Continental Engine Conversion Service Bulletin

[glbtrottr]

Many years ago I tried to head down this path with many friends at the mooney factory back then.

I have what I was told was the mod works demonstrator for the 231–> 262 conversion. 14v taio360mb4 in it.

I really wanted to go down the path of converting it to an encore; aside from the MB—> SB conversion, I was told that the landing gear drop testing had been performed on the 252 but not the 231, preventing our ability to perform the conversion back then. I believe Bill Wheat had been part of that chat brought about by Todd when Stacey, Mike, Bill Grebe and Wes were still at the factory.


Sent from my iPhone using Tapatalk

[carusoam]

Q,

You might try and find our intercooler guy….

He may have insight to parts like you are asking about…

For pre-flown parts… you know the list..

@Alan Fox

@Jerry Pressley

@SheryLoewen

-a-

[geoffb]

Don't all Rockets have the 3,200 lb gross weight increase, whether they were 231 or 252?

[Jerry Pressley]

brent at smoky mtn aeroplanes has all needed to convert   423 273 3557

[Fly Boomer]

On 12/1/2022 at 10:57 AM, geoffb said:

Don't all Rockets have the 3,200 lb gross weight increase, whether they were 231 or 252?

Separate STC (but can't be separated from rest of upgrades).

[Q The Engineer]

On 11/30/2022 at 9:21 PM, glbtrottr said:

Many years ago I tried to head down this path with many friends at the mooney factory back then.

I have what I was told was the mod works demonstrator for the 231–> 262 conversion. 14v taio360mb4 in it.

I really wanted to go down the path of converting it to an encore; aside from the MB—> SB conversion, I was told that the landing gear drop testing had been performed on the 252 but not the 231, preventing our ability to perform the conversion back then. I believe Bill Wheat had been part of that chat brought about by Todd when Stacey, Mike, Bill Grebe and Wes were still at the factory.


Sent from my iPhone using Tapatalk

Good post.  Do you know what are the differences are between the MB and SB hardware?  My understanding is it's nothing, just changing operating speeds. 

[Q The Engineer]

On 11/18/2022 at 7:25 PM, kortopates said:

The cowling change between 231 and 252/Encore is much more significant. Remember that two manual cowl flaps changed to 1 larger and very different electric cowl flap with alteration of the engine mount to accommodate the electric motor and cowl flap extension system mechanism. Change is lights, inlets and intake on side.
The only difference between Encore and 252 cowling is $12K in carbon fiber (pricing over 10 years old).
you’ll want to find a salvage 252 fiberglass cowling and engine mount.


Sent from my iPhone using Tapatalk

Thanks for the feedback.  I won't be going that way.  Finding some salvage hardware would be my preferred approach.  

[Q The Engineer]

On 11/17/2022 at 8:22 AM, tony said:

It does.  Your DER just approves the engineering and your A&P installs the engine to the FAA approved engineering.  Then references the drawing on his 337.  Just ask BOB if he is willing to do that.  

He's agreed if I'm willing to take it on.  One thing is clear, it's my ass in the airplane, I'll be doing the work and engineering on all of it.  I'm extremely fortunate to have a great A&P and IA I can work with.  

 

On 11/17/2022 at 2:04 AM, carusoam said:

Bob Minnis is a tremendous resource….

He helped guide my decisions when getting a 310hp engine and the TopProp to match… and selecting cylinders….n vs. g.

He is definitely a technical guru…

Make sure you have all the paperwork to match…

It would be a bummer to end up without the proper STC…. Getting around an unavailable STC would be outrageously challenging…

When talking to Bob… be prepared to write really quickly…. The good details come in hard and fast….   

Best regards,

-a-

Bob is good and a wild man! 

 

[Q The Engineer]

On 11/22/2022 at 1:49 PM, geoffb said:

If I was going down this path, I'd put the effort into seeing if I could build a Rocket.  Just not enough juice in LB to MB/SB for the paperwork squeeze.

Likely truth.  Just gotta watch engine weight and CG. 

[cliffy]

There are things about Bob Minns that not too many people know but none of which detracts from his ability with engines. 

They only enhance it. 

He's the smartest engine guy I have ever met in my 50+ years in aviation and I've met a bunch of aero engineers. 

Ask him sometime about how he made the dual turbos work on Mooneys! When Mooney couldn't get them to work

He's done projects that he can't even talk about.

[Q The Engineer]

38 minutes ago, cliffy said:

There are things about Bob Minns that not too many people know but none of which detracts from his ability with engines. 

They only enhance it. 

He's the smartest engine guy I have ever met in my 50+ years in aviation and I've met a bunch of aero engineers. 

Ask him sometime about how he made the dual turbos work on Mooneys! When Mooney couldn't get them to work

He's done projects that he can't even talk about.

He is clearly a diamond in the rough.  I consider myself capable in the engine, engineering field.  Bob is capable and as real as it gets! Not trying to spell check but its Minnis.  Names matter.   

Edited December 3, 2022 by Q The Engineer

[tony]

6 hours ago, Q The Engineer said:

He's agreed if I'm willing to take it on.  One thing is clear, it's my ass in the airplane, I'll be doing the work and engineering on all of it.  I'm extremely fortunate to have a great A&P and IA I can work with.  

