Position 1
Position 2
Position 3
Position 4
Position 5
Position 6
Position 8
Position 10
Final from Jig
IMG_0885
+1
WTF???I heated the web with the hole and froze the pin of the middle cylinder, as instructed. When i hammered it together, it moved all of 2~3mm before seizing. Is that normal? I suppose i shouldn't complain, it's a snug fit!
Red,
I went back through my posts and could not find any post that I made on the 23rd Feb, 2025
Well I'm a cranky old bastard whose not as nearly talented as the talented cranky bastards you refer to, but I understand what they are saying/doing and highly respect it as one cranky old bastard to another, especially this thread as I had my ball bearing center mains done by a snowmobile engine rebuilder in your city many a moon ago. Cheers
I downloaded information from several sites and one of them was a conversation between you and Ernest Schmitz regarding 'conrod 2 to be the start of pressing pins into webs', which i found very useful and gave me confidence. But, the second part of the same conversation, regarding the next inner webs which are pressed to centre pins and cannot be manipulated, i don't understand! The information regarding thermal contraction and expansion came from an AI site. I'll be more careful, i promise!
Unfortunately the snowmobile crank rebuilder in Winnipeg is no more. Harder and harder to get custom machining andcother work whete old school experience is useful done these days. The local expert was very experienced with snowmobile cranks, but if I needed my Laverda crank done I would want one of the Laverda crank experts on this forum to do mine.Well I'm a cranky old bastard whose not as nearly talented as the talented cranky bastards you refer to, but I understand what they are saying/doing and highly respect it as one cranky old bastard to another, especially this thread as I had my ball bearing center mains done by a snowmobile engine rebuilder in your city many a moon ago. Cheers
I will say tho that my neighbor at the time, a licensed Millwright and hard core biker (rode a Norton side car rig in Alberta winters}, brought his V blocks and dial indicator over and pronounced the crank almost perfect. Engine runs very smooth for a 180. I'd say that Winnipeg guy was pretty good, That many moons was probably 30 yrs ago, as you say another talented specialist retires from the trade, not to be replaced. Doubt there is any place in NA to get a Laverda crank done, unless Wolfgang has a secret source.
Part of the issue in this country seems to be that most of the guys still think a couple hundred dollars will get your crank rebuilt. I have a good friend who is in the business and is more than capable (literally hundreds of sled and bike cranks, with his notes and diagrams to back it). I may throw the idea at him and see what he says....... it may give those of us on the north side of the 49th an option, but I'm not holding my breath that he'll be enthused about the idea.
Red, I never cease to learn from your posts, and admire the way you do things!!depends on how you wish to do the crank pressing, am certain other people do their cranks different to the way I do mine
many years ago I spent around 8 days straight machining up my crank fixture and various spacer plates etc, is probably way over designed and is heavy as fuck but still works great
I start with the Inner web of No 1 and the No 2 web, so this is the point where you set the phase to either 180 or 120
My fixture is machined to accept the Big end pins, 36mm and the central hole in the plates is 35mm
Middle plate is bored to centralize the Outer diameter of the webs
To start, set press up, position fixture and middle plate
Position 1
Next I load the No 2 Conrod web in the bottom, this is because it is easier to position the Main bearing that way
Outer Conrod web Big end pin positions in the top plate and I use split full size machined spacers not to control the spacing so much but to control deflection when pressing offset to the center line
Position 2
Then remove the two pressed up webs on turn them over so now No 1 Conrod Big end pin is in the lower plate, move Middle plate up to position itself on the No 2 Conrod web and then keep building the crank up
Position 3
Position 4, shows the 180 pressing off No 1 and No 2 Conrods where I turn them over and also shows the spacer plates to spread the pressing load for future webs
Then install Number 2 Conrod, I use ground to size steel blocks to control the side clearance on the Conrod thrust plates, top press plate positions the next web in this case on the center line of the crank, press web on, normally they go on in the 8-10 ton range
It is this web and the inner web for No 3 Conrod that I refer to when saying they are difficult to manipulate due to the fact they are pressed on using the centerline of the crank
Position 5
Position 6
Shows inner web for No 3 being pressed on
Position 8
Shows right hand web being pressed on
Position 10
Crank is together apart from outer web for No 1 Conrod that I do seperately
Crank out of the fixture, easy as, now just to do final straightening
Or before you even start, machine off the Oil Slingers, get the grinder out if you don't have a Milling machine and drop 4.5 kgs off of the crank weight, press up new Oil slingers, roll them on, press crank together without Conrods, give crank to Crankshaft Engineering to balance, then strip crank, add Conrods, press back together and go racing
