w8ye

My Feedback: (16)

My one OS 52 has a non plated OS 40CS cam and one of my 91's has the surpass I cam which is not plated. My other 5 OS four strokes with the plated cams have not peeled.

Kweasel

My Feedback: (29)

Something to think about, if you never looked at the cam would you have ever been able to tell if the plating was damaged? I bet the cylinder and piston would die before OS cam and lifters would measure much wear. Loose rust inside the cam box has cause excessive wear. I think these parts are better plated, even if some of it flakes off.

gkamysz

My Feedback: (19)

Unless you look at the plating you wont know it's failing. If the engine is really smooth you might feel the flakes, by turning it over. I noticed it in one engine. Removing the cam cover will usually show the flakes. They probably won't make it into the cylinder area as they have a very small hole to pass through, and the flow is to the cam well and out.

The plating is a good idea. I have seen some very low use engines with a lot of rust because after run oil wasn't used. Maybe some other protective coating would be better.

The problem is that I don't think that there is anything the user can do to prevent the flaking.

XJet

Just as a matter of interest -- what oil (type/ratio) is being used in this engine?

Am I correct in thinking that it's been run on a fuel with straight-synth lube?

The only time I've seen any extensive cam wear in an engine has been when the owner ran straight synth. I use a small amount of castor in all my 4-strokes and last time I had my Saito 100 apart for new bearings both the cam and the lifters were merely "polished" rather than worn.

gkamysz

My Feedback: (19)

I don't know what oil was used. This one was bought used. The flaking seems to have started at the base, rather than the highest pressure areas.

w8ye

My Feedback: (16)

Looks as though it was a base metal preparation problem at the factory?

These are not the only cams that have peeled. I've heard about it long before. There are many people with peeling cams that don't know about it yet?

Iflyglow

My Feedback: (79)

I thought OS would have learned there lesson with soft nickel plating. This is the main reason I no longer purchase OS's. The replacemt parts are out ragious and the same thing will happen over and over, and then when they discontinue an engine parts are no longer available (OS 1.20II Pump).
I personally would research a Magnum crankshaft replacement.

gkamysz

My Feedback: (19)

I agree with both statements.

For now, I'll polish the loose stuff off with a stone and see what happens. The worst thing ithat can happen is that the gear starts peeling bad, because I won't be able to clean that up easily.

I'll consider the Magnum, but only after inspecting it. I hate to buy one and be stuck with it.

jaka

Hi!
From what I see in the pictures it's not a big deal! The cam looks just fine to me. Just run it an don't worry!

Motorboy

Think at nickelflake in the ballbearings and ruin later!!

TimC

I pulled the cam out of my .70 this morning just for a look-see. There is no peeling. The lifter faces have polished the plating, especially in the high pressure areas.

Waco Driver

When the camshaft plating peeled in my OS 52 FS, the first sign was a jet black oil discharge from the breather. When I pulled the cam cover, it appeared as if the cam case was full of black moly grease. The nickel has been finely ground by the helical gears.

Iflyglow

My Feedback: (79)

Has anyone tried the Magnum .91 camshaft in the Surpass II to get away from the plated cam.

gkamysz

My Feedback: (19)

I found a used OS cam without plating. The Magnum parts were mentioned earlier. I wouldn't buy one without seeing it. Sometimes they make changes when they "clone".

w8ye

My Feedback: (16)

I don't think everyone should be running back into the hen house just because one OS 91 surpass II cam peeled. A guy had one peel at the flying field a couple years ago but there were probably 20 other OS 91 Surpass II engines there and they didn't peel. I have 2 of the engines and they have never peeled. I would be willing to bet that the ones that have peeled is less than 1/2% of the ones made?

gkamysz

My Feedback: (19)

I agree, you should look at your engine prior to getting worried.

w8ye

My Feedback: (16)

Those of you that are spooked by the plated cam can still purchase the non plated cam

http://www2.towerhobbies.com/cgi-bin...?&I=LXCD54&P=7

AeroFinn

Hi w8ye,

I would be happy to hear what fuel you are flying with as you haven't had any such problems like this "peeling camshaft" phenomenon.

And vice versa, could some fuel blends be of cause for the peeling? I am just thinking that some commercial blends contain only 14-17 % oil (by volume) This is less than what is the manufacturer's recommendation (18%+)

Any thoughts or experiences?

w8ye

My Feedback: (16)

I have been running Rich's Brew 15% nitro fuel with the combination synthetic/castor oil package for 3 years. For thee years before that I ran Morgan's Omega 15%.

I have two OS 91 Surpass II's. One of them has a plated cam and one has a regular cam. I've never had any trouble with the one that still has a plated cam. Or either engine for that matter. The regular cam was in the one engine when I traded for it in 2002.

I attribute the peeling problem more to some that OS didn't do correctly.

gkamysz

My Feedback: (19)

I just acquired another FS-91SII. It looks to have a fair amount of run time on it and the plating on the cam is just fine. As I've mentioned before I'm pretty sure this is a process issue not an lubrication issue.

The Raven

Agreed, this is not worth strarting any 'the sky is falling' type stories about various engines having problems. It's a single case on an engine with an unknown history.

Looking at the cam pic I would take a guess that the previous owner had the valve clearances wrong (too tight) which placed extra load back on the valve train and eventually onto the cam lobes themselves.

OK, that explains the peeling on the lobes but what about the bearing surface? Well, that's probbaly a side effect from the plating coming off the lobes and any extra load on the entire cam assembly. If it's under additional load and minute amounts of metal are floating around nearby it's not unreasonable to see something like that.

Clean up the cam, check the bearings, reassembly, fly.

gkamysz

My Feedback: (19)

Actually, loads are increased with increased clearance. Tight clearances make sure the follower isn't crashing into the lobe. Ramps are used on cams to help with this also.

If the plating is put on incorrectly, or the base material is not of the correct hardness, plating will not adhere well.

NM2K

My Feedback: (14)

Sure there is - buy a Magnum clone of the same displacement. No more flaking. <G>


Ed Cregger

AeroFinn

w8ye, gkamysz, The Raven, Ed Cregger,


Thank you all for your comments. I also think this peeling phenomenon is an issue with some engines suffering some prolems related to manufacturing process.

So if you have bad luck you may or you may have got one of these engines in hand..In most cases this doesn't happen.


It would be nice, of course, to see some O.S. official service bulleting on the topic..


artto

NM2K

My Feedback: (14)

Sorry for the smartass remark.

I too am frustrated with OS' behavior. Why plate something if it is going to peel and make you look bad? It sounds as though OS' folks are disconnected from the real world and are buying into someone's theories that just aren't true.

I'm with the other folks in that I would clean the peeling debris from the engine and use it as it is. Of course, that is only after the OS warranty expires. Until then, I would return the engine to the distributor/warrantor and have them do the work. I hope that is your situation where you are.


Ed Cregger