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Long Term Engine Storage

Long Term Engine Storage

Long Term Engine Storage

(OP)
How do you guys feel about long term engine storage? Let's say 4 years in an indoor environment. Is motor oil adequate (fresh oil, not run) or does one need to use a preservative oil like MIL-L-21260?

RE: Long Term Engine Storage

CAT had a pretty detailed storage procedure for diesel engines, for that long, VCI oil in crankcase and other places may be a real plus.  

We used to ship smaller engines overseas for 2 years of onsite storage in a controlled environment warehouse to an OEM, preservation done per CAT method and then engine wrapped in a heavy duty shrink wrap.  Very few problems with those engines but did find after about three years had some issues with gumming in fuel system, but traced that to not fully draining diesel fuel and recharging fuel system with calibration fluid.

I don't have a copy but you should be able to ask your local CAT dealer for a copy of the Special Instruction for Long Term Storage to use as a reference.

Mike L.

RE: Long Term Engine Storage

@pat:  the valve springs should not take a set, regardless.

RE: Long Term Engine Storage

Dang, all the years I've been around the yellow giant and didn't know we had a pretty version of the instruction.  Guess that's what I get for being a part timer these days.

RE: Long Term Engine Storage

Isaac

With high lift cams they do. This is not a matter of opinion, it is directly from measured data. It was some time ago so exact details are fuzzy other than it was a Small Block Chev with over 0.600"lift.

I am reasonably sure the springs where Iskenderian Vascojets. I have no idea of the grade of steel or heat treatment other than they where what most racer used in the day.

Regards
Pat
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RE: Long Term Engine Storage

If they don't yield when they sit overnight at max lift, I'm not sure why they would yield after another week or year.

RE: Long Term Engine Storage

did you check 'em all before storage?  pehaps the low ones had already yielded?

RE: Long Term Engine Storage

to be honest, I would have expected the yielding to all happen within the first few crank revs, so that stuff I said about overnight was just to pad my story a bit & make it easier to sneak thru.

I would worry that yielding springs would later become breaking springs too.
 

RE: Long Term Engine Storage

It was a race engine. They where all shimmed up to within a pound or two on the seat. It was run a few times then left in storage for quite a while then pulled down to check before running again as it as a bit tight from corrosion as it was a boat engine. As I recall, about 4 of the springs where about 20# down on seat pressure.

I can't be sure it was the ones left compressed as I don't recall if I notice the crank position before dis-assembly, I just remember it was unusual for them to be so different after they where installed correctly and not used much, but had been left in storage. I concluded they had taken a set and always made a point of occasionally turning engines over if they where in storage in my workshop.

I guess on reflection the data is not all that strong, but it did become entrenched in my mind as fact and has never to date been questioned.

Regards
Pat
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RE: Long Term Engine Storage

I don't worry too much about springs taking a set, but perhaps I should.  
A number of years ago I was using Isky springs and having ready access to Isky, I asked if it was going to be a problem.  Now that was for a spare race engine that would probably sit for all season.  (I have a brand new TRD Toyota 2TC that's been sitting since 1997 without being turned over. HMMMMMMM!!!)  Ed himself said I should have no problems with their springs.  I did break a few and switched to another brand later on.  The few times I did a head R&R and reused the springs, I never found a 'weak' spring.  I never had a cam with anything over .5 lift, though. Anyway, these days on the Mini engine, I change all the springs at every head rebuild, no matter how few races they have on them.  I figure if they need attention, it's cheap insurance.

On the same note, springs taking a set, I collect some really old pistols and the question of the magazine springs 'taking a set' if left loaded all the time.  Several shops said yes they would, but some said no they would not.  I have a Browning that's been loaded for well over 70 years.  I still shoot it and it never fails to feed.  Either the mag spring never took a 'set' or if it did it did not make any difference.

Rod

 

RE: Long Term Engine Storage

I would be more concerned about the point contact of the cam followers on the camshaft.  The constant load on a non moving surface I think would force any remaining lubricant from the friction and wear surfaces.

Franz

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RE: Long Term Engine Storage

(OP)
Pat, could you elaborate on "bit tight from corrosion?" That is the kind of stuff I am interested in.

RE: Long Term Engine Storage

It was a flat bottom boat engine with water injected into the exhausts to act as rudimentary silencers. Some salt water spray inevitably found its way into the head and ports and cylinders.

Even with fresh water flushes and oil dribbled into the intake for a few seconds before shut down, a bit of salt stays there and a fine film of rust develops on he bores and valve stems.

Less likely, but of more concern is if it develops as pits or develops on the cam lobes, followers and valve springs.

I turn them over gently. If they feel tight I squirt some keroine/ATF mix down the plug holes and inlet system then rock the crank back and forth to wear the rust off. Provided it's only a light surface dusting of rust it cleans up quite good.

