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Engine overhaul questions


Candy man

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16 minutes ago, mike_elliott said:

The expensive roller tappets are replaced anytime the case is split for prop strike or overhaul.  Not anytime the case is split. Yes theyre 350$ each, but insurance pays for them in case of prop strike teardown, you pay for a straight overhaul, but at least it makes it to overhaul hours now.

Thanks, I thought it was anytime. They are proud of them for sure!

The DLC coated lifters sound like they may have fixed the spalling issue as well. I dont buy the claims of Ney nozzles and Centrilube eliminatinig spalling. they do nothing when the engine sits, which is where the lifter corrosion occurs.

yea, I just dont buy its all caused by corrosion. I threw away a cam that had been sitting in my garage since 1976 in 2012., uncoated with oil, NO surface corrosion. I guess they corrode if they are surrounded by other genuine Lycoming parts, though. Scott Sellmeyer may want to chime in, I know he has the centrilube STC. I also know relying on direct lubrication to the faces of the cam and tappet will result in better lubrication that happenschance splash lubrication.

I dont think its the cam that corrodes, its the lifter. Then the moon surface lifter wears the cam down.

 

the 20 degree timing issue can be fixed, Ive written pretty extensively about it. Its an optional service instruction. You basically reverse it, since its optional.

Yes It can, but rather silly to have spend at least another AMU  on top of the premium of a reman to get the power back legal department took away out of paranoia of suit. Perhaps I am making too light of this, perhaps the roller tappet engines are weaker and cannot tolerate the 25 degree timing in reality and engineering dictated this, in which case you should just live with the loss of power, accept the higher overhaul cost and enjoy the bandaid  of the "wee dont need no steenkin tappet lubrication"  design and the "wee dont need no steenkin quality tappet metalurgy" of the past product. But like you, most people feel the 25 degree timing is worth the premium to have the SB done to undo what Lycoming fixed.

that service letter was from 1975.  IIRC, all non-D IO-360s that left the factory since then have the 20 degrees timing. It runs cooler, because you are derating the engine. The roller engine uses the came crank, rods, pistons, etc. Only the cam, lifters, and case is different.  Like you, I think its worth it to get it back.

Thanks Byron

here is the SI1325.

SI1325#1.pdf

Edited by jetdriven
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no. But if I recall, your engine timing is often set by looking through a plug at some very small numbers.  It wasnt very precise at all. Using a piston stop and a Rite system digital timer, however, is very accurate. Make sure its set to specs.

Edited by jetdriven
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50 minutes ago, teejayevans said:


That changes the timing from 25° to 20°???

I noticed the date on that SB was 1975, prior to the manufacture of my aircraft ('78). It also excludes the A1B6D engine.  And it says it will be incorporated into all subsequent engines.  To me that means it does not apply to my A3B6D engine built in the 80's.  So be careful before making changes to the engine.

I'd love to be able to change the timing to something less than 25 BTDC to get lower CHT's in cruise, but I don't see how I could legally do that.

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1 hour ago, jetdriven said:

You do, but you need to understand the mechanism for which the timing was changed to 20 degrees, in order to have some method for changing it back.

I think I understand what you are saying. So if the engine was originally manufactured with the timing to 25° it could be set to 20° and subsequently returned back to 25°. But the engine that was originally manufactured with 20° cannot be changed to 25°.

yes?

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34 minutes ago, Bob - S50 said:

I noticed the date on that SB was 1975, prior to the manufacture of my aircraft ('78). It also excludes the A1B6D engine.  And it says it will be incorporated into all subsequent engines.  To me that means it does not apply to my A3B6D engine built in the 80's.  So be careful before making changes to the engine.

I'd love to be able to change the timing to something less than 25 BTDC to get lower CHT's in cruise, but I don't see how I could legally do that.

Usually Mooney owner's pine to go the other way. The thinking is that the 20 was done for lawyer sacrificing power.

-Robert 

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Just now, teejayevans said:

I think I understand what you are saying. So if the engine was originally manufactured with the timing to 25° it could be set to 20° and subsequently returned back to 25°. But the engine that was originally manufactured with 20° cannot be changed to 25°.

yes?

No.  any IO-360 engine covered by the 1E10 Type Certificate, that is Type Certificated with 25 degrees timing can run that. If it is at 20 degrees, reversing the service instruction is how you get the 25 degrees back.  The engines are Type Certificated with 25 degrees.

