Got a new engine for my savage, LRP ZR.30

[olds97_lss]

Well, after fighting and fighting one of my LRP 28S3's, I finally called it quits and ordered a new engine. A little of the history of that is here: https://www.hpisavageforum.com/threads/savage-half-tank-lean.15953/#post-194458

New engines always look nice when you open the box and this one was no different. Cooling head has an extra fin over the 28 and the crank case is considerably re-enforced with gussets and extra material.

As with any new engine, the first thing I do is take it all apart to inspect for loose shavings, proper assembly and sealing with RTV. When removing the head, I nearly broke my 3mm wrench as the bolts were so tight that they popped when they broke loose. Every one of them. I was affraid that the first thing that would happen before I even ran it was a bolt would snap off in the block. Luckily, they all came loose. Upon removing the starter housing, I don't know what I did as I'm usually pretty careful to avoid unwinding the recoil spring, but as soon as I released the last screw, BOING! Snarled mess. I moved that to the side to rewind later. Then when I went to remove the backplate screws, two of them weren't even finger tight.

Then I took the plate off and inspected the internals. One of the cleanest engines I've ever bought. I ran a cotton swab around inside all the recesses I could reach and removed only a very small amount of aluminum dust. After a few drops of ARO on the bearings, OWB, conrod, wrist pin and sleeve I procceded to RTV up the carb and backplate.

Before sealing the carb, I took a couple photo's of it next to the 28's carb. The carb neck is about 1mm larger in diameter:

The venturi is pretty similar:

The carb itself is a bit more bulky than the 28's. Not sure why. The HSN/LSN were way off. Per the book, HSN should be 2.75 turns and LSN should be 2.25. They were 4.5 and 3.5 respectively. I set them to 3.25 and 2.75. Figured a hair more rich would be best. The HSN recommended setting seems pretty lean to me anyway, but time will tell.

One thing I did notice was that the sleeve on the exhaust port for the 30 hangs down about 1.5mm further than the crank case is:

The 28 exhaust port is flush with the case:

Hopefully that's how it's supposed to be.

I rewound the recoil spring and put that back together then installed the flywheel/shoes/bearings/cb from the 28. Sticking with 17/49 gearing for now as that was a pretty good fit for the 28 when it ran somewhat ok.

Not sure when I'll start break-in. Temps around here don't look like they are going to get above 60 the rest of the week/weekend. If ti does get to 60 and doesn't rain... I might throw a hand warmer or two around the head and get started on it anyway.

Here's to hoping I didn't just get another aggravating engine!

 

[madgadget_1]

Sounds like you covered all bases with this one. Ever consider letting someone like erc diagnose your lrp issue? Just saying.

 

[olds97_lss]

erc? Not familiar with that.

 

[madgadget_1]

Extreme RC MODS, my bad

 

[X]

Nice comparison write up. Thanks for posting it olds!

 

[Messiahlee]

Dam I'm looking for new engine didn't know any of this I just thought out of box into car and all was good being new. Lrp zr30 the best engine for my xl?

 

[X]

Dam I'm looking for new engine didn't know any of this I just thought out of box into car and all was good being new. Lrp zr30 the best engine for my xl?

You're going to get alot of subjective OPINIONS on this. The LRP 28, 30 and 32 are all great engines. The best advice I can give you is to do alot of research and buy what is right for you.

 

[olds97_lss]

Dam I'm looking for new engine didn't know any of this I just thought out of box into car and all was good being new. Lrp zr30 the best engine for my xl?

Well, buy what suits your needs. I don't know how any of them compare to the stock engine, for all I know, HPI has it figured out. I've never had a NIB savage, always used and the engines were either not included or completely trashed. I've never ran an HPI engine or seen one run really, except many years ago, a couple guys I met at the skatepark were running old HPI 21's and 25's in their savages. That was 10+ years ago. They were amazed at my t-maxx and Savage at the time that I had an OS21RG in both of, and now, after having all the stuff I've had, the OS21RG was a very low power/RPM engine. Stable and consistent, but weak.

