OS.21 XM V11

[Hayden Bright]

Hi everyone I was just wondering what feedback everyone has on the new aircooled engine.

Just general stuff like is it easier to prop and tune?

Are you happy with it's performance?

Howz the piston/liner holding up?

Just what you think of the engine compared to the V1 in general....

 

[Kevin Krogness]

They are fast!!!! But unless you have a good reason to upgrade keep your water cooled unit and run that TT!!!!

 

[Hayden Bright]

Well I was under the impression that the V1 will no longer be available once the stock is gone? as the VII is the replacement,

Is that right then we will all have to run the VII!!!

Kroggs I'm just curious to hear what everyones opinion is, I won't need a new engine for awile fingers

crossed....TT will only be replaced by another TT I can asure you my friend, the TT I run now is older than my OS

and it still pops like brand new

 

[RodneyPierce]

But Hayden, as long as you dont kill the head button on your V1, you wont have to worry about replacing anything. As the V2 piston/liner is identical to the V1.

This is just from me watching Mike Z's tunnel a couple weeks ago in MN. My personal opinion is that the V2 lays down on the top end a bit sooner then the V1 did. It appeared and sounded to me like the V1 really liked to REV on the top end in comparison to the V2. I think adding that spacer in the V2 muffler added some torque to the motor (this seems to be the consensious) but it lost a little top end RPM. IF you can get the V1 into its upper end range, I think it is capable of being a faster mill.

So for me, Im going to stick with my V1 parts as long as I can

 

[Hayden Bright]

But Hayden, as long as you dont kill the head button on your V1, you wont have to worry about replacing anything. As the V2 piston/liner is identical to the V1.

This is just from me watching Mike Z's tunnel a couple weeks ago in MN. My personal opinion is that the V2 lays down on the top end a bit sooner then the V1 did. It appeared and sounded to me like the V1 really liked to REV on the top end in comparison to the V2. I think adding that spacer in the V2 muffler added some torque to the motor (this seems to be the consensious) but it lost a little top end RPM. IF you can get the V1 into its upper end range, I think it is capable of being a faster mill.

So for me, Im going to stick with my V1 parts as long as I can

Ahhh yes rodney good response mate thanks.....I agree yes but wonder if the added torque will mean you can prop it easier and it should be able to pull a touch more prop also.....

I just put the VII p/l in my engine and I'm guessing after reading a response from OS I'm thinking the VII got an extra nickel coating which may explain the different part# also...They quoted that they were aware of the nickel plate flaking and were doing a double coat to fix that on some engines, wether or not the VII xm got this how knows, but hopefully means a little more life out of the liner.

What hull was mike running the vs1 or ts3 rodney, curious how it pushed the ts3 if that was the case!!!

 

[LarryConrad]

What hull was mike running the vs1 or ts3 rodney, curious how it pushed the ts3 if that was the case!!!

Nemesis

 

[Kevin Krogness]

Mike was running neither, it was his Nemesis???? Spelling....

 

[Hayden Bright]

Mike was running neither, it was his Nemesis???? Spelling....

Thought the nemesis is the TS3?

 

[RodneyPierce]

No, the nemesis is most def. not the TS3

 

[Hayden Bright]

No, the nemesis is most def. not the TS3

Ok then, I was under the impression the TS3 was based on his nemesis, thats all I meant sorry for the misunderstanding.....

Of course he would be running his design the NEMESIS guys, yes I should have used nemesis not TS3......

 

[Hayden Bright]

Obviously I have no idea.......TS3 has nothing to do with mike's nemesis ok now I know, well I don't need to know how th OS VII went on that then.

I found the OS really hard to prop for the TS3, me thinks the VII would be a better match for the heavier hull of the TS3 with the extra torque and all...

 

[Slideblues]

Last we spoke Mike Z was still working on prop's for the Nemesis,

Gene

 

[RodneyPierce]

Hayden, why do you find the OS hard to prop on the TS3? Just cant get it into its sweet spot or what?

If thats the case, try less cup. mine didnt wake up until I had the prop at 2.4 or less cup. Then the thing all of the sudden seen more RPM then it ever had. Today, I put a decupped 40x52/3 on a buddy's HTB and he about crapped his pants. He gave the prop back and said "thats nuts, I have never heard it RPM like that before!" Almost like he didnt want to run it anymore. haha. I told him thats how its supposed to sound.

If there is another reason, let me know and I might be able to help perhaps?

 

[LarryConrad]

I have found the OS XM outboards to be an extremly easy engine to make run slow. I'm a firm believer in running my needles on the fat side, and have found if I try to adjust a 20J on any engine by ear to sag when the throttle is pulled, or to the range on my flow meter that my other .21 perform best at, the OS will be good for about 25 mph and suck down 8 oz. of fuel in about 5 laps. My Mac outboards runs best at around 65 on my Boris Mazor flow meter, my inboard Novas in the 70 range. Last time out with the VS-1/ V1 OS I was finally getting the acceleration down the straights like some of the faster XM's i have winessed with no loss of power through the turns. When I flowed the needle setting after the run it was 100 on my meter I'd never get any of my other .21's off the bank squeezed that tight.

