Is that the only head button that has an identification mark or spot? It still should not make a difference, when you install another glow plug, will it make any difference on how tight you make it? maybe 1/32 of an inch before it bottoms, from the previous glow plug? And if the heads shims have rotated, that could make a difference also? I would like to see some photos of that.

It doesn't really matter as a sleeve is supposed to be a perfect circle but 9 out of 10 times the sleeves are a little or of round,i am pretty sure that's why novarossi wants you to install the head button/combustion chamber the same orientation when assembling ;)

Thanks Monty, now that makes more sense, but, I doubt the out of roundness, will make any noticable difference that anyone could tell, unless you put it on dyno or a machine that can give you rpm and horsepower range.

Ya,i am sure it really isn't a huge deal but it wouldn't hurt if you put it on the same way every time either would it? ;)

I get this call pretty often," which way does the button go?" , its a circle, does it matter?

Lol, I can imagine, simple, round head button, round sleeve, now, MATE!

Rody button doesn't have a round dome. The combustion chamber isn't symmetrical.

That's an exception Rob , as I have said before I made the same style of combustion chambers and they worked well, just qwarky power

True, but close enough to put the head button in how ever u want.

no its not...the C6 USA has only 1 orientation you can use.....

How many times have you seen people take off the head and head button, and not remove the glow plug? Most people do not know to remove the plug before you loosen head bolts, how much do think that throws all the theory of head button installing out the window.

I think your totally missing the bus here... The C6 USA has a huge scallup cut out of part of the squish band...that scallop must face the exhaust port to function correctly... I am sure the engine would run with the scallop facing another direction but i bet the engine wouldn't run well...the inside of the C6 USA head button is not round....Thi has nothing at all to do with glowplug...We are talking about a very unique head button that needs to be installed correctly for the engine to function...

I never said anything about a C6 USA not being a one way head button, I spoke of most nova based engines. One or two engines out of all the nova based engines is very small. Your talking about a Rody engine, not a manufactured engine, Rodys were all known to be modified engines, not a manufactured engine.

Does any one have a part number for connecting rod. The tag on the piston and sleeve says it's for a s7. Thanks in advance.

O1121C. Amain Hobbie has some RB parts, look on there site for parts you need.

Amain has 0122c but no 01121c. U know who else might have one.