Rotor nut

[andy230]

Hello!

Back to work then!  The season starts on 12th April at snetterton, so we'd beter get our skates on!

Can anyone tell me, is the nut on the crankshaft holding the rotor on a left hand thread or anything daft like that?

And (as the crank is spinning, with no top end on it) is there a better way to get the nut off than as I plan?

put an old piston and pin on
use this to "lock" the rod in place (carefully) with a piece of slotted wood across the mouth of the cases?

Bill, thanks a lot for the rotor puller, you are a star.  Plus that postage was dear, very kind of you to cover it.

I now have a trick ignition system so can ditch the rotor and a CNC-milled plate:



Very tasty, huh?  I got it on loan/sale or return from this kindly chap, and am very grateful!

http://www.zabernet.de/bill/Tuning.html

Cheers for now, I await your learned knowlege on rotor nuts and their removal!

a



cheers,

andy

[Steve H]

The only way Ive found to be 100% sucessful is to use an airgun. The rotor can be held in your hand whilst the gun removes the nut, in fact it was the firts thing I did and I didnt even take the alternator cover off. You can get 12v impact guns but Ive no idea how good they are.

[andy230]

Cheers steve. 

normal right hand thread?

I'll try to shock it off.  Long bar and a hammer??  Or is that just trying to wreck the motor?  I dont have access to an airgun, but 12v (or maybe better with 240v) impact gun is an option...

a

[Steve H]

Normal thread. They are generally TIGHT, I know that money is at a premium, but I would really recommend getting an impact gun, they can be used for all sort of things and have saved me a few times. Managed to forget to undo the camshaft bolts before removing flywheel and primary drive, so I had nothing to get a purchase on/lock to undo the nuts. Rather than re-assemble it all again I used the the impact gun which had them off with no drama. Ive no doubt others would frown at this approach but in the past Ive made expensive mistakes when using big levers trying to undo nuts. May save you money in the long run.
Sermon over

[Steve H]

These are cheap but dont have a massive torque output
http://www.machinemart.co.uk/shop/product/details/cir13c-1-2in-impact-wrench-kit-12v

Mine is something like this
http://www.machinemart.co.uk/shop/product/details/cat231b-13pc-1-2in-dr-air-impact-wrench-/path/air-ratchets-wrenches

[andy230]

These are cheap but dont have a massive torque output
http://www.machinemart.co.uk/shop/product/details/cir13c-1-2in-impact-wrench-kit-12v

Ok..... the scotsman is coming round to the idea.... Plus its in keeping with the 12v solar shed!

However, nothing happened tonight.  Brrrrr!  Way too cold!
 
Steve, that link (above) reckons up to 175Nm from this 12v one.  Torque setting for that nut is 150Nm.  Thus it should work, right??  Is it "safer" to use an impact gun?  ie less likely to wreck the nut and/or the rod/small end when using a (n old) piston to immobilise the engine?

thanks again...!

andy

[OMEGAMAN]

Hello!

Back to work then!  The season starts on 12th April at snetterton, so we'd beter get our skates on!

Can anyone tell me, is the nut on the crankshaft holding the rotor on a left hand thread or anything daft like that?

And (as the crank is spinning, with no top end on it) is there a better way to get the nut off than as I plan?

put an old piston and pin on
use this to "lock" the rod in place (carefully) with a piece of slotted wood across the mouth of the cases?

Bill, thanks a lot for the rotor puller, you are a star.  Plus that postage was dear, very kind of you to cover it.

I now have a trick ignition system so can ditch the rotor and a CNC-milled plate:



Very tasty, huh?  I got it on loan/sale or return from this kindly chap, and am very grateful!

http://www.zabernet.de/bill/Tuning.html

Cheers for now, I await your learned knowlege on rotor nuts and their removal!

a



cheers,

andy

   From the looks of that leg in the picture, you seem to have put a bit of weight on over the christmas period?

[themoudie]

Aye Andy managed to stall a 240v B&D impact drill on mine £34-00 thank you!

Prefer gudgeon pin supported on wooden blocks either side of crankcase mouth with plenty of rag in the hole myself and a long lever with good fitting socket. However, nowt wrong with t'other method.

As for your calf muscles dear. looks like you've been training with my weeun who's aiming for 'toning'!

My regards, Bill.

[Steve H]

These are cheap but dont have a massive torque output
http://www.machinemart.co.uk/shop/product/details/cir13c-1-2in-impact-wrench-kit-12v

Ok..... the scotsman is coming round to the idea.... Plus its in keeping with the 12v solar shed!

However, nothing happened tonight.  Brrrrr!  Way too cold!
 
Steve, that link (above) reckons up to 175Nm from this 12v one.  Torque setting for that nut is 150Nm.  Thus it should work, right??  Is it "safer" to use an impact gun?  ie less likely to wreck the nut and/or the rod/small end when using a (n old) piston to immobilise the engine?

thanks again...!

andy

Andy, mine seems borderline on the rotor nut, but I had put that down to a compressor with a small reservoir. Before getting a gun, I took mine to the local garage, they undid the nut for a £5.
Since your engines out of the frame the biggest issue is not stopping the crank rotating in the cases, its holding the engine down. If you've got it mounted in a sturdy cradle you might get away with it. In my opinion the impact gun requires less force so is less prone to accidents when slipping etc.
The other advantage of going down the air route is you can use the compressor for cleaning oil ways, carbs, blowing out brake pistons (carefully) etc, but with only 12v to play with it may not be an option.

[andy230]

From the looks of that leg in the picture, you seem to have put a bit of weight on over the christmas period?

Hee hee!!!  No, thats from his bike John,  I take it they are also his legs...

Anyway, I have managed to blag a 12v impact gun.  Steve, ity was the same as the one you sent in that link above.   I'll give it a bash tonight and let you know...

cheers

a

Why buy, when you can borrow?

[guest146]

Andy

It sounded like you have the head of as you talked about the piston pin. Postion the crank with the pin half way down its stroke so it has the least leverage and block the pin both sides onto the crankcase with some wood as wide as possible then it will jam the wood and prevent the crank from turning and you can also torque it up if you wish.

Ken

[guest27]

Surely half stroke is max leverage? I would have thought BDC or TDC were min leverage as all the pins etc are lined up. BDC as it minimises leverage around the main bearings.

half stroke puts the gudgeon pin max distance from big end pin and all max distance from the line of the main bearing.

Have I been wrong all this time?  (Would not be the first time)

R

[guest146]

That would be the case in reverse If it was the piston forcing the conrod down it would have maximum torque half way down its stroke. But when trying to force the piston or conrod back up the bore by applying force to the crank its at the point where it needs most force to move.

Ken

[Steve H]

If the crank is at its middle(ish) position then the load imparted to the crankcases (through the wooden blocks) will be at a minimum. It will also provide a more stable/solid lock as any play in the bearings etc will result in less rotation at the rotor nut.
Even easier if you use an impact gun :-)

[andy230]

hi all

stop bickering and put your handbags away!  The 12v impact gun worked a treat.

Here's a bit of info and a pic of the new "bling"

http://team-thumper.blogspot.com/

Next I'm going to modify the cam chain tensioner.  Apparently the automatic tensioner is asking for trouble in a tuned motor.  Expensive trouble, and on good authority!  So I'm going to take out the spring-loading and make a manual tensioner, operated by a bolt.

I suppose it must be due to the chain thrashing around, over-tensioning, and "ratchetting up", resulted in detruction of the valve train. 

cheers for your help guys,

a