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Old 12-16-2010, 02:37 PM   #1
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Default 4Stroke powered Hyper 10SC Project

There may already be discussion on this.....

I currently have a Hyper 10SC nitro version with an O.S. .18 in it. I absolutley love this thing, even though there arn't many out there. It handles soooo much better than my old Jammin' SCRT electric. I hated the power delivery of that thing, and the 12 min run times sucked too. For racing ok, but for practicing at the track for an hour straight, not so much. The clutch, for me, makes it fly through the air just beautifully compared to e style.

So... after watching the vids below, needless to say they inspired me to go 4 stroke thumper power in my SC. It just seems to be a perfect compliment to the car in terms of natural vibe and mojo of Short Course ala ESPN. I would love some exhaust pipes coming out the rear end too .

Anyhoo....check these vids out and imagine a Hyper 10SC. Anyone with me?

GT2's:

http://www.youtube.com/watch?v=igEw0Hb1m0Y

http://www.youtube.com/watch?v=lrgHW...eature=related

Losi truggy:

http://www.youtube.com/watch?v=MXk1X...eature=related

Last edited by markhat250; 12-16-2010 at 03:03 PM.
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Old 12-16-2010, 03:29 PM   #2
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That 4 stroke losi truggy is mine, working on putting a 2-speed in it now. I also have a Hyper10sc and have looked into 4 stroking it. It wouldnt be that hard but, for me im just not really into that class. So probly not converting the hyper but, will help you out if you need it. Just let me know, i can machine any part you'll need for the conversion.

Adam
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Old 12-16-2010, 03:44 PM   #3
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That 4 stroke losi truggy is mine, working on putting a 2-speed in it now. I also have a Hyper10sc and have looked into 4 stroking it. It wouldnt be that hard but, for me im just not really into that class. So probly not converting the hyper but, will help you out if you need it. Just let me know, i can machine any part you'll need for the conversion.

Adam
What engine did you use for the 4 stroke Losi Truggy?? Was it a airplane engine or a Heli engine?? Was it ringed??
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Old 12-17-2010, 02:28 PM   #4
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What engine did you use for the 4 stroke Losi Truggy?? Was it a airplane engine or a Heli engine?? Was it ringed??
Thats was a Magnum .52 ringed airplane engine. Great engine for the price, on sale was $85 shipped if i remember right.
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Old 12-17-2010, 11:05 PM   #5
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I didnt know they made ringed motors. Cool. So is there no real break-in with those?

Yeh, 4stroke motors seem pretty cheap. I was thinking an O.S. .26 for my Hyper SC (same motor on GT2 track vid above). BTW, your truggy seemed to top out waaaay quicker than the .26 motor on the GT2. The GT2 in that vid seemed it could use a slightly bigger bell/smaller spur for more top, and it could afford to give up some bottom, but overall seemed in the ballpark. Your truggy however wasn't even close. But it sounded bad ass and I'm sure you'll get it nailed. I'm not sure 2 speed is the answer. You cant just get a waaay bigger bell/smaller spur combo? It looked like it had loads of bottom to give up.

Last edited by markhat250; 12-17-2010 at 11:20 PM.
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Old 12-18-2010, 05:23 AM   #6
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I didnt know they made ringed motors. Cool. So is there no real break-in with those?

Yeh, 4stroke motors seem pretty cheap. I was thinking an O.S. .26 for my Hyper SC (same motor on GT2 track vid above). BTW, your truggy seemed to top out waaaay quicker than the .26 motor on the GT2. The GT2 in that vid seemed it could use a slightly bigger bell/smaller spur for more top, and it could afford to give up some bottom, but overall seemed in the ballpark. Your truggy however wasn't even close. But it sounded bad ass and I'm sure you'll get it nailed. I'm not sure 2 speed is the answer. You cant just get a waaay bigger bell/smaller spur combo? It looked like it had loads of bottom to give up.
There is a break-in with a ringed motor but it is a lot different from a ABC motor. With a ringed motor you break them in super rich.
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Old 12-18-2010, 02:33 PM   #7
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I didnt know they made ringed motors. Cool. So is there no real break-in with those?

