I’m about ready to fit the con rods onto the 850 engine, and the manual says; “the oil hole in the left hand con rod must face upwards and on the right the oil hole must face downwards.” On both of my con rods there are two oil holes, one on each shoulder…so no matter which way round they are put onto the crank, there willl be an oil hole facing upwards. I assume that earlier models had only one oil hole in the conrod? Is this correct as it would explain this, or am I thick and missing something? I understand that the sides of the big end on the conrod that are machined go left when sat on the bike, or as the manual says “towards the clutch side?” That seems straight forward…I think?? One other quick question please, in the manuals, it shows locking plate for the main bearing bolts. On the Stein Dinse site, when you click the appropriate icon that shows the locking plate, in the picture that appears, it shows a locking washer and not a locking plate, also when I look on Gutsibits site, I can’t see any locking plates. Do I therefore assume correctly that locking washers are now considered adequate. I don’t want the mains to come loose when I’m riding the bike! Thanks in advance, Reggie.
ReggieV2012-06-01 17:24:16
Oh this is the Haynes manual. I have no idea what they’re talking about re oil holes
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Factory (MG) manual doesn’t mention them, apart from showing them on drawings.
“Bend up the ears of the locking plates”, these are usually strips of metal with holes in, sharing across two bolts, you bend up each end against a flat of the bolt to prevent it rotating. Example photo top left of page 36 (front main bearing). If your book is the same as mine. ((c) 1981) Also No. 33 in Fig 1.3 on page 37.
I presume from this there weren’t such “plates” on it when you took it apart, else you’d have noticed them. (?)
It is critical to get the con rods the right way round or else the pistons end up rotated and then you end up with a huge mess. Just like the guy who rebuilt Ray, ex smokin bikers bike just before he bought it. Valves hit pistons, valve top falls off, valve top smashes into piston and head several hundred times = Knackered engine.Advice from Guzziology_Some, but not all, Guzzi connecting rods have holes pointing up from the big end, designed to squirt a little oil onto the cylinder walls. The factory manuals show that the holes face upward and toward the right side of the engine during assembly.Some find the description confusing. I find it easiest to remember by ignoring any reference to up and down and just making sure the holes as well as the flats along one rod bolt hole are on the side closest to the right-hand cylinder._Don-Spada2012-06-02 18:54:35
Mike H wrote; “Bend up the ears of the locking plates”, these are usually strips of metal with holes in, sharing across two bolts, you bend up each end against a flat of the bolt to prevent it rotating. Example photo top left of page 36 (front main bearing). If your book is the same as mine. ((c) 1981) Also No. 33 in Fig 1.3 on page 37. I presume from this there weren’t such “plates” on it when you took it apart, else you’d have noticed them. (?) You’re correct, the plates weren’t on the engine when it was stripped. I cannot see them listed on Gutsibits or Stein Dinse site, and so was wondering if they had been superceeded by just using ordinary locking washers under the bolt heads, but from your reply, it doesn’t look so. I’ll contact one of the above suppliers and check on availability…or make my own. Regarding con rod fitment, in my manual, which is from Gutsibits and has a lot of Italian words attached to diagrams suggesting it is a MG version(and not Haynes), it states…“by looking at the engine, clutch side, the milled surfaces (of con rods and caps) must be on the same side. See fig 40”…which shows a con rod with an oil hole and two machined surfaces of a conrod. Don has written that Guzziology says to fit the machined sides to the right hand side of the engine! I took it from the above in my manual that it meant towards the left side for the machined faces? Anyway, as there are 2 X oil holes in both conrods (one left and one right), I can’t see how it matters which way around that the rods are fitted as the big end shells also have two oil holes in to let oil release, as long as I keep the correct machined faces together. Thanks for looking at this and for your advice. I will proceed…slowly.
ReggieV2012-06-03 18:02:10
We need a photograph of correct set-up really…
I do believe the conrods foul the piston cut out if installed incorrectly. If wrong, you have to reverse the pistons to allow them to clear the con rod and then the valve cut out are wrong so pistons hit valves etc Ray is the man in the know on this one from bitter experience.
Don-Spada wrote;I do believe the conrods foul the piston cut out if installed incorrectly. Don I assume that you are referring to the valve cut-outs in the piston, and valve to piston contact. At the moment the pistons are detached from the conrods on mine, and there is a deeper crescent shaped cut out on one side of each piston which will go on the inlet valve side, as the inlet valve is wider by diameter. Incidently, with regard to the tab plates that was mentioned earlier, I was looking on the Stein Dinse site last night at the “parts manual” for the le Mans 3 and 4, and the tab washers are not shown on the diagrams for these engines, which leads me to suspect they were deleted in favour of sprung washers/wavy washers,
It’s possible, the Haynes pictures do go back some years. Can’t see why you couldn’t use a bit of nutlock as well. (?)
Maybe shnoor washers would work best? they sure do not come undone and are thinner than spring washers ???
You don’t mention which engine it is. The MK2 Le-Mans parts list describes the bolt and nut as “Screw and self locking nut” Not sure I would rely on a Nyloc in that instance. Best talking to Motomecca or similar to get the correct ones
The spada engine i rebuilt had no washers on they if i remember right self locking nuts were supplied
dont think they were the nyloc type
Hi, yes the big ends have self locking castelated nuts (and no washers). What I was referring to though was the locking plates or lack of them on the main bearing bolts, and that in the l/m Mk 3 and 4 they only show washers in the parts diagram. Sorry, I shouldn’t run two topics in one thread
ReggieV2012-06-05 10:02:13
I know what you mean ~ he means like the bearing carriers and so on, e.g. on mine the rear drive cover bolts have the knock-up locking “ears” as well; big-end nuts and suchlike have their own, other, methods.
And yes I wouldn’t put nylock nuts inside the engine, but there are or were other types where the locking bit is metal not nylon.