Experimental Engine Condition Check

[Ted]

So on certified engines (or experimental derivatives thereof), we have prescribed compression checks and limits, etc. to be checked at annual.

For people like Ben who built their own, how do you define the annual engine inspections? Or do you? Just curious.

 

[Geico266]

The condition inspection requires experimentals to use a "checklist" per some FAR, and the Operating Limitations assigned to that aircraft. Compressions are recorded in the engine log, cleaning spark plus, oil changes, ect. Mag hours / overhauls, what ever, are recorded in the engine logs. Prop times and maintenance recorded in the prop log (if there is one).

Ben's operating limitations will prescribe how the engine is inspected. Alternative engine guys do about the same inspections as traditional engines. Some of the inspections (fuel injection & ignition systems) are left up to the owners as each alternative engine can be "unique", hence EXPERIMENTAL.

In Ben's case he has the 4 barrel carburetor overhauled by Jegs.


Does that answer your question?

 

[Ted]

I'm hoping Ben chimes in with some explanation of what he does and how the process worked for him. I suppose part of what I wonder is if it more closely resembles what I do on a car vs. a plane.

 

[Henning]

The condition inspection requires experimentals to use a "checklist" per some FAR, and the Operating Limitations assigned to that aircraft. Compressions are recorded in the engine log, cleaning spark plus, oil changes, ect. Mag hours / overhauls, what ever, are recorded in the engine logs. Prop times and maintenance recorded in the prop log (if there is one).

Ben's operating limitations will prescribe how the engine is inspected. Alternative engine guys do about the same inspections as traditional engines. Some of the inspections (fuel injection & ignition systems) are left up to the owners as each alternative engine can be "unique", hence EXPERIMENTAL.

In Ben's case he has the 4 barrel carburetor overhauled by Jegs.


Does that answer your question?

Nope, 2bbl carb...

 

[N801BH]

Nope, 2bbl carb...

Yup....

It is a racing 2 barrel with some nice mods done to it ....

http://www.holley.com/types/2 Bbl Keith Dorton Series.asp

 

[flyingron]

The condition inspection requires experimentals to use a "checklist" per some FAR

Eh? What FAR would that be? Annuals require checklists (43.15). The FARs are mute as to what's a condition inspection.

and the Operating Limitations assigned to that aircraft.

This is the key. The requirement is spelled out in the operating limitations. Still there's no strict requirement for a checklist in most cases. The sample operating limitations in the order 8130.2 says that it needs to be in the same "scope and detail" as 43 Appendix D. While a checklist is not a bad idea, there's no regulatory requirement for it.

Compressions are recorded in the engine log,

While this is commonly done, there's no regulatory requirement to do this even for CERTIFICATED birds.

cleaning spark plus, oil changes, ect. Mag hours / overhauls, what ever, are recorded in the engine logs. Prop times and maintenance recorded in the prop log (if there is one).

All maintenance and inspections need to be in aircraft records. There's not specific requirement for separate log books except it makes it easier to have the records go with the major part (engine or prop). Homebuilders typically get by with only one book.

Ben's operating limitations will prescribe how the engine is inspected.

Except in the cases of turbines, the operating limitations usually will not say anything about the inspecting the engine (other than the above scope and detail statement).

 

[Geico266]

Eh? What FAR would that be? Annuals require checklists (43.15). The FARs are mute as to what's a condition inspection.

This is the key. The requirement is spelled out in the operating limitations. Still there's no strict requirement for a checklist in most cases. The sample operating limitations in the order 8130.2 says that it needs to be in the same "scope and detail" as 43 Appendix D. While a checklist is not a bad idea, there's no regulatory requirement for it.

While this is commonly done, there's no regulatory requirement to do this even for CERTIFICATED birds.

All maintenance and inspections need to be in aircraft records. There's not specific requirement for separate log books except it makes it easier to have the records go with the major part (engine or prop). Homebuilders typically get by with only one book.


Except in the cases of turbines, the operating limitations usually will not say anything about the inspecting the engine (other than the above scope and detail statement).

Do you just wasn't to argue this morning?

 

[N801BH]

I'm hoping Ben chimes in with some explanation of what he does and how the process worked for him. I suppose part of what I wonder is if it more closely resembles what I do on a car vs. a plane.

Ok....

Treat any motor like your life depends on it.... Cause it does....

My motor is basically a full race 840 HP NASCAR engine derated to about 380 HP or so.. Using the 2 barrel helps limit the HP output similar to the restrictor plates used at Daytona and Talladega.. I have other HP limiting devices on the motor too...

For the record, the motor is an all alimunum 302 Windsor Ford stroked to 347 cu in. 10.4-1 compression with an all roller valve train. Ie... Roller cam, roller rocker arms and Ford racing caged roller needle cam bearings.. As long as the motor has oil in it the valve train will last FOREVER... Especially since it is a 10,000 RPM motor running only 4400 on take off and 2900-3000 RPM at cruise. The motor is just idling along so to speak.

To address Teds questions..

I do a visual inspection of the motor before every flight, check oil level and redrive belt tension...

In the beginning first 100 hours, the cowling came off after EVERY flight and a close inspection of my firewall forward creation was looked at VERY closely, especially my self engineered motor mount.

The yearly annual / conditional inspection for the motor consists of

1- Oil change with analysis

2- compression checked using a pump up test. I am not a big fan of leak down testing. Those numbers are compared to the previous years results. In the 10 years since the motor first started the comps have been consistantly 142-145 PSI. They have actually gone up a few PSI's because of slight carbon build up on the piston tops and cylinder head combustion chambers.

3- Valve covers come off and a inspection of the visual part of the valve stems, valve springs, roller rocker arms, rocker arm studs and valve seals are closely inspected.

4- Ignition system is closely checked , including checking timing as that will show the condition of the cam drive chain, distributor drive gear and cam drive gear. ANY result that might show a retarded timing will have me do an extensive research on why it is retarded... That inspection process is how I found the original MSD distributor drive gear was too soft from the factory and was failing. That is disclosed in my cheesy 25 minute video. http://www.youtube.com/watch?v=rCNnEgRkdXc&context=C3e091d3ADOEgsToPDskKmHo69I6bUDuoBHd5YSUfu

5- Fuel system is checked including the carb, pump and the Mc Neilly mixture adjustment device. Filters are cleaned or changed. The JPI 450 flow scan is checked and tested for proper caliberation.

6- Alternator, water pump and vacuum pump drive belts are checked for proper tension.. My geometry and custom made underdrive pulleys must be ok as I have never had to readjust those tensions since the first motor start.

7- Redrive is VERY closely looked at, including the bearings, drive belt and sprockets. I change the brushes in the IVO prop that change pitch at least once a year.. They do wear out pretty rapidly.

8- Exhaust system is looked at very closely too... Inflight fires scare the &hit out of me..

In closing, I do my overall inspection like anyone that depends on their motor to keep them safe would.. I CANNOT pull over and call AAA for a tow back to the hangar ya know....

If I forgot to address any of your questions feel free to ask for more answers as it is more comfortable for me to sit here on the puter then outside in the -21f air....

 

[Ted]

Makes sense, Ben. It sounds like you cover a lot of the similar items that you'd see in an aircraft engine, and then added other items to it. The basic summary I get is that as the builder of the engine/plane that is experimental and without guidelines from a manufacturer, you just create your own inspection criteria based on your judgement.

Making mental notes for when I do this someday...