Yeh, 4stroke motors seem pretty cheap. I was thinking an O.S. .26 for my Hyper SC (same motor on GT2 track vid above). BTW, your truggy seemed to top out waaaay quicker than the .26 motor on the GT2. The GT2 in that vid seemed it could use a slightly bigger bell/smaller spur for more top, and it could afford to give up some bottom, but overall seemed in the ballpark. Your truggy however wasn't even close. But it sounded bad ass and I'm sure you'll get it nailed. I'm not sure 2 speed is the answer. You cant just get a waaay bigger bell/smaller spur combo? It looked like it had loads of bottom to give up.
I just ran 1 or 2 tanks rich, throttling up and down untill tank was empty. After that ran it all out as seen in the videos. Took a good gallon before it was getting real good compression, like starter box struggling to turn it over!
Had to go out and buy the OFNA dual starter motor box

As far as engine id try this one http://www.hobbypartz.com/72p-fs30ar.html

They dont make the .26 four stroke any more. And the OS fs 30 is over priced. You will have to modify the crank shaft, cylinder head. And make a custom flywheel, fan cooling system,valve spring setup and intake manifold. Its not hard if you have the machines and know how to use them. With out machines it will never happen as there are no direct bolt on kits.

As for gearing, yes my truck was WAY off. It really needs a 20-22T clutch bell. But, anything bigger than 15T bell and it starts roasting clutch shoes. Just to much load for the clutch to handle. Yes the motor will pull it just fine, but need some sort of "lock up" clutching system. Thats why im trying a 2-speed, easy get up and go then shifts to the much needed taller gearing. Should be awesome if it holds up to the off road abuse.

Have any other questions just ask, hope i can help.
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Old 12-18-2010, 02:42 PM   #8
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I just ran 1 or 2 tanks rich, throttling up and down untill tank was empty. After that ran it all out as seen in the videos. Took a good gallon before it was getting real good compression, like starter box struggling to turn it over!
Had to go out and buy the OFNA dual starter motor box

As far as engine id try this one http://www.hobbypartz.com/72p-fs30ar.html

They dont make the .26 four stroke any more. And the OS fs 30 is over priced. You will have to modify the crank shaft, cylinder head. And make a custom flywheel, fan cooling system,valve spring setup and intake manifold. Its not hard if you have the machines and know how to use them. With out machines it will never happen as there are no direct bolt on kits.

As for gearing, yes my truck was WAY off. It really needs a 20-22T clutch bell. But, anything bigger than 15T bell and it starts roasting clutch shoes. Just to much load for the clutch to handle. Yes the motor will pull it just fine, but need some sort of "lock up" clutching system. Thats why im trying a 2-speed, easy get up and go then shifts to the much needed taller gearing. Should be awesome if it holds up to the off road abuse.

Have any other questions just ask, hope i can help.
I have been following your project on the forums...very cool ! Your clutch issue is likely due to the engine not having enough RPM and the shoes not having enough mass.....Your putting too much load at too low of an RPM for the shoes to have enough force to clamp the bell....basically operating a centrifugal clutch outside of its range... ( I am sure your 100% aware of this ) ... I am curious what clutches you have tried so far ? your going to need as much mass on the shoes as possible and possibly to have a custom clutch capable of clamping at a much lower RPM then what we use on the 2 strokes......


On a different note...we did our own engine conversion on a Hyper 10SC...we used a modified .21 and the truck is a real blast to drive...

http://www.youtube.com/watch?v=677bE6_te6w
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Old 12-18-2010, 03:42 PM   #9
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I have been following your project on the forums...very cool ! Your clutch issue is likely due to the engine not having enough RPM and the shoes not having enough mass.....Your putting too much load at too low of an RPM for the shoes to have enough force to clamp the bell....basically operating a centrifugal clutch outside of its range... ( I am sure your 100% aware of this ) ... I am curious what clutches you have tried so far ? your going to need as much mass on the shoes as possible and possibly to have a custom clutch capable of clamping at a much lower RPM then what we use on the 2 strokes......