That said, as each LRP engine goes up in size, they go up in torque/hp, down in peak RPM. These are just what's listed by the mfr from amain, not actual dyno numbers, but should be a fair comparison as to how they relate to one another.

Z28R Spec3
Max RPM: 38,500
Power Output: 3.81 PS
Number of Ports: 8+1 (8 intake, 1 exhaust)

Z30R Spec 2
Number of ports: 5+1
Max. RPM: 33,200
Max. Power: 4.12HP

Z32R Spec 2
Number of ports: 5+1
Horse Power: 4.34hp
Max RPM: 33,000rpm

So, as far as I was concerned, the 28 did fine for what I did in the savage X with 49/17 gearing and traxxas 3.8 tires. Also did fine in my aftershock (that was heavily upgraded) with the same tires and +2 on the stock CB (and +1 due to teh trans gear switch mod). Wheelie city on both and plenty of top end speed. It also is total overkill in my 1/8 buggy and big block revo. Ported the way it was, it's made more to get the max power from mid-top end of the RPM range. Less ports is usually intended/designed for torque in the lower RPM range.

I would expect the 30 or 32 to do well in an extended savage or a savage that is a bit heavier and/or one that runs larger tires than I do with similar gearing. I'm guessing for either, you would want to upgrade to a steel spur and alloy shoes along with BP diffs or odds are, your going to run into problems keeping things together.

For me, with any MT, an engine that is "good" for me means:
1 - I get good speed out of it (probably average 35-45mph)
2 - wheelies are easy to be had with the same gearing
3 - can run in up to 5" grass without overheating badly all day long
4 - tunes easy and holds a tune, doesn't require a lot of fussing
5 - lasts a long time (8+ gallons).

So, the LRP28's I've ran (except for the 1) have done all that in spades. I've had 5 of them, currently still have 3 of them. The one is being replaced with the 30 only because I need to get the bad taste of the 28 out of my mouth and it was a few $ cheaper, so figured why not give it a try. The "bad" 28 will be used for parts for the other 2 I still have that run well.

I forgot to mention, when I had my aftershock, I did try running the LST2 huge stock tires/wheels on it and the muggy 420 bowties. The LRP did ok with the bowties, but with the stock wheels and +1 gearing (trans gear flip mod) just felt like a dog. The muggy tires didn't feel a whole lot better to me and it really killed the wheelies.

 

[Rooky]

As far as it goes, the F4.6 I have (the old version) does a fine job. I know this is @olds97_lss thread but in comparison... my 4.6 has a hard time keeping the front end down. I can't remember if I'm geared 17/47 or 17/49. The only reason I'm looking to replace mine is in need a crankcase due to the previous owner breaking the corners off where the back plate screws on and the front bearing air leaking. By the time I fix all that I'd only save about $20 over an LRP .28.

 

[olds97_lss]

As far as it goes, the F4.6 I have (the old version) does a fine job. I know this is @olds97_lss thread but in comparison... my 4.6 has a hard time keeping the front end down. I can't remember if I'm geared 17/47 or 17/49.

From what I remember, they didn't rev near as high as the LRP though, so guessing you wouldn't have the speed you would with the LRP in it.

 

[X]

From what I remember, they didn't rev near as high as the LRP though, so guessing you wouldn't have the speed you would with the LRP in it.

This is very true. It probably depends on which version of the F4.6 you have, but I don't think they vary too much.

F4.6 specs:



The LRP Z.28R spec 3 leaves every engine HPI has made or makes in the dust. Though the K4.6 and HO K4.6 can rev higher.

K4.6 specs:



HO K4.6 specs:



The K5.9 is the closest in performance, spec wise, though in practicality I've heard it doesn't hold up.

K5.9 specs:

Specs:
3.75 horsepower
5.9cc
ABC construction
3 port
39,500 RPM
9.5mm composite slide carb (12mm with 9.5mm reducer)
3-needle carb adjustment
Bore: 20.5mm
Stroke: 17.5mm
Aluminium heat sink head (Gunmetal)
14mm SG-style crankshaft
Rear exhaust
R5 Glow plug

 

[Rmadrid7]

wow.. thats is a interesting info... thanks guys.

