Traxxasfreak1

I want to get a new engine for my revo. I like the new 3.3 engine but it seems like everyone has the OS 18TM. I want your opinion on which i should buy.

Douggiefresh2323

3.3 has CRAZY power......id go with that if u want somthing different. Im very impressed with the 3.3. None of my friends trucks could think about hangin with it. a savage SS, warhead, t maxx 2.5r, and a revo, i think it was the 2.5 too, Its a great engine. im impressed

rcdude37

do a search you'll find something...

Airpressure

The 3.3 is a great engine! More power than the TM by alot. Tunability goes to the TM though.

cardgabe

There's another thread with almost this EXACT title. If you scroll down to the next page or so in this forum, you'll find it. It has a lot of posts about both of these engines.

Gullwing72

They both have +and - the 3.3 while more powerful and full of low end torque, it will not be as stable on the tuning. The OS on the other hand is more stable on the tuning but you lose a little of the power. I have seen the 3.3 run and it is a very strong engine, but I went with the OS .18TM and have not regretted it. It will pull the front wheels on pavement and I tuned it once when I got it about a month ago and have not touched it sense, both are good engines. GW

JSRacer

I ordered the 18TM for my REVO. I should have it by the end of the week. I started reading about this 3.3 and nearly changed my mind but I'll stick with the 18TM and see how everything pans out. With the reliability and tuneability, it's sounds like I can't go wrong.

cardgabe

I just put the OS.18TM in my Tmaxx. I've gotten through 5 and a half tanks of gas so far. I don't see how anyone could need much more torque than the OS has. If I give it half throttle it just flips over onto its back. I have to finesse the throttle to keep all four wheels on the ground. (this is while its still at the factory very rich settings) I'm scared to see it once I lean it out. LoL On the other hand, I have see the 3.3 in action, and it's a very fast motor as well. It is a little faster than the OS, but I hear the tunability of it is a lot worse. This is why I chose the OS, because I'm fairly new, and don't want to have to tune every day I drive.

bdd012

i agree with cardgabe, from what i hear the 3.3 has a little more power than the OS TM, but i think the OS has enough. and if traxxas is living up to there reputation, you gotta ask yourself if you wanna get there and run, or you wanna keep tuning. with the OS there is little to no tuning, and if the 3.3 is anything like the 2.5 you will always be tuning and never get it right unless you are lucky cause it seems 1 out of 5 trx's are good. traxxas does have the engine replacement program, but OS has a 2 year warranty. im gotta go with the OS cause i love mine, recommend it to anyone.

JSRacer

Just got my OS 18tm for my REVO today! Probably won't put it in till Friday night. I've heard great things about it, can't wait to see it for myself. I also bought a LRP Z28R for my LST2. Can't wait to see what that's got. HP rating seems a bit high at 3.8! We'll see.

Traxxasfreak1

Thanks.

eehsnab

just picked up a 3.3 today... I'll report back in after break in

cardgabe

Well... My OS.18TM is completely broken in... I'm through a few more tanks and finally was really giving it some throttle. It pulls wheelies too easily and flips onto its roof. I was riding tonight in a school parking lot... I could be cruising along in first gear, then when I'd really punch the gas, the truck would spin all four tires and drift sideways... it was awesome. The downside to the OS.18TM in my maxx? I need new differentials now. LoL When I hit the brakes near me, i hear a lot of clicking. Probably during accelleration too, but the pipe is too loud. Still drives great though... I'll probably wait until the diffs are completely toast before I put new ones in.

Gullwing72

I broke my rear driveshaft yesterday with my .18TM. Didn't even know it till I got it home....LOL..........GW

cardgabe

LoL Gull, that sucks. I have a feeling I'll be doing some mods to my driveshafts in the future as well. So far they are holding up, but I haven't really gotten on it as much as I could. I've just made some "hot laps" in the high school parking lot behind my house. I'm really happy with the power of this engine. What do I need to rebuild my diffs? Just the ring gear set? (comes with ring gear and pinion gear for the diffs). Or do I need the set with the axle gears too? I've never opened my differentials up to get a good look at them. LoL Can someone post a link or two on tower or something so I can see the different things I need? I gotta go to work now... assuming the snow holds off, I'll be bashing tonight! (if it snows i'll be in the garage building a jump).

Traxxasfreak1

how fast will it go with the OS 18

Gullwing72

Well once you get the front wheels back on the ground and get it straight it blows 2.5s away. My wife and daughter hate my truck because there is no way in hell they can catch it with theirs.....LOL....No really I have no idea. The 2.5 says 40 but doubt it for the most part(maybe if tuned perfect) so if you go with 35 or 40 of the 2.5 I would guess 40 to 45 with the OS. It is not the top end speed that blows me away, it is the low end torque........GW

cardgabe......I have never torn into the diffs on any of my trucks(yet) so I really don't have a clue. So far(knock on wood) It has just fuel tanks and driveshafts.....GW

TGreg24

haha im about to sell my unbroken in os tm for 200 and use the 100 for the ERP and get a 3.3 and use the other 100 to get it modded by rb, OH YEA[X(]

JSRacer

Anyone have any good links on upgrade driveshafts for the REVO?

taimaster2005

Look for my post for my trx 3.3 engine review. http://www.rcuniverse.com/forum/m_39...mpage_3/tm.htm

cardgabe

Gullwing, You are absolutely right, the low end torque is awesome. I love going about 10 miles per hour, then punching it and having the tires break loose on the pavement and send the truck sideways! There's easily enough torque to sacrifice some if you wanted to change the gearing for more top speed. Although its much faster than my stock tmaxx was, it has way more torque which is what i was looking for. Someday I may get a bigger clutch bell or smaller spur gear and see what kinda speed I can do, for now, its wheelies and burnouts.

Gullwing72

Yeah I just like the torque, I don't do much racing or a lot of high speed jumps. I broke the driveshaft doing donuts in the dirt. I didn't even think it would do them. I had tried it stock and gave up. Then yesterday I did one by accident and thought WOW. So I pretty much emptied one tank going around the around....LOL...... I don't know why anyone would want more power in that truck but hey to each his own.......GW

cardgabe

I think the real test will be when I get out to the sand dunes around my house. With my Pro .15 the engine would completely bog down before I was half way up the dunes. My friends 3.3 would just fly up the dunes. With all this torque, I don't think I'll have a problem either. Unfortunately his truck isn't running now... in my opinion he just did too many modifications at once and now can't get it all to work together. LoL I could see the frustration in his eyes last night while trying to get it to move... then it stalled, then he pulled the pullstart and the cord came out. LoL He was done at that point. Still can't figure out why the truck won't go though... he put a SureFire .32 in it and it kinda revs up, but it can barely turn the tranny to get the truck moving. HIs slipper isn't too tight or too loose I don't think. It just seems that the engine can't turn the tranny cause something is binding? I don't know. ANy ideas?

cruiserx

1 out of 5 are good??? where in the heck did you come up with that number??? i bash with sometimes up to 10 +people on the weekend,some friends ,some family,that have a trx2.5 powered rc..they all have been fantastic power plants..no problem with tuning or power or reliability..some have 7+ gallons ran thru them and are still running great..we have 1 os.18tm in the group..it's a great engine..i have a revo 2.5r,among other r/c's, and can bash the whole weekend just like he can without ever touching my needles..not a big deal..traxxas builds a great high quality engine....yes os engines are the gold standard but dont be so hard on the trx engine..it's not that bad...

Revoman77

I say 3.3 its just all around good