oil consumption, black valves

[vuzzi]

I noticed quite some oil consumption lately, say 1 litre on 1500 km. Having read the topics on oil consumption I took al look in the air box, which turned out to be just a bit moist from oil.

I noticed oil on the intakes, between the injectors and the heads. Removing the intakes gave me a look at the intake valves (see pictures). They turn out to be black from carbon residues. I 'm a bit afraid this is caused by soft valves or guides. To be sure, I took the breather line from the airbox and lead it to a plastic botle to catch any oil, so any oil from the breather wont get to the intakes and valves any more. I just took as short 80 km ride, and haven't caught any oil in the bottle jet. I'll check the intakes after some more rides.

 

In case the valves are bad, are they hard to replace?

 

Does anybody have tips on what valves / guides should use to prevent this from happening again?

[docc]

Vuzzi,

 

How many total kM on your V11?

[Skeeve]

In case the valves are bad, are they hard to replace?

 

Does anybody have tips on what valves / guides should use to prevent this from happening again?

 

Mike Rich [one of the few Guzzi performance specialists here in the States] has stated pretty unequivocally that the stock valve guides are made of some kind of Italian cheese, and should be K-lined at the earliest opportunity.

 

Guzzi doesn't use valve seals: I've pondered the feasibility of getting some valve seals intended for some cage application w/ similar sized valves, and applying them to the intake side of things [oil blowby on the exhaust valves isn't going to do much harm, since we don't have cat-cons on our V11s stateside, and the ex. valves need all the cooling they can get!]

 

Part of the woes are undoubtedly due to the way the engine has "grown" over the years, with changes made to components & locations that has made the relevant angles btw parts go all whoopsy, so that the valves are under far greater lateral loads than they were when Carcano 1st engineered the motor for the Ambo 750... roller rockers might be in order at this stage of the game!

 

Good luck!

[vuzzi]

Vuzzi,

 

How many total kM on your V11?

 

She has app. 20.000 km on the clock. Runs good, vibrates a bit, but not too much. I use the prescribed agip oil, but filled up with Q8 10w50 4t full sinth I bought at a highway petrol station on holyday (almost a litre now).

[vuzzi]

 

Mike Rich [one of the few Guzzi performance specialists here in the States] has stated pretty unequivocally that the stock valve guides are made of some kind of Italian cheese, and should be K-lined at the earliest opportunity.

 

k-lined: taken out and replaced. But by which ones? Are there any aftermarked valve guides?

 

Any thoughts of the kind of italians cheese they are made of? There is a big difference between mozzarella and Parmesan. At least my girlfriend starts to show interest in my v11 for the first time now doing some research for me (see http://www.e-rcps.com/pasta/inf/cheese.shtml).

[pete roper]

 

k-lined: taken out and replaced. But by which ones? Are there any aftermarked valve guides?

 

Any thoughts of the kind of italians cheese they are made of?

 

The guides are sintered phosphor bronze, presumably rapid wear is an indicator of the relative proportions of the sintered alloy being a bit 'How's yer father'. Even so 20,000Kms is avery low to have excessive wear. K-lining is the best option. It doesn't require removal of the guides and so concentricity of valve and seat is maintained meaning less material gets removed from the seats when they are cut to the valves.

 

Our race bike runs a much more radical cams than the V11's and guide wear is not a problem with K-lines in. It's a far better option than re-guiding unless the guides are loose in the heads.

 

The carbon deposits on the inlet valves may be the result of either an overly rich mixture due to poor tuning or the fact that the ETS is getting a false signal, (This has been discussed to death in other threads but I generally find that once the ECU is getting an accurate signal things are usually better.). Another alternative might be that the breather system isn't functioning properly. Try removing the hose from the crankcase, cleaning the ball valve and flushing the frame after disconnecting the condensate returns with Kero and then blowing it out with compressed air. If the breather and return isn't working then more oil than should be will be being thrown through the airbox and will contaminate the incoming air and charge leading to deposits on the valves.

 

Pete

[raz]

k-lined: taken out and replaced. But by which ones? Are there any aftermarked valve guides?

Googling for k-line produces quite a few false hits. Here is one correct description: http://www.cylinderh...e-guide-liners/

 

Most head shops will know what you are talking about.

