Author Topic: go boil your head  (Read 898 times)

Offline spyke

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go boil your head
« on: 10.02. 2011 18:05 »
Hi chaps,

Going to bolt my head on tommorrow if my thick washers arrive, i know theres been a fair bit of talk on how to make the thing not blow/leak  and ive picked the bones out of lots of different views of how im going to do it.
Just to put one more idea in (not mine but someone whos knowledge i respect and is well known to some of us).
He puts the head on(annealed solid copper gasket) ,sprays surfaces with aluminium paint tightens head to 26ft/lbs all round then heats the head up to approx operating temp with a hot air gun then tightens to 32-33ft/lbs.Says never has one blow/leak. and the heating up is in lieu of having to whip the rocker box off later and retorque,which is appealing.
Ive heard the thing about the paint before and is an old tuners dodge from back in the day, which i will probably not do but i can see the science behind the heating idea.
Your thoughts?
Spyke
A10 spitfire style

Offline MG

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Re: go boil your head
« Reply #1 on: 10.02. 2011 18:16 »
hmm, I guess I would let the head cool down completely again before re-tightening! Doing up the bolts in the hot head could cause warping and all other sorts of trouble.

I give each bolt head a tap with a big hammer and a soft copper drift after fitting, then have the whole thing settle over night and re-torque it the next day. The annealed gasket is oiled slightly before installation to help it creep. Never had any leaks and no re-tightening required, but I always had the barrels and head skimmed on my rebuilds.

just my 2 Euro-Cents worth.  *smile*

Cheers, Markus
1955 A7 Shooting Star
1956 A10 Golden Flash
1961 Matchless G12 CSR

www.histo-tech.at - Restoration, Repairs, Racing

Austria

Offline spyke

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Re: go boil your head
« Reply #2 on: 10.02. 2011 18:38 »
If after running the bike for a few hudred miles and you check the bolts that lie outside the rocker cover, if these havnt loosened at all would that be an indicater that the ones that require a rocker box removal havnt either and conversley if the outer ones need another 5lbs for example to bring up to spec then yes you will have to pull off the rocker box to check all?
Spyke   
A10 spitfire style

Offline MG

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Re: go boil your head
« Reply #3 on: 10.02. 2011 18:53 »
good question, since all is nice and tight, I have never touched the bolts after fitting the head with the method described.
But you have to start with the innermost bolts when re-tightening, so the rockerbox has to come off anyway.
1955 A7 Shooting Star
1956 A10 Golden Flash
1961 Matchless G12 CSR

www.histo-tech.at - Restoration, Repairs, Racing

Austria