RR1 valve information

jleboida Sun Oct 27, 2013 10:50 pm

Do you have a one inch micrometer, a number drill set, good measurement skills, and an RR1? I have an RR1 in very good condition, but it is missing it's rear rotary drum valve. I have the skills and equipment (lathe, milling machine, dividing head, and measuring tools) to produce a new valve, using measurements of existing parts (crankshaft rotary valve drive pin, fuel tank rotary valve bearing, and the relative spacing between those parts), trial and error fitting, and best guess method to determine intake timing, but if I could get a few measurements of an actual valve, it would save a lot fiddling.

The basic measurements that would be most helpful, in descending order of importance are;
1. The outside diameter of the valve drum which slips into the fuel tank bearing +/- .0002 of an inch.
2. The thickness of the drive flange +/-.0005 of an inch.
3. The total length of the valve, drive flange and drum combined, +/-.0005 of an inch.
4. The number drill size of the inside diameter of the drum.
5. The number drill size of the drive pin hole in the flange.
It seems to me that 2 cycle engine timing is more art than science, so if anyone has any information on the actual RR1 intake timing I would really appreciate it. I was going to start with a total intake duration of180 degrees, and make both the opening and closing 35 to 40 degrees after bottom and top dead center, and see what happens.

**RknRusty** Mon Oct 28, 2013 2:28 am

If you don't get all the responses you need, send a PM to Mudhen. He's the best RR1 builder on this forum.
Good luck, and welcome to CEF.
Rusty

Kim Mon Oct 28, 2013 5:19 am

Sounds like a GREAT project, jleboida !!!!

Rusty's right...Mud oughta be able to get you the info. If possible, please keep us informed on your progress!

And Welcome to the Forum !!!!

Kim

Stephen Nelson Fri Dec 20, 2019 6:58 am

Looks like brass, four tabs...are they available?

balogh Fri Dec 20, 2019 7:56 am

Welcome to the forum Stephen. The genuine beryllium star reeds are difficult to find but more efficient mylar and stainless steel reeds are sold by e.g. Cox International or Exmodelengines:
https://coxengines.ca/cox-.049-reed-valve-performance-pack-3.html

getback Sat Dec 21, 2019 5:10 pm

Did mudhen get intouch with you i summoned him ? Christmas Tree

**Admin** Sat Dec 21, 2019 5:31 pm

Stephen Nelson wrote:Looks like brass, four tabs...are they available?

What engine do you have? The RR-1 uses a rotary valve. What you describe is a reed valve (not used with the RR-1), which replacements are easily available.

KariFS Sun Dec 22, 2019 2:51 am

EDIT: I was responding to the original post regarding the RR-1 rotary valve. Didn’t notice the post was from waaaay back. Anyone know whatever happened to the project in question?

EDIT 2: And yes, the reed valves are available, the plastic one is a direct replacement for the metal (beryllium?) one.

My original message:
Sounds like an interesting machining project. I have two RR-1’s but no equipment to measure anything with the kind of accuracy you require. I do have a cheap micrometer that is ok for setting up things like Harley transmissions, and even then I always calibrate it with a feeler gauge first Smile

For my micrometer 0.002 is a pretty good resolution, but for 0.0002 you’d need some special equipment probably. Or did I get my conversions wrong Huh...