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Kh experiment on BSA

Moderators: Curt!, Pa

Post Sat Dec 04, 2010 11:08 pm

Posts: 159
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! Image

Post Sat Dec 04, 2010 11:09 pm

Posts: 159
Sorry i forgot about pic size, i'll try again!

Post Sat Dec 04, 2010 11:15 pm

Posts: 159
Photobucket keeps changing, i give up. It seems to only copy supersize now and it obviously is only showing half of the picture!

Post Sat Dec 04, 2010 11:41 pm

Posts: 159
Once more! Image

Post Sat Dec 04, 2010 11:46 pm

Posts: 159
HeImagere's the test hack!!

Post Sat Dec 04, 2010 11:48 pm

Posts: 159
Thanks to American sidevalve knowhow! Cheers!

Post Sun Dec 05, 2010 3:42 am
jib

Posts: 575
Location: devon,england
looks like you have welded in a 'divider' or is that the light playing tricks?
Dude, check out that jibhead, he's crazy. Hasn't been sober for 40 years

Post Sun Dec 05, 2010 2:23 pm

Posts: 159
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?

Post Sun Dec 05, 2010 2:39 pm

Posts: 66
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.

Post Sun Dec 05, 2010 3:00 pm
jib

Posts: 575
Location: devon,england
wilko wrote:
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 ?
Dude, check out that jibhead, he's crazy. Hasn't been sober for 40 years

Post Sun Dec 05, 2010 3:58 pm

Posts: 159
That's one of my theories too. But once it fires it must overcome and starts sucking madly!

Post Sun Dec 05, 2010 4:02 pm

Posts: 159
Anyone got a pic of a WL head just to see their pattern?

Post Sun Dec 05, 2010 4:33 pm
jib

Posts: 575
Location: devon,england
Dude, check out that jibhead, he's crazy. Hasn't been sober for 40 years

Post Sun Dec 05, 2010 5:09 pm

Posts: 159
What a coincedence! I know that Leigh guy from Headworks. We jokingly call him Headjobs, but not to his face!

Post Sun Dec 05, 2010 11:31 pm

Posts: 1654
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 ) .
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Mon Dec 06, 2010 5:01 am
jib

Posts: 575
Location: devon,england
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?
Dude, check out that jibhead, he's crazy. Hasn't been sober for 40 years

Post Mon Dec 06, 2010 3:25 pm

Posts: 1654
I passed my test on a Noddy Bike! :lol:
Shoot, a man could have a good weekend in Dallas with all that stuff...

Post Mon Dec 06, 2010 4:45 pm

Posts: 159
As soon as i do another one to KR specs a little more professionally, i will investigate. Image

Post Tue Dec 07, 2010 11:13 am
jib

Posts: 575
Location: devon,england
wilko ,did you get any photos of the top of the barrel when the head was of?
Dude, check out that jibhead, he's crazy. Hasn't been sober for 40 years

Post Tue Dec 07, 2010 12:04 pm

Posts: 159
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!

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