 

[Rooky]

Thank guys. I wasn't trying to compare the two. Just throwing my .02 in on the stock engine. Today makes the third time this week I've wanted to use mine as a paperweight though. Lol

 

[olds97_lss]

Today makes the third time this week I've wanted to use mine as a paperweight though. Lol

Man, I know that feeling.

 

[Rooky]

It's great as long as I don't let it die once it warms up. After it's warm the damned thing won't restart. I will say it's a ton of fun running over my brother's T-Maxx.

 

[olds97_lss]

It's great as long as I don't let it die once it warms up. After it's warm the damned thing won't restart. I will say it's a ton of fun running over my brother's T-Maxx.

Sounds like your pinch has worn down. $25 to rayaracing.com could breath some more usable life into it. If he's still doing it.

 

[Messiahlee]

Well, buy what suits your needs. I don't know how any of them compare to the stock engine, for all I know, HPI has it figured out. I've never had a NIB savage, always used and the engines were either not included or completely trashed. I've never ran an HPI engine or seen one run really, except many years ago, a couple guys I met at the skatepark were running old HPI 21's and 25's in their savages. That was 10+ years ago. They were amazed at my t-maxx and Savage at the time that I had an OS21RG in both of, and now, after having all the stuff I've had, the OS21RG was a very low power/RPM engine. Stable and consistent, but weak.

That said, as each LRP engine goes up in size, they go up in torque/hp, down in peak RPM. These are just what's listed by the mfr from amain, not actual dyno numbers, but should be a fair comparison as to how they relate to one another.

Z28R Spec3
Max RPM: 38,500
Power Output: 3.81 PS
Number of Ports: 8+1 (8 intake, 1 exhaust)

Z30R Spec 2
Number of ports: 5+1
Max. RPM: 33,200
Max. Power: 4.12HP

Z32R Spec 2
Number of ports: 5+1
Horse Power: 4.34hp
Max RPM: 33,000rpm

So, as far as I was concerned, the 28 did fine for what I did in the savage X with 49/17 gearing and traxxas 3.8 tires. Also did fine in my aftershock (that was heavily upgraded) with the same tires and +2 on the stock CB (and +1 due to teh trans gear switch mod). Wheelie city on both and plenty of top end speed. It also is total overkill in my 1/8 buggy and big block revo. Ported the way it was, it's made more to get the max power from mid-top end of the RPM range. Less ports is usually intended/designed for torque in the lower RPM range.

I would expect the 30 or 32 to do well in an extended savage or a savage that is a bit heavier and/or one that runs larger tires than I do with similar gearing. I'm guessing for either, you would want to upgrade to a steel spur and alloy shoes along with BP diffs or odds are, your going to run into problems keeping things together.

For me, with any MT, an engine that is "good" for me means:
1 - I get good speed out of it (probably average 35-45mph)
2 - wheelies are easy to be had with the same gearing
3 - can run in up to 5" grass without overheating badly all day long
4 - tunes easy and holds a tune, doesn't require a lot of fussing
5 - lasts a long time (8+ gallons).

So, the LRP28's I've ran (except for the 1) have done all that in spades. I've had 5 of them, currently still have 3 of them. The one is being replaced with the 30 only because I need to get the bad taste of the 28 out of my mouth and it was a few $ cheaper, so figured why not give it a try. The "bad" 28 will be used for parts for the other 2 I still have that run well.

I forgot to mention, when I had my aftershock, I did try running the LST2 huge stock tires/wheels on it and the muggy 420 bowties. The LRP did ok with the bowties, but with the stock wheels and +1 gearing (trans gear flip mod) just felt like a dog. The muggy tires didn't feel a whole lot better to me and it really killed the wheelies.

Wow thank you for all that information

 

[olds97_lss]

Well, started the break-in today. Left the original tank/fuel line/primer bulb on it for the first attempt. The LRP fired right up, but was severely lean. Even with the needles both 1/2 turn more than factory. I richened up the HSN a ton just to get through a few heat cycles on the first tank. It was acting exactly like the 28 was. Lean bog really bad, stalling repeatedly, blubbery one minute, lean the next. I know this was the first tank and it's usually pretty rough, but it was sounding and acting exactly like the other engine.