On a different note...we did our own engine conversion on a Hyper 10SC...we used a modified .21 and the truck is a real blast to drive...

http://www.youtube.com/watch?v=677bE6_te6w
Maximo, You right on with the clutch shoe issue. Not enough RPM to make them fully lock up as a 2-stroke would. As for shoes, im using NOVA rc shoes with a 3 shoe setup. Thats with the set screw installed on the end of the shoe. Also have the lightest clutch springs i could find. With this setup i can ajust the idle to where the shoes just start to touch the bell while idling.

So what it all comes down to is RPM. With out it shoes slip, and motor isnt able to hold its own VS 2-stroke. Im working on more rpm's, lighter crank,rod and piston. Not much else can be done to the valves or cam. Hmmm, a reground cam would be awesome!

After seeing your video im just sitting here shaking my head..
That engine is crazy fast, great work! Any idea how much HP its making?
And if i remember right, i read on here you have a Dyno? Any chance i could get one of my 4 strokes on it
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Old 12-19-2010, 12:16 AM   #10
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Maximo, You right on with the clutch shoe issue. Not enough RPM to make them fully lock up as a 2-stroke would. As for shoes, im using NOVA rc shoes with a 3 shoe setup. Thats with the set screw installed on the end of the shoe. Also have the lightest clutch springs i could find. With this setup i can ajust the idle to where the shoes just start to touch the bell while idling.

So what it all comes down to is RPM. With out it shoes slip, and motor isnt able to hold its own VS 2-stroke. Im working on more rpm's, lighter crank,rod and piston. Not much else can be done to the valves or cam. Hmmm, a reground cam would be awesome!

After seeing your video im just sitting here shaking my head..
That engine is crazy fast, great work! Any idea how much HP its making?
And if i remember right, i read on here you have a Dyno? Any chance i could get one of my 4 strokes on it

thank you that is my modified JL .21...its a stout .21 but not my strongest...

here is the dyno of my JL modified vs my Werk's B6 modified for reference



And I would love to test a 4 stroke on the dyno...PM me and we could discuss it...

And thank you for the compliments...that little Hyper truck is a total monster...the truck is ultra durable and seems to handle the power without issue....For the dollar invested its one hell of a truck.....


From the look of it you need a bigger clutch system....Heavy shoes are what is needed, spring weight wont matter nearly as much...if the shoes don't have enough mass they will never clamp.... With some of my modified nitro's we have had issues with the common clutches not holding as well....The absolute best we have found are the M2C 4 shoe setups for clamping power.......I could talk with Mitch from M2C and ask him if he has any ideas on clutching a 4 stroke like yours.....
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Old 12-20-2010, 08:51 AM   #11
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........that little Hyper truck is a total monster...the truck is ultra durable and seems to handle the power without issue....For the dollar invested its one hell of a truck
Couldn't agree more. I just got sick of E and the heat, battery, retarded ariel manners, etc. I'm sure the E guys don't care if I race with them, they still probably have more power. But I bought this car to mainly practice with at the track for hours upon end. So far I love this SC!!
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Old 12-20-2010, 08:58 AM   #12
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Well crap, I thought 4-stroking an SC would be as easy as those GT2's looked. Sounds like it may be pretty involved. I was just fantasizing about it and thought it would just suit the mojo of this truck perfectly.

As far as clutch goes, i was actually thinking heavier springs so that the big bell could get moving off of initial take off, then have the top end it was looking for. But i never accounted for lower 4-stroke RPM's not grabbing "enough". But it seems that after 5k RPM's the shoes would already have plenty of contact though, right? Dunno.....I've never got that far, and a few here have first hand experience, so I'm just babblng about it.
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Old 12-20-2010, 02:30 PM   #13
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Maximo, Just shot you a PM about the Dyno...
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Old 12-20-2010, 02:50 PM   #14
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dam that 4 stroke is fast it defietly has a lot of torque the front end almost was going up.
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