Kh experiment on BSA

Well we got the mig welder out and started filling in the head chamber roughly and with a bit of rough dremel work we fitted the head to an M20 BSA and WOW! what a difference to power. Thanks to a rough copy of KH pattern head!

Sorry i forgot about pic size, i'll try again!

Photobucket keeps changing, i give up. It seems to only copy supersize now and it obviously is only showing half of the picture!

Once more!

Here's the test hack!!

Thanks to American sidevalve knowhow! Cheers!

looks like you have welded in a 'divider' or is that the light playing tricks?

Yes i decided to try a divider but was worried it might affect the exhaust gases on the way out. I wouldn't know if it's done anything unless i ground it off again.Strangely kickover compression is quite low after this mod, any theories on that?

You don't want to make it too fast or you'll start embarrassing the Goldies.

Do you have Irving's TUNING FOR SPEED? Lots of useful flattie and low buck hop up info for older British machines.

Yes i decided to try a divider but was worried it might affect the exhaust gases on the way out. I wouldn't know if it's done anything unless i ground it off again.Strangely kickover compression is quite low after this mod, any theories on that?

maybe the inlet is being shrouded and not getting full charge into the cylinnder ?

That's one of my theories too. But once it fires it must overcome and starts sucking madly!

Anyone got a pic of a WL head just to see their pattern?

look here

http://beautyofspeed.com/gallery/heads_ ... _index.htm

What a coincedence! I know that Leigh guy from Headworks. We jokingly call him Headjobs, but not to his face!

Ricardo wrote the book on sidevalve tuning in the 1920s, producing inserts like that for the ioe engines of the day ( the 'Riccy chip' ). Indian and ( to a lesser extent ) H-D copied his work without acknowledging the patent rights in the 1930s, but by that time he was a long way beyond developing sidevalve motorcycle engines, which were a stagnant
cul-de-sac in the European market by then. Bikes like the M20 and 16H inherited bottom-end and cycle parts technology from the ohv models, but the top end design was completely neglected from the early 1930s onwards. There was no incentive to do so, and metallurgical advances had largely eliminated the valve-gear problems of the 1920s ( at least until those basic designs were becoming increasingly over-stressed by the 1950s ) .

velocette le was still availiable to buy new in 1971!!

wilko how long will you leave the head on before you pull it off and see the pattern of carbon deposits?

I passed my test on a Noddy Bike!

As soon as i do another one to KR specs a little more professionally, i will investigate.

wilko ,did you get any photos of the top of the barrel when the head was of?

I'll get some pics today. Of course the valves are miles away from the bore and no troughing as in K's but even that will be doable by countersinking valve seats and dremeling.As i said these motors are a dime a dozen down here so nothing is sacred!