what's the difference between the ostr r spec and the ostr e spec??? any significant difference in horsepower rating and cooling head design??? how about the carb???

If I'm not mistaken, R Spec is ROAR/IFMAR spec, which means cranckshaft could have bigger inner dia. (8mm), and turbo scoop can be big enough to come from inside hole.

E spec must be EFRA spec engine with crank inner hole limited to 7mm without chamfer and turbo scoop doesn't meet hole.

Sleeve porting, timing, and rest of engine must be the same.

AFM

Thanks afm! I will check that next time i pull the engine....but the crank took the most work on my engine so i am sure it is not the same now lol. Thanks for the good explanation.

thanks bro for that update on the difference between the 2 engines. as for power difference, which of the 2 has more power???

If the R spec is making use of all the possibilities that IFMAR rules allows, it should have more power....not much but definitively more, and specially on long flowing tracks.

AFM

i;ve read in the manual that it says that the rear bearing has a plastic retainer. if the motor's temp reaches above 248 deg F the plastic retainer will cease. have any of you guys had this plastic retainer on the rear bearing fail on you?

I don't remember reading that. At any rate I've run the motor well past this so called 248 deg. "limit" numerous times without problems.

hehe thanks im just gonna run the motor hot as well from now on... well i wont call it hot ill just call it.. in tuned... i was running it 270 F today! to be honest not really happy with its power, im gonna get the full mod done to it next week. sleeve and crank! and maybe carb if it can be done. but i wonder what would happen to the fuel mileage.

I'm sure it will still make 5 minutes. Maybe you should try a colder plug.

Who's gonna do it?... do they know what they are doing?

I agree with Racing4Evo, you should try a colder plug, I've had great results with both the p7 & p8...

yea i've tried P8 and noticed much more top end and maybe 10 deg F cooler. but the bottom end seems not that responsive so i tried P7 inwhich i prefer. i think i might have to play around with my gears as well. maybe as i lean it, its hitting top speed quickly and staying there for a few seconds which might be the reason for being abit hot.

And Luis im getting a guy at my track to do the mod hes been in this hobby for 10 years. and hes motors go very very well! and very very reliable as well.

which is faster between the OSTR turbo version and the OSTR r spec???

I just wanted to post how my R-spec ran, It is modified to the 2005 specs by TQ Motors. It has work done to the crank, and sleeve, the exhaust port timing was changed and the intake ports improved.

I ran it at the last series race for the Southwest series here in Texas over the weekend.

It had as much if not more power than all of the other motors in the A-main. I was getting over 7 1/2 minutes of run time on the track and it was temping in the 210-215 range. The idle was rock solid and it started easily every time.

I never got a chance to run the tank all the way dry on a run and have a hard time believing how good the fuel economy was. I showed the tank to one of the Palmaris drivers after a 5 minute qualifier and it was still 1/2 full!! The track was large and my chassis was not working really well but the car was good enough to make the A-mian against some very fast drivers.

All I can say is that I am very happy with the motor and the work that TQ did on it. I can't wait to see how it compares to Ron Atomics motors, I know of one driver in the A that was running an X12 and I backed off many times on the straight to avoid running him down. I have no idea what condition his motor was in but he was also pretty fast.


I could not be happier with my choice.

Good luck
Cody

glad to here you like your os! Mine has been a rock solid performer for me. At the end of sundays race my os tr started to get tired out temps were still fine but it is just tired and compression has dropped and blowby can be heard. In no way is this a complaint as i have run this engine hard for around 20 liters. I am rebuilding it this week. Initial tear down showed that the bearings are in good shape and only p/s needs to be redone. I am very happy with how this motor has performed against the italian mills and for the price is definately a great choice.

ffr how much did your tq mod cost?

thanks.

your os/tr carburator has this rubber seal that goes into the cranjcase.

i have heard a few guys having problem with it either leaks or damage somehow.

is this normal...