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losi 42cc big block xxl

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Old 08-27-2011, 07:01 PM
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art2010
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Default losi 42cc big block xxl

the ultamate losi big block monster....lol
i found this truck at my local rc track in sarasota fl and snaged it i made it into and still working on it a 42cc chainsaw motor.
the truck is so huge that the engine just sliped right in no lie,as if it was made for it.i made several brackets for it so it sits flat and will most likley use the 2 speed that it came with.not sure if any one has done this but i would like to get any info on this to see what u guys think.in ur face ass kicking...lol
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Old 08-27-2011, 07:30 PM
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Default RE: losi 42cc big block xxl


Quote:
ORIGINAL: art2010

the ultamate losi big block monster....lol
i found this truck at my local rc track in sarasota fl and snaged it i made it into and still working on it a 42cc chainsaw motor.
the truck is so huge that the engine just sliped right in no lie,as if it was made for it.i made several brackets for it so it sits flat and will most likley use the 2 speed that it came with.not sure if any one has done this but i would like to get any info on this to see what u guys think.[img][/img]in ur face ass kicking...lol
I'd like to see some better, larger pictures of that beast. The pics you posted are teeny tiny. Upload to photobucket or something and link to them. Easier to see that.... masterpiece? haha.. looks like its gonna need a strong wheelie bar since the engine is over 10 times the size of the original engine.

The gear ratio will need to be changed. That chainsaw engine turns less than 1/3 the RPM the .28 that originally came in it did. Unless you mod the snot out of it, that engine will be lucky to see 9,000rpm vs. 32,000rpm.
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Old 08-27-2011, 07:33 PM
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Default RE: losi 42cc big block xxl

what i did the engine spins the same way as the tranny so i used the nitro cluch bell to keep the rpms up on the gears hopefully it works
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Old 08-27-2011, 11:42 PM
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Default RE: losi 42cc big block xxl


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ORIGINAL: art2010

what i did the engine spins the same way as the tranny so i used the nitro cluch bell to keep the rpms up on the gears hopefully it works
You can't use a clutchbell from a glow engine to fit on a big gas engine like that for one. For two, the gas engine cannot physically turn as fast as a glow engine. So... It won't work like your planning.
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Old 08-28-2011, 07:43 AM
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Default RE: losi 42cc big block xxl

the cluch bell on the engine has a gear that gear spins the nitro cluch bell and that turns the main gear of the tranny so i beleve it will work let say the engine turns 5-6000 rpms then from gearing the nitro cluch bell spins faster and then turns the tranny so hopefully it works
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Old 08-28-2011, 07:53 AM
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Default RE: losi 42cc big block xxl


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ORIGINAL: art2010

the cluch bell on the engine has a gear that gear spins the nitro cluch bell and that turns the main gear of the tranny so i beleve it will work let say the engine turns 5-6000 rpms then from gearing the nitro cluch bell spins faster and then turns the tranny so hopefully it works
Well, regardless of how its geared (it sounds like you have it set up so it should work), you just need to make sure that your rpm is turning fast enough at the spur gear to get the 2spd clutch to engage so it shifts.

I dont think the drivetrain is going to hold up for very long with that amount of power. I'll go out on a limb and estimate that 42cc chainsaw engine to put out a real-world 2-3hp, whereas the stock .28 glow engine probably put out 1.5hp and that might even be a tad optimistic. Also, the torque from the chainsaw engine will probably be in the 1-3 foot pounds whereas the glow engine is probably 150-175 inch pounds so I'd be leary of the stock drivetrain holding up.

I'd still like to see some bigger pictures, mainly to see how you have the engine mounted and the gear setup. Definitely a "thinking outside the box" idea, for sure.
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Old 08-28-2011, 08:09 AM
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Default RE: losi 42cc big block xxl

well thanks i cant figure out how to post other pics driving me nuts im not a pc person sry
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Old 08-28-2011, 09:59 AM
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well thanks i cant figure out how to post other pics driving me nuts im not a pc person sry
I use Photobucket as a host. Sign up at Photobucket.com, and when on the main page of your album click upload. should be a green button towards the top of the screen. Pick the picture from your computer, and upload it. When its done uploading it will show the picture(s) you uploaded on the screen. When you run your mouse over one of the pictures, a box below will appear with a few listings/options. Click the "IMG Code" which should say "copied" after you click it. Then in a forum reply box you can either right-click and paste or go under the Edit menu on the top of your screen and select paste. It was more complicated to explain than it is to do, trust me.

