im with ya. the pins wont have to be large at all but you are still introducing a new edge into a stressed area
Yeah, was thinking 3 to 4 mm dia at the most. They couldn't be very long either or they would block the oil passage inside the bush. I have seen this method used quite a lot in other applications but has anyone done this to a Duc?
Loctite bearing mount does work really well, so much so that you need to heat the case to soften it so you can get the bearings out.
Agreed, when I was a lad and skint many years ago I used loctite bearing fit on a rear wheel bearing on my Pantah. It was a very sloppy fit after it had seized and spun in the wheel. It was only supposed to be a very temporary fix until I could get a wheel. It remained in there for years and many thousands of miles and was still solid when I finally replaced the wheel! My excuse was I was only a lad and didnt know better!
what is the option of getting a bush made by a machine shop a few thou larger on the o/d. that is the option I would persue so it is a better interference fit with the casing.
I would say you had a main bearing picking up, due to the fact it and the bush were rotating. Either that, or the bore in the case is too big for the bush. There shouldn't be any need for pinning. look up limits and Fits, to see the kind of fit the bush needs to be in the casing, and the fit for the bearing in the bush. This is taken from the Ducati service manual, Important On badly worn engines bearing bushes may have lost their original interference fitting with the casing. After having removed the bush, check that the interference between casing and bush with the bearing installed is no less than 0.03 mm, if this is not the case the casings must be renewed.
Both bushes turned and as far as I know the bearings seemed fine. Good info though, thanks FE. I see that it has to be checked with the bearing in the bush as well, gets a little tricky to get the right size. Mile thought the engine looked like it had got hot at some point so that may have something to do with it. Not sure how he could tell that. Will ask him more next time we chat.
naturally you would take measurements and machine to size accordingly using a similar material. if you had to use a 10 ton press you know something isnt right lol
It sounds like the bush is a sliding fit in the cases which from a previous post I would guess is not Ducatis intention. As per the note, you are supposed to change the cases to get the correct interference. Or you could get new sleeves machined up. Or you could you could use some Loctite (as the saying goes I guess other products are available). Or if you wanted to be a real cowboy then you could use a centre punch to put a few dimples in the casing where the sleeve fits. That would secure it. For a while
loctite I feel may work but it largely depends on the gap its trying to bridge. a few though too large and the pounding will make short work of it. and by the sounds of it there maybe a little too much wear, also being careful not to block any oil galleries. the pinning sounds good if it wasnt in such a critical area in cast alloy. let us know how you get on perhaps take the bushes to an engineering shop and ask for a price. take accurate measurements of the bearing location in the case across the full diameter at different points and check for roundness of the hole too, making sure it hasnt gone oval
Hi Bront. You can actually get cases fairly cheap of ebay, or maybe even some of the guys/gals on here. I can also, as many others have, recommend Louigi Moto and CJS racing to build it the way it should be done. When i stripped mine originally some of the oil ways had so much of the casting left over them i'm not surprised the damn thing buggered itself up. I opened them all up with needle files to the diameters they should be, and even ran a wire wheel over a lot of the rough casting inside to stop any little bits falling off and floating about. I've also got a Corse style gear lever with quick shifter, and some race cams spare if you wanted to start going silly. But believe me it's very easy to spend a fortune on one of these when a 1098/1198 motor is quite an easy transplant and will give more power, more reliably than you'll ever really get out of one of these lumps.
Thanks again for all the ideas and advice. One problem with making an oversized bush is that the cases would still need to be bored to remove the scoring and the little ridge caused by the oil gallery in the bush itself. I'm not convinced that anyone here can do that accurately enough and my builder has had one fail after they tried that. The problem with getting second hand cases is that they may have exactly the same problem so unless the seller is willing to remove the bushes I could get them all the way to South Africa only to have the same problem. I am looking at this idea though so if anyone has a set and is prepared to do that then please let me know. Definately not going the cowboy route Ducv2 Thanks 1037 but I want try to keep the engine together after this so won't be going for any major power increases. I want reliability before power. She already kicks arse enough for me and more power doesn't always mean shorter lap times. I don't think the bushes have been turning that much so the Locktite idea still might be the best.
Well if you want reliable horses what you have planned should be perfect. The blueprint/balancing should keep it all together for a lot longer. Duke power comes from the heads so setting them up right and keeping them standard is the best route. Sounds like you're doing everything right for what you want to use it for. I admire you for using it for how it was intended, i just play on mine but would love to risk it all by actually racing the thing.
Speak to JHP or similar, send the cases to them for machining and o/s replacement bushes to be be made. Get them to assemble the case, bushes and new bearings, then send it back to you.
I know, he mentions it a couple of times. He says no one in SA can machine the parts accurately enough. That's why I suggested he send the parts here. :wink:
I just dont understand how can the cambelts jump some theets.Its happend at low speed or at bigger revs?