So, after getting through 3 heat cycles (1 tank), I packed it up and went home. Ripped off the tank, lines and primer bulb, then installed a brand new tank with HPI's supplied fuel line only. I did not reinstall the primer.

Took it back out again after resetting the needles to be 1/2 turn over factory (they were 2+ turns richer after fiddling with the first tank). Fired it up and it ran pretty good. Let it warm up, but it was blubbery rich, so I leaned it a bit so I could at least get the RPM's up enough to move the truck. Ran through 6 more heat cycles (2 more tanks), then ran out of my newly mixed odonnels (50/50 20% and 30% racing series (8% synthetic oil only) fuel to get 25%) and put in a tank of my old mix as all I had left was one 500cc bottle. It was the same ratio, but one gallon was race (8% synthetic) and one gallon was sport (8% synthetic/castor blend). Then it started running really poorly. Wandering idle really bad, stalling frequently, high revving off throttle... I suffered through the tank the poured the rest near a fence post. Went home and got another bottle of the 8% synthetic mix. Only had time to run 2 more tanks before the rain hit. I ran 1000cc's total today.

I had been slowly leaning the needles since tank 4. Up to that point, I was adjusting so it ran cool (around 210F). By the time I got to the 6th tank, I had a pretty snappy tune and the truck was like driving a jumping bean. Every time I touched the throttle when sitting still or coasting in first gear, it would slam up a wheelie. Towards the end of tank 6, I was a little quicker with ramping up to WOT. In the grass, I got a few 2nd gear wheelies that came up out of nowhere, one of which caught me off guard and I put a ding in my new engines head as it cartwheeled out of the grass and onto pavement.

So far, it seems my issues may have not been the engine, but rather something either in the tank or primer hampering fuel flow.

Hoping it warms up and dries up a bit by next weekend so I can get to the park before parents/kids get there so I can really start having some fun. To top it all off, I only got one tiny blister from all the starting. It showed up during tank 1 with the bad tank.

 

[madgadget_1]

There's a racer/basher/collector around here that hates those primer bulbs more than mosquitos. Thanks for sharing the experience sounds like fun.

 

[olds97_lss]

I ran them on everything for years without issue. Suppose I could put the old tank on without the primer just to rule it out, but at this point... kind of just want to run it as is. I may put new line on it though as the stock line runs the pressure line right over the carb. It's pretty short.

 

[Derekpike]

@olds97_lss I've been meaning to comment on this for a while, but always get distracted. I just wanted to thank you for the tutorial. As someone else commented, I wouldn't have thought of doing half that stuff, but when I get my first LRP I'll be sure to refer back to this post.

 

[madgadget_1]

I ran them on everything for years without issue. Suppose I could put the old tank on without the primer just to rule it out, but at this point... kind of just want to run it as is. I may put new line on it though as the stock line runs the pressure line right over the carb. It's pretty short.

look at my avatar bulbs on both engines without issue. But last summer at our annual drag and bash my x would not hold a tune, ate 2 plugs and the picco was getting spanked by axial 28's, sh 28, and half a doz other x and xl's. My bash buddy ripped all my tubing off plumbed all of it direct with prather fuel tubing gave me his last plug threw my bulb in orbit and the old picco 27 x represented. It's in my hellfire now. All said to say that every option for convenience is also an opportunity for failure. imo

 

[olds97_lss]

look at my avatar bulbs on both engines without issue. But last summer at our annual drag and bash my x would not hold a tune, ate 2 plugs and the picco was getting spanked by axial 28's, sh 28, and half a doz other x and xl's. My bash buddy ripped all my tubing off plumbed all of it direct with prather fuel tubing gave me his last plug threw my bulb in orbit and the old picco 27 x represented. It's in my hellfire now. All said to say that every option for convenience is also an opportunity for failure. imo

I guess they should be treated as a wear item and replace them every season. For what they cost, it would still be worth it for the priming convenience. Over time I could see fuel gunk them up as the hole for the fuel is very small as is the little bb that blocks the hole. I suppose I could drill out the holes, throw away the BB's and just pinch the line to the carb to fill the bulb, then pinch the line from the tank to push it to the carb. not quite as convenient, but it keeps dry cycles off the engine and dirty fuel line out of my mouth.