 

 

 

I thought he would.  So he'll throw an 8110 on the engineering documenting the mod for your serial number right?

[Pinecone]

9 hours ago, Q The Engineer said:

Good post.  Do you know what are the differences are between the MB and SB hardware?  My understanding is it's nothing, just changing operating speeds. 

The bottom line is this, but there are parts changes.

From previous threads:

The second drawing is to mod the engine from the MB to the SB configuration which is easier than the brakes. It requires a fuel pump, controller, prop governor plus some more misc parts  and then some additional Mooney airframe parts which are control surface balance weights for rudder, elevator and ailerons. Also some some imstruments need to be re-marked for different redlines and vspeeds including the IAS.,MAP & RPM gauges to complete the engine modification.

 

My difficulty is with converting the engine from MB to SB.  I understand the basic process in changing the engine specs.  I have seen a logbook entry calling it a TSIO360MBcSB and another TSIO360MBSB.  I think the correct way is to call its a TSIO360MBC, (C for converted) stamp a C on the data plate and list the changes in the logbook.  This is text from a Lycoming Service Instruction: 

• For all commercial engines in which the basic model has been altered or converted to another model designation, the letter “C” added as a suffix on the engine serial number indicates a change from its original manufacture.

>> I found the way that continental modifies the data plate M75-6 says it will become TSIO360MBCSB

Starting with the obvious things:

1) Prop & Governor - I see from a McCauley guide, the prop is identical but there is a slight difference in governor model.

2) I see from the Continental parts manual there is a different part number for the fuel pump.  And a slight difference in FF setup.

3) I believe the MP pressure controller can be adjusted.

4) I have not looked at the pop off valve, other to find out that on the MB engine it was set at 41.5".

So it is not as simple as adjusting the RPM and MP to the new settings. 

[cliffy]

15 hours ago, Q The Engineer said:

He is clearly a diamond in the rough.  I consider myself capable in the engine, engineering field.  Bob is capable and as real as it gets! Not trying to spell check but its Minnis.  Names matter.   

Just poor typing on my side as far as the spelling goes and I even carry his card.

 

[Q The Engineer]

7 hours ago, cliffy said:

Just poor typing on my side as far as the spelling goes and I even carry his card.

 

LOL I have a bad keyboard that misses stuff as well. Reall recognizes real! 

[glbtrottr]

The 252–>encore upgrade is well known.

The question is…

What are the chances someone will help with the landing gear issue so we can bring our 231’s to SB engines and the greater gross weight? Many of us are flying 231’s with MB’s and the proper STC’s….


Sent from my iPhone using Tapatalk

[cliffy]

What is the total market value in $$$$

What is the cost to succeed in the end?

Strictly a cost / benefit ratio  

If its worthwhile financially someone would do it.

[Aerodon]

On 11/15/2022 at 4:29 PM, Q The Engineer said:

I'll do some more digging. If I read that service bulletin, it looks like going from an LB to SB is legal.  The base engine is the same.  The major differences are the turbo, aftercooler addition, and tuned runner intake manifold and throttle.  Thanks for the response. 

And the cylinders on the MB/SB are different and twice the price.  I have a whole TSIO360MB core that you can buy.  But without an STC too install it in your airframe, it is useless.

I recently converted an MB to SB using this service bulletin and the Mooney instructions (they added one more part, an exhaust outlet support bracket), and the Mooney instructions / approval to convert from a 252 to an 'Encore'.

You are better off selling the 231 and buying a 252 or Encore, it is no longer possible to use the STC that allowed a 231 to 252, and there never was an STC to go from 231 to Encore.

Aerodon

 

 

[jlunseth]

Why would you want to convert a 231 to an MB/SB. You still have a 14V electrical system among other things. Spend the money on an actual 252. Spoken as one who owns a 231. It’s a great plane as it is.

[1980Mooney]

On 11/22/2022 at 12:49 PM, geoffb said:

If I was going down this path, I'd put the effort into seeing if I could build a Rocket.  Just not enough juice in LB to MB/SB for the paperwork squeeze.

Build a Rocket?  Only Rocket Engineering can do that. I thought I saw a prior post that said if you get 5 friends to each bring $120K to Rocket Engineering they might do it again.  Of course that was before the price increases at Continental and others so it is probably about $150K now if you can get a group together.  Darwin Conrad is still running Rocket Engineering and occasionally answers the phone.....

[geoffb]

On 12/7/2022 at 7:55 AM, 1980Mooney said:

Build a Rocket?  Only Rocket Engineering can do that. I thought I saw a prior post that said if you get 5 friends to each bring $120K to Rocket Engineering they might do it again.  Of course that was before the price increases at Continental and others so it is probably about $150K now if you can get a group together.  Darwin Conrad is still running Rocket Engineering and occasionally answers the phone.....

My point exactly.  To extrapolate from your thought, only the Mod Works or the Mod Squad can provide the STC to install a -MB engine, etc to make a 261/262.  Doesn't matter if you have a TCM SB to convert the engine.  Doesn't matter if you copy my entire STC documentation package and install per.  I believe you can't use an existing STC as approved data for a major mod.  No STC from the holder, no mod per the STC.

If it were practical to do I think you'd have seen a bootlegged 262 by now.  And I'd be starting to collect parts for my bootleg Rocket conversion.