Nicholas Kay Posted December 30, 2009 Share Posted December 30, 2009 Afternoon All, Merry Christmas and all that good stuff..... I am putting together my new xmas kit and come to install my trusty old Irvine 53 when I noticed the prop drive has moved back when I came to tighten the prop nut. On closer inspection I can see the harden insert inside the prop driver is split. I am searching various websites for spare parts and I now understand there are several versions of the Irvine 53 and this part differs be the versions. Would anyone be able to confirm the version number I have or the part number? I believe the alternative prop driver employs a flat on the crank shaft to drive the prop driver. I assume the model I have uses other means and this hardened insert. I would be pleased of anyone can shed some light on this! Kr, Nick Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted December 30, 2009 Share Posted December 30, 2009 Your "hardened insert" wouldn't happen to be the split taper collet would it? If so, it should be tapered on the outside with a single cut along its length to allow it to locate and tighten on the shaft when the taper in the driver compresses it. When you say it's moved, what makes you think that? Is it binding when the prop nut is tightened - there may be a washer missing from between the bearing and the prop driver...I haven't got an Irvine at hand to check but a lot of engines are designed to have a spacing washer there.. Edited By Martin Harris on 30/12/2009 16:29:59 Quote Link to comment Share on other sites More sharing options...
Nicholas Kay Posted December 30, 2009 Author Share Posted December 30, 2009 Hi Martin, Sounds like you understand the problem and have better knowledge of the internals than myself. Without a puller to remove the prop driver I am unable to investigate further myself. The engine have been running fine but last involved in a mid-air and a subsequent impact with mother earth. On initial inspection all seems ok. This being the first time I have tighten a prop on it following the incident and now I find it binding on the case. I noted that the shoulder on the crank shaft appears to be forward of the prop driver, by a very small amount. Perhaps it has always been like this,who knows. Would replacing the prop driver and split collet perhaps reset the horizontal position of the prop drive? Nick Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted December 30, 2009 Share Posted December 30, 2009 Nick, You may have shifted the bearings back in the impact. It's not great engineering practice but given that you don't have a puller, you could try removing the rear cover, heating the engine to @150 degrees C in the oven and, holding the crankcase with a gloved hand, giving the rear of the crankshaft web a sharp hammer tap using a piece of hardwood or plastic as a drift to relocate the bearings (piston set at top dead centre to get the con rod out of the way). Don't go mad with the hammer though - a gentle tap should suffice and holding the engine in your hand will lessen the shock. It is quite possible to damage the bearings microscopically doing this which will shorten their life - however they may already have been so in the impact and you're not likely to be much worse off. Cheers, MartinEdited By Martin Harris on 30/12/2009 21:49:03 Quote Link to comment Share on other sites More sharing options...
Braddock, VC Posted December 30, 2009 Share Posted December 30, 2009 Nick, in quite heavy impacts that are not at right angles to terra firma the prop driver can be driven back by the prop and you may find that it has been pushed back at an angle, it's happened several times to me with a laser and a saito. On the laser it actually bent the crankshaft which was quite an expensive job to fix. That aside the prop driver and the split taper (replace both) cost about a tenner by the time postage has been added. Quote Link to comment Share on other sites More sharing options...
Nicholas Kay Posted December 31, 2009 Author Share Posted December 31, 2009 Thanks for the helpful tips and advise. Bearing puller ordered and in the post and I will look at renewing the prop driver and collet. The good news is the crack doesn't seem to be bent, so I am hoping realigning of the bearings will be all that is required. Nick Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted December 31, 2009 Share Posted December 31, 2009 on my SC65 the propdriver actually split, allowing it to move back further on the taper collet, with the result the engine locked up on tightening the prop. Might be worth checking the propdriver for any signs of a crack. Quote Link to comment Share on other sites More sharing options...
revles Posted December 31, 2009 Share Posted December 31, 2009 you may have bent the shaft but be careful when trying to remove it best done with back plate off and put the engine on wood in a piller drill with the shaft facing vertical under the chuck close the chuck and use a bit of beech hard wood as a spacer gently pull down on the drills lever as if you are drilling a hole this will act as press dont start any thing up just use your common sense and increase the power you are putting on the shaft once it is out if you have a friend with a lathe get him to chuck it up and check the runout on the shaft don hope this helps Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted December 31, 2009 Share Posted December 31, 2009 Did you try reseating the bearings? It won't take 15 minutes to try and could save a lot of messing about. John mentioned Saitos earlier - from first hand experience, this method is normally needed on these after any significant impact on 45s and 50s - and probably the rest of the range as they are pretty much identical... I must say that I've never needed to replace a prop driver but perhaps I normally hit things head on! Quote Link to comment Share on other sites More sharing options...
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