The International Cessna^® 170 Association

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I've heard multiple references to light case/heavy case Franklin engines installed in Stinson 108's, but this is only the second time I've ever heard of a "heavy case" C-145. I'd like to know more: what identifies a light case versus a heavy case--serial number?

Eric

I sure would like to answer your question Eric, but I keep getting a notice that only members can post in trade mart.

So answer it here, Tom, unless you're trying to make a point about something.
The only differences I've heard of with C-145 cases is whether the s/n on the data plate has a "D" in it, signifying a dampened (counter-balance equipped) crankshaft.
Now what if a mechanic was OH'ing an early, non-dampened C-145 & needed to replace the crankcase due to damage. He re-assembles the engine using the original (non-dampened) crank but a later "D" s/n'd case cuz that's all he could come up with. I'm assuming all the parts would fit, of course. I was told that the original data plate on the case is not supposed to be changed. Can he stamp on there that there's no counterbalances installed? Or is he required to use a counterbalanced crank since the engine is now a different serial number/later model engine as per the data plate?

Eric

per TCM service bulletin M90-17, the latest version crankcase casting for the C145/O300 was released in 1948. They don't mention any beefups in any service bulletins or the overhaul manual that I could find. so the "heavy case" stuff was either a sales pitch or confusion over bigger engines' problems.

Eric, if you swap a newer case in for your old one when rebuilding an engine, the data plate from the original engine (not the newer case) is retained - so your engine would still be a C145 and the original configuration parts would all still be used.

Hans

I can't remember finding any reference to a beefed up case either when I rebuilt my c-145 which is from 1948 but a friend who's owned his 170 35 years seems to think there is. He claims the engine in his is a heavy case and the original from his '49A was not.

He can't tell me what the difference is just that there is. Go figure.

50-20-01 CONTINENTAL:

Applies to All Model C145 Engines, Serially Numbered 3000 to 5031 Inclusive, Except: Nos. 3612, 4650, 4652, 4654, 4671, 4676, 4679, 4683, 4690, 4710, 4855, 4889, 4904, 4996, 4997, 5002 Through 5021, 5023 Through 5029.

Compliance required by June 1, 1950, and each 25-hour period of operation thereafter.

To minimize possible engine operation difficulty due to crankcase and/or cylinder barrel failures, the following inspection procedure should be accomplished as indicated.

(1) Visually inspect crankcase for cracks giving special attention to those areas around each cylinder base.

This portion of the inspection need not be accomplished or new type crankcases (P/N 530836 and 530837) which are incorporated on all serially numbered engines above No. 4383, and on all engines overhauled by the manufacturer after September 1, 1949. This new type crankcase can be identified by throughbolts (extending through both halves of crankcase) located ahead of the front cylinder and adjacent to nose oil seal. The old style crankcase (P/N 6642 and 6643) requiring inspection has studs at this location extending through one crankcase half only.

(2) Visually inspect cylinder barrels for cracks at the base flange fillet. New flanged-typed cylinder base nuts, P/N 531001 and 531003 have been made available for service operation. This portion of the inspection may be discontinued upon accomplishing one additional 25-hour inspection including a torque check after installation of these new flanged nuts.

During installation of new cylinder base nuts, special attention should be given to the removal of paint and burrs from the cylinder flange nut seat and to compliance with the engine manufacturer's torque limits of 500 plus or minus 10 inch-pounds for the 7/16 studs and through bolts, and 420 plus or minus 10 inch-pounds for 3/8 studs. Improperly torqued nuts are a major contributing factor to cylinder barrel, cylinder base studs, and crankcase failures. The engines exempted from this inspection, as indicated above, have had the new flanged nuts installed at the manufacturer's plant.

Since small cracks are more easily detectable by oil leaks, it is recommended that each inspection include a run-up with a clean engine.

(Continental Motors Corp. Service Bulletin No. M50-2 covers this same subject.)

This supersedes AD 50-18-04.

