blown up 912 ??

[GASSITT@aol.com]

I just got a call from a customer that says he just bought a Rotax 912S engine from Lockwood and he bought it as a blown up engine $ 4000. and he knew it was blown up , two rods on the crankshaft are toast and the reason was climbout was too steep (PER LOCKWOOD) about 200 hrs TT , ITS BLOWN UP ! they tell the original owner that its not worth fixing , Well I have been working on Rotax engines now for 32 yrs and about ten of them with the 912 , and this one is beyond me , never heard of anything like this , The Rotax 912 doesn't have an oil pan its got a oil tank ,Its a dry sump engine , question , How friggen steep would you haft to climb to starve the engine for oil and for how long ?? I totally disagree with the diagnosis , Any thoughts ? ITS STILL BLOWN UP , Its not Lockwoods fault , they never worked on it , no one has , IT could have been caused by SUN SPOTS ?
GASSITT

[ClickClickBoom]

I just got a call from a customer that says he just bought a Rotax 912 engine from Lockwood and its blown up , two rods on the crankshaft are toast and the reason was climbout was too steep (PER LOCKWOOD) about 200 hrs , they say its not worth fixing , Well I have been working on Rotax engines now for 32 yrs and about ten of them with the 912 , and this one is beyond me , never heard of anything like this , The Rotax 912 doesn't have an oil pan its got a oil tank , question , How friggen steep would you haft to climb to starve the engine for oil and for how long ?? I totally disagree with the diagnosis , Any thoughts ?
Steve@ Airscrew Performance
More to this story than meets the page. Sounds like Lockwood doesn't want to fix the booboo.
Total time on cases, installation, ect. 200 hrs on an engine is just enough to guarantee break in, not much more.
Without many more details, not enough info to analyze accurately.
Rod toasting would suggest an oiling problem.

[rogerh12]

Engine mechanics have a general rule, "if it's going to let go after a engine rebuild, it will do it in the first 50 hours". I guess that means any mistakes in the rebuild will only last a few hours before those loose nuts start coming off the rod bolts. Anyway, 200 hours is a lot of time on a Rotax, the 582 only has a TBO of 300 hours, so any way you slice it, I suspect a breakage or part failure followed by oil pressure loss in the 912 was to blame.

That' my take on it, given very little information (though that's never stopped me from venturing an opinion before !!!)
Roger

[Av8r_Sed]

Steve,
Why do you join the forum today, make your first post and take Lockwood to task publicly? Is Lockwood a competitor and you're taking a shot? How about suggesting to your customer that they join the forum and ask the wise minds here for advice?

[DesertFox4]

Steve,
Why do you join the forum today, make your first post and take Lockwood to task publicly? Is Lockwood a competitor and you're taking a shot? How about suggesting to your customer that they join the forum and ask the wise minds here for advice?I read and re-read the OP and am not quite sure why the attack. :confused:
No accusations were made toward Lockwood, a know reputable business, by the OP who was relaying what a customer said to him.

Anyways- was the engine brand new or a rebuild?
Was it on a Kitfox? I'll assume it was and if so , no I've never heard of too steep of a climb out yet in a Kitfox that would do in a healthy Rotax 912 but as stated there just isn't enough information to conclude much yet. There are other aircraft using the Rotax 912 engines that may climb out even steeper than our Kitfox's do and no I've not heard of those having difficulty keeping their engines together either.

Sorry for his troubles. :(

[Woodennickle]

Gee Av8r-Sed, hope you received a better welcome to the site when you joined. What crawled up your butt?:eek:

[Av8r_Sed]

Perhaps an overreaction, but what I read is the third party just bought a motor, it blew up and the vendor is blaming the third party (climbout too steep). Sounded more like a poke at the vendor than a search for information on the cause.

Steve, sorry if you're just trying to resolve the cause of the failure. I know that's what the forum members are all about.

