I bought an LRP 28 Spec 3... what am I in for?

[olds97_lss]

Well, I didn't feel like futsing around with engines that just get the job done this year.

I have an Aftershock that this engine will be going into. I still have the stock engine and it's a good backup, but I want more speed and just generally more power overall. I figure with a bit more power it will really let the truck wind up. With the stock engine, it takes a long long run for it to open up and get to a decent speed.

So, did I buy a dud? I'm hoping at $170 it's not... How's break-in? What's the life of the engine like? Any problems that would help to know about? Does it tune well?

Thanks guys!

 

[chuck3]

hah, i just bought the same thing for the same truck!!

 

[savagecre]

Dude know way!!!!!!! I have an Aftershock But My LRP spec three is OH just a deal away but a major possibilite.....so please let me know....First I bought a Dyn platinum .28 just to see I've had a very good experience so far with them......Knock on Wood...

 

[rccars411]

those 2 are pretty much the same engines.

 

[savagecre]

really!!!!!!! how so same manufacture or?

 

[rccars411]

both made by SH engines.

 

[savagecre]

Ok thanks good know so I just paid lets see about 60-70 $ more for the same motor?? their has to be a differnece is some respect right?

 

[neobart]

The Platinum has a carb with three venturi inserts.

 

[chuck3]

i went browsing on youtube and found a couple videos of the lrp 28, it seems to have quite a bit of get up and go to it.

 

[olds97_lss]

Well... I have found out that the AS two speed can't handle the power. It wedges itself into second gear and stays there. I never had a problem running the stock 26SS the XTM 24.7. I've run about 15 tanks through the LRP. The first couple were pretty brutal. After about 5 tanks, it really started to run easier and start easier. After 5 or so, I started leaning it a bit just to get the temps up.

It now runs at about 220F, idles smooth, starts easy by loosening the GP, wraps up through the RPM's nice and clean.

If I'm a little quick with the first 1/4 throttle, it flips on it's lid. By tank 13 I was having two speed problems. I replaced the 2nd gear spur and the two speed shoes. It appears that the aluminum ring that is mounted to the 2nd gear warps under the torque and allows the two speed shoes to go beyond the flat spot on the shaft. Then it's stuck in second.

Looking at the aluminum ring on the second gear indicates that's what the problem is. The only other problem with this is that it jams into second, then contorts the shoes so they cause 1st gear to bind... When you spin 1st and 2nd at the same speed, bad things happen.

I'm bidding on a LST2 slipper/2 speed assembly now... The 2nd gear ring the shoes ride in is actually part of a billet piece instead of molded into the plastic gear. Hopefully it won't warp and cause issues.

So far, I'm very pleased with the engine. It gets stronger with every tank. Even with the AS stuck in second, the engine has enough grunt to get it going rather quickly. Top speed is quite a bit faster as well. I think it's due to the fact that the extra power actually can get the truck moving at a higher RPM.

 

[olds97_lss]

I wasn't able to get my hands on a LST2 2-speed, but I did get an LST1 2-speed. According to the parts explosions, the only difference between the LST1 and LST2 2-speeds are the gear cover.

I ran about 3 tanks through it today at a MX track. I'm at about 20 tanks through the engine total. It starts right up, idles nice, great low end torque and a much higher top RPM than I'm used to. Running it relatively hard today, I had a hard time keeping the temps over 200. I ran it for a tank or so, it was running good but sounded a bit rich, pulled it in, temps read 185! I leaned it out 1/4 turn on the HSN and my temps floated around 205 and it just goes faster!

At the track I'm at, there's one particular jump that we spend most of our time at. I used to have to get a good 25-30 yard run hard on the gas around a corner to get decent air and distance off the jump. With this engine, I can sit at about 10 yards, gun it and jump further and higher than I could in the past. There's just so much more torque in this thing that I need very little time/distance to hit the big jumps now. It's great, but it took some getting used to. I'm jumping further than a friend of mine does with his muggy! He was always getting a good 2-3 feet higher and 10 feet further. A little more speed and I can turn this MX double into a single!

