Convert 337D T337D?

[Geo]

Has anyone converted a normally aspirated 337 to a turbo 337, for example a 337D, to a T337D? Asking as the TCDS lists the same ranges of serial numbers, for early skymasters at least, as being eligible for either normally aspirated or turboed 337 versions.

George

[n86121]

As a former helicopter pilot/owner, I saw little need to even go to 1,000 ft AGL.

A heli can always autorotate and land w zero airspeed, so you just stay near open areas in case. No need for runways or BIG open areas either.

When I bought my T337D, I thought maybe someday cross the Rockies to my wife's family in Oregon,,,, Havent got around to that trip yet.

But, 25 years of flying Washington DC, Outer Banks, and up and down East Coast, it's nice to be able to maintain a rapid climb rate to get on top of the haze layer (bumps), whatever it may be on any given day. Generally summer 7-9k ft, sometimes higher.

The turbo 337 has automatic waste gate, so its pretty much set and forget. Still needs minor tweaks, but you're not chasing it around as you climb / descend.

Over 25 years I have replaced both engines and overhauled both turbos, once. I recall new turbos around $3,500 each when their time finally came.

I am pretty sure turbos only use more gas if you want to use the turbos. Down low stooging around they are mostly along for the ride. Generally, the turbo speed advantage is well worth it, even if only mildly higher up. 10-12k ish my RSTOL T337D really boogeys.

So on reflection, turbos are very nice to have.

[Geo]

Thanks David, yes, I definitely see the performance advantage of turbos. I trying to learn if anyone has actually converted a non-turbo 337 to a turbo'ed version. The type certificate data sheets appears to allow a 337D to also be a T337D if appropriately equipped - e.g. I am thinking if the right part, engines, exhaust, props, gauges, etc are installed.

George

[hharney]

I have not heard of anyone doing this. It would have to be either an STC or field approval. Even if you used everything from the original type certificate you would still have to submit for some kind of approval as it is a certified aircraft. Maybe change the catagory to EXPERIMENTAL and then carry on .......