Lycoming AD

a64pilot · Post by **a64pilot** » Thu Sep 06, 2007 5:42 pm

I think Toyota tried and quit. I think Honda was going to build the entire plane, and quit.

RobBurson · Post by **RobBurson** » Thu Sep 06, 2007 9:36 pm

a64pilot wrote: Unless I'm nuts roller tappets have a big roller on the surface that contacts the cam. I think the rollers are relatively a new thing. I feel pretty sure they were not OEM in a 97 engine. If possible, I would put a roller cam and tappets in at overhaul.

This may be comparing apples to oranges. Automotive hot rod/racing engines use roller lifters for high rpm efficiency. They don't last as long as the non rollers at normal rpm. Airplane engines run such low rpm, in my mind it doesn't compute. It sounds like the oil system is some what questionable. Not getting oil where it is needed in a timely manner.

This is a link to a pre engine start oil system. http://www.oilamatic.com/index.htm

There is also a less expensive type. Just a pressure tank which is charged while the engine is running. Before the next start you trigger the system and it pressurizes the system. I talked to a guy who had one on his Navion. I think he said it cost less than $300.00

We know the best way to make the engines last is fly them weekly. That's my goal. Regards...Rob

Green Hornet · Post by **Green Hornet** » Thu Sep 06, 2007 10:19 pm

Rob,
Looks like that is a pragmatic solution to bad it is not STC'd for a Maule. I believe the Mooney has a Lycoming 540IO. Maybe it could be STC'd with a little work. How about the $300.00 device. Can you find it model # and stc'S?
Thanks For the input

Green Hornet · Post by **Green Hornet** » Thu Sep 06, 2007 10:49 pm

Rob,
I sent an email to the President of oilmatics. He has a stc for a Cessna 182 with a Lycoming 540IO with a Mc Caulley prop.
I let you know what his reply is tomorrow.
Regards
Bill

maules.com · Post by **maules.com** » Thu Sep 06, 2007 11:07 pm

There are no oiling holes on the cam lobes or lifters so I cannot see preoilers helping, however the roller tappet system does have oil holes at the contact surface so it should help there.
It only takes one winter cold startup to spall the lobes and/or lifters and I have seen the damage done immediately in one occasion and also a hundred hours later in other instances.
Now Continentals have the camshaft at the bottom of the engine but traditionally has lower TBO requirements than Lycoming.

a64pilot · Post by **a64pilot** » Fri Sep 07, 2007 4:24 am

If you click on the link that 210 turbo posted, the one about Cessna owners, you'll find that those were Continentals. Lycoming is more prone to cam failures, but all cam failures are not in Lycomings.
Roller tappets are not anything new, yes there is less friction loss in a roller tappet, but I have not heard of their shorter longevity. I'm almost positive my Duramax diesel has roller tappets in it and automotive wise, it's a low RPM engine and I hope built for the long run.
Lycoming cam failures have been around for a long time, Lycoming has had years to ponder on it. I think the rollers were used for quite a while on their non-certified engines. I would bet that roller tappets are just one change made here. If I were faced with having to replace my cam and lifters, I would go with rollers, if allowed and if they were not stupid expensive.
Pre-oilers are excellent for any engine whose life is usually determined by oil lubricated components. I.E. crank and rod bearings. That is usually not the case here, but pre-oilers can't hurt and may help. I just can't say if they are worth the money and weight.

Green Hornet · Post by **Green Hornet** » Fri Sep 07, 2007 11:04 am

I spoke to George Mc Crillis, Oilamatics who explained that the STC is for the Airframe not the engine. He has some work he has previously done on a Maule and is doing research this weekend. I would have to get a field approval from FSDO. George has got this done more than once and said that if FSDO understands that it is an airframe change it is fairly cut and dry.
There is a company who has an STC -Firewall Forward- for holes in the Cam
http://www.firewallforward.com/
I need to ask how much.
The wt of the preoiler 5.5 lbs for the Maule.
I believe the 2 changes would be a good containment corrective action and may be considered in time a permanent corrective action.

