HP Increase on -E2D

[mahlon_r]

My take is this. Your engine could not be installed in a certified aircraft as a certified engine. It is modified from its original state and those modifications are not supported by FAA approved data or by FAA approve Maintenance record entries. Even, if all the work was done according to Lycoming maintenance data the certification was lost when you did two major alterations without approved data. The high compression cylinder installation and the electronic ignition installation. The rest of the engine beyond those modifications is certified assuming no other alterations took place. If the engine was taken off the experimental aircraft and low compression cylinders and mags were reinstalled it would then be able to be used on a certified aircraft with a sign off for an annual inspection for that aircraft. So your engine is a certified engine that has been modified from its' approved data. It's not an experimental automotive engine. Its not a experimental lawn mower engine. it's not a experimental snow mobile engine. It's a certified but modified Lycoming engine and can easily become a certified unmodified Lycoming engine. The rest is semantics. Some would call your engine experimental because of the mods and others wouldn't. It's kind of in the eye of the beholder. In my mind it's a certified engine that needs some work to be installed in a certified aircraft. My logic is this; if a certified engine had let's say 4 bad cylinders that wouldn't pass annual inspection. The aircraft would be grounded until the engine was repaired properly. The engine didn't loose the fact that it was a certified engine because it failed the inspection due to bad cylinders. It's still certified but unairworthy and it just needs to be brought back to spec. Same goes for your engine. It wouldn't pass an inspection in its current state and would be certified but unairworthy because of the mods. But it could be made airworthy if repairs were made to bring it back to spec.
Leaving the data plate on or off has no bearing on the engine's real state. As long as you keep the data plate and can reinstall it, the engine will be whole again. It's just a part that should be on the engine and is required by the FAR's to be certified. So to me you should leave it on.
If you remove the data plate and loose it then you will need to get a replacement from Lycoming, if the engine were ever to be considered certified, and that may be difficult because the FAA has to issue a letter to Lycoming saying it's OK to issue a new one. They might not do that until you unmodify the engine and prove it is unmodified. Bad can of worms to get into....
That's the way I look at it and am pretty sure the FAA would to. This all applies to the engine in the certified world and it's use in a certified aircraft. Use in it's current state on an experimental aircraft may be up to the DAR or FAA person certifying that experimental aircraft, I don't know the regs or stipulations for a modified certified engine as used in a non type certificated experimental aircraft but would assume again that that it's designation certified or non certified would be in the eye of the FAA doing the inspection..
Just my opinions but I hope it helps with your quest.
Good Luck,
Mahlon

[Kent Ashton]

Originally Posted by avrojockey

What I'm trying to prevent is any perceived devaluation of the aircraft because it has an "experimental" engine instead of the certified engine/prop combo.

I doubt any buyer will care much if your engine was kept "certified". True, if it was maintained and signed off by an IA for every maintenance inspection and procedure (other than ones permitted for owners), a buyer might consider the engine to be well-maintained and pay a bit more. But the premium will be offset by the cost of professional maintenance under IA supervision and your inability to do anything much more complex than an oil or plug change.

Fly often, change your oil regularly, cut open the oil filter, borescope the valves and document it in your logbook. This will mean more to a buyer than a "certified" stamp. At least, it would to me.

[avrojockey]

All great input lads! Thanks!

[n82rb]

it comes down to this: the FAA does not care what you call an engine on an EAB. the rules allow you to put anything on the airframe. the FAA only cares that an engine conforms to the TCDS of the engine and the airframe that it is on when dealing with a type certificated aircraft. so, when you put an engine that was on a EAB on a type certificated engine, there had better be a statement in the logs that the engine meets the TCDS. I would argue that the statement must be by someone holding a IA unless it is done during the sign off for a overhaul and then it is covered by the statement that it was overhauled IAW with the lycoming overhaul manual and the parts list contains the proper part numbers and certifications. personally I would not do it without a teardown to confirm parts anyway, so might as well overhaul it then.

the problem with saying that if you maintain the engine as a certified engine with it on a EAB, it is still certified, is that there is no requirement to have a A&P maintain the engine on a EAB. so there is no way to prove that it has been maintained IAW the TCDS and applicable part 43 FARS. No A&P would hang an engine on a type certificated aircraft that came off an EAB without a conformity inspection. Its a good way to get your ticket pulled.

as to the STC to make a 150 into a 160, with the RAM stc there are actually two stc's you have to buy. one is for the engine conversion and is does not relate to the airframe at all. the second one you need to buy is to put the engine on the airframe. You could buy the STC from ram and do the conversion on an EAB. the only reason to do that is then there is the stc paperwork there if you wanted to put that engine on a type certificated aircraft. however, you would still need to get the second STC do do that install and do a conformity inspection of the engine. there is no way to change the HP on a type certificated engine without the STC. years ago you could do it on a field approval on a 337 but the FAA wil not do that anymore.

bob burns
RV-4 N82RB