There should be help functions on photobucket's site also to aid in getting your album started.

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Old 08-28-2011, 10:51 AM
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Default RE: losi 42cc big block xxl


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ORIGINAL: 1QwkSport2.5r


Quote:
ORIGINAL: art2010

the cluch bell on the engine has a gear that gear spins the nitro cluch bell and that turns the main gear of the tranny so i beleve it will work let say the engine turns 5-6000 rpms then from gearing the nitro cluch bell spins faster and then turns the tranny so hopefully it works
Well, regardless of how its geared (it sounds like you have it set up so it should work), you just need to make sure that your rpm is turning fast enough at the spur gear to get the 2spd clutch to engage so it shifts.

I dont think the drivetrain is going to hold up for very long with that amount of power. I'll go out on a limb and estimate that 42cc chainsaw engine to put out a real-world 2-3hp, whereas the stock .28 glow engine probably put out 1.5hp and that might even be a tad optimistic. Also, the torque from the chainsaw engine will probably be in the 1-3 foot pounds whereas the glow engine is probably 150-175 inch pounds so I'd be leary of the stock drivetrain holding up.

I'd still like to see some bigger pictures, mainly to see how you have the engine mounted and the gear setup. Definitely a ''thinking outside the box'' idea, for sure.
Sorry, I just had to comment on the part above with regards to foot Lbs. and inch Lbs. 150-175 inch Lbs would be 12.5 -14.58 Ft. Lbs. Assuming that peak torque (150 inch Lbs.) came at 20,000 RPM on the nitro motor, that would be 47 HP. Probably more like 5 or 6 inch Lbs for the nitro engine, if I had to guess.
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Old 08-28-2011, 12:36 PM
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Default RE: losi 42cc big block xxl


Quote:
ORIGINAL: BigTb17


Quote:
ORIGINAL: 1QwkSport2.5r


Quote:
ORIGINAL: art2010

the cluch bell on the engine has a gear that gear spins the nitro cluch bell and that turns the main gear of the tranny so i beleve it will work let say the engine turns 5-6000 rpms then from gearing the nitro cluch bell spins faster and then turns the tranny so hopefully it works
Well, regardless of how its geared (it sounds like you have it set up so it should work), you just need to make sure that your rpm is turning fast enough at the spur gear to get the 2spd clutch to engage so it shifts.

I dont think the drivetrain is going to hold up for very long with that amount of power. I'll go out on a limb and estimate that 42cc chainsaw engine to put out a real-world 2-3hp, whereas the stock .28 glow engine probably put out 1.5hp and that might even be a tad optimistic. Also, the torque from the chainsaw engine will probably be in the 1-3 foot pounds whereas the glow engine is probably 150-175 inch pounds so I'd be leary of the stock drivetrain holding up.

I'd still like to see some bigger pictures, mainly to see how you have the engine mounted and the gear setup. Definitely a ''thinking outside the box'' idea, for sure.
Sorry, I just had to comment on the part above with regards to foot Lbs. and inch Lbs. 150-175 inch Lbs would be 12.5 -14.58 Ft. Lbs. Assuming that peak torque (150 inch Lbs.) came at 20,000 RPM on the nitro motor, that would be 47 HP. Probably more like 5 or 6 inch Lbs for the nitro engine, if I had to guess.
My numbers were total guesses, I think they should have been 50-75 inch pounds. I remember seeing a chart with dyno results from various engines. When I find it, I'll have better facts to answer back with. Nonetheless, a chainsaw engine is going to be hard on a .28 glow powered drivetrain.

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Old 08-29-2011, 09:39 AM
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Default RE: losi 42cc big block xxl

^Yeah, I wasn't saying your point was wrong. If anything, your point about the drivetrain not holding up is even more so considering the numbers were lower than those you first threw out there.

