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 mu...

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 own...

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

Paul Warping of amal carbs is always a problem, sometimes resulting in sticking slides or sucking air and altering the tune. John Healey cam up with a way to straighten them which is quite simple. See this link and click on the youtube video which will show the process as well as the tool to do the ...

Simes It depends on whether you want the looks or the performance. If you want the performance then fit polished steel flywheels balanced to 65-67%, a HS 9 to 1 piston, machine .040” off the base of the cylinder and the compression ratio will go to 10 to 1, then fit a 1956 mk1 cam preferably run wit...

The weather was ideal for riding with temperatures ranging from about 18c to mid 20s. There were 72 entries and there were clearly a couple of additional bikes that were not on the entry list, so a very good turnout for South Australia. My drive to the rally was 15 hours but there were others that w...

Thanks for the replies, and my reading may be a little low, although I was happy with how even they were. What I did not mention is that my 4 has 7.2 pistons and the head and cylinder were shaved .040” and .030” for a total of .070” due to distortion and some corrosion. My compression ratio would be...

Has anyone run a compression test on a square 4. Recently I had the carb off, so out of interest I decided to do a compression test. My gauge is held by hand against the plug hole and seals against bevelled rubber, rather than screw in, so not ideal. 3 cylinders at 115 psi and one at 113 psi which i...

Further to Rogers comments, the normal set up for using a Jawa pin is to use flywheels made from 4140 steel, generally nitrided. The press fit normally used here in Australia is .004”, and a greater fitment length in the flywheel than with the standard Ariel crankpin is achieved as there are no nut ...

you will find that nikasil is not suitable for coating direct onto the aluminium of existing Ariel cylinders. I tried and it failed, and others I know that have had other makes of older cast cylinders nikasil lined direct onto the aluminium have also had failures. Nikasil is however ok on new high q...