Sounds like the rear bearing failed maybe?, could be due to lack of lubrication/engine being too lean?

It's always a real heart ache blowing up a .21 on-road engine, they aren't cheap!

Hope you get it back up and running soon!

I'm not too good with C deg, In F deg is close to 240deg, Ambient temp at 80deg. It stalled out a few times cuz its too lean. Richen your LSN a bit, get it to 220-230C be a lot better. What % of nitro you using? Crankcase really looks too dry, unless you wipe it off with a paper towel!

Hi guys,
I use Tornado 25% fuel.
What I said the highest temperature was 117 C when we readjust the engine only for one lap.We run the engine at 100 to 105 C which is 220 deg F.
I don't think the engine was to lean, had lots of blue smoke coming out and it died always in a very slow corner...
When I disassembled the engine and saw the piston/sleeve I thought damn I got dirt into the engine...
So I started cleaning the crankcase, piston, sleeve and bearings. The carburetor looks clean, had only airfilter oil on the intake. During the cleaning I found fine metal shavings and heard that the bearing has excessive play...
At that time I removed already all the lubricant.

I contacted OS - still waiting for their feedback.

Michael

Your rear bearing is corroded. That is not a manufactor defekt. It is clear in the picture of your crankcase. That will eat ceramic balls very fast.

I love mine... Its a torque monster with a ton of mid range but very little top end

It is quite normal for bearings to fail, specially the rear.

If you are looking for answers why? It can be many factors, including being too rich. get new bearings, look on youtube how to change them (you must take of carby and all components and put in the oven and readh 150c and they can fall out or a small tap.

then warm up block and put back new "cold" bearings in.

Do not attempt to run the engine as it is.

They're producing their peak power somewhere in the region of 8,000 RPM lower than a Novarossi Virtus for instance, this means you're going to have the gear the car completely different, you need to keep gearing taller until you get that top end back with the OS engine.

How's this engine?

all i can say its amaze me even i got some minor problem due to rich on my qualifing heat but in final the engine totally give amazing power and torque, the temp of my engine give suprise 80deg till finish the race,usually my zac r2101 and my nova rex peak temp 130deg - 150 deg at 36deg wheather

coming from NOVA 35plus21 , I also love it
finishing the break-in period and now , will definitly see what it can produce
so far , easy set-up , easy breakin , can't wait to see more
already satidfied with the power delivered

Hope you sorted the issues out with your engine. This is the single best engine I have run with no problems.

Anybody using or have tried the HIPEX 2115 pipe with this engine yet. I know Collari uses it on his modified R2101 engines. Just would like some thoughts on how it compares to the OS Speed pipe.
I will be doing some back to back comparison next weekend at our first race meet of the year.

How was your testing? Which pipe /header combos did you try? Results of the performance?

Hey there fellow OS users. One the weekend I tried the short manifold with the HIPEX pipe. Results are not totally conclusive but the first thing i did notice that the pipe did give a bit more top end or the OS OEM pipe set, run time was much the same. Power band delivery was a bit earlier with the hipex pipe.

This weekend we have another race meeting and I will try the medium manifold and report back the results. I will have better data after this weekend as I can give a comparison on all three pipe combinations.

Sorry if this is not a totally comprehensive post on the results. But so far if you are keen to try these HIPEX pipes and manifolds, I would no hesitation in suggesting anybody trying these. They are excellent value for money and are very well made.

Stay tuned for another post after this weekend.

HI
Collari use 2069 HYPEX with conical C-
which pipe you used exactly. explain with better details . For you the HYPEX is better 2115 is better