Sloppage sheet prototype?

[dlaing]

For the curious:

[Guest ratchethack]

Actually, since the top bolt of the bracket mounts to the timing case you'll have to elongate the lower bolt hole and recess for the bolt which goes into the side of the sump.

I thought I had a picture of what I had to do to mine but I can't find it right now. I'll keep looking and post it if I do.

 

johnk

John K, just thinkin' ahead here -- I certainly don't want to annoy Pete with this kinda thing now, with his Mum in the hospital -- but for you and anyone else inclined to respond --

 

I'm not too keen on elongating the lower bolt hole mentioned above by 2 mm. You seem to've done some work on this, so y'er a ways down a bit of a learning curve, as it were. Just looking at it, it appears that the 5 mm spacer on the small lower bolt behind the steel forging could be shortened up to maybe 2 or 3 mm, which might be enough to allow for the 2 mm (plus 1 gasket) extra stretch created by the sloppage sheet, and allow a mounting "under tension" without elongating the bolt hole. This would also put the bike a few degrees closer to upright on the side stand, which (at least in my case, with the forks substantially re-sprung, preload set, and raised 8 mm) would be a welcome thing.

 

How about heating up the forging enough to tweak it a few degrees to suit, to relieve the tension?

 

Any thoughts?

[guzzi323]

How about heating up the forging enough to tweak it a few degrees to suit?

 

Any thoughts?

Well that casting is quite a sturdy thing though if you can bend it I'd think that would work. I wouldn't want to have it bolted to the cases under tension though. These are Italian aluminum castings we're talking about. We're lucky if they hold together without us putting extra stresses on them, you know?

I do like your idea about having the bike sit a little more upright when on the stand. I was just thinking about welding on something to the bottom of my sidestand to lengthen it a little bit.

 

I looked around and found the pic I took of the bracket. You can see for yourself what the issue is.

 

I hope this is helpful for you.

johnk

[dlaing]

Well that casting is quite a sturdy thing though if you can bend it I'd think that would work. I wouldn't want to have it bolted to the cases under tension though. These are Italian aluminum castings we're talking about. We're lucky if they hold together without us putting extra stresses on them, you know?

I do like your idea about having the bike sit a little more upright when on the stand. I was just thinking about welding on something to the bottom of my sidestand to lengthen it a little bit.

 

A major "group think" ditto on not bending the aluminum

As an alternative, how about enlongating at the big hex rather than at the lower 6mm allens

I would prefer the sidestand 2mm lower than not. But those with a propensity for sidestand grinding might not want to lose that 2mm clearance.

[Greg Field]

I modified one of Pete's Tonti plates and put it in Enzo's bike about two years ago. I have no recollection of the need for fiddling with any of the sidestand stuff.

[Guest ratchethack]

Well that casting is quite a sturdy thing though if you can bend it I'd think that would work. I wouldn't want to have it bolted to the cases under tension though. These are Italian aluminum castings we're talking about. I hope this is helpful for you.

johnk

Thanks, John K. This is indeed helpful, but I must make a correction here that will no doubt be important to anyone considering modifications here. The piece in question is forged steel -- not an aluminum casting. I think you're right about trying to bolt it up under tension - it will certainly flex a tiny bit in use, but not enough to make up for a mis-alignment between seating of the upper and lower bolts of several mm that would be the result of shortening the spacer.

 

Unless I misremember some of the rudimentary metalworking stuff I actually used to USE lo these many years ago -- this forging can be essentially "re-forged" and beat into a new angle in the manner of the blacksmith with anvil and hammer when heated to cherry-red.

 

But now Greg indicates there may be no need -- I reckon I'll just hafta cross any bridges when & if I get to 'em. . . .

[guzzi323]

I modified one of Pete's Tonti plates and put it in Enzo's bike about two years ago. I have no recollection of the need for fiddling with any of the sidestand stuff.

 

It could be there's some slop in the upper mounting bolt hole which allowed my bracket to sit a little on the high side. I didn't loosen it to see if the bracket would move down. I didn't even consider this problem when I was doing this until I couldn't get that lower bolt in. The easiest/fastest thing to do was pull out my dremel and grind away for a few minutes.

 

Looking now at the picture, perhaps if I had loosened the upper mount the bracket could have pivoted forward a degree or so and that might have been enough to get the lower bolt in. I guess once Pete's plates start arriving we'll know for sure.

