Rina and T&K drawings

[Jeff DaymanParticipant @jeffdayman43397]

The Rina carburetor drawings are some of the most unclear I’ve ever seen. A section through the body vertically would help immensely. I think there will be a lot of scrap carbs and stopped projects because of those awful drawings. On the carb valve spring, no hints at all are given about appropriate dia, wire dia, or pitch. The text just says “light spring”.

 

 In addition the ignition lever drawing in the same article is pretty much unintelligible and has at least one line (a horizontal one, at the step) that should not be there. I could make the assy from the photo but certainly not from the drawing.

 

JD

[John OlsenParticipant @johnolsen79199]

HI Jeff,

 

Well here is my interpretation of how it should go together. Note that I am not the original designer and I have never built one of these, so it could be wrong. It is just my interpretation from what was in the magazine. I haven’t attempted to show the carb spring, or the main valve springs or governor springs for that matter. They are not that hard to draw, but I would like to get the size and number of turns something like right.

 

I’m presuming that the way it works is that the valve drops down and cuts off the gas supply when the engine stops sucking air. So the regulator must be supplying gas at quite a low pressure. If the pressure is too high, valve will need too much spring  pressure and the engine will have trouble sucking in enough mixture to do any good. Any experts, feel free to correct me on this, I’ve played with a “LIttle Jumbo” running on petrol, but have never played with a small one running on butane.

 

The advantage of redrawing things in a 3D CAD program is that it helps you get a clear picture of how things actually go together, and sometimes helps explain what  some of the features are actually for.

 

regards

John

[David Clark 13Participant @davidclark13]

Hi There

I disagree that the drawing is unclear.

Both drawings look fine to me.

Yes, the line may be unecessary for the ignition drawing but it is in the photo so could be to do with setting up.

It was on the original drawing so was left.

I did not have information on the spring but it is shown in the photo and it can be seen it is a light spring.

regards David

 

[David Clark 13Participant @davidclark13]

Hi John

We don’t have time to redraw in a cad package.

All we can do is tidy up where necessary.

I do correct errors when I see them but short of building every model we publish we will occaisonally get errors.

regards David

[Jim GreetheadParticipant @jimgreethead]

No John, I don’ t think you sound too niggly. I agree that we can probably sort out the missing bits, given time, but some advice would be helpful.

 

As a newcomer to IC engines, I am very grateful to Jim Service for the effort he has put in to this project; without people like him, I would be unable to get started. And without people like you, I would probably be unable to finish.

 

 Your drawing of the carburettor is superb! I must confess that I have not had a close look at it but there are features in your drawing that I had not noticed.

 

You mentioned that details of the inlet valve are missing. Other people to whom I have spoken have mentioned difficulty (with other engines) in getting the spring tension just right. This has led me to speculate about some spring tension adjustment: maybe a threaded collar or similar. What to you think? 

 

Jim 

[John OlsenParticipant @johnolsen79199]

Hi David,

If you can get the necessary details from Jim Service I can update my drawings with them. Having done my drawings mainly as a learning exercise, it would seem a pity not to make some use of them. As I have mentioned elsewhere, one possibility would be to put the Adobe PDF of the 3D model up on the website. This would allow people to view it from different angles, and also to remove parts and see the internal details. (At the moment they would see that I have not bothered to draw in the gudgeon pin or the rings!) The Isometric views of the more complex parts are also possibly a help for people to visualise what they are going to make

 

Details I would like to clarify are the overall length of the valves, the details of the collets and spring retainers, and the details of all the springs including the governor springs. (Wire gauge, diameter, number of turns and free length) The gudgeon pin is no problem, although I would like to know if the intention was to make it hollow or not. It is retained by a screw in the piston, so presumably doesn’t need end pads. The rocker post height may need to vary depending how long the  valves are supposed to be, but I can change that in my drawings very easily, either for the original post or for my suggested variation. The little collar for the governor is also not too much of a problem. A sketch of the fitting in the exhaust might help too…We don’t want to put to much back pressure on. I suspect that it will probably not be too loud when running, even with a minimal muffler. 

 

regards

John

 

 

[David Clark 13Participant @davidclark13]

Hi John

Jim is not on email so I will have to phone him or write to him.

Not sure if I have his phone number.

regards david

 

[John OlsenParticipant @johnolsen79199]

Hi David,

 

I have heard from Jim directly so I now have the details, I will do some drawings later today. 

 

regards

John

[John OlsenParticipant @johnolsen79199]

Hi All,

 

As mentioned above, Jim Service has provided me with some dimensions for the  governor sleeve, the rocker post, and the valves. I have modified my drawings, but would suggest sanity checking all this before going ahead too far. I have not made any of these parts, other than in a 3D modeling program.

I found the  E circlip for the valves in a catalogue, and it is intended for use with 1/8 inch shaft. If you use a different one, say a metric one be prepared to adjust the groove to suit.

 

There are three new drawings, which can be found in my album, I will just link to the governor one here to avoid filling the page up too much.

