This guy makes me feel like a hack!

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That is F@#$&* awesome!! I was just thinking the other night about laying the motor down for a better CG. I was just thinking about, this guy was making it a reality. I have to give that guy some props for that one :resp: Shame he's on that forum and not ours :nono:
 
I gotta say, he did a really good job with it! It looks really good, and I must say, it does make you think.

I will say this however, I hate the idea of the motor being sideways like that. I've been working with different engines for a long time, and I must say; I don't like that idea at all. If you think about it, you'll understand my point. Don't get me wrong here, I'm not trying to pick a fight or cause an argument. Just my reasons for not liking the idea here.

The piston would be laying on the cylinder wall too much for my liking. It may not be a big difference, but it'd cause some additional wear on the side of the cylinder. The fact that the weight of the piston would actually be on the cylinder wall, much more than when the engine is vertical, just makes me wonder how much wear it would cause. The piston might not weigh much at all, but every bit counts. I'd rather just have the motor vertical, where the pistons weight is actually being held by the connecting rod and crankshaft.

Like I said however, that's my opinion on it. It's a really nice looking savage, and the video shows that it works pretty well (why didn't it shift?). I'd like to talk to him sometime about his mods too. It looks really nice, and I'd like to hear the different ways he mounted all the gear like he did. My favorite part was the turn buckle ends. That really is a good idea, and I think I'll have to try that one! 🙂
 
I have the same thoughts on motor position and am interested in this debate.
It didn't shift because it has a center diff and yes I think it's an incredible build too.
 
I'm not real sure how to put this....

oh yeah...

it hasn't seemed to affect VOLKSWAGEN​

for the last 60 or so years.​

I addition to that, any V-style engine has the piston somewhat on it's side - Dave, you have had them apart... any wear because of that?​

Lawn mowers, generators, snowblowers - many of them lay on their sides.​

On to the next arguable point...​
 
The F-1 style r/c's also have their engines laying sideways. Thats what got me thinking about the lay down motor in the first place.
 
MotoPsycho said:
I'm not real sure how to put this....

oh yeah...

it hasn't seemed to affect VOLKSWAGEN​

for the last 60 or so years.​

I addition to that, any V-style engine has the piston somewhat on it's side - Dave, you have had them apart... any wear because of that?​

Lawn mowers, generators, snowblowers - many of them lay on their sides.​

On to the next arguable point...​
Click to expand...


there's that, plus the fact that the piston literally weighs next to nothing, plus, since the con rod is actuated by the crank, it's techincally pushing against the sides of the sleeve, no matter which way it's oriented, the sleeve changes the rotational motion to an in-line up and down motion. :resp:

plus, since the main point of lowering the center of gravity would be in a racing application, and most race tracks (with the exception of drag racing, or any tracks that are figure eight, or criss-cross at some point) generally go in generally a circular pattern which would put centrifugal force againt one side wall of the sleeve, the one towards the outside of the track.
 
I thought it looked a little slow. 2nd and even 3rd gear would have helped a lot with that I'm sure. I don't think the Hellfire is a 2 speed is it? Hmmmmm.
 
I could only dream of thet kind of time on my hands! Sweet build and good find. I don't like the idea of one of the tvp taking the load of a big block. But other than that its mint!
 
Well, I've done a bit of work on lawn engines, and the like. Most of the time,you'll notice (specially on older motors that have seen many hours of use, most wear and tear; such as scratches; are on the bottom side of the cylinder wall. But, that's not the same idea behind the point I was getting at.

A four stroke engine, such as lawn engines, or a VW engine have rings, which help contain the piston between the cylinder. These small engines don't use the same concept, and the piston would have more chance of running against the cylinder walls. This give me a hint that it would cause additional wear on the cylinder wall, and probably the piston as well.

Don't get me wrong, I'm not saying it'd kill it instantly; but I just think it'd be a playing factor in the total lifespan of the engine. It might not have any effect at all, who knows. That's just my opinion on it. But as a whole, that is one really awesome rig. And thanks dave, for pointing out the center diff. I'm not totally certain I understand that totally though. How does it work?

Does it work something like this?

Engine > Tranny/Diff > Front or Rear Diff > Tires?

If so, wouldn't that make for single wheel drive in really bad situations? Or how would it work? I am look at it closer, it's really interesting! 😀
 
And also the fact that VW motors have a wet sump for lubrication. And like Steve has pointed out a full set of rings. And most have skirted pistons-all of these factors have a benefit for wear that a Nitro motor doesn't have.
And yes I have seen wear on a V style motor on the bottom side of walls several times. Usually from caked up oil control rings causing lack of lube.
The debate is not dead lol.
 
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Real men drive rotaries!