 

johnk

[pete roper]

The Centauro I stuck the first proto in has the same stand fittings. The plate slipped in with no modifications to anything .

 

Oh, John, and anyone else who has tried to send me paypal payments, I'm sorry, I simply don't have the time at the moment to do anything about processing them.

 

Pete

[Ryland3210]

how about 10 or 12 gauge Aluminum in a quality grade, like T6?

The aluminum should be fine if it is thick enough, right????

And the extra benefit is that it is an even deeper sump!!!

I suppose all the kick stand grinders out there might be turned off by the few millimeters lower sidestand <_>

 

And then I can gold anodize the edge to match my Ohlins!

 

I agree. I like the idea of avoiding the thermal expansion issue and the gold anodize. Another one is buckling. It's hard to imagine with 2mm stainless steel, but if the screws on the periphery were really tight and the sheet thin enough, it could buckle. A 0.004" change over, say, a 10 inch wide sheet, would result in about a 0.14" "bubble" in the middle of the sheet if unsupported except for the periphery.

 

According to my calculations, assuming a 0.004" expansion over a ten inch length, if it didn't buckle, stainless would develop about 12,000 psi in compression stress if physically constrained by the aluminum block fastening screws. This translates into a force of 960 pounds for each inch along the edge of a 2mm sheet. What is more likely, is that the aluminum casting will take most of the deformation. That leaves the question of whether that would cause enough stress to cause a fracture.

 

Therefore, in my opinion, if stainless is used, the expansion issue argues for avoiding gasket sealing compounds which can develop shear strength, and mounting hole diameters should provide clearance for the screws. During installation, I would want to make sure the sheet has adequate screw clearance, and use grease on the gaskets.

 

 

 

For the curious:

 

I'm new to Moto Guzzi's so please excuse my ignorance. Can you tell me what the hose port on the rear of the sump is for? It appears to be connected to a frame member over the engine on my '04 Cafe Sport.

 

Thanks,

 

John

[Guest ratchethack]

I agree. I like the idea of avoiding the thermal expansion issue and the gold anodize. Another one is buckling. It's hard to imagine with 2mm stainless steel, but if the screws on the periphery were really tight and the sheet thin enough, it could buckle. A 0.004" change over, say, a 10 inch wide sheet, would result in about a 0.14" "bubble" in the middle of the sheet if unsupported except for the periphery.

. . .

I'm new to Moto Guzzi's so please excuse my ignorance. Can you tell me what the hose port on the rear of the sump is for? It appears to be connected to a frame member over the engine on my '04 Cafe Sport.

 

Thanks,

 

John

John, rest easy, my friend. A .004" expansion of the plate over the width of the sump, even if this were the delta in expansion between the sheet and the block, presents no potential problems, and there is no concern about buckling a 2 mm stainless sheet. Assuming your calculations are correct, and that this is the actual delta, this would amount to a mere .002" movement at each end. It's not a critical clearance consideration. Any gasket sealant used (it seems that many use none anyway) would accomodate this tiny amount of movement without any problems, as has been the experience of those who've installed and used these things for decades, including Pete, our most experienced and adroit manufacturer.

 

The oil line at the rear of the sump is the return from the in-frame oil condenser. The frame oil condenser is fed through the large diameter breather hose that runs from the top of the engine case just in front of the flywheel housing to the bottom of the frame through a port under the spine just behind the steering head. The condenser is vented through the banjo union bolt above the spine and just aft of the steering head, which routes into the air box.

[mike wilson]

Stainless has about 2/3 of the expansion of Aluminium. There will be some creep but it will probably be less important with regard to gasket integrity than the difference caused between the original parts by the heat block of the gasket.......

[pete roper]

Jesus! Youse blokes just *love* to try and overcomplicate things. Why not try re-inventing the wheel instead? hours of fun with that one

 

Pete

[Ryland3210]

John, rest easy, my friend. A .004" expansion of the plate over the width of the sump, even if this were the delta in expansion between the sheet and the block, presents no potential problems, and there is no

 

The oil line at the rear of the sump is the return from the in-frame oil condenser. The frame oil condenser is fed through the large diameter breather hose that runs from the top of the engine case just in front of the flywheel housing to the bottom of the frame through a port under the spine just behind the steering head. The condenser is vented through the banjo union bolt above the spine and just aft of the steering head, which routes into the air box.

