Mounting a .18 in a Super Nitro Rally SUCCESS & Video  
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Mounting a .18 in a Super Nitro Rally SUCCESS & Video - 2/10/2007 4:18:08 AM   
Dirt4dinner


 

Posts: 26
Joined: 5/17/2006
From: Mesa, , AZ, USA
Status: offline 		It's time to come to the world wide web for help!

I have a Super Nitro Rally that I just built out of a box of parts I bought from a guy locally. He was running the stock HPI .15, but it's shot and I don't want to buy another one. I have a Sirio 18 sitting around as a back up engine for one of my revos. I have spent the last two days trying to mount the Sirio in the SNR. I have tried every mount I can get my hands on and no matter what I do I can't get the thing mounted right.

Here are the problems. With the stock mounts the clutch bell hits the spur (engine to far forward). If I try the mounts in the back set of holes on the chassi the clutch bell is about 1/2" from the spur gear. So I set to try other mounts....I tried adjustable mounts, but the pull starter gets in the way and I can't slide the engine forward. What I need is a set of mounts that have off set holes. Let me try to explain. I need it to mount up to the holes on the chassi...but I need the holes on the top of the mounts to be forward of the holes that hold the mount to the chassi. Make sense? I have been plowing through page after page of engine mounts on Tower and other sites and some look good...but I would rather see if someone out there has put a .18 in the SNR and how they did it. Don't forget, this is the Super Nitro Rally, so it's only a single speed.

My next step is to go buy aluminum bar stock at Home Depot, buy a tap and die set and make my own stinkin' mount...but that seems pretty extreme. Any advice would be great...and forgive me if I shot down the obvious ideas. I am not new to RC and I have tried everything I can think. I even tried figuring out a way I could get the bellcrank lower on the engine shaft...but it's just not possible.

Any help would be great...and I can take photos if I need to. Put your thinking caps on!

< Message edited by Dirt4dinner -- 3/13/2007 8:24:54 PM >
       Post #: 1

RE: Mounting a .18 in a Super Nitro Rally - 2/10/2007 8:00:26 AM   
iexion


 

Posts: 758
Joined: 8/1/2006
From: Sioux Falls, SD, USA
Status: offline 		Hey bro. Just to mix things up a bit. I checked out http://hpiracing.com/index2.htm and looked up the engine mounting page http://hpiracing.com/graphics/instr/snrally/snr_21.jpg and it looks like the engine doesnt use mounts, It sits on the chassis by its self with out mounts.

Looking at the stock engine that would fit the SNR, Is that Sirio a sg (Or its called Pilot) shaft?


< Message edited by iexion -- 2/10/2007 9:15:03 AM >

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RE: Mounting a .18 in a Super Nitro Rally - 2/10/2007 8:46:55 AM   
HeLLsGoD



Posts: 719
Joined: 2/10/2007
From: hellJP, ANTARCTICA
Status: offline 		Pullstart engines stick out more, thats why u need pullstart engine mounts for it. How much does the clutch bell overlap the spur? You can take out the washer behind the flywheel collet(if you have one). It will make the clutchbell shorter

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RE: Mounting a .18 in a Super Nitro Rally - 2/10/2007 9:34:25 AM   
iexion


 

Posts: 758
Joined: 8/1/2006
From: Sioux Falls, SD, USA
Status: offline 		What about Switcing to some form of roto start for the engine??? might take up less space. I've already cut off that little part that sticks out behind the pull start. Not like you really need it.

Hmmm what about taking a drimmal drill and making the holes go more in the direction you need?

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RE: Mounting a .18 in a Super Nitro Rally - 2/10/2007 4:30:30 PM   
Dirt4dinner


 

Posts: 26
Joined: 5/17/2006
From: Mesa, , AZ, USA
Status: offline 		Thanks for the replys guys.

