Running in

[Minto]

Well, I'm expecting to get some time this weekend to finish putting the Ten back together, the lump and box are in the frame, and the clutch is back in. So just barrels, head, rocker box, oil tank and filter, re-timing the ignition and a few other loose ends to tie up. If, I get it running over the weekend, seeing as it's had new lMD pistons in honed out to size bores, new big end shells (not reground crank), new main roller bearing, what sort of running in do you reckon is required? Gently gently for a few hundred miles (which at my current rate of motion could literally take forever) or less careful but with oil changes every 100 miles for a while??? Advice and opinions welcomed.
Cheers
Jase

[Triton Thrasher]

Take off with a big handful of throttle, the very second it starts!

Then give it bursts of hard pulling for a few miles.

That’s it run in, apart from retightening things.

[Triton Thrasher]

Now you’re going to get the opposite advice!

[Swarfcut]

 Jase. Pour oil down the pushrod tunnel via the rear rocker box. This will give the cam a nice oilbath start. This oil will soon reach the sump, and you can check the oil return is working and as the instruction manual says you can assume the pressure side of the system is OK. In other words the oilpump has drive.

  Prolonged idling should be avoided, the bores, rings and pistons need to have some load, otherwise modern oils with their anti friction additives are said to contribute to glazing of the bore and poor bedding in of the rings. My preference is for the cheapest supermarket own brand oil as a first fill and to expect a fair amount of fine particulates to appear,

  So like TT, I'd get under way fairly soon, but I would not be as brutal to severely wring its neck as TT's method, altho' this motor will already have a fair amount of internal clearance. Even so, no need to be a true pussyfoot but avoid heavy loading and constant high speed to start with. Light throttle, light load for the first few miles when there is the greatest potential for the new pistons to tighten up. If it behaves itself, sure, a little more spirited riding will not be amiss. Also ignition timing and mixture may require adjustment later on to get full benefit from the new parts, bearing in mind published data was for the fuels of an earlier time.

 Swarfy.

[Greybeard]

... Prolonged idling should be avoided...

... no need to be a true pussyfoot but avoid heavy loading and constant high speed to start with. Light throttle, light load for the first few mile..

This 👍

[Minto]

Thanks guys,
What about adding some oil directly into the sump before I drop the barrels back on?
Should I oil the pistons and bores before assembly or will this hamper the bedding in?
What about oil changes? 50 miles first then every 100 for a couple of changes then at 500 sound about right?
Cheers

Oh, and for next time, is there an easier way to get that €~©π|∆¢ timing side engine bracket in place????
Jase

[Black Sheep]

Shut the throttle occasionally - lets oil get to the thrust faces of the pistons. Vary the load on the engine. Let it run on the downhills. The old 30mph for the first 1,000 miles was somewhat unscientific. 

[Greybeard]

Thanks guys,
What about adding some oil directly into the sump before I drop the barrels back on?
Should I oil the pistons and bores before assembly or will this hamper the bedding in?
What about oil changes? 50 miles first then every 100 for a couple of changes then at 500 sound about right?
Cheers

Oh, and for next time, is there an easier way to get that €~©π|∆¢ timing side engine bracket in place????
Jase

I always oil the moving parts while I'm building the engine.

[Triton Thrasher]

Shut the throttle occasionally - lets oil get to the thrust faces of the pistons.

Sounds highly unlikely. What’s stopping oil getting to the bores and thence to thrust faces of the pistons when the throttle is open?

[Greybeard]

Shut the throttle occasionally - lets oil get to the thrust faces of the pistons.

Sounds highly unlikely. What’s stopping oil getting to the bores and thence to thrust faces of the pistons when the throttle is open?

I've always understood that closing the throttle creates a semi vacuum in the cylinders so sucks oil up to the piston skirts etc.

[Swarfcut]

Jase. The first few moments of running are the most critical for a newly built engine. Every moving part needs to have a lick of lube, makes sense and even if the motor just goes back into store the machined parts are protected from corrosion.

 Bit late now but if the oil pump is off, prime the timing  bush, crank and big ends by pressure fed oil into the oil gallery. Raise the ball valve on the pick up pipe and fill the scavenge side with oil as well by pumping oil into the ball valve housing. If the timing side is assembled, remove the PRV and pump oil to the timing bush etc from there. The oil  pump can be primed before the oil tank goes back on or on assembly.

 Oil in the bores will aid initial sealing and will soon be burnt off. The critical part of the running in process is to ensure all parts continue to be lubricated adequately to prevent seizure. How you Vary the speed, load, duration etc is subjective and there are varied opinions as you can see.

 Don't forget to clean out the oil tank and oil lines, and a check of what's in the sump after a few miles is a wise precaution. I would consider 50 miles to be OK for a check, but if all in order, a bit early to change the oil.


 As for that cursed engine plate, it's all a matter of technique. Having the lump down to basics, cases, crank, pistons, gearbox all helps and  it's a matter of  holding the loose mounting plate in place on the engine and almost diving the unit down and then to swing upwards at the front into position with a final sideways twist at the rear to locate the gearbox mounts as you rattle the mounting plate to fit.

 Those folks with S/A bikes can laugh now, those engine plate gymnastics only apply to Plunger Frame Semi Unit Models.

 

 Swarfy.

[Rex]

 Oil in the bores will aid initial sealing and will soon be burnt off.
 Swarfy.

Depends on "how much" oil though. I find a thin smear on the rings will "bed in" the rings far quicker than 1/2 pint of 20/50 sloshing around the bores. Some modern oils are too effective and never allow the rings to seal properly.

[Triton Thrasher]

Blindly following trendy Americans on the Internet, I stopped applying oil to new rings many years ago and get very good results.

I also make the second ring gap 25-30% bigger than the top ring gap.

[RDfella]

TT - why have a larger gap for the 2nd ring? Makes no sense to me as it doesn't get as hot as the top ring.

[Triton Thrasher]

TT - why have a larger gap for the 2nd ring? Makes no sense to me as it doesn't get as hot as the top ring.

I’m no expert, so I can’t declare it to be right or wrong, but it’s fairly common knowledge these days.

The larger 2nd ring gap relieves pressure buildup between the 1st and 2nd ring, so the effect of compression pushing the top ring out against the bore is not compromised by pressure equalising above and below the top ring.