This is a really cool looking truck, I must say ... but it just looks to me like it might be a hassle for some of the standard maintenance.

On a side note - the new Hyper 9 has a more sideways oriented engine. It's not laying completely on it's side, but it is turned at an angle, and the way the head is shaped is pretty cool looking actually.

hyper-9-buggy5.jpg
 
Hello Gentlemen, I forgot this thread was here, heh heh. So I will chime in with my thoughts. 🙂
You guys bring up some interesting points. The thought of premature wear of the piston/cylinder never occurred to me until you all brought it up. But after mulling over it in my mind, I wonder if it would even be enough to notice? I was thinking that the internal forces caused combustion would counter act any force of gravity, kinda like how centrifugal force counteracts gravity. So wouldn't gravity be a negligible force compared the pressures and forces created inside the engine (small engines for that matter). I know( I think? lol) that gravities effect ultimately depends on the size of the object it is affecting. (Ah, so cute, look at me trying to sound educated, ha ha 🙂). This is where I either sound like a dufus and you guys correct me and I learn something or maybe I know something after all. Add to that the constant up and down of jumping and maybe it'll even out the wear.

I am installing a LRP.28R Spec 3 Truggy engine in a few days. I plan on breaking it in with the heat cycle method(first time). I will keep this in mind if the engine dies prematurely and keep you updated. So what is the average life span of a LRP28 so I'll know if it dies before it's time.

Cheers guys, you got me thinking. 🙂
 
Feel proud of what you done, it's looks great and you can tell there was alot of work put into it. Glad to see you here. With every new design there are going to be some flaws that you wont notice tills months down the road. (For example, the engine might have some extra wear.) But until that happens, this is easier the favorite custom Savage I have seen. Good job.
 
Hey at 30,000+ rpm I'd say there are forces slingin' stuff everywhere. And with an engine that may see 8-10 gallons of fuel before it is tired, who cares?! Drive it like ya stole it!
 
JAPANSAV3POINT5 said:
Hello Gentlemen, I forgot this thread was here, heh heh. So I will chime in with my thoughts. 🙂
You guys bring up some interesting points. The thought of premature wear of the piston/cylinder never occurred to me until you all brought it up. But after mulling over it in my mind, I wonder if it would even be enough to notice? I was thinking that the internal forces caused combustion would counter act any force of gravity, kinda like how centrifugal force counteracts gravity. So wouldn't gravity be a negligible force compared the pressures and forces created inside the engine (small engines for that matter). I know( I think? lol) that gravities effect ultimately depends on the size of the object it is affecting. (Ah, so cute, look at me trying to sound educated, ha ha 🙂). This is where I either sound like a dufus and you guys correct me and I learn something or maybe I know something after all. Add to that the constant up and down of jumping and maybe it'll even out the wear.
Click to expand...

I'm not saying it will cause any additional wear, but you never know. I look at the possibility myself. It could be possible that it will effect the total life. It may only cause one less stroke of the engine, or it may cause 3 gallons worth of life to be lost. I don't specifically know, and I'd certainly love to find out. You have a great build there, and MAN that looks AWESOME! I'd love to see it in person, maybe even drive that thing! How does it hold up? Is it as tough as the rest of the savages? Any certain problems hold the build up for you? It looks like you took a BUNCH of time, and a LOT of effort making that. I gotta say, 5 of 5 stars man!

MotoPsycho said:
Hey at 30,000+ rpm I'd say there are forces slingin' stuff everywhere. And with an engine that may see 8-10 gallons of fuel before it is tired, who cares?! Drive it like ya stole it!
Click to expand...

Heck yeah man! Drive it like ya stole it! I know I drive mine like I stole it, so don't let the debate stop you at all! I would love to know if it does have an effect on life for you however. It'd be an interesting thing to find out! I know, a few years back Honda's ATV line changed their engine orientation in a few of their ATV's as it created less drag, and longer engine life. I'd be willing to say it changed the engine life moreso because of the inline design with the drivetrain. Instead of changing the power a the transmission at 90 degrees to a drive line, it's now one straight line into the rear differential/axle.

Let us know what all effects it does have, hopefully it doesn't change a thing, and everything works perfect! That build is probably the best I've ever seen! More pics! LOL 🙂

Again man, great job on it! 🙂
 
Here's a good question. How tight is the tolerence in the crank to the connecting rod and connecting rod to the wrist pin on these nitro engines? It can't be much, until mabye a person puts a few gallons of fuel through the engine. Am I right or wrong? Come to think of it, why do you not see manufactures using horizontal mounted engines in r/c cars and trucks? I think I have only seen a couple of R/C airplane engines that are horizontal.

Hats off to the builder of that Savvy, its killer!!
 
