High ratio B50 rocker arms

Here you can talk about all kind of TECH for the B50 B44 B25 And Other BSA unit Singles

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High ratio B50 rocker arms

Post by Momus » Sat May 23, 2020 1:22 pm

Does, or has anyone produced alternative high ratio rockers, or rockers and rocker box, for the B50?
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Re: High ratio B50 rocker arms

Post by beat » Sat May 23, 2020 7:18 pm

Momus wrote:
Sat May 23, 2020 1:22 pm
high ratio rockers,
was'nt it Stan doing something the like ? but I can't find it...

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Re: High ratio B50 rocker arms

Post by Momus » Sat May 23, 2020 8:29 pm

Nothing came up in the search.

I thought someone may have had a line on a Jesel or T&D machined from solid production rather than cut and shut.
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Re: High ratio B50 rocker arms

Post by minetymenace » Sun May 24, 2020 5:35 pm

Try Searching for "Rocker Arm Ratio", Stan mentions changing the ratio of the inlet in two topics and there is a fairly exhaustive topic under the same name...
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Re: High ratio B50 rocker arms

Post by Momus » Mon May 25, 2020 7:31 am

Thanks, I've read a few of the discussions Minty- more wondering if any of the vendors had something solid made rather than set up theories.

Looks like something else to make. Not to worry. It was my stated aim to replace every BSA made moving engine part.

I think that apart from the cam drive spur gear that aim has been accomplished, at least on paper.
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Re: High ratio B50 rocker arms

Post by SteveS » Mon May 25, 2020 8:29 am

Hi Momo

Some of the guys have done more than just theorise, but I don't think you will get anything off the shelf. If you check Stan Millard's Photobucket page here there are a few pics of the mods he did to B25 rockers to improve the ratio. I'm fairly certain he used the B25 rockerbox (eccentric adjustment) on some of his B50's. Stan also completed impressive (and successful) work on his B50 heads. You will need to scroll through his album to see all the detail - HPStan forever :thumb
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Re: High ratio B50 rocker arms

Post by Momus » Mon May 25, 2020 9:46 pm

Thanks for the link.

I saw those photos some time ago when looking for something completely unrelated to BSA's. What does he do with that bike?
.
As Arthur would have said about the B25: "We've dragged a 1950's design kicking and screaming into the 1960's".
A lot of work. I wonder what the results were as far as increasing the torque?

We once brazed some thick iron washers to a 4 cylinder car head inlet side so we could port into the spring seat area. Long valves, mucking around with rocker arms, valve cover work.
It was a success in the broad sense but it probably failed to lift the specific torque although more power was made because revs.
I learnt that what happens further down the port, from around the valve guide and into the chamber is really important well after that.


I am doing something similar to that blokes B25 my experimental B50 head going on The Boris Johnson, straightening the port- the high ratio rockers are/were for my B50.
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Re: High ratio B50 rocker arms

Post by SteveS » Tue May 26, 2020 6:57 am

Hi Momu

That "bloke" is Stan Millard - HPStan, very well known and respected in the Flat Track community over in the US.

Did you see Stan's high port B50 head? May help with your head plans - see here.

If you get time it's worth checking out Stan's posts. If you use the advanced search and put his username 'HPStan' in the 'Search for author' box all of his posts will show up
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Re: High ratio B50 rocker arms

Post by koncretekid » Tue May 26, 2020 12:20 pm

Ed Valiket makes them. You will then want to sand them down and polish them. You also have to open up the pushrod tunnel, as the pushrods now move at more extreme angles where they intersect the shorter ends of the rocker arms.
B50 hr rocker arms.jpg
high ratio rocker arm
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P.S. Has anyone heard from Stan lately?
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Re: High ratio B50 rocker arms

Post by SteveS » Tue May 26, 2020 2:57 pm

Hi Tom

Thanks for posting the details about E&V's rockers, I wasn't aware he was making them.

I was thinking the same as you about Stan
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Re: High ratio B50 rocker arms

Post by Barry Creary » Tue May 26, 2020 7:45 pm

My thoughts to about Stan <1011

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