Oil pressure gauge response to heavy acceleration or braking?

[docc]

1 hour ago, Scud said:

I chased a low pressure situation for a while on a 2003 LeMans. Turned out that part of the gasket (as pictured in Rolf's post) was missing. This internal leak allowed oil to escape but maintained low pressure - the light would sometimes come on at idle, but would always go out with a blip of the throttle. It ran like that for a long time without any failure, but I did find excessive wear on the washers on the rocker-arm shafts.

The problem with the warning light is that it only tells you about dangerously low pressure. If you care for a lengthly and somewhat philosophical exchange about this issue, see my topic about it at: "Oil Pressure vs. Oil Flow"

So, with a "Roper Plate", two of these would sandwich the plate above the spacer?

 

[docc]

10 hours ago, Guzzi-in-Vancouver said:

Thank you all, and to clarify, yes the Roper plate is on the bike, there was some hard acceleration and braking, but no wheelies. I remember the light being on for a few seconds after I stopped at the light (directly after the hard braking) but I drove slowly for a bit and it went away, though not immediately, and I wasn't diligent in checking on it. I rode the bike again the next day and there was no light. So I don't suppose it was a loose or disconnected wire.

I will check the oil level, it was refilled during a recent service but I suppose the shop only put in the standard amount. Does adding the Roper plate call for more oil? I read a thread about drilling the dip-stick, and then another about a similar oil-gauge situation that was traced to a loose washer on the oil filter... since mine was recently replaced I should get it checked.

With this occurring after a recent oil change, it would be good follow-up to check the oil level (yes, a Roper Plate moves the sump oil lower and away from the pick-up. Seems to me that the upper mark on the stick remains valid as the full mark, regardless of the volume added.

It has been so common that the old oil filter gaskets remains stuck in the engine when the new filter is installed. I have made myself a BIG NOTE IN RED to check this at every oil filter removal. Certainly, the tightness of the filter is another matter of debate. The old method of "hand tight" is not adequate for these filters. One of our members diligently derived "one and one-eighth turns past gasket contact.

[docc]

15 hours ago, pete roper said:

If this happened under extreme braking it is unlikely to be pressure loss due to pick up exposure. The pick up on the 'Broad Sump' motors is at the front on the right of the sump. Under heavy braking the oil will slosh forward and there is little chance of it being exposed. It's on hard acceleration, and especially if you wheelie it, that the pick up is likely to be uncovered.

In this case, if I'm interpreting the OP correctly, the light remained on for ten minutes after the event during which time the motor was running and the bike was being ridden. If there had been a catastrophic loss of pressure the crank would be toast. Plain bearings simply can't survive without a constant supply of oil at the correct pressure. We are talking seconds, not minutes for irreparable damage to occur.

That leads me to think it is far more likely that the cause for the light coming on is far more likely to be something as simple as a dodgy switch, (A well known and documented issue.) or even simply the connector on the wire that goes to it being loose and just the inertia of the cable hurtling forward as the brakes were applied may of caused it to slip and break the circuit.

I'd still suggest the installation of a sloppage sheet as it really is very cheap protection for your crank but in this case I don't think it would of helped.

+1

True, as the oil pressure switch rides ahead of the left cylinder, vulnerable to the weather. IIRC, the connector to the oil pressure switch on the V11 are all just pressed on with no shielding. Worth a careful clean, crimp, seal (Vaseline®).

I sourced a switch boot from the EV series for mine . . .

[Speedfrog]

The problem with the sump spacer to crankcase oem gasket blowing out around the oil delivery galleries has been well documented with the CARC 8V engines and it’s been one of Pete Roper’s crusade to have them replaced with available aftermarket thicker gasket as routine maintenance, to prevent it from happening and the consequent loss of oil pressure. 

These oem metal core gasket recommended by Rolf are new to the 1400 engines and are now spec’d by MG on 1200’s as well.