[GASSITT@aol.com]

Well since AV8r sed can't read and someone ****ed on his parade I think I'll go fly and let him just wish he could ! BTW hard ass the post said it was BLOWN UP when it was bought from Lockwood , its nothing against Lockwood (they send me cranks to do) its just that they sold the BLOWN motor to another person and sold a new one to the climb out king . CHEERS GASSITT

[Paul Z]

One question did the owner prop it through until it burps, to pump the oil through the engine. Having taken the Rotax training, maintenance & repair classes, according to Rotax, the engines do not have brass bearings races, it is steel to steel rod to crank, and crank to case. They are ground to fit. The engine does not like to run dry. They told us that at least 50 to 100 times in the classes. Did the owner wait for the engine to get to temp before taking off? There are a lot of questions that need to be answered.

[szicree]

I guess I can't read either. My understanding of the original post was that the guy bought an engine from Lockwood, it blew up, and that they were basically telling him "tough luck".

Additionally, I'm floored by how quickly the O.P. has ratcheted up the attitude.

[DesertFox6]

Having the deepest respect and personal knowledge of GASSITT's uncanny abilities with Rotax 912 engines (an opinion shared by Lockwood who sends him parts to repair) I too am pondering his excellent original questions concerning climb angle and time versus oil pump output pressure.

As a rough estimate, the engine's oil pump pressure output, under wings-level, straight-ahead-vectored, positive G loading, should be adequate up to AT LEAST 45 degrees of pitch (.707 G at that angle) with no lube problem. This is also about the same point that the carbs would start to "unport" and falter; long before the oil pump output pressure would drop below that required to maintain adequate lubrication in the journals.

In this latter case, combustion would cease, and, in all likelihood, so would the engine along with the mechanical oil pump, but if the engine isn't turning, no oiling is necessary. I've not tested the airspeed required to rotate a flamed-out 912 up to the point the oil pump will rotate fast enough to deliver normal-range pressure, nor am I about to investigate this situation. Observing the severity with which a 912 stops at shutdown, I'm thinking I'd have to install a mach-meter to run such a test! :rolleyes:

Assuming positive Gs are maintained, light aerobatic maneuvers have always been a no-sweat issue with a 912, so it's obvious to me that a whole lot more details concerning the conditions of flight at the time of the alleged "blow-up" are needed before any conclusions can be drawn. Something here is just too fishy for fact-finding.

Anyhooo, WELCOME ABOARD GASSITT! I often wondered why you hadn't joined us earlier; I'm awfully glad to see you in this forum and, after your initial experience with us today, I sincerely hope you aren't rethinking the wisdom of your decision! :D

I'm personally delighted that the Desert Fox Squadron's personal Engine Guru, "Doctor" (I like to call him that) GASSITT, is now on board...operators are standing by!!!:)

"E.T."
Desert Fox 6
(Opposing Solo)

[Dave Holl]

Well the way I read the post( just got a call from a customer that says he just bought a Rotax 912 engine from Lockwood and its blown up) the its suggests to me that it has just happened! if it said was I would have said that it had been bought in that condition. Maybe thats the difference between English and American!!!;)
With all that said it is an interesting subject and worthwhile discussion.
It is better if we all try and get on together and have a good debate on the issues after all thats what this forum is all about and not overeact would the responses have been the same if we were face to face?

[GASSITT@aol.com]

OK , iI got my fix this morning , BEAUTIFUL and smooth , eat your hearts out , Alright i changed the original post so ANYONE capable or piloting a Kitfox or anything without a training wheel on the front should have no problem (THIS TIME) understanding my post , My whole thought about this scenario was knowing the Rotax 912 as i do and it being a dry sump engine and the thought of residual oil in the system that it would take some doing to starve the engine ENOUGH to damage it , I was just looking for others input and thank you Michael for yours .

GASSITT

[Dave F]

Perhaps an overreaction, but what I read is the third party just bought a motor, it blew up and the vendor is blaming the third party (climbout too steep). Sounded more like a poke at the vendor than a search for information on the cause.

Steve, sorry if you're just trying to resolve the cause of the failure. I know that's what the forum members are all about.



post say from Gassit - ( credible FYI) that the engine wasa blown up turd to begin with ......... ahahah some just cannot read.

Prolly oil starvation..... from climb out ? doubt it.
high g's - doubt it
from operator errror -- I would be 98 % that is the problem....

[DesertFox6]

Dave Holl wrote;

..."Maybe that's the difference between English and American!!!;)" and I'd have to agree with him!


