O.S. .21TM question

[Greywolf74]

After looking at the specs on alot of .21 engines lately I'm wondering why the O.S. .21TM is so popular. Spec wise it has roughly the same RPMs as much of the motors in its price range or lower but you can buy engines like the Dynamite Mach 2 that put out .5 more HP than the .21tm for about half the price. Is the .21tm a small block and thats why it has less HP than other .21 buggy engines? Maybe because they come with either a revo or maxx headers and they are a direct drop in? Sorry I'm not overly familar with nitro engines as I've only had about 3 different models one of them being the .21TM that I've never used I'm just curious why this is such a popular engine. I mean i know that OS quality is higher than dynamite but other than that can anyone shed some more light on this for me?

 

[pugs2300]

well in my case it was just the most suggested replacement motor...many reasons were given when i was asking this question but mostly people said it was a good quality engine that held its tune well and had more power than the 3.3 i was replacing...i also read a lot of reviews and no one seemed to be having any unusual trouble out of them so that's what i ended up goin with...i think if i had it to do over i may go in a diff direction but i am satisfied with my purchase so far...but then again i haven't really ran it much...its just 3-4 tanks past break in so...but there is no way it could be as big of a pos as the 3.3...those have been nothing but trouble for me...went through three of them in three diff trucks in a summer...got a hpi 4.6 that has been an absolute pleasure...stays tuned and always starts right up...even after a long time not being run that thing will fire right up and run like a beast...i hope the .21 turns out to be as good as the 4.6 has been to me...time will tell i suppose

 

[3_Stroke_Motor]

+1 on the 3.3 problems, nothing but little nit picky things, nothing serious, just little nagging problems, won't hold a tune too well, and the idle I have found to be sporadic no matter how finely I tune the LSN and ISS. It's got some kick to it, but more of a value engine than a performance engine, I would consider it a beginners engine (maybe?) just because it has an EZ start mounted on it and very cheap ($115). I've got an O.S. 21 on order. I also saw a .19 that was made by Dynamite I think, that is supposed to be a direct drop in in traxxas rigs, Jatos in particular.

 

[moe7404]

just my idea. small amounts of HP can be off set by pour tuning. not that iam a expert tuner. course you can all ways add extra nitro.

 

[Phins Fan]

IMO the OS name has a higher reputation for higher quality and thats probably what your paying for most. I have an os cv-r .18 thats seen 2 gallons and has just about the same pop as it did after break in. Holds a tune excellent as well. I run this in my Maxx and run a Dynamite BigRed in my MGT. Also a great mill but does seem to be a little more finickey with holding a tune. Both solid brands IMO but I lean towards the OS due to durability over Dynamite

 

[Zdragon71]

I had a dynamite .19T in my tmaxx and loved it for about 3gallons till it shred the rear bearing. I opted for the picco .26 after that. I did rebuild the dynamite and sold it. I have a few guys in my rc club that run nothing but the OS .21tm engines and swear by them. One in particular has that engine on his revo and his drag racer jato and they are both impressive rigs and the os sounds and performs very well in both rigs.

 

[Phins Fan]

The best way to look at it is its a consumable item in this hobby that it will eventually have to be replaced/rebuilt every once in a while. You cannot necessarily believe the HP ratings as they are inaccurate to say the least but finding something in your price range with a high rpm range will only lead to more power in your rig. Buy what you can afford/want. Your gonna blow it eventually so why not get something you want?

 

[Greywolf74]

Good way to look at it Phins....Thanks guys