 

I have not modified the height of the alternative design of rocker post yet, if you decide to make that one increase the height to be the same as the original one, eg 13/16″ long. Jim Service had no problem getting the original one to line up nicely, so either way should be fine.

 

regards

John

 

 

[Ian S CParticipant @iansc]

John, re the ignition lever; the horizontal line should be there, if you look closely at the photo the vertical part has a step there, but the edge veiw shows no thickness dimentions.  Ian S C

[David Clark 13Participant @davidclark13]

Hi There

It looked like marking out to me but I left the line in as it might be useful for setting up.

regards David

 

[Jim GreetheadParticipant @jimgreethead]

I understand why Jim would make the conversion shown in Fig 8 if the machine was already constructed but I can’t help thinking that there might be a better way to incorporate the CDI system than by modifying the ignition lever.

 

Since we no longer need the lever to adjust the timing, a more unobtrusive arrangement should be possible. I will give it some thought; anyone else have ideas? 

 

Jim 

[Ian S CParticipant @iansc]

David, i used a manifying glass on the photo, there is a step where the line is, and a line continues round the circular part. The 1/8″ hole marked on the drawing is not in the same place as the photo. The two items are quite different. Ian S C

[John OlsenParticipant @johnolsen79199]

Hi All,

 

Jim Service has kindly taken the head off his engine so that he could measure the springs for us. Note that these were springs from his collection of bits that might be useful someday, so you may not be able to match them exactly. But this should give a good starting point for experiment.

From Jim:  >==

Exhaust valve is 5/8 ” long and the outside diameter is 0.278″. The gauge is 22 SWG or 0.028″ and there are 8 turns.

 

Inlet valve is 11/16 ” long but has been stretched somewhat and the outside diameter is 0.278″. The gauge is 22 SWG or 0.0148″. There are 6 turns.

 

Carb is 5/16″ long and the outside diameter is 0.12″. The gauge is 35 SWG or 0.0084″ and there are 6 turns.

 ==<

 

 

regards

John

[Graham BirdParticipant @grahambird65048]

Hi All

 

Can anyone please advise recommended spark plug for Rina hit and miss engine? 

 

Regards

 

Graham

[MichaelRParticipant @michaelr]

NGK CM- 6 10mm should be OK, seehere

[Jim GreetheadParticipant @jimgreethead]

Hello Graham, I have just checked the dimensions and I agree with Stick that the CM-6 will have the required reach. It should just drop nicely into the hole when the washer is compressed to half size.

A couple of things to note about the CM-6 are:

1. The thread is M10 x 1.0 which is neither metric coarse nor metric fine so you have to ask specifically for the M10 x 1.0 tap,

2. The cap is not the usual screw top so you need a special connection. I have seen a spade terminal used (not very pretty). The RCEXL ignition (as in Part 8) has a CM-6 version with a connection that fits right over the plug if you push hard enough. 

Jim

 

[MichaelRParticipant @michaelr]

Jim, Plug cap for CM-6 Part No LC05EFK  I use these caps on my RLE engine a neat fitting with a nice push fit.

 

Stick.

[David Clark 13Participant @davidclark13]

Hi Stick

Does this mean you use the CM-6 for the RLE?

Where does the cap come from?

Same place as the spark plug?

regards David

 

[MichaelRParticipant @michaelr]

Hi David,

Yes I use the CM-6 plug on my RLE, the cap comes from the same place as the plug.

see Here.

Stick.

 

 

[David Clark 13Participant @davidclark13]

Hi Stick

Thanks for that.

Looking forward to starting my RLE.

What sort of ignition gubbins did you use?

What fuel do you use?

It is a great shame this engine is not still available.

regards David

 

[Howard JonesParticipant @howardjones35282]

can someone please tell me what the T&K part of the tread title refers to?

I have read the magazines and I have no idea.

[MichaelRParticipant @michaelr]

Hi David,

I have made two RLE’s, on one engine I use  the TIM-6 Transistor Ignition (Hall Effect) with a Exciter Coil, and the other engine has a electronic Buzz Coil Transistor ignition(Hall Effect) using a 6 Volt motor coil, for fuel I use petrol with a squirt or two of  WD 40.

 

See my enginesHere for more detail.

Stick.

[Graham BirdParticipant @grahambird65048]

               hi  all

      re rina engine the recess round the valve cage on the cylinder head is 0.250 dia

      which makesit difficult to insert the spring of 0.278 dia. as shown in picture.

      iwould like your comments. please.

      

      could anyone tell me the dia of the bob weights scaling the drawing they seem

      about  5/ 16 dia.

 

[james service 2Participant @jamesservice2]

jim service  19/11/10

 

Hi Graham

 

The recess holes are 5/16 inch diameter. My original drawings were approximately one to one scale and was shown as 3/8 inch although the actual dimension was omitted.

 

The bob weights are 1/4 inch diameter.

 

Edited By james service 2 on 19/11/2010 16:32:36

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