Yes the stock engine mounts directly to the chassi. However they make engine mounts for engines that don't have the "flat bottom" like the stocker. There are two sets of holes in the chassi. 4 of them for the stock motor, and the 6 oval holes for different engines...just not mine. I could go to rotostart...but that would still the spur clutch bell in the wrong spot. With roto start, don't you still have the larger backplate like you do with a pull start? I fell like it's still a pretty big mechanism for roto start and that might leave with the same problem. I have tried removing the shims behind the collet, however if I take them away my clutch nut will not get bite on the flywheel. I have it shimed as little as possible. I found a few more mounts that look like they might work. It looks like the mounts for the Losi XXX-NT have 2 sets of holes in the top, and one set appears to be offset towards the front of the mount a little bit. I am going to try and locate those locally.

I will keep you posted, in the meantime keep thinking.

Oh, my last resort is to attempted to drill out the holes in the chassi. I have an old chassi laying around and I tried to do it....it didn't work. There is ZERO room for error when drilling holes, if you are off even a hair it will mess up the mesh. I have a brand new $40 chassi on the car right now, I would much rather not have to go drilling holes through it.

Thanks for the work....keep thinking about it! -DIRT

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RE: Mounting a .18 in a Super Nitro Rally - 2/10/2007 9:23:34 PM   
Dirt4dinner


 

Posts: 26
Joined: 5/17/2006
From: Mesa, , AZ, USA
Status: offline 		Turns out the XXX-NT mount is going to do the trick. It's not a PERFECT fit...but it's close enough! I am going to have to not use the tapered washers on the underside of the car as they take away that last millimeter I need to get the mesh right. I also had to use the provided HPI engine mount spacers, but that's not biggy. So with that...the SNR w/ Sirio .18 is just about ready to go. I am just waiting for my header from Ebay!!!!! I will try and post pics when I get a chance...just in case someone else is trying to stuff a .18 in the SNR.

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RE: Mounting a .18 in a Super Nitro Rally - 2/10/2007 10:22:30 PM   
iexion


 

Posts: 758
Joined: 8/1/2006
From: Sioux Falls, SD, USA
Status: offline 		GREAT WORK BRO!!! I bet the things gonna fly like hell!!

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RE: Mounting a .18 in a Super Nitro Rally - 2/14/2007 5:15:50 AM   
Dirt4dinner


 

Posts: 26
Joined: 5/17/2006
From: Mesa, , AZ, USA
Status: offline 		Pictures as promised. I had to do a TINY bit of dremeling to get the engine mesh just right. Not even enough that you can tell when the screws are in place. I think it came out good. I am just waiting for the header to arrive from ebay. I am going to run the Traxxas Resinator pipe from a Jato....this thing should FLY! Other upgrades on the way are CVDs and turnbuckles...they are laying on the work bench right now waiting for me!

Here are the photos.







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RE: Mounting a .18 in a Super Nitro Rally - 2/14/2007 11:55:13 AM   
iexion


 

Posts: 758
Joined: 8/1/2006
From: Sioux Falls, SD, USA
Status: offline 		Hey bro, Looking at the pics, im sure your already thinking this but i hope it doesnt eat up the trans gear, but it looks good. I think if i can find a good SNR roller for cheap (80-110) might have to get it, Im thinking that a SNR would fit my TZ engine better then my rs4 3 would. but it would HAVE to be a 2 speed


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"All you read and Wear or see and Hear on TV Is a product Begging for your Fatas dirty Dollar So Shut up and... "

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RE: Mounting a .18 in a Super Nitro Rally - 2/15/2007 3:54:01 AM   
Dirt4dinner


 

Posts: 26
Joined: 5/17/2006
From: Mesa, , AZ, USA
Status: offline 		I am a little worried about the spur gear...but I just can't get it any closer. Hopefully with the right mesh they will be ok not lined up completely. I run the OS 18TZ in two of my three revos...and I agree...that would be a SICK engine in a SNR. However you are going to run into the same problem as I did with mounting it. You would be better off to build your own engine mount with aluminum bar stock and a tap and die set. Only problem then, is that you aren't going to have any adjustability unless you have access to a water jet or some other means of boring out the fabricated mounts to allow the engine to be slide around within the mount. I have been staring at this issue for the last 2 weeks trying to get this Sirio in there. I am not a big Sirio 18 fan, but it came in one of my revos and I swapped it out for a new TZ...so it was just laying around.

