Who makes the best cam? I am O/H-ing an 0-540 J1A5D with new lycoming cylinders (flow-matched/ported from Lycon). My AP wants to send my old cam in and use it if it passes.. The engine has 2700 hours on it and flown hard most of it's life.

Lycoming Cam Shafts are prone to wear causing pitting and lifter, tappet valve damage primarily due to lack of lubrication and heat. Firewall Forward has an STC for Cam shafts that addresses this issue Centri-lube.

http://firewallforward.com/

I put one in last year and everything is AOK!

There's nothing wrong with Lycoming's camshafts, and your cam with the oil holes may help a LITTLE, but not much.

What kills Lycoming cams is that the engines don't get flown often enough.

The camshaft on a Lycoming is on TOP of the crankshaft, compared to below on a Continental. That position of the cam on the Lyc means that the cam sits up high and dry in a region of the engine which is often pretty moisture laden, after shutdown. So, the cam sits there and corrodes. Till the next time the engine is run.

Hopefully, when the engine is run, the oil temps reach at least 180, and stay there for 20 minutes at least (no ground runs just to "warm it up").

But, nevertheless, the camshaft is up top, sitting in that very moist air trapped in the top of the case.

Now, the cams with the oil holes are supposed to help that. Point is, however, that they sit there, unmoving just like the stock cams do UNLESS you fly the plane regularly. The cams with the oil holes only move oil when running, not when parked.

So, these cams aren't going to help a bit. Save your money and spend it on gas.

Run that engine every chance you get, and you'll not have corrosion problems with a Lycoming cam. Park it for weeks on end and you will, regardless of what cam is in the engine.

Oh, yeah--and add some ASL Camguard every time you change the oil. That is the ONLY snake oil additive that has actually been documented to do something about corrosion.

MTV

Does the Lycoming Roller Cam help at all? I understand it is still in the same place, but was curious if not having the force of the lifter on the cam helps, or even hurts with the corrosion? I have the same motor, and I do use Camguard.

Dokmow wrote:Does the Lycoming Roller Cam help at all? I understand it is still in the same place, but was curious if not having the force of the lifter on the cam helps, or even hurts with the corrosion? I have the same motor, and I do use Camguard.

I think you mean Roller Tappets, available on the newer Lycoming engines, which do require a new cam. Yes, they do help and are smoother. Automobiles have been using them for some time. TBO is the same however, either way.

http://www.amtonline.com/publication/ar ... =1&id=1466


MTV is correct to the letter. Cam's wear out because of sitting, not from running.

Anyone know where to get a decent price on Camguard??? My local parts dealer wont even carry it. I've been using Avblend but want to switch.

I get it from http://www.aircraft-specialties.com/.
How many hours do you have on your roller tappets?

mtv wrote:There's nothing wrong with Lycoming's camshafts, and your cam with the oil holes may help a LITTLE, but not much.

What kills Lycoming cams is that the engines don't get flown often enough.

The camshaft on a Lycoming is on TOP of the crankshaft, compared to below on a Continental. That position of the cam on the Lyc means that the cam sits up high and dry in a region of the engine which is often pretty moisture laden, after shutdown. So, the cam sits there and corrodes. Till the next time the engine is run.

Hopefully, when the engine is run, the oil temps reach at least 180, and stay there for 20 minutes at least (no ground runs just to "warm it up").

But, nevertheless, the camshaft is up top, sitting in that very moist air trapped in the top of the case.

Now, the cams with the oil holes are supposed to help that. Point is, however, that they sit there, unmoving just like the stock cams do UNLESS you fly the plane regularly. The cams with the oil holes only move oil when running, not when parked.

So, these cams aren't going to help a bit. Save your money and spend it on gas.

Run that engine every chance you get, and you'll not have corrosion problems with a Lycoming cam. Park it for weeks on end and you will, regardless of what cam is in the engine.

Oh, yeah--and add some ASL Camguard every time you change the oil. That is the ONLY snake oil additive that has actually been documented to do something about corrosion.

