The International Cessna^® 170 Association

Yep!

bagarre wrote:

T. C. Downey wrote:Acorn Welding ( http://www.acornwelding.com/productsEngineMount.htm ) quoted me a 3650.00 price for a new engine mount. IO-360-C to a C-170

That's the same price they gave me when I called them. It's based on the price to make the HawkXP mount.
Keep in mind, they can't give you any approval for that mount as they have no approved design drawings for it. You'd still need that from XPMods or other means of approval.

for comparison, engine mount for a Falco from Sequoia Aircraft costs $3500. No certification. Also, a dozen years ago or so XP Mods was selling the STC and engine mount for $5K. (Tried to look up a price for Vans Engine mounts, not quoted separately on the website )

Also by comparison, a NEW engine mount for a Maule M5 220C (TCM IO-360) costs $980.00.
Might be easier to buy that and have the modification approved. There is a 337 on this site that did that.

There are a few rear engine mounts from 337's around for sale, even one from Acorn Welding. Usually go for about $1500.

bagarre wrote:

T. C. Downey wrote:Acorn Welding ( http://www.acornwelding.com/productsEngineMount.htm ) quoted me a 3650.00 price for a new engine mount. IO-360-C to a C-170

That's the same price they gave me when I called them. It's based on the price to make the HawkXP mount.
Keep in mind, they can't give you any approval for that mount as they have no approved design drawings for it. You'd still need that from XPMods or other means of approval.

Keep in mind, that when you buy the STC from Tom Anderson, you get the drawing for the mount,,,, you can have any one build that for you. Tom Anderson will actually give you a list of those who can do it.

The STC does not come with the drawings to fabricate the mount.
Tom is willing (last I talked to him three months ago) to sell the drawings separately, licensed for one airplane of course.

I was told by Tom that The 1500 bucks got the STC and a set of blue prints, and they would produce an engine mount for 5k, or that he would give us a list of manufacturers that would make the mount for us.

That's what he told me too
$500 for the STC paperwork and $1000 for the drawings.

Keep in mind, Tom CAN NOT make the mount for you nor can another shop simply MAKE it for you.
Tom does not have a PMA for the mount so it's not an approved part. No other shop has a PMA for this mount as well.

You'll have to talk to your FAA rep about getting the motor mount approved some other way.
Your best bet (I think) would be approval as an Owner Made Part but your local FAA will have to agree with that.

The "rule" already allows "Owner Mfr'd Parts" ...and no further approval is req'd. IMO.
(The problem is..... are the drawings offered by Tom/XP ...."approved".)

Per Tom, they will be copies of the approved drawings he used to make the mount licensed to your tail number.
He does say the plans call out his fixture to be used in the fabrication and he's not giving drawings of the fixture. But he will rent the fixture for another grand. I don't think it's needed but this may complicat fabrication or drive up the cost.

I don't know of anyone who has seen the drawings tho. They may be general layout and lengths with instructions that say, "Put it in the jig" ... Dunno

With a C-145/O-300 crankcase and crankshaft mounted in a C-170 engine mount, I can't see that it would be too big a job to build a fixture to make the engine mount. One would also have to have an IO-360 case and crank, or engine, to work with also.

gahorn wrote:The "rule" already allows "Owner Mfr'd Parts" ...and no further approval is req'd. IMO.
(The problem is..... are the drawings offered by Tom/XP ...."approved".)

Yes….The STC is the approval.

The STC is the approval to install the mount on your aircraft.
The STC is does not contain the approved data to fabricate the mount.
That would be the extra drawings that Tom is also selling but you need to verify that the provided drawings are in fact Approved data.
Then you need to use approved methods to fabricate it.

You can't just take the drawings at face value, block up some tubing in your garage and weld up a motor mount.
21.303(b)2 is an incredibly generous gift of the FAA to aircraft owners but it's not a free pass.

So, if the motor mount drawing are approved, under 21.303(b)2 you as the aircraft owner should be allowed to fabricate the part for your aircraft but you still have to use approved methods and materials.

Also, if you go the Owner Made Part I'd talk to your IA (at least) to make sure they agree.
They can not make the part for you but they have to sign off on it when it's installed.

bagarre wrote: ... Also, if you go the Owner Made Part I'd talk to your IA (at least) to make sure they agree.
They can not make the part for you but they have to sign off on it when it's installed.

That's a common misconception among A&P's -- or else an excuse to avoid a difficult job or the liability involved in making a part. If you as the aircraft owner give the mechanic (or whoever) the approved data they need to make a part it is legal for them to make it for you. This is why you'll find aircraft owners who are A&P/I.A.'s talking to themselves a lot! Check out what George has posted here.

bagarre wrote:The STC is the approval to install the mount on your aircraft.
The STC is does not contain the approved data to fabricate the mount.
That would be the extra drawings that Tom is also selling but you need to verify that the provided drawings are in fact Approved data.
Then you need to use approved methods to fabricate it.

You can't just take the drawings at face value, block up some tubing in your garage and weld up a motor mount.
21.303(b)2 is an incredibly generous gift of the FAA to aircraft owners but it's not a free pass.

So, if the motor mount drawing are approved, under 21.303(b)2 you as the aircraft owner should be allowed to fabricate the part for your aircraft but you still have to use approved methods and materials.

Also, if you go the Owner Made Part I'd talk to your IA (at least) to make sure they agree.
They can not make the part for you but they have to sign off on it when it's installed.

How can the drawings not be authorized when they are a part of the STC data that was approved by the FAA for the STC issued?
STCs are an approval to modify the aircraft in the manor the drawings and engineering data states. they do not direct who must make the parts.