R/C Tech Forums

R/C Tech Forums (https://www.rctech.net/forum/)
-   Offroad Nitro Engine Forum (https://www.rctech.net/forum/offroad-nitro-engine-forum-157/)
-   -   New engine w/ crankshaft play!! (https://www.rctech.net/forum/offroad-nitro-engine-forum/547258-new-engine-w-crankshaft-play.html)

Hsv7ltr 09-01-2011 05:34 PM

New engine w/ crankshaft play!!
 
I am new to this forum so sorry if I haven't posted correctly.

I have a new force .46 engine that I need to fit into my GV Cage 1/8 buggy but I am worried I damaged the crankshaft as it has about 3-4mm of horizontal play. My previous force .32 doesn't.

My main question is: Is this a problem??

I haven't got the collet or flywheel on yet because Im not sure how.... Haha
Tried hitting it lightly with a hammer to get it on.. YouTube wasn't Too helpful though I haven't researched much yet.

motomatt 09-01-2011 06:16 PM

the collet is what secures the crank to the inner race of the front bearing. Make sure the crank is all the way forward and the collet is seated against the inner race of the front bearing when you tighten the flywheel nut. There should be very little or no end play once the flywheel is tightened.

Use a small tuning screwdriver to wedge the slit in the collet slightly, it will slide on easily when done this way.

Hsv7ltr 09-01-2011 09:25 PM

Thanks mate, cheers

Hsv7ltr 09-05-2011 01:42 AM

Flywheel on and STILL play in shaft!!!
 
I have installed the flywheel and all looks good but the crankshaft will still slide in about 5mm. It does seem to hold itself forward against the front bearing but I can still push it in easily. Only about 5mm bit I am still really worried!!

motomatt 09-05-2011 06:15 AM

I hope you mean 0.5mm. Even that is more than I would consider acceptable.
Are you sure you had the crank pulled all the way out with the collet seated against the bearing?

Hsv7ltr 09-05-2011 02:35 PM

The collet is on as far as possible but im thinking I need a shim between the collet and bearing. The collet isn't thick enough to sit against the inner race and instead sits against a lip on the actual crankshaft, the collet will slide into the bearing Aswell.
5mm was probably a bit much but it slides back in at least a couple mm.
From what you say I gather any play isn't really acceptable so I think a shim would fix it. But how long will a tiny shim last in there?

Thanks for you input though mate! Everything helps

am 09-05-2011 11:22 PM

If you mean .5mm it is ok. Some small aksial play is ok ;-) It wont kill your bearings as fast as when all is tight. my best nova engies has a slight play, maybe .1-.2mm ....

Hsv7ltr 09-06-2011 02:26 AM

Ok, just measured it. It's actually only 1 mm of play. Still too much in my opinion. I read another post somewhere and someone had suggested running it and seeing if there is wear on my backplate, if all seems ok then it should be fine. I think I'll just try running it.
But that won't happen until I work out how I'm going to fit it in, another post for that tho. Ah rc cars, love it but hate it.

Hpisavage18 10-11-2018 03:26 PM

I recently purchased the force .46 engine. Does anyone no where to get a flywheel? Being the o.d. of crankshaft is bigger.

timjs 10-11-2018 03:46 PM


Originally Posted by Hpisavage18 (Post 15315339)
I recently purchased the force .46 engine. Does anyone no where to get a flywheel? Being the o.d. of crankshaft is bigger.

Force .46 I thought has been out of production for a long time. Do you have a link?

Roelof 10-11-2018 10:38 PM

Check if the front bearing is flush with the crankcase. But when you pull out the crakshaft, at the same time push the collar against the bearing and mount the flywhel the shaft should still spin free. If that is the case then the bearings are mounted right.

Matt Piva 10-15-2018 01:32 AM

What the hels is a .46 doing in a buggy? For real the biggest big block I’ve ever heard of is a.32?? Are you sure you have an 1/8th scale engine?

one mil is a lot of play, big engines maybe have more. Maybe try n start it, then post a video of it tuned for high speed on the track so we can watch a monster big bore tear up your buggy. :)

timjs 10-15-2018 05:12 AM

The hot bodies (made by force I believe) .46 used to be produced. Nowadays Force makes a .38.
http://www.rc-willpower.com/Cart/index.php?route=product/product&product_id=15028

For the record on crankshaft play:
ASSUMING the bearings are seated properly in the crankcase, the front bearing alone locates the crankshaft front to back.
The crank and the collet sandwich the front bearing inner race. If theres play, you need to push the collet further down the crankshaft while also pulling the crank forward or pushing forward if you have the backplate off. There should be no play front to back ideally but a tiny amount is fine. Too much and you may wreck the connecting rod or crankshaft pin.


All times are GMT -7. It is currently 02:34 PM.

Powered By: vBulletin v3.9.3.9 Patch Level 3
Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.