I asked HPI if they knew of any 2 speed kits that would be applicable to the SNR and they said no. But hey might just be to closed minded to think outside the box.

I did some research and the only issue I see is that the 2 speed shaft (that the spurs sit on) is longer by almost a 1/2". If you could over come the length difference with different dog bones you might be able to pull it off. Space is also a MAJOR issue...my carb is millimeters from my brake disc, and the flywheel is even closer! I am not sure there would be enough room to fit it all in there. If I had one of the HPI cars that has a 2 speed I would try and fit it in, but I am not going to buy all the parts for the 2 speed only to find I can't fit it in. If you get the ich to experiment please let me know. If it can be done I would go for it!!!

Another option I was looking at, was to move the brakes to the front of the center diff rather than on the back. It seems to be set up to accept the brakes in either spot. I left mine in the back...but I might end up changing it once I start toying with the throttle and brake linkage. I am still worried that I don't have enough room between the carb housing and the brakes...and also between the carb and the throttle servo. More on that later.

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RE: Mounting a .18 in a Super Nitro Rally - 2/15/2007 4:49:52 AM   
VDub99AML


 

Posts: 403
Joined: 10/23/2005
From: Canton, OH, USA
Status: offline 		I just put an O.S. 18TZ in my onroad SN. I'm just waiting for the carbon fiber upper braces, and some higher gears to come in. Unfortunately, tower is now saying that stuff is on backorder till March, and we just got a foot of snow the last couple of days. So, it'll have to wait till spring. I got this car with an O.S. .15 CV engine, and it came with the engine mounts, but here's a link for them if you're interested for future reference. http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXN373&P=6

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RE: Mounting a .18 in a Super Nitro Rally - 2/15/2007 8:13:50 AM   
iexion


 

Posts: 758
Joined: 8/1/2006
From: Sioux Falls, SD, USA
Status: offline 		Hey Dirtfordinner, the attitude your showing when trying to get the all this modding to work makes me think " If i was going to own my own Business, you'd be the first person i would hire " because you see theres a way to get it to work, its just getting the correct tools.

Now on that whole "TZ" thing. An OS .18 TZ (TX) is what would fit that car perfectly. Trust me on this. The TZ is an sg shaft for the Revo and most track type cars (r40, kyosho rrr etc) BUT they have a standard shaft with a pull start (TZ-TX.) .So like i said, the engine fits my rs4 better then the stock engine did. And the stock engine was a 12Rss. Im talkin stock engine mounts and everything. All I had to do was find a .21 air filter and exhaust manifold, but other then that, I put a .18 TZ on that chassis with no issues

Now im saying this because the stock engine on the SNR was a 15-fe or whatever. So i think of it like this, if i can mount the engine that came on a SNR to my RS4, i can mount the engine i have on my TZ (TX) to a SNR right now.

The shaft looks kinda of small but its the perfect fit
http://www.prop-shop.com/g/o/osm18tztx.jpg
see what im saying?


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"All you read and Wear or see and Hear on TV Is a product Begging for your Fatas dirty Dollar So Shut up and... "

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RE: Mounting a .18 in a Super Nitro Rally - 2/15/2007 6:01:06 PM   
Dirt4dinner


 

Posts: 26
Joined: 5/17/2006
From: Mesa, , AZ, USA
Status: offline 		Thanks for the compliment. And yes you are right, I just remembered that to get the TZ in my revos I have to cut the drive shaft shorter. A TZ would be a direct drop in for the SNR...and CRAZY STUPID FAST! So for the record, I don't recommend going the route I did with the Sirio .18....it was a nightmare and I am not even completely convinced that I won't be going through spur gears like underwear.

VDub, there is ONE major different between the Super Nitro and the Super Nitro Rally....the SN has a belt drive, and the engine sits facing "east west" whereas the SNR has simple clutch bell to spur gear set up and the engine sits "north south" on the chassi.

I still want to find out if I can stick a two speed in the SNR...how about one of your guys get to doing your homework and see if you can find something I missed!

Until next time. -DIRT

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