[vuzzi]

 

The carbon deposits on the inlet valves may be the result of either an overly rich mixture due to poor tuning or the fact that the ETS is getting a false signal, (This has been discussed to death in other threads but I generally find that once the ECU is getting an accurate signal things are usually better.). Another alternative might be that the breather system isn't functioning properly. Try removing the hose from the crankcase, cleaning the ball valve and flushing the frame after disconnecting the condensate returns with Kero and then blowing it out with compressed air. If the breather and return isn't working then more oil than should be will be being thrown through the airbox and will contaminate the incoming air and charge leading to deposits on the valves.

 

In my case I guess it's an oil issue and not a fuel one, considering the oil on the intakes (both sides) and the deposits that still look wet.

In case the breather system is not working properly, could the presure in the engine increases the presure under the rocker covers (through the cannels that normally let the oil run down) , pushing oil through the valve guides?

Somewhere else I read decelerating on the engine breaking power with closed throlte causes extra vacuum in the cilinders 'sucking in' oil through the valve guides (I know, pete, as you wrote somewhere else (topic on oil pump), there is no such thing as suck, it pushed by the gass preasure on the other side of the valve guides, and I agree).

Driving style may have an effect too in this way.

 

I already took the hose from the spline to the airbox of and send it to a small bottle. I hope to find out soon what the effect of that is. As soon as I get a chance (next wednesday I guess) I 'll clean the ball valve and the spline.

If the problem remains I 'll have to look for a place to get the k-line in.

[vuzzi]

Try removing the hose from the crankcase, cleaning the ball valve and flushing the frame after disconnecting the condensate returns with Kero and then blowing it out with compressed air. If the breather and return isn't working then more oil than should be will be being thrown through the airbox and will contaminate the incoming air and charge leading to deposits on the valves.

 

 

Before I start dissembling my bike, where is the ball valve? I took al look al the parts manual and the workshop manual, but there doesn't seem to be a ball valve?

[vuzzi]

Well, this story needed an update.

 

I have taken the heads off. Checked:

- the piston rings, piston and cilinder: very good condition. Almost like new, apart from the carbon deposits on the piston

- intake valve guides - valves: thight, no exessive play. Only carbon deposits on the intake valve

- exhaust valve and guide: slight play on both sides when valve is at max. open, maybe due to overheated head. Carbon deposits on valves too.

- all the valve stems are still like they are brand new. No wear.

 

- the engine breather hose is still off the air box. Checked all hoses from and to the engine: all OK

 

Since the heads were off I had the exhaust valve guides replaced.

Also all the carbon deposits are removed.

After refitting the whole bunce I went for a ride. The bike runs fine like before.

 

I then checked the intakes again by taking the manifolds of, I noticed there is still oil in the intakes and on the valves.

 

So since the breather hose is off, where can this oil still come from?

- past the piston rings? Might get less when I lower the Oil level. Might get less when I run the bike in again since the cilinders and pistons have been off?

- still between the valve and the guides, although they are thight?

- between the guids and the head???

 

 

I can't see any other options. Any ideas anyone?

[luhbo]

Fuel leftovers, water, things like that. The intakes are seldom dry. Could be oil as well, the valves aren't sealed, but what's the problem then? Does your engine need oil? How much?

 

Hubert

[raz]

Before I start dissembling my bike, where is the ball valve? I took al look al the parts manual and the workshop manual, but there doesn't seem to be a ball valve?

It seems to me the spine frames don't have a ball valve:

 

40

It's #38 in the above picture (Cali 1100).

 

Here's a V11, that ball valve is not there!

 

(Pics from Stein Dinse)

[vuzzi]

Fuel leftovers, water, things like that. The intakes are seldom dry. Could be oil as well, the valves aren't sealed, but what's the problem then? Does your engine need oil? How much?

 

Hubert

 

the problem is that she uses 1,5 litre of oil on 1500 km, resulting in carbon deposits in the combustion chambre and an empty wallet.

[vuzzi]

 

Here's a V11, that ball valve is not there!

 

 

The ball valve (not being there) does not seem to be the problem cause I took off the breather hose.

 

There is still fluid in the intakes. I suppose it is oil. At least it feels and looks like it. Defenitely no water.

Fuel? I don't know if that can be on such hot intakes. Would evaporate.

Or could it be droppng from the injectors after the engine cools down?