Green Hornet · Post by **Green Hornet** » Fri Sep 07, 2007 11:24 am

UPDATE: I ordered the Firewall Forward CAM the STC is an additional $540.00. Firewall said they have done this for 5 years with zero reported failures.

a64pilot · Post by **a64pilot** » Fri Sep 07, 2007 1:46 pm

If you get the field approval for the pre-oiler, are you willing to share the 337?

Green Hornet · Post by **Green Hornet** » Fri Sep 07, 2007 5:08 pm

If you get the field approval for the pre-oiler, are you willing to share the 337?

I am not that familiar on how the field approval 337's works or exactly what strings are attached. Oilamatic will provide as much help as possible in obtaining the 337.
BTW the Centri Lube CAM STC from Firewall Forward is guaranteed for 4 years.

Green Hornet · Post by **Green Hornet** » Wed Sep 12, 2007 5:03 pm

One culprit for premature lobe wear is using oil without the additive specified in Lycs bulletins which is also in Exxon Elite and Aeroshell Plus oils. It helps the oil stay on the shiny surfaces inside the engine when hot after shutdown, thus giving some protection at next startup even if it is a week or more.
There is moisture in the cooling crankcase which rises to the shiny surfaces which if not protected, can settle, causing corrosion, thus the need for regular oil changes, to help eliminate these moistures and acids or a dry air pump can be used to help.
The camshaft on a Lyc is on top of the engine and so not bathed in oil. At startup when cold there is no oil pumped to the lobes so it must be splashed up there and when the oil is thick, this takes a while and if idled after startup, no oil gets there for a while.

I spoke to the owner (IA) repairing my engine. I asked his opinion of preoilers whereby he told me about LYC_LW1670, Oil Lycoming Engine Additive. At some time there was an AD that addressed Lycoming's problem with cam lobes. He has been using it for all Cessna's ever since no matter what the size of the Lycoming engine because " it works". He thinks it may also be included in the Areo Shell 100+ but all his Cessna owners continue to use the LYC_LW1670 additive.

RedMaule · Post by **RedMaule** » Thu Sep 13, 2007 7:08 am

Apparently a California judge has approved a class action suit filed by owners of aircraft with the Lycoming crankshaft problems. Let the games begin. RM

Green Hornet · Post by **Green Hornet** » Thu Sep 13, 2007 7:56 am

My research has confirmed that Aero Shell data sheet specfies that LYC 16702 is mixed in their AERO 100 plus. However a QT. of AERO 100 plus cost $4.95 .
LYC 1670 ( note the 2 is missing) cost $21.50 a bottle.
Note: Engine oil additive for Lycoming 0-320 H engines. One bottle to be added at each oil change. Must be replenished at 50 hour intervals.
Since I was using AERO 100 plus I suspect the 2 additives are not identical and it is misleading to believe that Aero 100 plus will protect cams and lifters as advertised? Especially as a replacement for the LYC 1670 mixture in quality or quanity.
Just out of curiosity how many of you use LYC 1670 per the AD?

a64pilot · Post by **a64pilot** » Thu Sep 13, 2007 8:54 am

I don't know anyone that uses the Lycoming additive. I think the better grades of oil don't require it. I do not have an 0-320 engine either so...

Green Hornet · Post by **Green Hornet** » Thu Sep 13, 2007 10:09 am

I am just fencing with windmills I suppose. Aero shell 100 does have the LYC 16702 mix in their oil so I guess with 8 quarts you probably get a bottle. I would think a 540 would wear the same as a 320 or more?
I wish I felt better about the preoiler. For all the work getting the STC it appears it does not actually get the oil to the cam/ lifters on the Lycoming so what is the point except time and money. I"ll probably just stick with the stc for the cam shaft (holes) and fly as much as possible. Meanwhile I am grounded.

Lycoming AD

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