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Old 08-10-2009, 02:10 PM   #16
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Originally Posted by builtb16a View Post
clutch bell is not hitting. with my motor plates, and mounts, its quite high. my pull start is clear also, so there's no contact with the chassis.

i don't have a flex bracket, or anything to prevent the chassis from flexing, but the whole outside of the chassis has a rolled lip, and has braces from the front and rear diff cases to about 5/8th's into the middle from each side. i don't think im having a chassis flex problem, it has to be these mounts. those holes lining up concerns me.



1st motor.. 2nd motor is the same thing, just completely broke off.
by the looks of it, your back mount screw backed out just enough to alow some movement (look at the area around the hole...see where the black is missing) causing enough stress to crack the ear....as far as different mounts go, look on fleebay, you may be able to find a one piece mount there. that's just my .02...it could just be crappy Q.C. on axial's part....
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Old 08-10-2009, 07:11 PM   #17
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i didn't have a engine movement issue. when the ear broke off, it was still solid on the mount.

i bought those SC8 mounts, and they dont' line up.. so now im back to square one, needing those adjustable sliders.. or pay out the ass and have some made.

if anything, i don't know why they make the adjustment at the top on those sliders. if they used common sence, it would make more sense to slide them on the bottom where your mount could have more meat to grab. might be hard trying to start the screw/bolts from the botton while there's a nut in the channel, but it just makes more sense to me.

so.. im taking the SC8's back. i might take a shot in the dark, call amain, and order all the mounts i see on the website.. and return what i can't use.

re-cuting the chassis isn't an option since the holes already in it, would interfere with the new holes.. 4 countersunk, and 4 oval slider holes..

or.. junk these 2 .28 spec ones, and buy a XTM motor that i know will fit. how crappy.
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Old 08-10-2009, 09:01 PM   #18
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I don't like what I see with that engine mount design. Doesn't look like much support for the ears on the engine block.

Does your pull start mechanism hit the chassis when you tighten the engine mounts?
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Old 08-10-2009, 10:10 PM   #19
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the pull start doesnt touch.. theres plenty of room. i dont like the mounts either.. id rather have 2 plates bolted together rather than a piece of channel tubing bolted to a flat plate. also you can see on the axial block its shallow. the sc8 mounts had the bolt threads really close to the edge where the factory channel sliders put the bolts mid way. im stuck. eithr grind the case or grind the mounts.. either way.. somethings going to weaken.
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Old 08-11-2009, 04:48 AM   #20
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Replace your chassis braces.

If the stock AE mounts work then use them, but the longer Kingheads AE rc8 mount would prevent chassis flex in the engine area.

Looks like classic chassis flex. Kills blocks, kills throttle servos.

Did you case any jumps hard?
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Old 08-11-2009, 10:42 AM   #21
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the RC8's dont' work. even if i changed the mount plates, my holes wouldn't line up, and i would'nt be able to get the right distance on the clutch bell to the spur.

this sucks. im going down to the LHS that sold me this axail motor, with my truck, with my mounts, and try and figure something out. im almost forced to used these slider universal mounts. problem is theyre too thick, and cause stress on the case arms. only solution is to grind. which weakens the mounts.

i was at a track. and they do have some pretty good jumps. but nothing i did seamed like it deserved a fatal engine crack. all my landings were flat, and seamed ok.

i'll keep you posted on what the LHS says. its 100% their products, so i would think they would try and help me. i bought their truggy, and their hop up motor.. so after 2 cracked engines, i would think they would feel obligated to give me a solution.
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Old 08-11-2009, 12:10 PM   #22
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Easy now. The LHS did not manufacture the mounts, truggy or the engine. They only reason they will be obligated to do anything is if they really care about you and your business. If they don't it is between you and the manufacture.

Good Luck, I know you are frustrated.
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Old 08-11-2009, 02:35 PM   #23
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I had that problem using a novarossi 528xr with the XTM mounts. The sides of the case were touching the mounts and pushing them out a little when I tightened it down. That made the mounts sit un-level to the chassis.. I had to grind a little off of the back side of the mounts to give clearance. Never broke an ear off but check and see if thats it.

bolt the mounts on and see if the bottom of the mounts are level. I finally made my own mounts for novarossi's.
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Old 08-11-2009, 03:04 PM   #24
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You are Right on the Money avdub i have seen this happen 2 time to motors and it was the mount and not the motor we had to grind a little off of the back side of the mount and it works to this day and i bet the guy has had 5 motors on his truck and not one has broke after we done a little grinding on the mounts.
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Old 08-11-2009, 07:22 PM   #25
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Originally Posted by builtb16a View Post
there is plenty of room.. but the guy that posted his ears breaking off.. same as mine, same mounts... same stress. so it has to be in the mounts, not the substandard cast aluminum they're making these cases out of.

ok.. now round 2. i picked up some RC8 mounts. although the mount to the engine fits GREAT! even alittle room in the back, now my mount to chassis holes are wrong.

gezz.. i don't know what to do. its almost like i need to use the universals.. or a new truck. this is rediculous.

