Associated LRP Z.28R Spec 3

[Thirdgen89GTA]

Hows this motor? I'm considering one for my truggy. Reminding all that i bash, so pitstops for a fuel hungry motor aren't a problem.

The Piston/sleeve isn't bad at $75, certainly not super cheap, but its not a bad replacement if it lasts a while. This would be going in a LSPR with a pipe similar to a JP3 in the powerband (what I have laying around).

I love my OS 30vg, and I love OS's product support (which is why I really love it, they'll repair anything I've noticed) The power is nice too.

[Czech-it-Out Graphics]

Saxton ran it in his truggy at finals it ripped had tons of power but after 4 quals and practice it was just about toast lol

[rocco79]

They are very similar to the motors i used to run (24/7 pro, sh 28) They are strong performers... And you will get 5,6,7 gallons if you dont overheat it... They seem sensitive to this..

A 24/7 pro which has a smaller displacement than a .28 had enough power to throw my lsp around no problem! Infact a friend has one in his lsp now with 6+ gallons on it and it was nearly as fast as my p5x!

[Thirdgen89GTA]

I read that I wouldn't get that much out of my OS30, but 4 gallons later its still plenty hard to turn that crank over by hand, requires alot of effort, so I figure I can get a bit more out of it.

So they don't like to run hot then. My OS 30 runs about 210 on average at a track, but when bashing with the LONG WOT speed runs I"ve seen it creep up to 250. What do the LRP's like to run at?

For $170, its not a bad price. I can get a Axial .28 spec 1 for $106 w/tax, I've seen them in savages and I'm impressed, they do very well. But I'm just curious if its worth the extra money.

[Tex]

I thought you had two infinity.27's?
A motor usually runs hotter on a track opposed to WOT bashing 99% of the time. The air flow (air cooled motor) when doing high speed runs is much better than a track which doesn't see nearly the airfow and the motor is working just as hard.

[Czech-it-Out Graphics]

dude a motor will run much hotter doing WOT high speed runs

[Tex]

no it won't, not from my experiences.

more air flow, cooler motor.... kinda like a real car when it's over heating (because then it's only hope is air cooling)
on the highway the motor works less and gets more airflow...in the city it will overheat like a banshee at a single stoplight...

I know that was an example of real motors against nitro RC motors which is a hell of a difference but the same thing happens.


Imagine how much the nitro motor works to propell the 8lb rc up to speed....(multiple times per lap on a track)
Now invision how much power it takes a nitro engine to continually pull an 8lb rc once up to speed....

which one works the motor more?

I know your answer is going to be something to the fact of 'but the engine is at 35K RPMs at speed and it's only at 10K-30K on a track'

doesn't matter....look at the airflow your getting at 40mph in a parking lot.

The only way a high speed run is worse than track driving is if your doing grass runs

[Thirdgen89GTA]

Well, in theory you are right Tex.

But when I'm doing 400' long runs the motor runs substantially hotter. The head does a good job of cooling the engine off, OS did there homework there.

But at the bash when just tooling around it runs fine, but start pouring on the speed for 6 seconds, turning around, and doing it again and it the engine does start to overheat. I've already enlarged the cooling vent in the front window of the body to help with this, but it still raises temps. I'm accelerating HARD for 6 seconds, slamming on the brakes, then doing it all over again in another drag race. I'm not reaching a speed then backing off the throttle and holding it, I'm accelerating the whole time.

[Czech-it-Out Graphics]

Tex u have to also take into account the fact that the air is generally only hitting the cooling head, how much effect can that have on cooling and engine running at its peak performance at around 40k rpms where at full throttle it is using as much fuel as it possibly can, it will start to lean out without a doubt more and more the longer u stay at full throttle. comparing a 2 stroke to a full size engine is like comparing apples to oranges, the cooling aspects of it are totally different and just the way they work is completely different. A car has a transmission which will keep it working less on the highway and at a higher rate of speed. imagine driving ur car in say second gear every where its not gonna get hot at slower speeds but when u go on the highway its got no chance. also with our motors while ur running at quarter to mid throttle the low end really isnt acting much, when u start to hit that part of the power band the HSN is dumping fuel into the motor which is going to get used up before it takes on much more or it will inevitably load up. this is also why a motor is going to use much less fuel on a short track.

[Traxxas_Junkee]

Tex you also have to remember on a 1:1 car it will have different gears. So even if the car is going 75 MPH it may only be running at 2700 RPM as opposed to a nitro motor that in order to get to the top speeds it has to go alot higher in the RPM range.

[Czech-it-Out Graphics]

echo echo echo

[Tex]

I know that was an example of real motors against nitro RC motors which is a hell of a difference

understood

[Traxxas_Junkee]

echo echo echo

Wow, somehow I missed your whole post. lol. Sorry.

[Thirdgen89GTA]

Hey, someone recomended looking into the XTM 457 instead, and well from what i can see its the exact same motor. Or atleast using the same block. I know they share parts.

Anyone have an opinion on the two? LRP Z .28r vs XTM 457?

[rocco79]

Same thing....

[Thirdgen89GTA]

So no difference then. Thats what I thought, they looked the exact same.

Reason i was asking is that the Axial .28 is the same as the Savage 4.6, but the Axial makes more power.

[Thirdgen89GTA]

Well, the search starts again. Looking for a motor with the same power in the same price range.

Turns out they won't be able to get the non-ps version till Jan 8th, I wanted it for the Monster Jam on January 5th. Need it, gotta have something to stick in the truggy with some serious power.

So what other engines have similar power and are in the same price range? They have the pull start version in stock, but I the engine mounts I have will not work with a pull start motor. And I don't want to pay to convert to a non-ps motor later.

[Tex]

What about a XTM 247 pro for around $130? those are good motors and powerfull

[Thirdgen89GTA]

The XTM 247 just isn't enough for what i really do with my stuff. If I have to I'd rather step up and pay more than to step down and pay less.

[rocco79]

then get a mach .26 and be done with it.... Or a Mach .28..

[satoch]

Or the SH P6 Prospec .28

[rocco79]

Thats a six port right? i think the mach .28 is only a three...

[Tex]

People sell used NR 528's for around $200 with 2-3 gallons on them...If you want the sickest motor, there it is.

[Thirdgen89GTA]

After buying my OS i'm not too hot on used motors unless I can see them in person before laying down the money.

[satoch]

Thats a six port right? i think the mach .28 is only a three...

Yeah, it's a six port. SH is making some serious race motors lately.