Colin , what pipe will you be starting with , are people using the Werks 2058 .

the Orion had stock 0.65 between piston and button...I didn't change anything yet

I suggest test n tune and run the engine as tight as it will allow you to run it... first sign of trouble is a hanging idle that won't tune out..different fuels and conditions play a big role in what the ideal head clearances are .

Hey Floss,
Yes will be using 2058 pipe with Optima Manifold.

Cheers,
Colin

What tuning characteristics does this engine like (lean top, fat bottom, etc.)? If I'm running in 70 degf weather, what range of temps would be good for this motor? We are having trouble dialing one in.

so im looking to get a new motor
The SLR-5 or the Atom GTR .21 engine , - I have had good luck with the OS vspec engine , love the way it tunes and the incredible level of confidence I get from it reliability If I could buy another new I would , correct me if I'm wrong but I believe the GTR Atom engine is a VSPEC copy with improvements such as the oiling hole on con rod. has anyone ran both motors to compare - or even ran a vspec then GTR - are they the same. thx

stick with OS.... it works for you....

Sorry Rex, been busy for sure but did get to run the engine and mess around a bit with it in my buggy. The engine is VERY smooth...so smooth that I was messing with the needles too much trying to get more out of the bottom. Mid to top is outrageous with the matching 2058 pipe (same as the werks). Fairly easy to tune and break in went simple enough. This is a great buggy engine for a loose track imho. A little too soft for my liking in truggy but didn't get to try a 2013 on it. Not sure what Orion CRF engine this matches though.
Again, apologize for the late feedback..I have since donated the engine to a fellow racer who was in need of another engine...He really loves it in his buggy, coming from a mito7. Said its really smooth and easier to drive.

I completly agree , and if the vspec was still available i would buy it , i dont want to spend 500+ on a os speed , i understand the atom gtr engine is a copy of the spec long stoke design, and im planning on getting one next. That being said , i see this engine on the dialed site amd just curious if this engine perfroms similar to the atom ,

The Optima is made by the same manufacturer as the Orion Crf engines and is very similar at a better price.

Rex

In my experience the 2058 can feel very dead at low speed, probably the pipe.

Rex

Partially correct , imgoing to get the samuri b321 ! Found my vspec !!