Rust on my camshaft!

[Dean Pichon]

I just "wasted" $1500 on a new camshaft. My engine was in the shop for a sudden stoppage teardown inspection and I was informed I would have to pay for a new camshaft due to corrosion.

I'm very frustrated as I feel I have always babied this engine and now have no idea how to prevent it in the future.

This camshaft is from a factory new (2001) O-360 A1A. I fly regiously once a week and have accumulated a little better than 450 hours over about 7 years since the first flight. It has always been hangered and for most of its life, it has been stored in a heated hanger. I change the oil and filter twice a year. I perform an oil analysis and add AvBlend at every oil change.

In the fall/winter, I block off the oil cooler and see oil temperatures around 180F. In the summer, I run between 190 and 200F.

The rebuild shop told me replacing the cam is very typical in this situation. The returned cam had very little visible corrosion, but I have no frame of reference with which to judge.

I could use help with two questions:

Have others had similar experience with needing a new cam early in an engine's life?

What can I do in the future to extend the life of this expensive part?

All input is most appreciated.

 

[gpiney]

I can't help you with your particular 'why' , but I recently saw a presentation by the formulator of the product 'CamGuard'. Not a sales pitch, an engine wear/corrosion/oil lecture. Most of the presentation is Here.
I Don't work for them, I Don't use the product.

 

[hevansrv7a]

FWIW

I'm sorry for your troubles but perhaps this will help..

1. Camguard: I've seen the presentation, too, and I am impressed with the developer's credentials. I'd choose it over AvBlend which in automotive form has been controversial at best. I doubt it would hurt and it might help as it is designed to do so. Of course, if it's not on the cam then it won't protect it and I've seen much argumentation about just how long the oil film lasts. I have no specific reason for this but I would not use them both at once.

2. Rust - corrosion on steel - probably came from water rather than from acids in the oil. Is there corrosion elsewhere? Even with your nearly ideal storage conditions and frequent flying, you can't prevent moisture from forming inside the engine every time you shut it down. This is natural and unavoidable since CO2 and H2O are the result of combining O2 in the air with a carbon-hydrogen compound we call avgas. Since the hot air inside the engine can hold much more water in absolute terms than even the air in your heated hangar, condensation is inevitable every time you shut down. The dewpoint of hot moist air is higher than that of warm moist air. Ensuring that you get the oil hot on every flight, IMHO, does absolutely nothing to help with this problem as you are creating new moisture.
Try this calculator: http://einstein.atmos.colostate.edu/~mcnoldy/Humidity.html

OK, my suggestion is to keep the air in the engine way drier than ambient so that the dewpoint is always lower. Yes, you can pump dry air into the engine and thus remove the water that results from running it. You can dry out the engine before the oil drains off the parts. Tannis makes such a device. So does Engine Saver. See:
http://www.aviationconsumer.com/issues/36_9/maintenancematters/5585-1.html
This is what I use. When I got my engine, not pickled, it had those clear plastic dehydrater plugs in the top 4. After a while they started losing their deep blue color and going pink (from good to bad). When I hooked up the Engine Saver they went back to deep blue and stayed that way. I use it immediately after every flight and keep it running all the time, all year. Yes, you can make your own and there have been threads on this forum for that. Some of my friends have done that - copying my factory version. Lastly, I think that the chemical approach is superior to the compressor approach even though it's a PITA to monitor the indicator beads and bake the silica gel when necessary.

 

[rgbewley]

Camshahft Rust

For what it's worth. The company that makes Camguard is Aircraft Specialties. They also regrind cams. Request that the cam be sent to them for regrind. Not a guarantee, but the chances are pretty good that it can be reground. If not, there aren't a lot of choices but to replace it.

Good luck.

 

[deene]

Dean, unfortunately, your cam situation is a common occurrence on Lyc's. Interestingly, a major cuprit in this situation are the cam followers. The mushroom followers are notorieous for rusting as they are cast iron which rusts very easily and quickly. Then each time you start the engine, they accelerate cam wear as the rust is worn off.

As suggested, try to get the cam reground...but don't expect too much luck as the hardened cam surface is not real deep. Otherwise, expect a big bill for a new cam, but do shop as discounts and prices vary.

The new roller cam followers offered by Lyc and others should help the situation, but I believe are not retrofits. And as noted earlier, many owners are beginning to use air drying systems after shutdown to lower the corrosion while some have used a low power heater (light bulb) for many years to keep the engine at a high temp than ambient to forstall moisture formation.