 

[Hayden Bright]

Hayden, why do you find the OS hard to prop on the TS3? Just cant get it into its sweet spot or what?

If thats the case, try less cup. mine didnt wake up until I had the prop at 2.4 or less cup. Then the thing all of the sudden seen more RPM then it ever had. Today, I put a decupped 40x52/3 on a buddy's HTB and he about crapped his pants. He gave the prop back and said "thats nuts, I have never heard it RPM like that before!" Almost like he didnt want to run it anymore. haha. I told him thats how its supposed to sound.

If there is another reason, let me know and I might be able to help perhaps?

Rodney thanks for the offer and don't worry I will ask..... I don't have the OS hanging on the TS3 anymore but thats where it first went, I found the sweet spot but it was a mission I tell ya....on 30% fuel aswell.

The 40x52/3 is on my VS1 combo dude and yeah it screams for sure, but yeah less cup would have helped the OS spin behind the TS3 I often found myself going back to the carbon prop lol just to get some rpms :blink:

 

[Tim_Duggan]

My Mac outboards runs best at around 65 on my Boris Mazor flow meter, my inboard Novas in the 70 range. Last time out with the VS-1/ V1 OS I was finally getting the acceleration down the straights like some of the faster XM's i have winessed with no loss of power through the turns. When I flowed the needle setting after the run it was 100 on my meter I'd never get any of my other .21's off the bank squeezed that tight.

And there is a very good example of what a full tuned pipe, higher compression ratio and higher timing does verses a tuned muffler, low CR and low timings. Directly effects how much fuel is burned when the engine is in it's "happy place".

I have tested the VerII OS on a TS3. Tried quite a few props on it too. Settled on a "Lynx cut" X442, but feel the hull is still a little too much for the VerII on smooth water compared to other smaller / lighter hulls. My water cooled OS / villain is a little faster in good conditions. In bad conditions, I'd dare say the TS3 would really shine.

 

[Dan Hutchinson]

i thought i would chime in ! i run only OS air cooled motors in both of my new cobra 2 hulls. my stock boats runs well. but i havent found the sweet prop it likes yet ( m440 v cut , 40/53 v cut ) are some of the choices ive tryed. and i always go back to the best out of the 2 the m440 v cut. now on the other hand my piped OS with a silver bullet pipe and the 40/53 v cut really hauls the mail !! i cant wait to put it up against a trully fast 3.5 nova piped engine to see how it compares. in my opinion the air cooled motor is better than the older version and ive had many of both

here are some pics

 

[Hayden Bright]

My Mac outboards runs best at around 65 on my Boris Mazor flow meter, my inboard Novas in the 70 range. Last time out with the VS-1/ V1 OS I was finally getting the acceleration down the straights like some of the faster XM's i have winessed with no loss of power through the turns. When I flowed the needle setting after the run it was 100 on my meter I'd never get any of my other .21's off the bank squeezed that tight.

And there is a very good example of what a full tuned pipe, higher compression ratio and higher timing does verses a tuned muffler, low CR and low timings. Directly effects how much fuel is burned when the engine is in it's "happy place".

I have tested the VerII OS on a TS3. Tried quite a few props on it too. Settled on a "Lynx cut" X442, but feel the hull is still a little too much for the VerII on smooth water compared to other smaller / lighter hulls. My water cooled OS / villain is a little faster in good conditions. In bad conditions, I'd dare say the TS3 would really shine.

Tim

So you have tested the VII on TS3 and the hull was still a bit much tim....

Has anybody noticed the pinch with the VII after some use, is it holding up well to the extra heat from the aircooled setup?

Dan are you getting much more out of the engine with the pipe....is it worth a try?

Well thanks to everyone keep the results coming as you may all still be in the middle of testing....

 

[Dan Hutchinson]

ill tell you i was alittle worryed that i wouldnt have much more power than i already had. but after i put it together and ran it i was very pleased . on my new hull it was really fast. so in my opinion the cost to put a pipe on a OS is around 120.00 which makes to whole engine costing around 520.00 new. when a nova outboard new would be over 700.00 so it all depends on how much you want to spend. so dont get me wrong i loved the nova i had but it was costly and it wasnt as reliable. Dan

 

[Hayden Bright]

Has anybody had any success with spp pipes on the OS engine and which pipe was it?

SPP is all thats really available here in OZ....

Was thinking the NR pipe because I think it's a high rpm nature pipe, being designed for the nova this may not be suitable for the OS though, any info guys would be appreciated thanks....