Aftermarket thicker gasket:

https://www.mgcycle.com/index.php?main_page=product_info&products_id=34

 

Oem metal core gasket:

https://www.mgcycle.com/index.php?main_page=product_info&products_id=5495

[Scud]

54 minutes ago, Speedfrog said:

The problem with the sump spacer to crankcase oem gasket blowing out around the oil delivery galleries has been well documented with the CARC 8V engines and it’s been one of Pete Roper’s crusade to have them replaced with available aftermarket thicker gasket as routine maintenance, to prevent it from happening and the consequent loss of oil pressure. 

Good to know... gonna get one on order for my Stelvio.

[pete roper]

40 minutes ago, Scud said:

Good to know... gonna get one on order for my Stelvio.

Yeah. It doesn't happen to all of them but it's common enough that Michael and I recommend it to all of our customers who are having their bikes rollerised and inform other people and let them make the choice but we do encourage it.

I've had it happen on two of my engines. Both required new big end shells as a result. Many people go essentially the life of the motor with no problems but failures are frequent enough to be a concern. Unfortunately the first symptoms are usually big end knock at idle. If it is allowed to progress from there it can get to the point where the cam chain tensioner plungers aren't getting enough oil to prime and they rattle! By then delivery to the top end must be well marginal and I'd expect there to be further damage to the tappets and cam bearings.

[docc]

5 minutes ago, pete roper said:

Yeah. It doesn't happen to all of them but it's common enough that Michael and I recommend it to all of our customers who are having their bikes rollerised and inform other people and let them make the choice but we do encourage it.

I've had it happen on two of my engines. Both required new big end shells as a result. Many people go essentially the life of the motor with no problems but failures are frequent enough to be a concern. Unfortunately the first symptoms are usually big end knock at idle. If it is allowed to progress from there it can get to the point where the cam chain tensioner plungers aren't getting enough oil to prime and they rattle! By then delivery to the top end must be well marginal and I'd expect there to be further damage to the tappets and cam bearings.

What changed with the 1200 that this has been almost unheard of on the V11?

[pete roper]

It mainly affects the 8V's and the problem seems to be that the gallery in both block and spacer is larger and the bottom of the gallery in the block has a largish chamfer on it. This means that the actual thickness of the clamping surface for the gasket is very thin. Couple this with the clamping force being applied still by only two 6mm bolts and the shitty quality of the original gasket and it's a recipe for disaster.

PS. It has been known to happen n 2V CARC bike engines too, but it's much rarer. I wonder if it became an issue when they went to the trochoidal pump from the gear pump but I'll likely never know.

[al_roethlisberger]

So is there a metal core sump gasket for the V11 that should be considered for extra insurance, or is this only available for the later bikes?

[docc]

2 minutes ago, al_roethlisberger said:

So is there a metal core sump gasket for the V11 that should be considered for extra insurance, or is this only available for the later bikes?

Not so much the sump gasket, but the upper gasket between the spacer and the block.

Rolf's image shows that the later metal gasket would replace the earlier V11 gasket for those so inclined . . .

[al_roethlisberger]

1 minute ago, docc said:

Not so much the sump gasket, but the upper gasket between the spacer and the block.

Rolf's image shows that the later metal gasket would replace the earlier V11 gasket for those so inclined . . .

 

 

Well, it looks like I need to order 2 of those better metal-core gaskets in anticipation of installing my original Roper plate I've had "ready to go" for many years  

[docc]

8 hours ago, docc said:

So, with a "Roper Plate", two of these would sandwich the plate above the spacer?

 

 

Just now, al_roethlisberger said:

 

 

Well, it looks like I need to order 2 of those better metal-core gaskets in anticipation of installing my original Roper plate I've had "ready to go" for many years  

I asked that, but it occurs to me that is the block interface of concern.

[al_roethlisberger]

6 minutes ago, docc said:

 

I asked that, but it occurs to me that is the block interface of concern.

 

Other than cost (paper is about $5, metal core is about $13), why wouldn't two of the better metal core gaskets be a better choice to sandwich the Roper plate between?

Is there some concern or drawback to using two of the metal core gaskets?

[al_roethlisberger]

So I guess I'll wait to order two of the metal core gaskets until there is some clarification on that question 

 

I'm not installing the Roper plate any time soon, so no rush.  But I will forget about these special gaskets if I don't order them soon 

[pete roper]

I see no reason not to use the metal core gaskets.