 

[Russ McCutcheon]

My Cam and followers only had 900 hours in 16 years, stored in an un-heated hanger hear in the NW. On tear down it looked pretty good and both the cam and followers where re ground and are running now with over 650 hours in 4 years.

If you say they have very little visible corrosion then they where probably still just fine and would have kept right on if you had not had the unfortunate opportunity of inspecting it early, maybe the shop was more worried the engine mite come back to them before TBO if they re installed your old cam. Send it to ECI or one of the other shops and have it inspected and reground to sell or use later, send the followers to.

 

[rocketbob]

Dean, what brand and weight of oil have you been running?

 

[mculver]

As others already mentioned, this is a realy issue with Lycomings. I have done four things to mitigate the problem on my Lycoming O-235, located in the Pacific Northwest (a terrible place in terms of rust):

1. I use a premium oil that Aircraft Consumer found to be superior in terms of protecting the cam when the engine is run infrequently (on weekends is infrequent). I use Exxon 20W50, which was their top choice.

2. I use an engine dehumidifier. Google for this term and any number of solutions pop up. BTW, in my opinion this is the #1 best thing you can do for your engine.

3. I also use CamGuard. BTW, Aviation Counsumer said that this is good enough to make premium oil less than cost effective.

4. I always get an oil analysis with each oil change, and keep an eagle eye on "iron" (rust). It is this analysis that tells me the dehumidifier is most effective, and in fact I am not as certain about CamGuard as the glowing reports frin others. (Because the reports don't prove it out as helping -- although I am waiting for the latest report as I write this.)

 

[rv72004]

Sorry about your cam. More often than not, rust is linked to geographic location. If you hanger in a area with high humidity and large temp fluctuations, it will form much more readily than in a dry climate. Lycomings cam is in the air, whereas Conti has their cam in the oil. This helps a lot with corrosion.
If you have corrosion on the cam, there should be some corrosion in the cylinders too. Was there any? What about on the gears?
Maybe a second opinion on the cam is called for. Im no engineer, but there is a quantity/limit to the corrosion allowable. Engine shops may vary on this decision as I have found.
Rhonda from Barretts and Mahlon from Mattituck post a lot on this site and could maybe enlghten us with facts/advice.

 

[gasman]

Sorry about your cam. Lycomings cam is in the air, whereas Conti has their cam in the oil. This helps a lot with corrosion.

So does this mean that when the engine is shut off that the cam is covered by the oil in the sump??..............

I don't think it works that way.

 

[gasman]

If you say they have very little visible corrosion then they where probably still just fine and would have kept right on if you had not had the unfortunate opportunity of inspecting it early, maybe the shop was more worried the engine mite come back to them before TBO if they re installed your old cam. Send it to ECI or one of the other shops and have it inspected and reground to sell or use later, send the followers to.

BINGO!.....

 

[rv72004]

Gasman, I am no expert, but was told by a engine builder that the Lyco cam is above oil level when engine is shut off.
The conti cam is lower and sits in the oil.
As I said this is what was told to me when I had corrosion problems. Hope I wasnt being fed incorrect info.

 

[Mel]

The conti cam is lower and sits in the oil.
As I said this is what was told to me when I had corrosion problems. Hope I wasnt being fed incorrect info.

The Continental cam is below the crankshaft, but it does NOT sit in the oil. This is a better position in that "dripping" oil goes onto the cam, but with the engine at rest, the oil drains into the sump.

 

[mahlon_r]

Dean,
The camshaft - tappet face is an extremely critical area in the engine. Minor rust pitting is a formula for spalling, which in turn eventually ruins the cam and it?s corresponding tappet or tappets. Some shops/mechanics will be more tolerant in this area, then others but all should be very careful in this area. So what one mechanic might pass, another might fail. There is no cut and dried tolerance unless the lobe or lobes have metallurgicaly failed already. If you did your research and choose a shop/mechanic to do the work on your engine, you shouldn?t be second-guessing their or his decision now. You trusted them enough to send your engine to them and you should trust their decisions. What you consider minor or insignificant, very well might be and then again it might be very bad. Obviouly, your mechanic didn't like what he or she saw and wanted the cam replaced. In most cases rust pitting and the eventual spalling it causes, isn?t a catastrophic failure type thing. It is a relatively slow cancer that will ruin the cam and very likely other parts in the engine, if the cam situation is left to blossom from its initial stages.