"The British and the Americans; two people separated by a common language." - George Bernard Shaw

Ever since spending some "guest time" at RAF Bentwaters many moons ago, I've never ceased to marvel at how a Brit can bring not only order to anarchy and sense to insensitivity but also a touch of class to what otherwise might be considered collectively uncoordinated, open season mud-wrestling: Thank you ever so much Mr. Holl!

And thanks too to all your countrymen who so marvelously hosted the rest of the world this past fortnight (including some of we colonial hold-outs!:rolleyes:) as we no-doubt again attempted to track mud on your carpets, ingrates that we are! :D

And..."bob's yer uncle!" ;)

"E.T."
(Good thing GASSITT got airborne early today, 'cuz it's just now noon here and it's already a hundred 'n' 'lebenteen Fahrenheit with more to come...! :eek:)

[N276KM]

I can understand the climb-out oil starvation if the setup is like what was intended for my Avid Mk 4. The oil reservoir was meant to go under the baggage compartment, and connect to the engine through long oil lines. In this situation, during a steep climb, particularly with cool oil that doesn't pump well, the oil pump could fail to keep adequate pressure at full throttle and a steep angle.

I never ran my engine with the oil reservoir in this location since I was concerned about oil starvation during startup, and following Rotax's mounting guidelines for sump elevation. My system is the Airedale engine mount location for the sump.

[szicree]

.... ahahah some just cannot read.

Prolly oil starvation.....

And still others spell like second graders.

[GASSITT@aol.com]

Proolly usin se**** grad enlish in concideration of the receipets ?

[Av8r3400]

Okay guys any more and this thread is gone.

[War Eagle]

Okay guys any more and this thread is gone.


Thank you Larry.

[Dorsal]

I also find the tenor of this thread inconsistent with the norms of the group.

[DesertFox6]

I agree with you Dorsal; let's see if we can't turn this thing back onto its original heading before the crosswinds started.

This entire situation is all academic at this point anyway, but after considerable cranium-scratching since my original nose-high pitch analysis, and then pondering N276KM's eye-opening input, a plumbing configuration I'd not heard of before, (but it would probably do the trick!) I'm left with two conclusions.

First, assuming the oil tank wasn't in the trunk/boot area as N276KM described, the sustained-climb scenario may still hold true if the pitch was held somewhere in excess of (??) degrees positive pitch for a sufficient period of time to allow CHTs to cross the critical point and fry the heads and/or internal components, to the point of seizure, but prior to fuel starvation. Frankly, I don't see how this could happen to a 912 with its liquid-cooled heads, but a Cessna 182 can be held in a nose-high (usually >20-25 degrees pitch) power-on stall position, without stalling, until the CHT and oil temp start impinging their red zones. With a light-weight sport plane, I'm willing to bet this situation could be even more easily attained and the safety parameters exceeded prior to carburetor starvation. But you REALLY gotta have your "head up and locked" to let it go that far!

The second scenario, which would lead to the same end result, would start with an engine over-speed, from a dive perhaps, and the seizure (for the sake of argument) resulting while in the nose-high recovery phase pulling around 4-5 Gs. We really don't know what the original pilot did to blow the engine but this diving-to-overspeed scenario seems more likely to me barring a more forthcoming testimony from the ersatz "Climb King."

Desert Fox 5 had such an engine in his shop many years back: Several of we Phoenix-local guys used it as a temporary dummy-mount to allow cowl-fitting/trimming/plumbing-routing while awaiting arrival of our own 912s. That engine sent a rod and remnants of the piston through the case, ventilating the No.1 head quite nicely; the result of an unfamiliar pilot flying aerobatics without understanding the need for power control on a fixed-pitch prop unlike the constant-speed propeller which his competition-aerobatic Glassair had! Nice.

Regardless of how the engine "got blown" this situation gives each of us a chance to stretch our "what-if" curves a bit and wind up adding to our collective knowledge of how our engines work...or won't...based on OUR actions. We need to engage each such opportunity earnestly to learn from the mistakes of others, 'cuz we sure as heck won't live long enough to make them all ourselves! ;)

"E.T."

Oh, and one more thing...I'll bet GASSITT will wind up fixing the dang thing just because somebody said it wasn't worth it! :D