WNG Head torque secuence

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LuisPaz
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WNG Head torque secuence

Postby LuisPaz » Wed Jun 20, 2018 1:49 am

Hi
Can tell me the correct torque and secuence to tighten the cylinder head?
Thanks in advance!
Regards
Luis, from Argentina

nevhunter
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Re: WNG Head torque secuence

Postby nevhunter » Wed Jun 20, 2018 12:52 pm

There's no gasket so it's not particularly critical. Do opposites lightly at first and increase to full tension in about 3 sequences. There's no "give" so doesn't really need checking later. With a gasket on a twin for instance, I just get it hot and retighten it even before use on the road where it has a soft gasket with a lot of settling in. You might have to retighten a few times or you will get a leakage at the joint. Nev

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LuisPaz
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Re: WNG Head torque secuence

Postby LuisPaz » Wed Jun 20, 2018 2:02 pm

Thank you for your reply Nev!
I had not noticed that between the head and cylinder there is no gasket ... and now that you say it, the parts manual is not listed.
Why is not Gasket?
ft/lb??
Luis, from Argentina

Simon.Gardiner
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Re: WNG Head torque secuence

Postby Simon.Gardiner » Wed Jun 20, 2018 3:06 pm

Luis
It's a ground joint, the spigot on the barrel should seat on the recess in the head for the gas-seal with a very small clearance between the outer joint faces to make sure that it's the spigot that's doing the work.
The practice I follow for this is to finish lapping in the barrel and head with fine grinding paste on the spigot and coarse on the outer faces.
There is at least one fairly recent thread on the forum relating to this.
Ariel torque figures (for bolts and studs) were not commonly given, for the singles doing the head bolts 'tight' is usually adequate. I think the best figure anyone has arrived at is 300inch/lbs(25ft/lbs).
There has been some discussion on this as well - the level of official documentation can be seen in this thread!
viewtopic.php?f=7&t=6189&p=40462
(The doc referred to has all the figures for all the model range - don't expect too much!!)

Hope that helps

SG
'55 Huntmaster, '56 VH, ' 51 VH, '80 R100RT, '00 Sprint ST (but all those Ariel parts can only make one running bike...)

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LuisPaz
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Re: WNG Head torque secuence

Postby LuisPaz » Wed Jun 20, 2018 11:14 pm

Thank you very much Simon! Great info!
Luis, from Argentina

nevhunter
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Re: WNG Head torque secuence

Postby nevhunter » Thu Jun 21, 2018 2:22 am

All pretty much covered. Don't overtighten any head that is threaded into to cylinder close to the bore as you may cause distortion in the top area near the bolts. With 3/8 x26 tpi ,25 ft Lbs is enough. Nev


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