To repair a spalled camshaft requires the same amount of work and initial expense of the prop strike inspection you just had done. The engine has to come all the way apart and if nothing else has been affected by the cam failure you just replace the cam, tappets, bearings, rod nuts and bolts and gaskets. If the pistons are shot with metal impregnation they too must go and sometimes also oil pumps are scored and possibly crankshaft journals can suffer significantly as well. So there are other financial internal risks other then just the cam and tappets if it is left to progress. So fixing a bad cam is very expensive, to say the least.

If you engine is apart and a shop/mechanic wants to replace a cam due to rust that you feel isn?t significant, trust me it is way less expensive to change it now then wait until the engine is back together and has run a couple hundred more hours. One poster suggested that maybe the shop or mechanic replaced the cam because they were afraid it might go bad going forward. I would have to agree with that. Obviously, from your description, your cam wasn?t in severe spalled condition but was in a condition the engine people didn?t like. They made a decision in you best interest. As said before, that is what you hired them for! Trust in their decision?? If an engine shop was doing the job they have likley seen hundreds upon hundreds of cams and can make educated decisions. If it was a local mechanic doing the job, he or she may not have as much experience, but if you felt they were qualified to do the job when you hired them, you should should trust in in the decision you made.

It seems you have tried your best to prevent this from occurring. But even the best laid plans don?t always work out. I think you should continue doing what you have done in the past and you might think about some of the other poster?s suggestions and try them as well. Maybe try a different brand of oil to, as oil that is your primary rust deterrent inside the engine.
Good Luck,
Mahlon
?The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

 

[FrankK90989]

Mahlon, so well said. The feeling you get at 9500' over rough terrain knowing everyting is right... Pirceless!
The things you think about when there are no good place to land.

 

[rv72004]

Mahlon , what is your take on Avblend as a rust preventative?
I am using it at the moment but wonder if its worth the effort.

 

[rv72004]

The Continental cam is below the crankshaft, but it does NOT sit in the oil. This is a better position in that "dripping" oil goes onto the cam, but with the engine at rest, the oil drains into the sump.

Thanks for clearing this up Mel. Do Conti have less cam corrosion generally ?

 

[Dean Pichon]

Good question...

Dean, what brand and weight of oil have you been running?

I meant to include in my initial post that I use 15W-50 Aeroshell.

Thanks,

 

[frankh]

A theory

There has been a lot of talk of the ambient humidity having an effect on the moisture inside the engine..

Well I'm not so sure this effect is that significant...Here is an alternative thought process..

the fuel we burn is a long carbon/hydrogen chain...When we burn this we make primarily CO2 and H20.

I'm wondering if the moisture that ends up in the crankcase comes more from the water vapour generated by burning fuel and gets in the crankcase by piston blowby.

The engine cools and the steam from combustion then condenses out on the internals of the engine.

I have been suspicious of engine dehydrators, but if there is merit to the above hypothesis then ventilating the crankcase with relatively dry air (even ambient air unless its warm outside with high humidity) would be a very good thing.

Any thoughts?

Frank

 

[Mel]

Thanks for clearing this up Mel. Do Conti have less cam corrosion generally ?

Yes they do, mainly because of the lower cam location, everything drips onto the cam, whereas on Lycoming, everything drips OFF of the cam. Another anomaly is that the cam lobes are oiled only by "splash", so unless you have the "NEY" nozzles, pre-oiling does nothing for the lobes.

 

[frankh]

I have cam nozzles and an accumulator

I use the accumulator to preoil before start..One day I will pull a cylinder at annual to see if the cam is actually prelubed by this method.

Frank

 

[Rivethead]

Heating your hanger may work against you. MTC

Warm air holds more moisture than cool air. Any exchange of warm air to a cooler invironment (possibly the internals of your engine) would cause more moisture to be available to precipitate out on any cool metal. Instead of heating a hanger I would keep it cool and dry. No matter how well an engine is sealed it's going to exchange air if for no other reason than pressure changes in the atmosphere. I tend to agree with replacing a cam that shows a little corrosion or wear if the engine is split anyway since the cam lives in one of the most inaccessable areas of the engine. While at it I would also change the followers. I once had a mechanic change the clutch on my truck. That repair cost me $850.00. A year later the ring gear on my flywheel needed to be replaced, that cost me $850.00. Nearly the same repair as far as the general area taken apart and relitively the same as far as parts cost. Any mechanic that's worth a da mn will replace parts as needed rather than wait for failure.