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All well and good with factory engine and roller tappets but here's the 60K$ question: Does Lycoming give a choice in mags? Or are we stuck with the Slicks? If the answer is no, is there such an animal as a D engine with roller tappets?

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3 minutes ago, PTK said:

All well and good with factory engine and roller tappets but here's the 60K$ question: Does Lycoming give a choice in mags? Or are we stuck with the Slicks? If not is there such an animal as a D engine with roller tappets?

I believe the answer is no to both.  The crankcase is specific to the roller tappets, and AFAIK, the Bendix dual-mag can't be installed on it.

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6 hours ago, PTK said:

All well and good with factory engine and roller tappets but here's the 60K$ question: Does Lycoming give a choice in mags? Or are we stuck with the Slicks? If the answer is no, is there such an animal as a D engine with roller tappets?

You can sell those at mags for 800 bucks apiece and use that money to buy Bendix cores and exchange those for overhauled Bendix magnetos. There is a way to do this, me and another guy have done it long ago. 

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6 hours ago, jaylw314 said:

I believe the answer is no to both.  The crankcase is specific to the roller tappets, and AFAIK, the Bendix dual-mag can't be installed on it.

 I don’t know of anybody specifically who has done it but the roller cases can be ordered and retrofitted to the IO360s. LyCon has done this.  Not sure if that specifically excludes the  D engines. 

Edited by jetdriven
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5 hours ago, jetdriven said:

You can sell those at mags for 800 bucks apiece and use that money to buy Bendix cores and exchange those for overhauled Bendix magnetos. There is a way to do this, me and another guy have done it long ago. 

That's good to know. Thank you Byron. According to their rep Lycoming doesn't seem too concerned about the Slick. Not sure if it's rep's personal "opinion" or Lycoming's official position but he says that he has seen Slicks and bendix mags break down about equally. Not sure how accurate that statement is as I have heard of way more Slicks go down than bendix.

Going on a tangent here but I think it's appalling that we're asked to pay upwards of 35$K and more to the factory no less and we are not given the option of an engine accessory. What's next? They'll tell us we can only use one manufacturer's oil filter and not the other? Or one manufacturer's hoses or ignition harness? They won't even sell us the bendix mags even if we are willing to pay extra. They're pushing Slicks. That's a sad example of how we are helpless hostages.

Incidentally, this is not about the Lycoming engine. I love my engine. It's been great to me and I feel I trust it. This is about their business practices.

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Slick magnetos on Lycoming engines likely has more to do with not buying magnetos from Continental their competitor.  Based on the prices for a compete Slick mag and harness set, you should do well selling them.  

Bear in mind that you will need to find suitable cores to return to Continental when you buy their magnetos, they will take an old Slick set.

Clarence

 

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38 minutes ago, RobertGary1 said:

Been flying slicks for thousands of hours and found them to be extremely reliable in my experience. 

-Robert

I have personally changed about twenty of them in the  past 3 years. Most had 300 hours or less. Arced and melted rotors. Melted breaker point lift cams. Lots of coil failures. One school brought over a Cherokee for annual. Coil bad on left mag wouldn’t start.  After the annual they brought a 172 over to fetch it. The 172 was stranded. Bad left mag. You guys run what you want but my opinion. they’re  garbage. 

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I have personally changed about twenty of them in the  past 3 years. Most had 300 hours or less. Arced and melted rotors. Melted breaker point lift cams. Lots of coil failures. One school brought over a Cherokee for annual. Coil bad on left mag wouldn’t start.  After the annual they brought a 172 over to fetch it. The 172 was stranded. Bad left mag. You guys run what you want but my opinion. they’re  garbage. 

Arcing could be caused by champion spark plugs with they’re well know resistance problems.

Bendix has it’s failures too, ask kmyfm20s about his.

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4 hours ago, jetdriven said:

I’m sure that contributes. But Bendix mags don’t self destruct with champion plugs. Stranding the pilot and costing 1500$ to repair 

I don't know Byron,  I just had my second Bendix mag fail.   That makes 2 Bendix and 1 Slick in 900 hrs....  Not sure either is worth a crap.  Each time the bill was in excess of $1500.  It would be nice to have something reliable..... None of them "self destructed"  but they all quit working.

 

 

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