Converting foot pounts to inch pounts is as simple as dividing inch pounts by 12 to get foot pounts, and multiplying foot pounts by 12 to get inch pounts. I.E., 12 inch Lbs. is 1 foot Lb. 48 inch pounds = 4 Ft. Lbs., etc.

HP = (Ft. Lb. Torque X RPM)/5252. So, if the engine makes 2.0 HP at 30,000 RPM for example, that works out to approximately 4.2 inch pounds of torque at 30,000 RPM. 4.2 inch lbs is 0.35 Ft. Lbs. So 0.35x30,000/5252=1.999 HP

Sorry, this really doesn't have anything important to do with this thread. I'm done, haha.
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Old 08-29-2011, 04:57 PM
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Default RE: losi 42cc big block xxl

Honestly, the drivetrain should hold up fairly well. The reason i say that is because there was about a 20 page thread on here about converting t-maxx's to weedeater engines and several guys did it with decent success. The T-Maxx is smaller and harder to get the engine to sit on, and the driveline in the losi is probably 3x as strong so it should hold up reasonably well. Those guys were saying to just let the 2 speed shift VERY early so that the engine didnt get a lot of rpm before it caught 2nd gear that way there wasnt any real shock. Having the truck shift to 2nd as soon as it started moving would probably be ideal really. It should have enough torque to not be a problem.
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Old 09-04-2011, 06:13 AM
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Default RE: losi 42cc big block xxl


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ORIGINAL: cummins driver

Honestly, the drivetrain should hold up fairly well. The reason i say that is because there was about a 20 page thread on here about converting t-maxx's to weedeater engines and several guys did it with decent success. The T-Maxx is smaller and harder to get the engine to sit on, and the driveline in the losi is probably 3x as strong so it should hold up reasonably well. Those guys were saying to just let the 2 speed shift VERY early so that the engine didnt get a lot of rpm before it caught 2nd gear that way there wasnt any real shock. Having the truck shift to 2nd as soon as it started moving would probably be ideal really. It should have enough torque to not be a problem.
I guess if it were me, I would do the single speed hub conversion that way you can eliminate the shift altogether. I know the LST transmission is tough, I have 2 LST2's myself, FOC and gear flip mods. I think they're tough, but I dont know if they are 42cc gas engine tough.. I'm eager to find out how this one pans out though. Definitely an "outside the box" idea.
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Old 09-04-2011, 06:35 AM
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Default RE: losi 42cc big block xxl


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^Yeah, I wasn't saying your point was wrong. If anything, your point about the drivetrain not holding up is even more so considering the numbers were lower than those you first threw out there.

Converting foot pounts to inch pounts is as simple as dividing inch pounts by 12 to get foot pounts, and multiplying foot pounts by 12 to get inch pounts. I.E., 12 inch Lbs. is 1 foot Lb. 48 inch pounds = 4 Ft. Lbs., etc.

HP = (Ft. Lb. Torque X RPM)/5252. So, if the engine makes 2.0 HP at 30,000 RPM for example, that works out to approximately 4.2 inch pounds of torque at 30,000 RPM. 4.2 inch lbs is 0.35 Ft. Lbs. So 0.35x30,000/5252=1.999 HP

Sorry, this really doesn't have anything important to do with this thread. I'm done, haha.
Well, Here's a list of many popular car glow engines tested on the X-Dyno.
http://www.chitownrc.com/engine-driv...o-results.html

I know these results may be skewed somewhat, but there is some consistency to the "typical" RTR sport engines. An SH .28 (unknown model) turned 1.22hp at 20,500rpm and 61.40 ounce inches (5.11 ft. lb.) of torque at 14,750rpm.

I couldnt find this table as this is what I was looking for when I tossed those really high numbers out there. I stand better corrected as far as numbers go. I will revise my original thought on torque of the glow engine vs. the torque of the gas engine. The torque may very well be similar between glow and gas in this scenario, however the gas engine will rev much much lower.

I was wrong, thanks for straightening me out.

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