 

[hevansrv7a]

It's the internal humidity

There has been a lot of talk of the ambient humidity having an effect on the moisture inside the engine..

Well I'm not so sure this effect is that significant...Here is an alternative thought process..

the fuel we burn is a long carbon/hydrogen chain...When we burn this we make primarily CO2 and H20.

I'm wondering if the moisture that ends up in the crankcase comes more from the water vapour generated by burning fuel and gets in the crankcase by piston blowby.

The engine cools and the steam from combustion then condenses out on the internals of the engine.

I have been suspicious of engine dehydrators, but if there is merit to the above hypothesis then ventilating the crankcase with relatively dry air (even ambient air unless its warm outside with high humidity) would be a very good thing.

Any thoughts?

Frank

There is no question that the engine is filled with moist air from blow-by when you shut it down and in most climates, when it cools that water will condense and precipitate. I have a hard time imagining ambient air being worse. The dehydrator fills the engine with extremely dry air and keeps it that way; the dry air leaks out through on exhaust on mine and is pumped in via the breather tube. I've seen other arrangements, too.

 

[frankh]

Think I may

be building a dehydrator this week.

The design I saw recirculates the air through the silica gel but I'm wondering if the oil mist would contaminate the gel?

I assuming the flowrate would be pretty small so dehumming ambient air in relatively cold Western Oregon won't load up the gel too much..Guess I'll find out.

I also have a 100W block heater that (by reference to my Psychrometric chart) will prevent moisture if indeed that moisture cames from the outside air..But if it is primarily from combustion blow by then the block heater won't work..I.e air at 180F will hold a huge amount of moisture..and its dew point will almost certainly be much higher than the block heater can manage.

I'll report back

Frank

 

[frankh]

Cool

I can get indicating silica gel locally for $3.50 a pound as long as I buy a 5lb tub!...Might make two cartridges and swap them out at the appropriate interval.

I have a container and a few fittings and the local pet store..i think I'm building one of these things tonight!

Frank

 

[jrs14855]

CAMS

Firewall Forward in Ft Collins CO has STC for drilling Lyc cams for improved lubrication. Don't know if this would be any help when the engine is sitting but it might be.

 

[hevansrv7a]

Indicator Beads

I can get indicating silica gel locally for $3.50 a pound as long as I buy a 5lb tub!...Might make two cartridges and swap them out at the appropriate interval.

I have a container and a few fittings and the local pet store..i think I'm building one of these things tonight!

Frank

Be sure to use a clear or translucent bottle and indicator beads.

 

[mahlon_r]

Mahlon , what is your take on Avblend as a rust preventative?
I am using it at the moment but wonder if its worth the effort.

I think it might help....
Good Luck,
Mahlon
?The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

 

[frankh]

Yup

Be sure to use a clear or translucent bottle and indicator beads.

Got it...The lady in the craft store thought I was into drying flowers...How great it was that a guy was into flowers


er right....

Got the pump (currently on test) and a bottle, just need a few 1/8th fittings and my hot glue gun and its off to the races.

Frank

 

[frankh]

Anyone wants a dehydrator

Locally I bet I got enough silica gel for three bottles worth

Frank

 

[AZtailwind]

"Lycosourus"

This camshaft is from a factory new (2001) O-360 A1A. I fly regiously once a week and have accumulated a little better than 450 hours over about 7 years since the first flight. It has always been hangered and for most of its life, it has been stored in a heated hanger. I change the oil and filter twice a year. I perform an oil analysis and add AvBlend at every oil change.

I Have had and seen the Cam follower issues on Lyc's top cam- had to replace the cam on a PA28-140. Have seen more than a few cams go dead at the local shop- likes to happen at the sharing lobes where two valve/followers share intake and exhaust duties... On one occasion I have sent out-regrind the cam with good results after a 1700 hr overhaul in a 172. But most of the time it is thrown out.
FWIW and just My opinion but some shops look a liability as a "make it all perfect" rule at all times. I would suggest a real hands on learning experience and ask to look at the follower and wear marks that are showing the problem. "Show me the lobe wear in the scope for my own curiosity please". For me if the marks are small and "minor", I would run the engine until 550 hrs and pull the one cylinder- See what the marks are doing after 100 hrs. The shop may even agree that it could last another 100-500 hrs. Cut the oil filter at each oil change- you WILL know when a cam is going then. Oil analysis is secondary baseline for me. Oil filter inspection is first. But as my experience with all lycs- when a cam starts to go- it will go fast: as a 25 to 100 hours that lobe/follower will be going going-gone and all that metal will show up in the filter paper. Your flying average is "only" 65 hrs a year. That is not enough believe it or not. More like 150 hrs/twice a week will see the engine through to 2000 hrs. Again....FWIW

