upshur twin picture

[raym 11]

I finished this from Model Eng. Mag. last year. I'm in the process of making a propane demand valve for it to see if it will run as well as it does on camp gas & Mystery Oil.
I used Tygon tubing for the inlet manifold connections and I am not happy with it. Anybody suggest some other tubing that might work? How about hose clamps for same?, thought a few times about using 'O' rings stretched over the ends of the tubing.
Ray M

 

[Brass_Machine]

Ok now that is pretty cool.

What about the Tygon tubing do you dislike? As far as hose clamps go, on some of the Japanese bikes I work on they have rings for hoses for the airbox and such. They are just wire rings that are looped at the end. The almost look like circlips. Maybe mcmaster carr has them

You can see them Here. Item #15.

Eric

 

[Brass_Machine]

Page 245 on mcmaster carr

Eric

 

[Powder keg]

Nice looking engine you have there. Do you happen to have a video?

Wes

 

[raym 11]

thanks for the hose clamp ideas Eric.

The Tygon doesn't want to bend and conform to the stubs as well as the fuel hose I usually use. (elasticity)? The stubs are 1/4 od tube and fuel hose not readily availablle here in the boonies. I can order the hose & clips as you suggest.

Maybe I should just break down and try to bend thin wall brass tubing for the whole manifold. I have never tried that. :-\

Ray

 

[raym 11]

Yes Wes I have a video of the engine running but it is difficult to upload with this dial up service I have to use. Any suggestions?

 

[Brass_Machine]

Where is the boonies?

Eric

 

[b.lindsey]

Beautiful engine!!! Have you thought about using silicon tubing? It tends to be much more elastic, goodo chemical (fuel) resistance and can also stand higher temperatures if that becomes an issue with extended running of the engine. You may have to order that as well but should be available from McMaster-Carr or similar suppliers.

Regards,
Bill

 

[Bogstandard]

Raym,
Have you tried the late Bob Shores fuel mix of pump gas with 10% WD40 for running in, and pump gas but with 5% WD40 for general running.
It really worked for me, and when stripped down, any internal deposits just wiped away with a cloth, and I never suffered with fouled plugs.
Also rather than using propane I would suggest you have a look at Jan Ridders site and look at his fuel vapour system he has designed. It would be ideal for a wet sump and open valve engine like yours.

John

 

[cfellows]

Hi Ray,

Great job on the engine. Did you make the carburetor from the plans in Mod Eng Builder? Any modifications to the carb?

Thx...
Chuck

 

[raym 11]

Thanx Bill, I will try to find silocone tubing. Maybe @ 'Small Parts'.
Ray

 

[mklotz]

Most aquarium supply stores sell silicone tubing. I can tell you that it stands up to live steam because I've used it thus. Most I've seen is 3/16" bore but there may be other sizes.

 

[raym 11]

Chuck;

I built the engine from drawings in Model Engine Builder. Most mods were cosmetic.
The carb is as built. Are there any carb mods I could make to upgrade that you know of?

Some mods were made to distributor rotor and other minor stuff.

Ray

 

[raym 11]

John;
I have used Bob Shores mix and it seem to work about the same as 5% Mystery Oil. both good.

Great minds! I also have the srawings and most bits and pieces for the 'petrol foam carb' laying on the bench.

Of interest to you might be these pictures of some of Bobs engines.

 

[raym 11]

Eric;
The boonies are in northern ca. @ ~40.02n x 124.04w.

Ray

 

[Bogstandard]

Ray,
Lovely trio of engines there.
It is a shame we lost Bob, his engines were such good designs, could even be made by a beginner with a bit of forward thought.
I gave up ic engines because of the costs involved in getting them running. Here in the uk the plugs alone cost about $34 each, and there is nowhere in the UK to obtain coils from now, so they have to be brought in from the States, which more than doubles what you pay for them.
I started to do a few experiments with piezo ignition units out of cheap lighters to get around the coil/points/electronic ignition cost problem. They fire the plug OK but they wouldn't be robust enough to stand up to continuous running.

John

 

[Brass_Machine]

Nice engines. I love the obvious use of brass... go figure right? The engine look great. Nice helper in your avatar picture too!

Eric

 

[DICKEYBIRD]

Bee-yoo-ti-ful engines Ray!

Silicone tubing is readily available at hobby shops that sell to r/c airplane and car guys. However, silicone is not usually recommended for gasoline use. It softens over time and gets gummy. Tygon or neoprene is better. The clear stuff (vinyl?) for string trimmer engines from the lawn mower shops should work well also.

 

[cfellows]

I gave up ic engines because of the costs involved in getting them running. Here in the uk the plugs alone cost about $34 each, and there is nowhere in the UK to obtain coils from now, so they have to be brought in from the States, which more than doubles what you pay for them.

John,

I haven't built a lot of IC engines just because they add so many extra levels of complexity. To build an engine where it would probably run on air, then have to puzzle through and build the fuel and ignition systems makes IC engines somewhat onerous to build. I do admire these and other excellent examples of IC engines, however. My hat is off to those who do such a wonderful job.

Chuck

 

[Stan]

bogstandard: Your local Honda dealer should have 10 mm plugs on the shelf. they use them in one of their small engines. They are small enough for most small models.