XRAY - Model racing cars

Hello,
I'm in the middle of building my first XRay kit, an XT8. I love the quality of the kit

I have a question about fitting the clutch/flywheel to my engine. I have an OS 28XZ truggy engine and at the moment I'm using the standard flywheel that comes with the XT8 kit.

Basically, when I fit the flywheel and clutch, there is still more engine shaft sticking out from the bearing in the end of the clutch housing than I would expect. See below


20110228-OSClutch-00.jpg [ 51.6 KiB | Viewed 3790 times ]


I'm just about to order the XRay Flywheel Collar (358540) and I realise this might space the flywheel a little further from the engine, but to approximate this, I have all 3 different size shims that come with the kit between the engine and the flywheel.

The manual also shows a 1mm washer that can fit at the end. Luckily there are actually two in there, it seems to need both


20110228-OSClutch-01.jpg [ 42.85 KiB | Viewed 3790 times ]


Is this correct? It's almost like it needs a slightly thicker flywheel, another reason I think this is that when all fitted together, the engine mount needs to be slid as far forward as possible for the gears to mesh, and even then it's not right in the middle (although it's good enough to mesh well, but would be still nice if centred), see below


20110228-OSClutch-02.jpg [ 64.03 KiB | Viewed 3790 times ]


There are OS flywheels, but I am not sure if they would be any different, and if so, which one? As they seem to list flywheels for various car makes (Mugen and Kyosho)..

Thanks for any information!
David

David you are heading in the right direction, Its just about getting the shimming right. I have a shim kit that comes with tube style shims that slip over the SG shaft on the crank and they are different heights i just swap around til when i get bite on the end of the clutch bell it just squeezes down on the inner race of the bearing but allowing the bell to spin freely still. Ill try and get some pics up tomorrow after work if i get the chance....Normally when i do a new engine clutch shim it take it on and off a number of time until im happy then do a final build so its right.

David,
From what I can see, you're in good shape. Add shims of various thicknesses until you find the optimal shim stack. It is not uncommon to have that much of the crankshaft sticking out. As long as the clutch bell spins unhindered by the shims or flywheel you'll be alright.

Just get it as close as possible without any binding.

Regards,

Speed Metal

Oh and I forgot, if you want, you could also try putting a thin shim in front of the flywheel nut (I call them Internal Shims)to move your clutch bell forward a bit. Just make sure you're not not uncovering the clutch shoes.

Alignment looks fine as is, but just in case you want it perfect you can try different combos of "internal" and "external" shims.

Regards,

Speed Metal

Hi guys, thanks for the replies so far

That sounds promising! I guess everything else had gone together so exacting, I was kind of expecting the clutch to go on perfectly with everything lining up. I'll have to see where everything sits once I get the collar on as well, hopefully that might move it forward a fraction.

I found this picture, does anyone know where I might get a cone shaped washer such as on the front of this?



I assume online hobby stores would stock additional shims if needed (such as the internal ones you mention?)? I might need a mixture of other sizes to juggle things around a bit, any links would be helpful to make sure I get the right ones.

Thanks for your help! As this is my first kit and first race truggy, I'm probably worrying a little more about details than I should (but I like to make sure everything is just right!).

Thanks! (bed time here now!)
David

Never use shims with so large outer diameter between outer bearing and the screw These shims will touch the clutchbell and the outer part of the bearing - and that must not happen!

You should shim the flywheel further away from the crankcase - put shims between engine crankcase and the flywheel collar. Then put some shims between the flywheel nut and inner clutchbell bearing, but make sure the clutch shoes stay inside clutchbell. And then to adjust the final play use some shims between outer bearing and the screw. Then leave about 0.5-0.7 mm play, it might seem a lot, but trust me

I hope it all works out! First time getting it right takes time if dealing with new car or engine or clutch.

OFNA has some nice shim sets which are nice to have but to be honest not really needed with modern buggies and truggies.
http://www.amainhobbies.com/product_inf ... s-Shim-Kit
http://www.amainhobbies.com/product_inf ... s-Shim-Kit

Actually you should use "special" thicker shim between the crank shaft and the screw (I think it is included with Xray kit). And also use socket head screw, which uses larger hex screwdriver! Never use round head - you'll strip it soon which gives you headaches