Engine mounts

[Flymu2]

I just had a factory reman installed in my M20S. The mechanic did not replace the engine mounts, saying that he replaces them only "on condition". He couldn't give me an estimate of how long they should last. He's quoting about $1500 just for the mounts, not for the labor. Should I have the engine mounts replaced now, or just wait until they appear to need replacing?

[RJBrown]

Western Skyways just did the engine on my MSE. They recommended and I bought new mounts. $650 parts NO labor. I don't know how much mounts for your plane are but that sounds high.

[Lood]

Here in SA, replacing the mounts are mandatory when doing a major and my AME actually recommended it during my recent overhaul.

[carusoam]

For the IO550 there are four mounts, three of one and one of the other... Over 1AMU for parts.

The mechanic followed the instruction on what went where, but we don't know the detail of why there is an odd one...

Since it is expensive to pull the engine and put it back, and the parts are known to wear, it seams to be false economics to NOT change them out....

If they are to wear out in a couple years, you will be paying several AMU plus the hardware to change them out later.

Right?

Did you select an IO550(N) or IO550(G)?

Did you stay with the same RPM limit you had before?

Did you trade up for a TopProp while you are down?

These are the questions facing a few long body owners recently.

Best regards,

-a-

[John Pleisse]

It was just under a grand to do mine with the OH (incl labor-J model). While he is right re: condition, why would he and you not? The engine is out, the labor is committed. Everything should serviced and examined at OH for best results and worry free flying for years to come. Mounts, firewall, baffling, hoses, prop, cooler, etc.

 

IA's love owners who go all the way, do it right and they are in turn, more motivated to see your job through.

[Flymu2]

For the IO550 there are four mounts, three of one and one of the other... Over 1AMU for parts.

The mechanic followed the instruction on what went where, but we don't know the detail of why there is an odd one...

Since it is expensive to pull the engine and put it back, and the parts are known to wear, it seams to be false economics to NOT change them out....

If they are to wear out in a couple years, you will be paying several AMU plus the hardware to change them out later.

Right?

Did you select an IO550(N) or IO550(G)?

Did you stay with the same RPM limit you had before?

Did you trade up for a TopProp while you are down?

These are the questions facing a few long body owners recently.

Best regards,

-a-

I just replaced the IO550G. I did the reman because the plane was damaged during Sandy and the engine required a teardown. It had about 1500 hrs on it. Financially the cost of the teardown was a little more than the value of the remaining time on the engine, plus the insurance paid for the R & R. I decided for the same money to fly behind a new engine and have a newer engine when it came time to sell the plane.

 

The biggest cost to upgrade to 310 hp with the 2700 RPM limit is the new propellor. If the prop had been damaged I probably would have done it, as the insurance would have had to pay for a new prop. Alas, no prop damage. I think the upgrade is worth it, but it's about 18K with the STC, new prop and labor. More than I care to spend at this point. I think the 2 blade prop is a little more efficient, but the 3 blade climbs better. Probably not much difference.

 

I agree that they should have just replaced the mounts while the engine was out. I was PO'd at the mechanic that he didn't.

 

I also asked him about the hoses. He said all the fluid carrying hoses come new with the engine from TCM. He did not replace the transducer lines, again saying they were "on condition". I'm less PO'd about that, but I just don't understand why he wouldn't offer me the "kitchen sink" firewall forward treatment. Maybe most of his customers are stingier than me, but at least let me make the choice.

[N177MC]

I'm an A&P and I've been  looking after a Screaming Eagle for about 2 years now.

 

The first time I saw the acft I noticed the prop wasn't centered in the cowl, sagging a good inch maybe more.

 

Yesterday I pulled the cowl for an oil change and found the left exhaust bracket had worn a hole in the left exhaust fairing, the forward left engine mount heat shield had been contacting the engine support and the right side engine baffling had been blown back.

 

All of these are items are indicative of worn and/or sagging engine mounts.

 

My question is what are M & R model owners experiencing in engine mount life ?

 

Also, is shimming the mounts acceptable practice on these models ? (I ask because I own a Cessna Centurion and even with new mounts the engine tends to sag and Cessna issued a SB that calls out thick washers to shim up the front as needed.)

 

Thanks !

[yvesg]

I'm an A&P and I've been  looking after a Screaming Eagle for about 2 years now.

 

The first time I saw the acft I noticed the prop wasn't centered in the cowl, sagging a good inch maybe more.

 

Yesterday I pulled the cowl for an oil change and found the left exhaust bracket had worn a hole in the left exhaust fairing, the forward left engine mount heat shield had been contacting the engine support and the right side engine baffling had been blown back.

 

All of these are items are indicative of worn and/or sagging engine mounts.

 

My question is what are M & R model owners experiencing in engine mount life ?

 

Also, is shimming the mounts acceptable practice on these models ? (I ask because I own a Cessna Centurion and even with new mounts the engine tends to sag and Cessna issued a SB that calls out thick washers to shim up the front as needed.)

 

Thanks !

Check this article by Don Maxwell about shimming Mooney engines:

http://www.donmaxwell.com/publications/MAPA_TEXT/Alining%20Engine%20Using%20Shims/ALIGNING_YOUR_ENGINE.HTM

Yves

[N177MC]

Thanks for pointing out that article Yves.

 

It only addresses the m20J models with the Lycoming IO-360.

 

Has anyone had any experience shimming the big bore IO-550s in the long bodies ?

[carusoam]

The Io550 has 4 supports. Three of one type and a fourth of something visually different. My mechanic followed the directions but could not explain the details. Engine is properly centered in the cowling...

This experience comes after the engine has been swapped out with a factory reman'd one. The mount was sent out for inspection at the time.

I would think something has changed and needs to be identified.

My last similar experience turned out to be a broken engine mount on an O360. The engine would drop a 1/4" if the welds didn't accidentally realign themselves... Took me a few days to realize what was going on. I won't wait as long next time.

Sagging an inch is visually huge. Checking weld points should reveal something out of the norm. Something has slid un usually.

How many hours do you have on the engine?

Good luck,

-a-

[N177MC]

Carusoam - You raise some very valid points, ie. has anything changed and is the engine support cracked or bent ?

 

The engine was indeed sent out for a complete tear-down inspection following a minor prop strike incident about 3 years ago, before I started to look after the acft. So there is a real possibility that something was changed or omitted at that time.

 

This weekend I made a very complete visual inspection of the support and didn't see anything out of the ordinary.

 

I have requested all of the logs to see when the last time the mounts have been changed, but I suspect that they are original and thus over 12 years old !

 

IIRC the engine has @ 1,500H TT