 

Thanks much. That's an elegant solution. Do you know if the Cafe Sport's drain plug is magnetic? If not, can you tell me what its thread diameter and pitch is?

 

To find the ideal sump full point, as I understand it is just below the block/sump gasket, I'm thinking of temporarily disconnecting the condenser return hose while filling. I might even attach a clear plastic extension on it so I can see exactly where the level is as I fill it up. Then I'll know exactly how much oil to put in each change thereafter.

 

I really enjoyed the break in link. I noticed the implication that the rings were softer than the cylinder walls.

 

In my technical field, high velocity hydraulic cylinder piston rings are cast iron, a good deal softer than the tool steel cylinder barrels. Surface finish is deliberately less than mirror smooth in order to prevent oil from being totally wiped off by the rings, to avoid metal to metal contact. This is not to seat the rings, but to extend long term life. The seal is virtually gas tight from the beginning. I have seen that oil control rings are often chrome plated and blocks are generally cast iron on engines. I'm not sure about the composition of the compression rings, but I am left wondering about whether the rings are actually worn to fit by the cross hatch pattern on the cast iron cylinder walls as the link claims.

 

Any comment?

 

 

 

 

 

Jesus! Youse blokes just *love* to try and overcomplicate things. Why not try re-inventing the wheel instead? hours of fun with that one

 

Pete

 

Ah, yes, but the devil is in the details. I'm sorry to say I have found myself re-inventing the wheel more than once. I hope I'm not boring too many. I'm addicted to seeking knowledge and perfection. That's where the fun is for me.

[Guest ratchethack]

Thanks much. That's an elegant solution. Do you know if the Cafe Sport's drain plug is magnetic? If not, can you tell me what its thread diameter and pitch is?

John, I can't answer your question about the Cafe Sport drain plug -- sorry. Mine's got a magnetic insert, and I ought to know the dia. and pitch of the threads, having heli-coiled it on the first day of ownership shortly after discovering that some knucklehead at the dealership had torqued it until it stripped, and made it look nice and secure by glueing it in place with some godawful rhino smegma , but alas - the thread tap and heli-coil drawer is now full, and despite the vivid memories of the sump-off helicoil procedure whilst my Pals were spending an IDEAL afternoon riding in the local mountains , none of 'em look familiar to me today.

I really enjoyed the break in link. I noticed the implication that the rings were softer than the cylinder walls.

. . . .

I am left wondering about whether the rings are actually worn to fit by the cross hatch pattern on the cast iron cylinder walls as the link claims.

 

Any comment?

By break-in link, if you mean this: http://www.mototuneusa.com/break_in_secrets.htm

 

Yeah, I pretty much agree with everything he says, but I don't spend a lot of time wondering which is harder or softer, rings or (in the case of the Guzzi) the nickasil bore. As he says, the rings are worn to fit by the cross-hatch pattern. I think there's also more than an implication there that properly broken-in, the cross-hatch pattern also wears to fit the rings. If the rings and bore were biotic, I reckon it'd be a symbiotic relationship.

[dlaing]

 

I really enjoyed the break in link. I noticed the implication that the rings were softer than the cylinder walls.

 

In my technical field, high velocity hydraulic cylinder piston rings are cast iron, a good deal softer than the tool steel cylinder barrels. Surface finish is deliberately less than mirror smooth in order to prevent oil from being totally wiped off by the rings, to avoid metal to metal contact. This is not to seat the rings, but to extend long term life. The seal is virtually gas tight from the beginning. I have seen that oil control rings are often chrome plated and blocks are generally cast iron on engines. I'm not sure about the composition of the compression rings, but I am left wondering about whether the rings are actually worn to fit by the cross hatch pattern on the cast iron cylinder walls as the link claims.

 

Any comment?

I have wondered that myself.

MotoMan says nickle silicate cylinder walls like the Guzzi also benefit from the fast break in.

But from what I understand, the hatching on the walls of guzzi lasts longer than walls of other engines.

I imagine the honing surface is much like that of knife sharpening steel, only the cutting abrasiveness wears away quickly.

I think this explains why Guzzis take over 10,000 miles to "break in"

I think the motoman method accellerates that process.

A quick break in may then result in cleaner pistons, better combustion, etc., while the more slowly broken in motor may get more carbon build up.

But that is mostly theoretical.

Scientific evidence is somewhat is lacking.

Those who try the agressive break-in swear by it.