Leak Down Test (Don't Laugh!!)

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click said:
Don't worry, there will be a part2. I'm sure I'll be back on looking for lots of info. about running in a motor and, wait for it . . . . . . . . .WHAT'S THE BEST OIL TO USE!!!!
Click to expand...

I have heard good things about
PALOQUETH Premium lubricant.
 
Oh No!!
Jim that is a slippery slope you are leading us to. I realize your knowledge base is extremely diverse, but.............
Pete
 
Soooooo, Redline seems to be an excellent product. Is it safe to switch to it from 20-50 mineral that I have been using since my engine was rebuilt 3 years ago?

(Tongue in cheek mode: 'on')
 
and I thought we were having a serious discussion JB now you're off topic.:D the highjack has us using the Comnoz recommended solution.... not sure where to add it...:confused: are we laughing now ? for a thread that started "...don't laugh".... were out of the ball park.
 
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What are you guys like:rolleyes: I leave the forum for a few hours & you all get distracted by lubrication and not the kind for your Norton, well I hope not!!

I got an email back from a mate of the chap who built my bike. I was told that he had worked part time for Fred Barlow (Jeff Smith’s old factory mechanic before moving over to Norton) and he also did a couple of days per week for Pete Lovell for several years. So he would have known what he was doing with Norton's.

I can only put this down to a bad day on behalf of the builder or a bad product! I really think the 920 is pushing the Norton Commando to the absalute limit. Norvil's original conversion worked but was not very reliable, issues like mine are not uncommon and worse can happen!!

I count myself lucky!!, considering the state of the pistons, especially the RH one, I'd say it would not have been long before an engine seizure/lockup, not something I'd want to experience!!

I have the barrels boxed up with the gudgeon pins, so Jim can match the pistons to them. I've also included the old 920 pistons for Jim to have a look at. I might be cheeky & ask Jim if he can measure the bore against the LH piston, which is in slightly better condition than the right. As somebody else said this might be a waste of time due to the damage to the pistons but Jim can call this one!

I'm going out to the Norton to trace the electrical problem:eek:
 
click said:
I really think the 920 is pushing the Norton Commando to the absalute limit. Norvil's original conversion worked but was not very reliable, issues like mine are not uncommon and worse can happen!!
Click to expand...

Well, if you get an unexpected inheritance or win the lottery, there's still the Maney 1007 cc option.

Ken
 
comnoz said:
I might suggest sleeving it to an 880. That is the largest bore that has the potential to last very long on the street.
I will have to check on piston availability as I haven't done one for a couple years.
Click to expand...

I`ve got some heavy weight barrels on the shelf that measure out at about 890cc and would be interested to know what pistons might fit if you`ve come across these before.

http://s628.photobucket.com/user/skip-rat/media/Norton/IMG_2283_zpsdqqg1zgx.jpg.html?sort=3&o=7

Regards, Al.
 
80mm would be the same as Laverda 750SF if my memory is correct...ASSO and Meteor make forged pistons of that size...
 
Lets see if we can bring this discussion back on point . . . . . . . . you in the back, yes you, put that tube of whatever you have down and you on the right, yes you, put that brochure down about Drouin parts, wipe the drool off your face and pay attention :D

I have the barrels packed up & ready to be sent to Jim, but they won't be sent till Monday, So . . . . .

When I get the barrels back my next jobs will be fitting the rings + fittings the pistons + barrels.

Any advice on the best way of doing this?

Some guys have suggested fitting the pistons into the bores first then fitting the pistons to the rods, can't see how you can hold all this together while fitting the gudgeon pins!!

Fast Eddie had a great picture of a piston holder, (see below). I can see this being useful while lowering the barrels down but it would be fiddly getting the rings to spring into the bores or is it easier than I think?

How about the use of ring compressors?

For Fast Eddie, what's the red 'gunk' on the cam? some type of run-in goo?

Anything else worth doing while the barrels are off?

I've been trying to check the oil return hole in the casing but it seems to take a right angle turn from the hole in the case so getting wire down is difficult. I've squarted oil down the hole & it flows nicely down without overflowing. I've also used compressed air & again there is no restriction that I can detect, I'm happy to call the passageway clear.

I'm going to try & measure the lift of the cam later with a digital vernier and report the results back here so you clever Norton chaps can tell me what type of cam it is, I'd say it's a standard cam.

Leak Down Test (Don't Laugh!!)
 
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What ever way you decide to install your pistons just make sure to stuff rags or something similar around your connecting rods to prevent a circlip falling into the engine. Could be a PITA to find.
I used a piece of plywood resting on the barrel bolts to support the pistons. Plywood had a notch to clear the rods. I also used ring compressors. Mine were standard bore so there was plenty of chamfer on the bore bottoms allowing them slide in pretty easy. I don’t know how much chamfer is on an 880 so it might be easier to have the piston in the bores ahead of time.
I would also be thinking about base and head gaskets I don’t know how easy they are to locate. When in doubt ask Jim, he will have the answer.
Pete
 
you need two ring compressors and 4 bits of wood . Slide these under the pistons so they are fully supported and cannot tilt Do protect the rods with tape so they are not scratched or marked by a tilting piston skirt.
 
Deets55 said:
What ever way you decide to install your pistons just make sure to stuff rags or something similar around your connecting rods to prevent a circlip falling into the engine. Could be a PITA to find.
I used a piece of plywood resting on the barrel bolts to support the pistons. Plywood had a notch to clear the rods. I also used ring compressors. Mine were standard bore so there was plenty of chamfer on the bore bottoms allowing them slide in pretty easy. I don’t know how much chamfer is on an 880 so it might be easier to have the piston in the bores ahead of time.
I would also be thinking about base and head gaskets I don’t know how easy they are to locate. When in doubt ask Jim, he will have the answer.
Pete
Click to expand...

Thanks for the reply Pete, good suggestion about the rags!!. I've already asked about the copper head gasket for the 880 & Jim can supply same. I did not ask about base gasket, thought a standard one would fit? The 920 barrel had a standard base gasket fitted.

I forgot to attach Fast Eddies pic, see above, this looks like a similar setup to your plywood. Did you have enough space for the ring compressor to slide down with the plywood supporting under the piston?
 
My piston support is a rather extravagant slab of PTFE left over from another job, but plywood or alloy etc would work fine.
With piston ring clamps and a support like this, it is a piece of cake.
The ‘red gunk’ is Redline assembly paste.
 
oldmikew said:
you need two ring compressors and 4 bits of wood . Slide these under the pistons so they are fully supported and cannot tilt Do protect the rods with tape so they are not scratched or marked by a tilting piston skirt.
Click to expand...

Good call on taping up the rods!
 
Fast Eddie said:
My piston support is a rather extravagant slab of PTFE left over from another job, but plywood or alloy etc would work fine.
With piston ring clamps and a support like this, it is a piece of cake.
The ‘red gunk’ is Redline assembly paste.
Click to expand...

I might have a chunk of thick perspex lying around somewhere! Thanks for the 'red gunk' identification!
 
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