Aluminium heads on singles

[david.anderson]

Does anyone know what grade of aluminium was used for the Ariel cylinder heads. And was the same grade of aluminium used in the pre 56 sand cast heads and post 56 die cast heads.
Has anyone used 4043 rods for welding the aluminium head? Thanks
David

[Roger Gwynn]

From the works drawings, so not the latest spec
3-52 DTD 424
36-50 'Y' alloy
35-54 DTD 324
12002-54 DTD 324
35-55 DTD 324
51-56 DTD 424 die casting
35-56 DTD 424
46-56 DTD 424
51-56 DTD 424 die casting
47-49 MKI 'Y' alloy
47-53 MKII DTD 424 (heat treated)
K2-53 KH 'Y' alloy

[david.anderson]

Thankyou Roger. BSA of the same era used the DTD 424 alloy so I thought Ariel may have also. The current equivalent is 4043 (US) so the 4043 rods should be ideal. Now I just need to find someone capable and willing to do this job.
I have done possibly 200,000 miles on my 57VH in over 50 years of ownership. The exhaust valve guide has come lose on several occasions and was repaired with an increasingly larger valve guide, in a trued guide bore, on numerous occasions. About 1000km ago the guide was lose again so I took the head to a specialist head repair shop and on their advice they bored the guide hole larger and fitted an alloy sleeve that was held in position with weld around the top of the sleeve. The sleeve broke up and the bottom of the valve guide broke off resulting in quite a clatter as the valve rocked around. Fortunately the pieces exited through the exhaust and some pieces have been recovered from within the muffler. No cylinder or piston damage. So now I am looking to have the guide bore welded up and rebored back to standard. It appears that this would be best done with a laser welder as they can be focused within a small hole to achieve the weld. The laser also means there is minimal heat build-up in the head. None of the shops that have a laser welder that I have contacted are prepared to take on the job. And I have been given a pre 56 alloy head that someone has bored the exhaust guide bore out to about 1”. So I thought I would get both heads repaired at the same time. When I can find a suitable welding shop that is.
Has anyone managed to have a valve guide bore welded up and machined back to standard.
David

[nevhunter]

DAVID, I tend to heat the alloy up to high temp and that reduces stresses and the likelihood of cracks. Most welders don't do that at the temps I do.IF you're welding in the Gut's of a head, THINK BIG'. Chop a lot away and come in from the easiest side making sure every metal lay down in the puddle has no inclusions in it. With TIG and an argon shield you float all crap to the top of the weld pool and it zaps away like magic. Don't have any drafts from open doors. Car heads are much harder. They have water passages and are harder to keep at the right temp.. I spent over 3 hours continuous on a race head where the spark plugs were relocated and 4 new ports formed .Money just couldn't pay for that sort of work. IN theory you could start with the shape of the head gasket and make your complete head up from that.. Some CNC every thing from a billett. Some cast by Lost wax. At "OUR stage we can't waste a lot of time on Lost Causes. Those alloy heads were trouble from the day they went on the Market IF you wanted to work them HARD you'd have them OFF a lot.. Compared to the cast IRON ones. Now that John Budgen's not around. I must have gotten some where near his Last Head. Is anyone else likely to try? IF so it might be worth wile to consider a few changes to the design or do we just want something like they were. They are NOT likely to be cheap. Thoughts ANYONE. There's some just lovely G 50 and Norton MANX heads made. The COMPLETE Engines in fact. Will our offspring see this the same way? Id doubt it. Karols work should give some a bit of inspiration.It's ALL ART. Nev.

[Roger Gwynn]

We have had heads welded up at Draganfly, Which I think was done after machining a large countersink so that the weld could reach lower down into the hole, not just round the top. We do this when repairing pulled studs on SQ4 heads but have only had to resort to this a couple of times with VH heads, boring out and oversize guides usually doing the job.

[Vincent.vanGinneke]

Maybe contact Terry Prince TPV Vincent, if he is still around as the website does not work anymore..
or the guys at Irving Vincent ? https://www.irvingvincent.com/
Australia is big...so maybe they are to far from you but at least on the same continent.

[nevhunter]

Those Irving Vincent motors make the Most impressive noises at Broadford I've ever heard any bike make. Getting back to the metal used in the finished product you can see some alloys look whiter and ringing sound through the fins more This is generally an indication of the hardness. Some head metals strip the threads prolifically. Heat treating for hardness is affected by overheating the heads in use and is permanent once a certain temp is reached. Probably about 240 C .Hardening is a brutal method with aluminium and you may need temporary reinforcing to prevent warpage and some castings mat crack. A used head for all intents and purposes Cannot be rehardened. It's done BEFORE any machining is commenced except for trimming bits of the casting where the Dies or coring leaves bits sticking out at the point where they contact. That's usually done by hand and by the least senior at the foundry.I tnk it referred to as "fettling Most Al castings are Porous but the Vaccuum DIECAST (Metal dies) and degassing the metal Just before pouring to help to avoid that. I used Moth balls to degas the metal I cast." Napthaline You have to plunge it to the bottom of the crucibile and move it around in the molten metal to do the process evenly..
Maybe our ARIEL KLUB. "Action" Man might wish to add to what I've said. He's till doing it currently and may have some better advice. Nev

[david.anderson]

Thanks all.
After doing some research on the effects of welding in such a critical area, then considering rehardening and tempering the head after welding I came to the belief that the laser weld would be the best as there is no need to preheat, and the heat build up in the head during welding is much less with the laser. As such there is not any need to consider hardening and tempering. Also the correct laser can be focused to successfully weld in the valve guide bore. But the difficulty that I am having is finding someone with a suitable laser that is prepared to do the job.
If I have to get the head welded with a TIG then I will try to find someone that has a small water cooled torch that they can also work from inside the port and I will get the port roof built up a little approaching the guide to provide some additional support. And a large countersink on my diecast head may have to be the go.
Cylinder head repair specialists in Canberra and Melbourne, who advertise cracked head repair alloy welding and machining are not prepared to take the job on.
Clive Harrop in Melbourne does manufacture 4 valve heads for the VH, but unfortunately they are open valve gear.
David