 

[mannanj]

Cut the oil filter at each oil change- you WILL know when a cam is going then. Oil analysis is secondary baseline for me. Oil filter inspection is first. But as my experience with all lycs- when a cam starts to go- it will go fast: as a 25 to 100 hours that lobe/follower will be going going-gone and all that metal will show up in the filter paper. Your flying average is "only" 65 hrs a year. That is not enough believe it or not. More like 150 hrs/twice a week will see the engine through to 2000 hrs. Again....FWIW

I agree. I got my engine from a Mooney 201 with only 1300 hrs total time in 20 years. They had used Phillips multigrade with AvBlend. Two lobes on the cam and four followers were toast. The spalling that occured was unbelievable. The piston skirts had large chunks of metal in them. An oil change with an oil analysis only five hours previously showed no abnormality.

When this happens, it goes quickly.

I rebuilt the engine with a new cam and followers and use Exxon Elite multi grade. I try to fly at least once a week and am seriously considering building the air pump with the silica gel dessicant to preclude future rusting.

 

[dtw_rv6]

For the sake of argument

Which way should the air flow if we are building our own engine dryer? I have the Tannis dryer, and it pumps air into the Crankcase Vent, and returns through the oil filler.

I think I would have designed it to go the other way. Does it matter? Why?

(Primer wars were getting dull )

Don

 

[osxuser]

Well I'd just run it. It's a darn tractor engine, and it's not gonna fail just because it's got a little surface rust. Most of these engines make the TBO in spite of corrosion, and yours probably would have too if you hadn't had to split the case. Ours lasted 35 years and 1600 hours before it got to the point where the corrosion started affecting engine performance.

Just me.

 

[frankh]

Well

I have a grand total of $40 into my dryer system..the parts for which are sitting here on my desk.

They will be assembled and connected to said airplane engine this very afternoon.

I mean $40 might get you another 500 hours to major overhaul!

Frank

 

[frankh]

Oh and

I don't think it matters which way you pump the dry air into the crankcase..The bigger question is..Should it be a recirculating system or once through?

I'm planning on a once through for now..primarily because its just not that humid in Western Oregon so the desicant should have a long life between regens.

Frank

 

[mannanj]

Dehydrators

I don't think it matters which way you pump the dry air into the crankcase..The bigger question is..Should it be a recirculating system or once through?

I'm planning on a once through for now..primarily because its just not that humid in Western Oregon so the desicant should have a long life between regens.

Frank

Frank:

If you don't mind, would you post some pics and a schematic for your system?
I know this has been around before, but it will help some of us that are "technically challenged" (searching archives) and bring maybe a new perspective to the dryer system. Thanks.

 

[frankh]

Will do

Dryer is installed and running..I took a couple of pics which I will post.

Cheers

Frank

 

[frankh]

Schematic of dryer

Tetris 40 Gallon fish tank pump-----Translucent container-----empty container to catch oil drips------crankcase vent pipe....Remove diptstick to allow flow.

To make the connections I simply self tapped the pipe fittings into the plastic.

Pics coming as soon as my friend finds the phone adaptor..


Frank

 

[frankh]

Ok forget pictures

Its too painful to post pics here....

See schematic from above..The pipe fittings I used I simply self tapped into the containers...i.e drill a hole and screw them in and connect everything with 1/8th tube

Frank

 

[638RS]

Frank...

If I understand correctly you are blowing dry air into the engine and not circulating the air as the system shown in the Sport air article did. Is that correct? Makes it a lot simpler to not have to make a fitting for the Oil filler

 

[frankh]

Correct

In Western oregon its faily cold which means "dry" in psychrometric terms...yes even though it rains all the time..

So that means the desicant should last quite a while between regens, so i just do an open loop once through type system..in through the crankcase breather..and I leave the dipstick loose and "to one side" to allow for air to escape.