Anyway, just reporting that the LST1 two speed seems to be holding up and the engine is a great buy so far. I'll post more once I get a gallon through it. Supposedly thats when this engine really lays it down... I'm ecstatic with the power it has at 1/2 gallon!

 

[Colide]

Yea baby...... LRP is no joke. Having to wait for mine to get shipped is friging murder with a capital (M) I guess patients is wisdom. I just feel like that comment that Jack-(McMurfy) said, in the film 'One Flew Over The Coocoo's Nest' Quote: "Patients?......Patients?..................We don't have any patients!!!" End Quote. Hey Olds, What kind of break in regiment are you imposing on the LRP?...How tight is the "pinch" on her? Brand and type of fuel? heat cycling? temps? ect. One guy I,ve chatted with said that he ran about 25 - 30 tanks through it before he finally fine tuned the mill. I believe in the heat cycling method, myself. I try to run with a 20% nitro/18% oil blend, for the break-in phase, if I can find the blend at the time. There's seems to be a lot of approaches out there to choose from, but I figure if I take the best of every method out here in to consideration, (I hope...lol) I'll have a solid basis for good some results with it all. I've never had a spec.3 mill before and would assume that I should have a heat gun handy for starting up the little sucker. Since it should have a pro "pinch" and all.

 

[olds97_lss]

Well, the manual said to use 25% nitro or higher. I ran the first 3 tanks with trinity MHP 20% nitro/12% oil and it was a real pain. Then I picked up a bottle of byrons 25% nitro/11% oil and it became much easier. With the 20%, I couldn't get it to idle very well, it kept sounding lean even though there was fuel coming out of the pipe. I've never ran anything but trinity MHP (except for experimenting) in any of my engines.

For the first 5 tanks, I put the truck under the heater in my car and got the head temps up around 120F. I also backed the glow plug out 1/4 turn. The first tank was brutal to keep it running. By tank 5, it felt like it was starting to loosen up a bit and thats when I started leaning a bit to get the temps up. Up until tank 5, temps were below 180F. I didn't start leaning for performance at all until tank 10. Tanks 6-10 were much easier to keep it running. I don't know if it was because I switched to 25% or if it was just not fighting itself as much.

I heat cycled it through all tanks, but didn't hit 200F until tank 5. Through tanks 5 and 6, I'd run it until it hit 210F, then I'd shut it down, put the piston at BDC and let it cool. I did that about 5 times per tank through 5 and 6. Tanks 7-10, I kept it running.

I've run about 20 tanks through it total now and I've been running the 25% since tank 4. It starts right up, idles perfectly and screams through the RPM's without any hesitation once it warms up. I had to lean it a bit yesterday to get the temps up (tanks 17-20) while I was running at the track. It was running around 180F. I leaned it a bit on tank 19... then it just screamed! Still ran around 220F and idled/wrapped out cleanly and was very crisp off the line.

 

[Colide]

Wow... Up to tank 7, It sounds like were doing an identical break-in, almost. I to had the same lean sounding yet very oilly pipe drool with Eliminator 20% nitro/18% oil from my Dyna 28. I'm going to jump to Blue Thunder 25% which is dirrected in the engine manual. Out of the 7 tanks I've run, I idol'd the first and second tank, achieving 7 cycles. I used some metal hvac ducting tape to make a nice and snug cylinder to insulate the heatsink which really helps in getting those temps up for some cycling. With some throttling, now and then, I was able to reach 225 degree's per cycle. The remainning 5 tanks yielded 4 cycles per, totally 25 heat cycles. And then, my pipe issues came in to focus.

 

[olds97_lss]

I used a baby sock around the head... failed to mention that. I didn't use it after tank 10. I don't like using tape. Leaves a residue. Especially if any fuel/oil gets on the sticky side.

 

[Colide]

I used a baby sock around the head... failed to mention that. I didn't use it after tank 10. I don't like using tape. Leaves a residue. Especially if any fuel/oil gets on the sticky side.

Yea.. I hear ya on that one, Olds. I used the kind of metal tape that has a paper backing on it so there's no adhiesive issue to be conserned with. I just kept the metal side of the tape on the inside.