDIT: wrong :doh: - see Steve's message below

... nor Andrew sells one, for example.* And, hey - 'There's more ways of killing a cat ....:)

* EDIT
Found one, at our friend's at Kämna.
Image
http://www.ducati-kaemna.de/kataloge/du ... profi.html

But at 48€ plus postage? Hmmm .... :?. Remind me - when's Christmas this year? :-D
Last edited by Craig in France on Mon Feb 24, 2014 12:33 am, edited 2 times in total.
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Craig in France
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Re: 860GT head nut wrench and torque setting

Post by Craig in France »

rjk40 wrote:Thanks kindly to all; I really appreciate the info.

No worries. Just note, Richard, if you do decide to make you own tool, you need to use a 12 point spanner, not a 6 point one. You'll see that both the one Andrew sells and the one Kev has are 12-pointers. There's not a lot of free space around those nuts :shock: .

Ciao!

Craig
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BevHevSteve
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Re: 860GT head nut wrench and torque setting

Post by BevHevSteve »

Well yes I do have a good crank turning tool available here

https://store.bevelheaven.com/workshop- ... v-engines/

I also usually stock the head nut spanner shown above with 16mm 12 point that has been ground narrow on the outside edge so you can use it . Snap in your torque wrench perpendicular to the wrench and use the factory torque spec. I'll have more shortly...
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Craig in France
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Re: 860GT head nut wrench and torque setting

Post by Craig in France »

BevHevSteve wrote:Well yes I do have a good crank turning tool available here
https://store.bevelheaven.com/workshop- ... v-engines/
My bad, Steve - apologies. Don't know how I missed it :oops: . Is this the type you can fix a degree wheel to as well?
BevHevSteve wrote:I also usually stock the head nut spanner shown
Also 'Good to Know' <>
Spagjet
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Re: 860GT head nut wrench and torque setting

Post by Spagjet »

I cut the end off an open ended spanner and welded a socket to it so you end up with a tool as short as possible (about 40mm long) to minimise the effect on torque reading. You do have to grind the sides of the spanner down to fit in the limited space but with a bit of patience with a hammer and a file you can actually 'dress' the spanner size in very close on the head nut size (a lot closer than a stock spanner) which makes it work a lot better. A ground down spanner is always going to open a bit under pressure but if you close it up nice and neat to the nut size it lessens the chance of damage or slipping. I used to work in a big engine rebuilding business and actuall used the torque wrench calibrater we had to do an experiment to see how much the extra 40mm in length affected the torque setting on a standard 1/2" drive 2 foot long torque wrench.

It doesn't. I did it a few times as I was surprised but it's true. Just set it to the setting you want and go for it. Something that has much more of an effect is not putting oil on the head studs. The fact you are having a pregnant dog of a time getting the head nuts off means to me the last bloke never put oil on the studs so it was probably the wrong torque setting anyway. I made a lapping tool for the fire ring to make sure it was flat, in all the bevel heads I've had off they have all had shrinkage on the fire ring right next to the exhaust valve seat. Doesn't matter how accurate the torque settings are if the fire ring isn't flat...
Zanetti
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Re: 860GT head nut wrench and torque setting

Post by Zanetti »

Regarding offset spanners & torque for the head nuts, here's a handy calculator

http://www.cncexpo.com/TorqueAdapter.aspx
Spagjet
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Re: 860GT head nut wrench and torque setting

Post by Spagjet »

that's an interesting thing but most torque wrenches are out by a bit or a lot anyway (you'd be surprised by how much sometimes) and you can only rely on their accuracy by calibrating them on a special tool. You've only got to drop it once and it can be out. Most people couldn't swear they know the torque wrench they are using hasn't been dropped (or used as a breaker bar) so it's a bit variable. Also the fact you are using an open ended spanner on bevel head nuts means that a little bit of the 'indicated torque' gets soaked up by the spanner flexing open a bit. It's good enough to just set the torque setting and carefully torque the head up in stages like the book says, the worst that can happen is that the short adaptor means that the torque will be very slightly higher but from what I learnt through experimenting it's next to nothing and not worth losing sleep over once you add all the other potential variations in. You have to stop when you hear the 'click' but I have watched people give it a "bit more for good measure" lots of times or just react slowly so turn it a bit too much without meaning to. The torque specs are 24.6- 31.1 ft lbs so there is a bit of wriggle room. Just make sure your studs are oiled and fire rings/top of barrel are true (check with bearing blue) and go fo it. If the nuts are so hard to remove you might have to hit up the stud threads with a wire brush and run a tap through the nuts anyway, if the are a bit tight from corrosion it will really affect the torque readings.
machten
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Re: 860GT head nut wrench and torque setting

Post by machten »

I totally agree that you can only be sure by calibrating them, but for a somewhat different reason. The calculation link provided seems to me to depend on at what point on the lever that the base ("true") measurment occurs. In a clicking torque wrench it occurs not on the fulcrum and not at the end, but usually 1/3 to 1/2 way up the lever. So how does that affect tourque readings with a straight lever extension? Steve Foster???

From Craig:
Not this fella by any chance, Kev?
http://www.ebay.com/usr/discusprinlo
Yes, that's the chap, Craig.

Of course I'm in Oz, so postage from the US (and now exhange rate!) matters. (12 months ago it was better to buy from the US!)

His timing wheel is quite useful because it allows you to check your dynamic timing with a running engine. Useful to check out the function of your automatic advance unit with a strobe light. (Are your distributor advance springs doing what you think?)

Kev
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