MTV

I don't dispute your point about engines not flown is the cause of cam shaft issue. Nevertheless Lycoming made an additive lubrication to address this issue specifically which to me indicates they are aware that it is a problem. It is a psychological tactic to tell a buyer that the engine has to be flown once every week or 2 depending on who is using the ploy. Especially if there is an stc that will allow lubrication to get to the area effected quickly on start up. The firewall forward web site has an excellent presentation on the subject. Reality is that some owners just don't have the luxury of flying every week for what ever the reason. We are not all professionals who have to fly to make a living no matter what the circumstances.
What makes sense to me is that if you either have the issue or the opportunity to have the lube holes done then it is one more guard toward preventive maintenance. For the price not to have to have the engine broken down again because you went through one of life's curve balls ( like not be able to fly for some period of time is worth it.) Good intentions often get side tracked.
Besides getting lubrication to the top end of the engine can't be all bad. That is why the use of snake oil hoping it remains there for a period of time not dripping down to the bottom of the engine.
Since I got bit by buying and an aircraft that was claimed to be flown all I can say is caveat emptor. I was tempted to put a preoiler in until I learned that it does not build up enough pressure to go to the top of the engine.
I have no dog in this hunt as far as firewall forward. The question was asked about Cam shafts and I threw this out there for the pilot owner to be aware of the option.
I personally being aware of the issue prefer not to hold my breath every time I can't fly. I have been grounded for 2 weeks going on 3 for an annual waiting for carbon mag brushes. Sh*it happens that prevents routine.
As far as your opinion "that the holes may help a little, but not much" look at the thermal imaging photos.
The bottom line is these are all methods of keeping the cam shaft lubricated. I would rather have a mechanical approach than a " because we have the cam shaft designed at the top of the engine if you don't fly it once a week its your fault if it wears because of friction." That is marketing spin to cover poor Quality Assurance and no design of experiment.

I know nothing about about cams for lycomings but I had a thought that sorta goes along with what MTV was saying. I work in a research lab doing corrosion test on metals used in turbine engines. One of the things we do is polish a sample of the metal so it is extremely smooth and place it in a oil bath in a controlled environment for a specific time...about a day. The we take the sample out of the bath and weigh it and check it for corrosion spots. I was amazed at the difference between oils, some would not corrode at all and some would corrode like mad. We redo the ones that corrode significantly to ensure the results. Wish i could share which oils aren't as good but I can't. I will say there is one brand that I won't be putting in my plane.

If the samples are left out for just a few minutes after polishing they get corrosion pits on them and I have to start over...makes you wonder what is goin on inside you engine during the week your not flying it. I dont get out much in the winter and after seeing what I have seen I might just pickle the engine for the winter and not fly at all Better that having the engine corrode to pieces.

Your fortunate that you know via reliability testing which oil is best. I think if you use Camguard, Lycoming additive and the oil you know to be good. ( No one expects you to violate any non disclosure agreement but recommending a brand is not the same as saying one is bad by testing.) I have been using the Shell 100 and some swear by the Exxon Elite. Although take a look at the pictures and you will see pitting on the tappet valve and lobe damage. They do not exhibit corrosion but more damage from friction due to lack of lubrication. Could there be corrosion sure but I believe that if one can do all of the above mentioned, a good oil, an additive, fly as often as possible, and if the engine is dismantled consider the holes in the CAM STC you will have taken all the preventive action available. Flying in the winter can be some of the most enjoyable flying you will ever encounter.


By sojorrn at 2007-09-05


By sojorrn at 2007-09-05

Green Hornet wrote:

mtv wrote:There's nothing wrong with Lycoming's camshafts, and your cam with the oil holes may help a LITTLE, but not much.

What kills Lycoming cams is that the engines don't get flown often enough.

The camshaft on a Lycoming is on TOP of the crankshaft, compared to below on a Continental. That position of the cam on the Lyc means that the cam sits up high and dry in a region of the engine which is often pretty moisture laden, after shutdown. So, the cam sits there and corrodes. Till the next time the engine is run.

Hopefully, when the engine is run, the oil temps reach at least 180, and stay there for 20 minutes at least (no ground runs just to "warm it up").

But, nevertheless, the camshaft is up top, sitting in that very moist air trapped in the top of the case.

Now, the cams with the oil holes are supposed to help that. Point is, however, that they sit there, unmoving just like the stock cams do UNLESS you fly the plane regularly. The cams with the oil holes only move oil when running, not when parked.

So, these cams aren't going to help a bit. Save your money and spend it on gas.

Run that engine every chance you get, and you'll not have corrosion problems with a Lycoming cam. Park it for weeks on end and you will, regardless of what cam is in the engine.

Oh, yeah--and add some ASL Camguard every time you change the oil. That is the ONLY snake oil additive that has actually been documented to do something about corrosion.