 

[olds97_lss]

@olds97_lss I wouldn't have thought of doing half that stuff, but when I get my first LRP I'll be sure to refer back to this post.

I do this with every engine, cheap or expensive. Typically in cheaper engines (losi M26SS, XTM24.7, SH28...), I've found more flashing and aluminum bits inside the engine and occasional pinched o-rings. I've had 2 lrp's with loose back plate screws out of the box. My OS21TM ($260 engine) was pretty pristine inside. The LRP30 even had less aluminum dust in it though, which was surprising to me.

With as many engines as I've had over the years, spending an hour tearing it down, cleaning, lubing and sealing it up right with RTV not only rules out many issues, it makes you familiar with the engine. I do find that when I have an engine shipped on a Saturday that I do find it very difficult to not just throw it in and go run it... but I fight the urge.

 

[Bauerdog]

I guess they should be treated as a wear item and replace them every season. For what they cost, it would still be worth it for the priming convenience. Over time I could see fuel gunk them up as the hole for the fuel is very small as is the little bb that blocks the hole. I suppose I could drill out the holes, throw away the BB's and just pinch the line to the carb to fill the bulb, then pinch the line from the tank to push it to the carb. not quite as convenient, but it keeps dry cycles off the engine and dirty fuel line out of my mouth.

I just put one on my truck and I'm loving it. If it only lasts a year or two, still worth it I'll buy another.

 

[Derekpike]

I do this with every engine, cheap or expensive. Typically in cheaper engines (losi M26SS, XTM24.7, SH28...), I've found more flashing and aluminum bits inside the engine and occasional pinched o-rings. I've had 2 lrp's with loose back plate screws out of the box. My OS21TM ($260 engine) was pretty pristine inside. The LRP30 even had less aluminum dust in it though, which was surprising to me.

With as many engines as I've had over the years, spending an hour tearing it down, cleaning, lubing and sealing it up right with RTV not only rules out many issues, it makes you familiar with the engine. I do find that when I have an engine shipped on a Saturday that I do find it very difficult to not just throw it in and go run it... but I fight the urge.

I don't think I'd have such an issue with the urge since you have to break the motor in and the first few tanks aren't that exciting (I assume from reading break in procedures as I've never done it yet). If it was an already broken in motor, then I'd definitely have to fight the urge.

 

[olds97_lss]

Finally found time to run more fuel through the 30... what an abysmal day. To recap, engine has around 1500cc's through it, new HPI savage X tank, new fuel lines, sealed engine.

Starting was a pain. Once it finally fired up, it was so pig rich from previously running ok that it couldn't hardly move. I had to lean the HSN almost a full turn after trying to get it to warm up. Then it seemed ok, but still had a rich bog at WOT. Tank 1 today was a pain. Lots of stalling, weird exhaust note, bad performance... and it just got worse. By the time I finished off 500cc's of fuel, I had reset the engine back to factory 3 times and had to richen both the LSN/HSN at least one full turn due to seeing temps north of 300F. I ended up with it very rich and running like crap, then the tank was almost empty and it stalled, then I threw it in my car and came home before I set fire to it.

I'm ditching the HPI tank... not sure what I'm going to use in it's place, but probably an OFNA 125cc tank I found that is close to the shape of the old OFNA 125cc tank I had. I have a feeling ti is either the damn tank, or my fuel. THe fuel is fairly new, but the LHS I got it at doesn't seem to have a high throughput of nitro rigs and/or fuel. Luckilly, I have 2 gallons of it... lol. Probably goign to just bite the bullet and order 4 gallons of byrons 2500 that I've used for years from amain for $160.

I knew I should have just stayed home...

 

[madgadget_1]

How much does break in service?

 

[olds97_lss]

How much does break in service?

Not sure what your asking.

 

[francis Labarbara]

I assume he omitted cost.

I run both LRP .28 and .32 on my stock tank with no problems. The .28 took out my rear diff yesterday.