That's a really good question mackanon. I know I've rebuilt a few engines before, and I never did see any tolerance ratings. I do know, HPI has a 1mm max throw on the conrod connection to the crank. That's a HUGE gap though. I don't even think the engine would run right with a 1mm gap on the conrod/crank assembly.

By horizontal, do you mean like this?

Engine --- Clutch

instead of

clutch
|
|
|
Engine

If so, I know the RC10 is sideways compared to the savage.

If you mean actually laying down, I know what you mean there. I've never seen one personally, except for an aircraft engine. Good point!
 
Originally posted by AoD:
How does it hold up? Is it as tough as the rest of the savages? Any certain problems hold the build up for you?
Click to expand...

It has held up great! Knock in wood... I was kinda surprised, I was expecting loose/stripped/broken screws/bolts, bent cross bracing or TVP's, stripped diff gears, but it has gone through about a gallon of fuel with out any structural problems. I haven't really beefed it hard yet, several cartwheels and head-ons into the sandbags on our track. I will say one thing, though, it is VERY hard to roll. Now that I think about it, I think the only time it is on it's back is if I dork the jumps.

All the mods I did pretty much went off without a hitch, knock on more wood... The only thing that held up the build was me staring at the truck trying to figure out how to set it all up. That probably burned up 8 hours of build time, easy. But I'll say that it was due to fatigue(Building till 0400 in the morning) and inabillity to concentrate fully(usually through a six-pack around 0400) :drunk:

Just curious, does HPI participate in these forums? I wonder if they have caught wind of my build and are making future plans :Xfingers: I sent them an invite a couple weeks ago through their customer support email, but no response. Wonder if they got it? Maybe a free XR in the mail for me?? lol that would be cool!

Thanks again for the awesome comments, they mean alot to me. :FarleyParty:
 
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Yeah I would think some big wigs have caught wind of your build by now but I wouldn't expect to hear from them anytime soon-I could be wrong.
And on our little debate we don't mean to take away from your thread or anything and not to say it's a bad thing just kinda voicing our thoughts on it.
I would have to say it's a minor wear issue for the motor to be in that position and I'm sure if you ever see any problems you'll update us.
A friend of mine was a little concerned about the drive shaft angle being a problem too but I think you run universals at all points there?
Again nice build and thanks for sharing with us all.
 
Pineapple- I don't mind the engine discussion at all, it's all good info. One thing I've learned is there is always a negative trade off for every performance mod you do(same for my 1:1 car) High torq steering/throttle servos=Faster receiver batt drain, wider stance=less steering, more powerful engine=less gas mileage, horizontally mounted engine=possible premature engine wear, And last but not least, the biggest negative trade off has been on my wallet. lol, It's all part of the game, I like this game...
 
I guess HPI's ear's were ringing, look what I got in my inbox today...Sounds promising, hee,hee,hee...

From "Unnamed" source at HPI...
Robb,

Wow, that is a pretty neat design, great job! You truly have a passion for the hobby. I will forward your link on to others in the building to see. We have often thought of using a lay-down engine design like that and who knows you might see it appearing on a vehicle of ours soon. 😉 Thanks again!

HotBodies/HPI Racing
Click to expand...
 
Heck yeah man! That's awesome! Excellent even! Hope they do use your idea! That'd be totally awesome! 🙂

Another good question I had for you. Did flopping the motor like that change any tuning aspects of the engine? I doubt it'd have much of an effect, but it is possible that it could change the precise flow that the fuel normally has. Not sure if it'd impact it at all. I was thinking about that at work also.
 
AoD said:
That's a really good question mackanon. I know I've rebuilt a few engines before, and I never did see any tolerance ratings. I do know, HPI has a 1mm max throw on the conrod connection to the crank. That's a HUGE gap though. I don't even think the engine would run right with a 1mm gap on the conrod/crank assembly.

By horizontal, do you mean like this?

Engine --- Clutch

instead of

clutch
|
|
|
Engine

If so, I know the RC10 is sideways compared to the savage.

If you mean actually laying down, I know what you mean there. I've never seen one personally, except for an aircraft engine. Good point!
Click to expand...
AOD, I guess I ment lying down as Japansav3 did. I think my question was not in good form. I hope I can explain why.

I was thinking yesterday that the wrist pin and crank were facing North/South, but after looking at Japansav3's video a couple more times, the pin and crank actually face East/West. So the piston would apply more preasure to the bottom side of the cylinder. The piston would act like a wet noodle. My brain hurts! I hope everyone can understand what I've written, because I'm starting to confuse myself.LOL
 
AoD, I haven't noticed any changes in how the engine runs with it in it's side. RUns just like it did right-side-up. Only difference is I have to adjust the lsn from the bottom of the truck, no big deal. 🙂

Mackanon- Now you got me confused, lol 🙂
 
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