OS motor gear combo?

[BamaFan]

So I got the os motor waiting to go in my revo when I get the header in and i was wondering whats a good gear combo for this motor? I was running a 15/40 with my 3.3 motor and I liked it but i figure that will be too low to harness the power of a BB so I was wondering what you guys run? I went ahead and put a 36 tooth spur since I had one and I do have a 17 tooth CB but I don't want to gear up too much where I can't get a wheelie out of it.

 

[2revo1maxx]

What "motor" is it?
15/36 would be a good all around ratio for a 21 tm....I actually use that on my 18tm and it's good.

 

[BamaFan]

os .21 TM. I am still waiting on the manifold to get to my LHS where I can break this baby in. My LHS called me today and told me they would have the manifold Wed. The only os motor they had left was for a t maxx so they had to order me the correct manifold and they did it for free so that was pretty cool. Least they could do I pay there rent, light bill, water..... LOL.

 

[2revo1maxx]

Divide the bell gear teeth into the spur teeth for a ratio number: 15/38 is a 2.53:1 ratio and 15/36 is a 2.4:1 etc.
The os 21tm has more power but revs a hair lower than the 3.3, so 15 or 16/36 would be good.

 

[BamaFan]

Sweet thanks for the advise. I have read a dozen different break in methods for the os motor what would you advise to do to break it in since you have a os motor? I really want to do it right I got a lot of cash tied up in this motor vs 100 bucks for a 3.3.

 

[2revo1maxx]

Go by the manual, and if you have a temp gun you should wrap the head so it will run rich AND reach 200 degrees. It's very important to have it up to temp and rich so the metal dust will be flushed out the exhaust. You also want the engine to loosen up, which won't happen if it's cold. Finally make sure you don't lean it or rev it hard until at least 8-10 full tanks.

I like to do it all (or mostly) at once if possible, that way the engine stays warm and isn't under alot of stress.

 

[BamaFan]

Yea that's how I break mine in just making sure. What about making sure the pistonis at BDC during cool off inbetween tanks is that important with os motors as much as it is with trx

 

[2revo1maxx]

Yes, it's recommended with any abc engine. I personally think it's a myth but I do it anyway.

 

[BamaFan]

LOL yea me too why chance it? Thanks for your advise!

 

[BamaFan]

Is 25% nitro ok to use with this engine thats what I have always ran in my trx engine's

 

[2revo1maxx]

Yeah, but for best results you want about 12% oil content and not something with 16% oil.

 

[BamaFan]

Ok sweet. Thanks.

---------- Post added at 7:26 PM ---------- Previous post was at 7:23 PM ----------

I just went and looked and mine doesn't have a oil content %. It's odonnells 25% clear is all it says I checked the whole bottle and it doesn't have a oil content anywhere.

 

[TRXaddict]

Looked on google and it says that the 25% odonnel has 8 % apparently.

I personally think that's alittle low but IMO i know 12% is the average for most fuels but maybe that fuel is for specific engines ? never had experience with odonnel but I'm thinking about switching to it soon. as long as they have the same oil content as my original fuel.

http://www.towerhobbies.com/products/odonnell/odop3310m.html

 

[BamaFan]

Hummmmmm. I wonder if I need to switch to a different fuel? I can always switch back to traxxas 20% but I think it has more than 16% cause it is extremely oily IMO. What do you run?

---------- Post added at 8:08 PM ---------- Previous post was at 8:01 PM ----------

I was told by my lhs any nitro fuel over 9% will make your nitro run hotter. That was like 6 months ago when I switched off 20% to 25% and he also said pretty much all brands of nitro run about the same oil content to nitro ratio. So basically if 25% has 8% other brands will be close to that within a % does that sound right to you.

---------- Post added at 8:10 PM ---------- Previous post was at 8:08 PM ----------

Lol. Typo... So basically if odonnells 25% has 8% oil content other brands will be within a % does that sound right?

---------- Post added at 8:14 PM ---------- Previous post was at 8:10 PM ----------

I'm thinking it really doesn't matter LOL. I'm pretty sure the lhs wouldn't sell it if it wasn't any good. I doubt the brand of fuel will make a difference in engine life. I'm thinking the only thing that comes into play with fuel and engine life is the % nitro you use and thats why I don't run more than 25%. If I raced I would run 33% but I don't and thats why I chose 25% kinda the middle of the road.

 

[TRXaddict]

Hummmmmm. I wonder if I need to switch to a different fuel? I can always switch back to traxxas 20% but I think it has more than 16% cause it is extremely oily IMO. What do you run?