HA wrote:.....
Eric, if you swap a newer case in for your old one when rebuilding an engine, the data plate from the original engine (not the newer case) is retained - so your engine would still be a C145 and the original configuration parts would all still be used.
Hans

My crankcase was replaced when had the engine OH'd 4 years ago, due to a connecting rod letting go & knocking a big hole in the case below the #4 cylinder. I was told by both the overhauler (an A&P operating as a CRS) and my own IA that you cannot replace the data plate on the new (used, of course) case with the one off the old damaged case. I can see their point, what if their was an AD put out on a certain s/n range of cases due to catastrophic failures? You might have one of the defective cases & not know it because the data plate had been replaced with one off another case.
In my case, the overhaul was written up in the original engine logbook, and "replacement crankcase s/n XXX" was included in the parts list. Other people have said that a new logbook should have been started as this should be considered a completely different engine due to the different serial number.
I woulda rather had the same s/n carry on, but I'm OK with the way it was handled. If it was done with a new logbook, when I sell my airplane I'd have to say "engines logs back thru 2001" which wouldn't help the selling price any.

Eric

[quote="zero.one.victor"]So answer it here, Tom, unless you're trying to make a point about something.
The only differences I've heard of with C-145 cases is whether the s/n on the data plate has a "D" in it, signifying a dampened (counter-balance equipped) crankshaft.


The "D" has nothing to do with the cases, it has to do with the crank, all C-145 thru 0-300-D CASES are the same. There is a difference in the accessory case, and oil sumps some of which have a three bolt sumps and later versions have a 5 bolt sump.

Now what if a mechanic was OH'ing an early, non-dampened C-145 & needed to replace the crankcase due to damage. He re-assembles the engine using the original (non-dampened) crank but a later "D" s/n'd case cuz that's all he could come up with. I'm assuming all the parts would fit, of course. I was told that the original data plate on the case is not supposed to be changed. Can he stamp on there that there's no counterbalances installed? Or is he required to use a counterbalanced crank since the engine is now a different serial number/later model engine as per the data plate?

Replacement cases do not come with a data tag. So what are you supposed to do? always use used cases? Yes you can change data tags iaw FAR 45


§45.13 Identification data.

(a) The identification required by §45.11(a) and (b) shall include the following information:

(1) Builder's name.

(2) Model designation.

(3) Builder's serial number.

(4) Type certificate number, if any.

(5) Production certificate number, if any.

(6) For aircraft engines, the established rating.

SNIP

(b) Except as provided in paragraph (d)(1) of this section, no person may remove, change, or place identification information required by paragraph (a) of this section, on any aircraft, aircraft engine, propeller, propeller blade, or propeller hub, without the approval of the Administrator.

(c) Except as provided in paragraph (d)(2) of this section, no person may remove or install any identification plate required by §45.11 of this part, without the approval of the Administrator.

(d) Persons performing work under the provisions of Part 43 of this chapter may, in accordance with methods, techniques, and practices acceptable to the Administrator-

(1) Remove, change, or place the identification information required by paragraph (a) of this section on any aircraft, aircraft engine, propeller, propeller blade, or propeller hub; or

(2) Remove an identification plate required by §45.11 when necessary during maintenance operations.

(e) No person may install an identification plate removed in accordance with paragraph (d)(2) of this section on any aircraft, aircraft engine, propeller, propeller blade, or propeller hub other than the one from which it was removed

What this amounts to is that the data tag and log book are the engine, every thing else is a replaceable part.

The way I read it, FAR 45.13 as quoted sez you can install a new data plate on a new case, but you can not remove a data plate from one case & install it on another.

" (e) no person may install an identification plate removed in accordance with paragraph (d)(2) of this section on any aircraft, aircraft engine,propeller, propeller blade, or propeller hub other than the one from which it was removed."

So my overhauler & IA were right in not putting the data plate off the old case onto the (used) replacement case. Or does FAR 45.13(d)(1) say it's OK? Seems pretty vague-- is (d)(1) saying it's OK to go changing data plates whenever you want?
Guess it depends on whether it's "in accordance with methods,techniques,and practices acceptable to the administrator". That sure clears things up!

Eric

Eric- in my humble opinion, the case is just an engine part, data tag happens to attach to it on these engines. I've replaced many cases, when I buy an overhauled or new case it doesn't come with a data plate - I have to supply that, and it comes off of the old (hole knocked in it or BER or whatever) case. as long as the case is certified by somebody allowed to do that (your overhauler at least supplied a case with a yellow tag - or now, an 8130 form?) then it has a history that can be used for AD compliance.

lots of Lycoming engines have the data plate attached to the oil sump - same thing applies there. or think of your airplane - if you had to replace the skin that the data plate was riveted to, would you have a different airplane then? nope.

hey Tom, good catch on that old AD - I didn't dig far enough. maybe if there had been a beer riding on it, I'd have been more ambitious...