After it frees up I start it if possible, change oil and start it again.

I also, normally use Mobil 1 as I find it leaves a very fine protective coating for longer than mineral oil.

I know that is far from ideal, but sometimes circumstances dictate.

Once the damage is done, there is nothing to lose, as it either runs OK and your in front or scores a bore or pulls a ring land or knocks or loses a lobe or bends a push rod and your no further behind. It needs a freshen up anyway.

Sometimes a ring sticks for a while, but they normally free up then seal up with a few minutes running.

Sometimes a valve spring breaks. That is the worst as it might drop a valve.

Regards
Pat
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RE: Long Term Engine Storage

NMMA FC-W engine oils must pass a severe corrosion, so a fresh charge of one of those juices may afford an extra layer of insurance for long-term 4T engine storage.  They are API SG or above performance, so in many cases could be run a normal OCI straight out of storage.

RE: Long Term Engine Storage

"If they don't yield when they sit overnight at max lift, I'm not sure why they would yield after another week or year. "

Creep.  No, not you personally, ivymike, but it's a real phenomenon.  Google the term, or see:

http://en.wikipedia.org/wiki/Creep_(deformation)

Ok, loss of spring load would be more of a stress relaxation problem, but it's arguably the same physical phenomena.

Normally only a worry at high temperatures, but it can also be a concern for structures loaded near yield for long periods of time (years).

   

RE: Long Term Engine Storage

Quote:

Normally only a worry at high temperatures, but it can also be a concern for structures loaded near yield for long periods of time (years).

Ahhhh.  There might be one key reason some engines sustain no discernible damage while others seem to fail in short order after long term storage.

Franz, that would be my concern and if/when I ever do anything with that TRD engine (never had oil, only assembly lube) I'll most likely pump high pressure oil through it while slowly turning it over prior to any actual startup.  Especially since it's a flat tappet cam.

Rod
  

RE: Long Term Engine Storage

On the creep issue.

I deal in thermoplastics and creep is a very real issue with them but metals I thought reasonably immune except for aluminium and the need to re-tighten aluminium wheels for example.

Having said that I think it is fairly well beyond dispute that car springs take a set and old cars certainly sit lower than when they where new.

Regards
Pat
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RE: Long Term Engine Storage

they do?  I've never noticed that either... but I have not had any cars older than 1978 m/y in my life (I put a new set of lift kit springs on that one), and all but two of mine have been newer than 1995.

RE: Long Term Engine Storage

Pat,

Creep is usually a high-temperature concern for steels (it played a part in WTC collapse; it's also a concern for rocket scientists - I used to be in charge of some long-duration testing for an advanced high-temperature rocket engine and part of my duties was to measure the accumulated creep distortion of the combustion chamber).  

Technically, creep happens at any temperature above 0K, in any solid material, it's just that at normal temperatures with normal materials, over normal durations, it is negligible.  Except when you (a) load steel very close to or beyond its yield, and then (b) hold it there for very long durations (years).  Springs that "take a set" are by definition being loaded up to and slightly past yield, so part (a) is taken care of.  How long the force is held is the next question, and how much creep would be noticeable is the last part.  

Piano tuners worry about it...

http://www.astm.org/DIGITAL_LIBRARY/JOURNALS/TESTEVAL/PAGES/JTE11908J.htm
 

RE: Long Term Engine Storage

To the sagging springs in old cars deal....I do a lot of old car stuff and I must say that I have NOT seen a huge deal with sagging springs.  It does happen, but I never put much thought into the reason.  It seems more of an individual mfgr problem than a systemic problem.   I restored a '37 Buick Roadmaster that was not sagging at all...My 30 Ford is at normal ride ht.  Several British cars around here, '58 Morris, 60's era Cortinas, Anglias, MG's and a few Austin Healy Sprites...All without any discernible degree of sag.  However, one big Healy and my '59 Nash Met both had terribly sagged rear leaf springs and, my (bought new) '64 Ford Fairlane also had sagging rear springs.  Go figure.

Rod

RE: Long Term Engine Storage

As a general rule of thumb, starting it a couple of times a year will hopefully rotate the engine to scrape away accumulated rust and gunk, and also alter the load on all components (e.g. relax springs that were tightly compressed, etc.) and so on.

If you can't start it, even manually turning it over will do the same trick.

Does anyone know what is the protocol for military equipment in long term storage?

RE: Long Term Engine Storage

Rod, having owned many '60's Fords with rear leaf springs, I can tell you it was unusual to see one go more than 5 years without noticeable sagging.  Mustangs, Falcons, Comets, Fairlanes, etc.  Extended shackles to "cure" this were widely available.  MoPars weren't a lot better.

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