---------- Post added at 8:08 PM ---------- Previous post was at 8:01 PM ----------

I was told by my lhs any nitro fuel over 9% will make your nitro run hotter. That was like 6 months ago when I switched off 20% to 25% and he also said pretty much all brands of nitro run about the same oil content to nitro ratio. So basically if 25% has 8% other brands will be close to that within a % does that sound right to you.

---------- Post added at 8:10 PM ---------- Previous post was at 8:08 PM ----------

Lol. Typo... So basically if odonnells 25% has 8% oil content other brands will be within a % does that sound right?

---------- Post added at 8:14 PM ---------- Previous post was at 8:10 PM ----------

I'm thinking it really doesn't matter LOL. I'm pretty sure the lhs wouldn't sell it if it wasn't any good. I doubt the brand of fuel will make a difference in engine life. I'm thinking the only thing that comes into play with fuel and engine life is the % nitro you use and thats why I don't run more than 25%. If I raced I would run 33% but I don't and thats why I chose 25% kinda the middle of the road.

I run trinity monster but thats mainly because my closest LHS is like 40 miles away and they didnt really have anything besides that and another fuel bran I've never used so i got that. and they didnt seem to let me buy what i wanted.. I was going to buy 30 % because i personally think that would actually run nicely with the 4.6 but they literally said dont buy 30 % please take it back and get 20 %... and I'm like well whats wrong with 30 % ? and they kept going on about how it ruins engines really fast but from what I've read its actually quite better because it runs cooler. but I've never ran 30% so i have yet to find out. and then i wanted air filter oil and the guy said * dont buy air filter oil just put alittle fuel in your filter and let it dry and it will be oiled. and i didnt wanna argue so i left with just fuel and then tried the filter thing and its not nearly oiled enough... and plus i dont like to waste any of my fuel at all because since they are so far away i need to save every drop i can.

Honestly... i think trinity fuel is more oily than traxxas lol.. maybe is me or my tune or something. but when i have it on my tailgate warming up there is literally a puddle of oil and i know its not to rich because at idle theres not really any smoke. Only when accelerating but yeah I'm never doing business with them.. too expensive i dont like paying retail lol i guess the best option is to stick with online shopping because since the closest place takes about 15-20 in gas i can save that and the miles on my car but the waiting does suck but its worth it in my opinion.

I've heard nothing but good stuff about odonnel.

 

[BamaFan]

Yea I'm lucky I have 3 rc shops within 15 miles of me so I have options but I do have a favorite lhs that I try to stick with directly across the street from my work. LOL. I guess thats why I love rc's so much been working there for 12 years and that hobby shop has been there for prob 15 years so it's really easy for me to get my stuff. They offer every type of fuel on the market but for some reason they really push odonnells so thats what I use. I'm thinking there is plenty of oil content also cause when I'm warming mine up on my tail gate there is a puddle of oil as well and like you said it's not my tune I'm actually pretty pretty good at tuning but I do run mine a touch rich and try to stay around 205-215 with 25% nitro. I know a lot of people will say thats too cool but my cars run good at that temp any hotter they don't run right and the motor starts spuddering. Thanks for all your input. Also do I need to put a couple drops of ARO in the motor before the first start I was told it was a must with BB?

 

[RenegadeScout]

i used o donnel and loved it but our lhs stopped selling it

 

[BamaFan]

Man up till like 6 months ago I was stuck on traxxas fuel and my lhs tech talked me into odo and I have been really pleased with it runs cooler and runs better and the fuel is cheaper.

 

[TRXaddict]

I like to put a few drops in a bran new engine but I've never used after run oil thats specifically for RC's i used 3n1 oil because its really great stuff. Idk what it is about it but literally when ever I'm having alittle trouble with the engine running smoothly i add a drop in the glow plug hole and runs amazing. Just the other day my friends t maxx 3.3 was acting up and I'm like let me use my magic oil and put 2 drops and literally it started right up just needed alittle tunning after that . I think thats the only oil ill ever use in my engine just because i noticed nitro engines really like it. and its just good for everything.. bearings, cleaning, engine, basically anything that needs lubed 3n1 does a great job IMO.

I'm guessing odonnel uses less oil because maybe they use a thicker weight ? There has got to be a better weight oil in there to compensate for the lower percentage.

 

[BamaFan]

Maybe man all I know is my new os has a warranty and I'm using there fuel they recommend so if it f's up there replacing it. . 3in1 oil is the best thats all I use on my guns never thought to use it in a rc may try thats vs buying ARO. Thats TRXaddict!