TCM provides for adding information for engine updates to their datatags in their Maintenance Bulletin M-75-6R1, available at their website http://www.tcmlink.com/ under "aviator services" which is free. You may need to register.

In addition to M75-6R1, engine data plates are addressed in TCM SIL 00-9A. Both bulletins are posted in the MX Library.

With regard to "heavy" crankcases: A little research has revealed that
the "heavy case" can be identified by 3 thru studs in the vicinity of the fuel pump area (the right side, forward portion of the case ahead of cyl #5.) Since they are thru-studs, the "heavy case" will present three 7/16" nuts in that location while the light case does not.
Additionally there are a couple of different types of heavy cases. The heavy O300 case is identified by 3/8" pipe plugs at the front end of the oil galleys (visible on either side of the crank/prop flange.) The earlier C-145 cases have 1/2" pipe plugs.
Early TCM cylinders can be identified by bronze inserts for the spark plugs. Later O-300 cylinders have helicoils.
The early non-dampened cranks have a 1/4" hole drilled between the prop-bushing holes, while dampened cranks do not. The early 8-bolt cranks for the C-145/O-300-A engines have built-in nuts on the prop flanges for 3/8" prop bolts, while the later O-300-C/D/E engines had 6 holes in their flange for 7/16" prop bolts and separate self-locking nuts.
The early C-145 oil sumps had a sheet-metal divider riveted into it just above the carburetor, while the later O-300 cases had this divider cast in during mfr. (If the rivets ever loosen you can find oil in your intakes, sometimes mistakenly mis-diagnosed as worn intake valve guides.) The rivets for the sheet-metal divider can be observed when the carb is removed. Early sumps (irrespective of the divider) had 3 bolts for attachment of the accy-case while later sumps had 5.
There are other differences between these engines, but these are the most obvious for identification purposes.

zero.one.victor wrote:

HA wrote:.....
Eric, if you swap a newer case in for your old one when rebuilding an engine, the data plate from the original engine (not the newer case) is retained - so your engine would still be a C145 and the original configuration parts would all still be used.
Hans

My crankcase was replaced when had the engine OH'd 4 years ago, due to a connecting rod letting go & knocking a big hole in the case below the #4 cylinder. I was told by both the overhauler (an A&P operating as a CRS) and my own IA that you cannot replace the data plate on the new (used, of course) case with the one off the old damaged case. I can see their point, what if their was an AD put out on a certain s/n range of cases due to catastrophic failures? You might have one of the defective cases & not know it because the data plate had been replaced with one off another case.
In my case, the overhaul was written up in the original engine logbook, and "replacement crankcase s/n XXX" was included in the parts list. Other people have said that a new logbook should have been started as this should be considered a completely different engine due to the different serial number.
I woulda rather had the same s/n carry on, but I'm OK with the way it was handled. If it was done with a new logbook, when I sell my airplane I'd have to say "engines logs back thru 2001" which wouldn't help the selling price any.

Eric

I agree with HA. What if you replace the Case with newer Case and its Data Plate but retain all the other older parts, you could still miss an AD thinking you have a newer engine. Logbook entry should show what SB, AD or parts replacement was complied with.
Can you build up and engine using that new case and Data plate?? Yep, but you better list what parts you put in it. If you put the old parts from the early engine in it, Are they legal in the newer "engine"
Bottom line its your call -- Newer approved case in an old engine or old maybe unapproved parts in a newer engine.

In my "case" ( case-get it?), the replacement case was not new but used yellowtagged part. I suggested just reinstal;ling the old data plate on the "new" case, but both the OH'er & my IA said that was not the proper way to do it. So the "new" case (s/n noted) was included in the parts list for the OH, and the engine logbook ammended as to the "new" serial number. Not the way I would have preferred, but all legal & proper according to my IA & the OH'er (an A&P operating as a Certified Repair Station), and I figure they both know what they're doing.

Eric

Another scenerio to consider, The case from a TSIO-520T is the same as the IO-520D. I have replaced one with the other. I wouldn't think of leaving the original Data Plate on it cause it isn't even the same engine.
I really think your IA is wrong, but like I say, to each his own. Probably won't matter until you sell the airplane and something in the engine goes wrong. (Since you were probably just replacing with case from same exact model, it probably won't ever matter.)

I don't imagine there'd be a (legal) problem even then-- the replacement case is also a C-145 case, and everything is all documented.

Eric