OK - These are very similar to the Hot Bodies mounts I use on my Pro 2 evo -

Looking at the picture it looks like the ear maybe hitting the mounting plate. That's the black plate where the mount - mounts to.

ALSO - if you look at the clutch flywheel - you need to either change the brass collet (sp) so the clutch flywheel sits just about flush with the engine, or change the flywheel to fit deeper in the collet. In fact, you can use a clutch flywheel that has a little ridge that will cover the front of the front bearing case. Yet, still allow a few thousands of clearance. Once the flywheel sits deeper, then you can shim out the clutch bell to set the mesh with the pinion gear.

Even though you can see a couple marks where the clutch bell has hit the chassis, I don't believe this is your problem. I believe the problem is in the mounting. I have an OFNA LX comp and it uses the those same mounts but silver. I decked my OS V-Spec and used those mounts and never cracked a block. And I gave the OFNA some real strain. I know they will hold the power.

Also, keep this in mind. If you land flat and smack the ground when landing. Its very easy for something (Even dirt) to smack the clutch flywheel and pop the engine up hence crack the ear.

These are the stock hot bodies mounts for the lightning 2 pro



I've ground down the back end of the left side (Your broken side) to clear the pull start using a back up motor to bash around the house. Even brought it on the track to do some back flips and never broke.

Keep at it and don't give up, I hope your LHS helps you out.

Good luck
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Old 08-11-2009, 07:47 PM   #26
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Originally Posted by avdub View Post
I had that problem using a novarossi 528xr with the XTM mounts. The sides of the case were touching the mounts and pushing them out a little when I tightened it down. That made the mounts sit un-level to the chassis.. I had to grind a little off of the back side of the mounts to give clearance. Never broke an ear off but check and see if thats it.

bolt the mounts on and see if the bottom of the mounts are level. I finally made my own mounts for novarossi's.
Yeah that'll do it!

If the case touches the mount its toast. Only the mounting ears should touch, and you have to be gentle installing the engine. It has to lay flat on it's own. Can't torque it down to get it straight. If you use the bolts to wind it in, it'll crack.

Safe enough to grind the inside edge and corner of your mount. It's alot stronger than yourengine block!

All motors, cheap and expensive that I've seen, use cheap cast blocks. Very, Very, fragile. I've only seen strong billet blocks in better airplanes.
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Old 08-12-2009, 02:55 AM   #27
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ok update.

i went to the LHS, and explained my frustration. and the store managers answer was, "maybe that engine wont fit in your truck..."

my jaw dropped. and i asked, well... why did you sell me that engine. and why did you sell me a truck. its not like i bought all my shit on ebay, and im coming to you with my problems.. this is stuff you sold me. and i can't make any sense of buying cases and motors because the mounts aren't right. i asked, this XTM truggy, your telling me there isn't an option for more power, more performance.. only replacement XTM motors.. which are JUNK... why would you sell me a hop up engine.

he kinda gave up, but the store supervisor, a off road nitro veteran, stepped in before i got buck wild up in the store.

i explained my problems and how im breaking these case mounts.. twice. and showed him a ground down modified mount, these RC8 moutns, and how the RC8 fits soo much better than the XTM slider style mounts..

its kinda hard to explain, but on that axial block, right next to the backing plate, is a raised edge from the cast. my option was to grind that down, or oblong the mounting holes on the case ear. EITHER WAY, ONCE THE GOOD CASE BREAKS, IVE MODIFIED IT, AND IM SHIT-OUT-OF-LUCK!

so i refused to take that answer. he installed the smallest collet he could find. used about 5 shims on the outer clutch bell housing, and it was SUPER close to fitting. it was on the outer edge of the clutch bell, and barley flush, so we went option 2. XTM mounts bolted up to the hump near the backing plate, and had to move the bell the other way. basically opposite.

so after understanding what he was trying to do.. and what i was doing before (just grinding down the inside to get over the hump) i took the handy dremel, and notched about 4MM out of the inner side of the mount on each side, near the back, in order for the mount to clear the hump.

that worked. and so far, so good. the store sup. had to bust out his personal tools, find shims.. a different collet, and well, about an hour of his time, to work on this motor. (not that he wasn't getting paid) but atleast he felt my frustration, and the store managers answer of "you bought the wrong motor"...

i'll post pics of my modified mounts, and how its sitting on the spur tomorrow. im glad i got this under control, and i can start enjoying this .28 instead of kicking rocks, and beating my dog.lol
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Old 08-12-2009, 03:27 AM   #28
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again, its easier to explain with pics.. and i'll take pics of my mounts tomorrow and how the engine sits in the truck right now. im happy with it. i just hope i don't crack another case. im going to be PISSED!
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Old 08-12-2009, 04:00 AM   #29
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It's going to break again. You can thank me later for the vote of confidence. Catch you on the flipside!
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Old 08-12-2009, 04:19 AM   #30
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It's going to break again. You can thank me later for the vote of confidence. Catch you on the flipside!
gawd... please don't listen to this guy.. he has no clue what he's talking about. (personal friend)
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