Anybody using Camguard? (merged)

There is no proof that this additive does anything good in other Lycomings. Not sure what Lycoming was thinking of...

Maybe more than us external observers? Lycomings do have issues with the camshaft causing excessive wear of the tappets. A friction modifier apparently solved the issue for the most affected engine and I wonder why you think that it might not have any value on other Lycoming engines.

AeroShell/Total 15W50 complies with the Lycoming AD / service letter. No need to spend more than 30 € on a dose of LW-16702.

Only one engine that was built by Lycoming which is affected by the AD to use an extreme pressure additive. That engine was built with an automotive style cam and produced high pressure points between cam and tappet. I am not sure that Lycoming improved their design with this idea, but that is my opinion. This engine was used for a very short period towards the end of SE production at Cessna. Restarts used a conventional Lycoming design again, as they had done for all of those years before. Achim, your engine is also a conventional Lycoming cam and tappet design. So to summarise, if you don't run that engine affected by the design change, the AD does not apply.

However, there is a secondary problem that we are all very aware of today. Lycomings have an exposed cam and tappet. If the oil film is removed, or runs off after a prolonged period of inactivity, corrosion occurs on either face. It is generally accepted that this is linked to spalling of tappet and cam face later in the life of such an affected engine causing a catastrophic failure of the metal faces.

Since this is a different issue, I have been using a different additive for more than 1.5 years, one that has a lot more corrosion protection, than any aviation oil on the market. This is of course Camguard.

The other problem with Lycoming engines are stuck valves. Again Camguard promises a lot extra protection, which I have not been able to disprove whilst using the product.

That Lycoming stuck valve issue is propable a seperate discussion, in order to avoid deviation of this thread.

Achim, have you come across any proof out there that the extreme pressure additive intended for that AD has any benefit on any other engine?

Further, don't forget that the additives in AS+ oils breakdown in our engines and only one of those side effects is that grey sludge one will find in such an engine using that oil with that particular additive.

I am one, who is glad to be rid of that sludge in my engine!

Miroc, do you have the O320H2AD? If you run that engine then yes you have to use that additive, no then you don't.

I have the IO360-L2A in C172SP and there is a 'Service Instruction No. 1409C' mandating the use of LW-16702 for:

"All Lycoming piston aircraft engines except for installations that utilize a friction type clutch and a common engine oil system for the transmission and clutch assembly. Check with airframe manufacturer prior to use in these installations."

Miroc

A service letter is just a "recommendation", there is nothing mandatory about it. Only the authority (EASA/FAA) can mandate anything through an airworthiness directive.

However, it is not easy to make a judgement on the benefits of LW-16702 on other Lycoming engines. complex-pilot has some good points but the opposite argument can be made as well. LW-16702 does improve the contact between tappet and cam and it is very likely that there is a positive effect with other Lycomings, too.

Ed Kollin (creator of Camguard) did want to put something like LW-16702 into Camguard but couldn't as it would have made the slipping starter adapter issue on Continental engines much worse. So Ed too believes that a friction modifier is beneficial.

A service letter is just a "recommendation", there is nothing mandatory about it.

That's true... I did not realise that difference before to be honest.

However, in my opinion the manufacturer should know a thing or two about his own product. More important to me that an 'edict' of some government employee at FAA/EASA.

Here is a video in which a reference to LW-16702 is made. It should improve the friction characteristics under high pressure. Camguard is rather protecting the metals against corrosion according to the former contributions.

There is the annual check waiting for me in October, I am probably going to use the Aeroshell 15W50 with Camguard for the winter period. I am not expecting to fly more than 10 - 12 hours between November and March, will need every corrosion protection I can get.

However, in my opinion the manufacturer should know a thing or two about his own product. More important to me that an 'edict' of some government employee at FAA/EASA.

Fair enough but be warned, that point of view will not get you very far in aviation. Manufacturers recommend all kind of nonsense, sometimes to make money, sometimes to cover their a** from lawsuits, very often it is completely unrealistic to follow their recommendations.

Personally I don't feel at ease skipping LW-16702 with my turbocharged O-540. However, I also do not want the semi-synthetic AeroShell 15W50 and the sludge it creates.

There are two compounds that are interchangable and that meet the LW-16702 specification: TCP is an extreme pressure additive. The other one Butylated triphenylphosphate (bTPP) is unstable in the presence of water and heat. When an aero engine is running at cruise power it will put up to a gallon of water through the oil per hour. As explained by Ed Kollin: "One or two of the three ester linkages break and we're left with a phosphoric acid derivative and isobutyl phenol . It is this acid that goes after the soft metals. Methylated triphenylphosphate (tricresylphosphate or TCP)is fairly stable and the three ester linkages do not readily hydrolyze. Shell and Lycoming made the change to bTPP for safety reasons because one isomer (the ortho) of natural derived TCP is a nerve toxin. Exxon sources of TCP do not contain the ortho isomer. Along with the copper corrosion Lycoming is seeing some seal degradation but they're blaming it on people adding the LW-16702 additive to Shell additized oils doubling the concentration of bTPP, at least that is the story they're sticking with. Shell had a copper corrosion problem when they made the switch in the 90's(copper levels going from 10ppm old oil with TCP to 700ppm new oil with bTPP). They addressed it by putting additional inhibitor in the oil. This does not address the seal problem. Fortunately it is a slow degradation of the seals. I made Shell and Lycoming aware of the seal problem a few years ago."

And then Ed goes on to say: "The only things I would add is that Camguard contains anti-scuff additives that are MUCH more effective than the butylated TTP [TPP] that Shell is using (and even more effective than the (ineffective) TCP that Exxon is using) " This information might make some decisions easier regarding use of extreme pressure point additives, outside the scope of the AD.

Personally I don't feel at ease skipping LW-16702 with my turbocharged O-540. However, I also do not want the semi-synthetic AeroShell 15W50 and the sludge it creates.

Looked up the recommended Phillips 20W50 at Aircraftspruce.eu and that's my next option. It does not contain LW-16702 though. Thinking about Phillips + LW + Camguard for the winter period.

For summer there will be the AS W100 Plus + Camguard.

Reading the contributions above it seems to me that this is a pretty complicated science...

Miroc