MTV

I don't dispute your point about engines not flown is the cause of cam shaft issue. Nevertheless Lycoming made an additive lubrication to address this issue specifically which to me indicates they are aware that it is a problem. It is a psychological tactic to tell a buyer that the engine has to be flown once every week or 2 depending on who is using the ploy. Especially if there is an stc that will allow lubrication to get to the area effected quickly on start up. The firewall forward web site has an excellent presentation on the subject. Reality is that some owners just don't have the luxury of flying every week for what ever the reason. We are not all professionals who have to fly to make a living no matter what the circumstances.
What makes sense to me is that if you either have the issue or the opportunity to have the lube holes done then it is one more guard toward preventive maintenance. For the price not to have to have the engine broken down again because you went through one of life's curve balls ( like not be able to fly for some period of time is worth it.) Good intentions often get side tracked.
Besides getting lubrication to the top end of the engine can't be all bad. That is why the use of snake oil hoping it remains there for a period of time not dripping down to the bottom of the engine.
Since I got bit by buying and an aircraft that was claimed to be flown all I can say is caveat emptor. I was tempted to put a preoiler in until I learned that it does not build up enough pressure to go to the top of the engine.
I have no dog in this hunt as far as firewall forward. The question was asked about Cam shafts and I threw this out there for the pilot owner to be aware of the option.
I personally being aware of the issue prefer not to hold my breath every time I can't fly. I have been grounded for 2 weeks going on 3 for an annual waiting for carbon mag brushes. Sh*it happens that prevents routine.
As far as your opinion "that the holes may help a little, but not much" look at the thermal imaging photos.
The bottom line is these are all methods of keeping the cam shaft lubricated. I would rather have a mechanical approach than a " because we have the cam shaft designed at the top of the engine if you don't fly it once a week its your fault if it wears because of friction." That is marketing spin to cover poor Quality Assurance and no design of experiment.

Lycoming's oil additive LW-16702 was actually developed to address the myriad of problems in their 0320-H2AD four cylinder engine in the mid 70's. They were really under the gun to fix that thing and the anti-scuff TCP helped with high bearing wear that was taking those engines out. Turns out, it helps with most all friction issues in the motor. It was many years later that Lycoming approved it for use in all of its engines.

Lycoming SB's 446C and 471, and SI 1409A (you can get them faxed to you free by calling Lycoming at 1-800-258-3279 or 570-323-6181) will explain all the above.

As far as cams that have holes drilled in them, they won't hurt and probably help some but really don't address the main weakness of the design which is moisture in the top of the engine where the cam lives. These cams are not bathed in oil and rely on the lubricant film to protect them from the elements during periods of disuse.

The key is keeping the cam coated as long as possible which has created the snake oil industry. Camguard appears to have an angle on this issue and some data to back it up. Hopefully, it works as described because many of us cant fly weekly and need the cams to last. My flat cam caused an early overhaul last year.

The reason you can't see corrosion on your photos is because of spalling, the hardening is likely gone, and wear accelerates to the extent in the photos. Corrosion won't sit on the lobes if the engine is ran for any length of time but its effects remain.

I just changed a clutch bushing on my near new Honda motorcycle under a service change. The new part had holes drilled in it much like your cam so I understand its merits. No dig on you or FF. Point is, its unnecessary (like the additives I use) if the engine is excercised regularly.

Lycoming isn't using psychological tactics or ploys on any of us, they just aren't that smart.

As for the oil companies.........

call steve at performance air 208-455-7400 he is the master of all things lycoming

That's correct, the H2AD engines were the ones that Lycoming addressed with the TCP additive. That had nothing to do with the "current" crop of cam and lifter problems.


Camguard was developed by a lubricant engineer who worked for Exxon. Exxon opted not to incorporate the additive package that he developed.

You can buy Camguard direct from the manufacturer, go to: http://www.aslcamguard.com/

It is good stuff, and is an approved additive by Lycoming.

Nevertheless, corrosion is the worst enemy your engine will ever have, and non use is the primary cause.

And, I'm as guilty of this engine abuse as anyone.

I do and have used Camguard regularly for a number of years. I'm a believer, but my cam could be next....

MTV

I did not recommend a brand because the oils we test are for turbine engines so they are different than what we use, but if one type of oil from a company is crappy why would I think that another type is any better? Most of the oils come in generic containers and are coded so we do not know what is what, some are normal turbine oils are some are experimental. Sometimes they send us oil in original packaging and so I know what they are.

I do not know if we have tested shell or exxon...there is only two brands I know we have tested, one was good and one was not, the rest have come in generic bottles. I haven't seen anyone mention the not so good brand here.