If for some reason the desicant should load up quickly it would not be hard to fashoin a rubber cork for the dipstick tube and return the air to the inlet of the desicant.
not sure what oil fumes would do to the desicant though.

Frank

 

[frankh]

Nerd alert

I hate it when this happens but I have an improved design for my desicant dryer!

Still once through design but should give better distribution of air through the silica gel media.

Will report back in a couple of days..Maybe with pics this time.

Frank

 

[SvingenB]

Warm air holds more moisture than cool air. Any exchange of warm air to a cooler invironment (possibly the internals of your engine) would cause more moisture to be available to precipitate out on any cool metal. Instead of heating a hanger I would keep it cool and dry. No matter how well an engine is sealed it's going to exchange air if for no other reason than pressure changes in the atmosphere. I tend to agree with replacing a cam that shows a little corrosion or wear if the engine is split anyway since the cam lives in one of the most inaccessable areas of the engine. While at it I would also change the followers. I once had a mechanic change the clutch on my truck. That repair cost me $850.00. A year later the ring gear on my flywheel needed to be replaced, that cost me $850.00. Nearly the same repair as far as the general area taken apart and relitively the same as far as parts cost. Any mechanic that's worth a da mn will replace parts as needed rather than wait for failure.

Warm air can hold more moisture than cool air. When it is cool and moist outside, the best thing too keep it dry inside is to warm the air.

 

[frankh]

right

which is why I have an engine block heater to go with my new desi dryer..

Frank

 

[L.Adamson]

Warm air can hold more moisture than cool air. When it is cool and moist outside, the best thing too keep it dry inside is to warm the air.

That's correct! For example, a furnace running, will often dry out the winter air to 15% humidity or less. So we actually need humidifiers to bring the levels back to 35%+ to keep our wood floors in shape, and out throats from being scratchy and dry.. This is what I do for a living.

L.Adamson --- RV6A

 

[Rivethead]

There has been a lot of talk of the ambient humidity having an effect on the moisture inside the engine..

Well I'm not so sure this effect is that significant...Here is an alternative thought process..

the fuel we burn is a long carbon/hydrogen chain...When we burn this we make primarily CO2 and H20.

I'm wondering if the moisture that ends up in the crankcase comes more from the water vapour generated by burning fuel and gets in the crankcase by piston blowby.

The engine cools and the steam from combustion then condenses out on the internals of the engine.

I have been suspicious of engine dehydrators, but if there is merit to the above hypothesis then ventilating the crankcase with relatively dry air (even ambient air unless its warm outside with high humidity) would be a very good thing.

Any thoughts?

Frank

There's no doubt that moisture comes at us from every direction. I also recall seeing a post that said that Western Oregon isn't all that humid, and that's pretty much true. A case worth mentioning though Frank was an aircraft that had been owned for quite some time by a local Corvallis owner that had a new engine installed and flown for some fairly low time before being hangered for five years. What I mean to say is ignored for five years. I don't know any of the reasons for leaving a plane just sit but that's what happened. Eventually intrest in flying the plane came back to the owner and an annual was given this particular plane. Long story short the engine ended up being pulled and replaced because as the A&P said it, it was the rustiest engine he'd ever seen.
On the other hand, I think you're right, significant water vapor does get past the rings. Therefore, it probably would be a good idea to remove the dip stick and allow vapors to vent out as much as possible while the engine is still hot before replacing the stick or better a device to remove the remaining water vapor. I believe, and this is about as close to religion as I get folks, that if a person takes really good care of thier engine it will take really good care of you back.

 

[Randy Walls]

Dust?

It might be a good idea to put a filter on the inlet line. A lot of air will pass through the engine each month and with it a lot of dust as well.

 

[frankh]

Yes

It might be a good idea to put a filter on the inlet line. A lot of air will pass through the engine each month and with it a lot of dust as well.

Cheap insurance I agree

Frank

 

[frankh]

To Jim

Is that your system your showing there?

Looks like a nice compact unit!!

Yes it is true Western Oregon is not all that humid primarily becuse the tempterarture is pretty low.. At 50 degrees 100% relative humidity air can only hold 54 grains of water per pound of dry air. (1lb of H20 is 7000 grains).

At 80F air can hold 156 grains..i.e 3 times as much.

In Western oregon (and I don't have the Bin data handy) I think we run at around 50% RH which is about 28 grains of water per pound.

I.e not that humid.

Shame about that engine though!!

Frank