Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: Prof on August 13, 2011, 08:50:27 AM

Title: Torque multipliers and reaction points
Post by: Prof on August 13, 2011, 08:50:27 AM
Been looking more and more at these things, and it got me to wondering...
 
In the Haynes guide and the FSM it shows one being used to undo the flywheel nut - and knowing that I\'ve had to swing my 16 stone of frame on the end of a 6 foot extension just to shift that 54mm nut makes me think this is the more gentlemanly way of removing one.
 
But it\'s my understanding that these need a reaction point - something to lever against, in order to get the torque onto the nut and not just spin the thing off!
 
Has anyone had any experience of using one on the flywheel nut?  What reaction point do you use?
 
Ta in advance...
Title: Torque multipliers and reaction points
Post by: m1tch on August 13, 2011, 08:59:09 AM
Wasn\'t that 54mm nut stuck on there because of it being tightend too much onto the e-shaft, when I went over to Driftworks to pick up my BP engine from Phil we just used a standard impact tool on the flywheel nut and it came right off lol
Title: Torque multipliers and reaction points
Post by: shaunwil on August 13, 2011, 09:09:38 AM
How many Nm should it be torqued up to ?

At 450Nm you would need 45kg on a 1m bar away from the fulcrum.

Shaun
Title: Torque multipliers and reaction points
Post by: Dualist on August 13, 2011, 09:51:13 AM
I used a hammer and chisel to get my nut off, worked a treat :Giggle
Title: Torque multipliers and reaction points
Post by: Brett on August 13, 2011, 10:14:41 PM
Ive used all of the methods mentioned... I found getting two blokes to hang on to the lump, and me on the end of a scaffold pole worked as well ;)
Title: Torque multipliers and reaction points
Post by: TiddlesRX7 on August 13, 2011, 10:53:32 PM
I\'ve used them in industry but never for this purpose. Yes they do need a stop to butt up against for them to actually produce the desired effect. On a flywheel I\'d guess you\'d have to screw something in to one of the clutch bolt holes as there isn\'t really much of anything else.
Title: Torque multipliers and reaction points
Post by: SmbFD3S on August 14, 2011, 12:42:59 AM
Quote from: TiddlesRX7;782094I\'ve used them in industry but never for this purpose. Yes they do need a stop to butt up against for them to actually produce the desired effect. On a flywheel I\'d guess you\'d have to screw something in to one of the clutch bolt holes as there isn\'t really much of anything else.

You mean like this as i\'ve always done :)

(http://i185.photobucket.com/albums/x125/smb2200/DSC01837.jpg)
Title: Torque multipliers and reaction points
Post by: jackaleks on August 15, 2011, 09:36:48 AM
jesus... i\'ve just seen how expensive these things are! a scaffold pole seems much better value for money.
Title: Torque multipliers and reaction points
Post by: Prof on August 15, 2011, 09:42:10 AM
Quote from: jackaleks;782323jesus... i\'ve just seen how expensive these things are! a scaffold pole seems much better value for money.

They aren\'t cheap, but I see them on ebay from time to time - but I was thinking for those occasions when you might want to swap a flywheel whilst the engine is in the car.  It seems to me that the issue is where the force is being applied.  Basically it\'s between the nut and the flywheel, but that means anchoring something to the flywheel so that the torque can be multiplied and applied just on the nut itself, with the car potentially on a driveway on stands.
Title: Torque multipliers and reaction points
Post by: jackaleks on August 15, 2011, 11:31:18 AM
Quote from: Prof;782325but that means anchoring something to the flywheel so that the torque can be multiplied and applied just on the nut itself, with the car potentially on a driveway on stands.

it looks like you can wedge the Norbar ones against something (like the driveway/car floorpan) using an extension? they are proper money though! there is a 5:1 on ebay for just over £100 at the moment, however...
 
(http://www.armedforces-int.com/upload/image_files/articles/images/companies/346/norbar15.jpg)
Title: Torque multipliers and reaction points
Post by: Prof on August 15, 2011, 11:37:07 AM
It\'s my guess that if you want the multiped torque to only act between the flywheel and the nut, you need to have a reaction point on the flywheel, that way, the forces aren\'t being transmitted through the flywheel, engine mounts, suspension etc.  So the moment of force is between the flywheel itself and the nut - then a simple flywheel stopper can just make sure that doesn\'t rotate when you operate the normal wrench on the unput side.
 
to be fair a £100 for a tool like this isn\'t that crazy - blind bearing pullers are similar money - and essential to remove the pilot bearings cleanly.
Title: Torque multipliers and reaction points
Post by: TiddlesRX7 on August 15, 2011, 11:40:48 AM
The ones I used had an arm on them with a sliding pin that could be adjusted to locate onto a fixed point (something to leaver off basically). Not sure the arm would be long enough though to reach the outside edge of the flywheel. You could probably use a block of wood to chock it in place though, but stand back cause if it lets go you\'ll know about it.