Looking awesome ASA. much nice working under the panel with a flat floor vs bending over backwards over the seat bar in the Maule.

A1Skinner wrote:Looking awesome ASA. much nice working under the panel with a flat floor vs bending over backwards over the seat bar in the Maule.

Thanks! And yeah I agree. When I did my panel in the Maule, I was lucky that there was no windshield, glareshield, or boot cowls and that was the best of the best. For retrofit panels though, I’ll choose a Cessna any day.

asa wrote:I'm gone now but before leaving I focused on firewall forward and worked on getting the engine hooked up. Made new fuel/oil lines, mounted the carb, etc etc. Will resume progress eventually, as it's still in my garage...

Interesting oil cooler location. How will the oil cooler get air fed to it? Still hunting for the location on my Bearhawk Patrol with 0-360.

skyward II wrote:

asa wrote:I'm gone now but before leaving I focused on firewall forward and worked on getting the engine hooked up. Made new fuel/oil lines, mounted the carb, etc etc. Will resume progress eventually, as it's still in my garage...

Interesting oil cooler location. How will the oil cooler get air fed to it? Still hunting for the location on my Bearhawk Patrol with 0-360.

This is the doyn conversion and allegedly there is a tunnel-ish thing built into the cowling or baffling. I haven't seen the cowling my customer has, just installed the oil cooler based on the documentation.

asa wrote: This is the doyn conversion and allegedly there is a tunnel-ish thing built into the cowling or baffling. I haven't seen the cowling my customer has, just installed the oil cooler based on the documentation.

It was my understanding that the Doyn conversion used the (uncommon, and unsupported) Lycoming O-340.
It only makes sense to substitute a 360, but I'm curious if there was a field approval or something done to allow that change?

hotrod180 wrote:

asa wrote: This is the doyn conversion and allegedly there is a tunnel-ish thing built into the cowling or baffling. I haven't seen the cowling my customer has, just installed the oil cooler based on the documentation.

It was my understanding that the Doyn conversion used the (uncommon, and unsupported) Lycoming O-340.
It only makes sense to substitute a 360, but I'm curious if there was a field approval or something done to allow that change?

Nope, the Doyn conversion paperwork I has says O-360-A1A or -A1D. This is the -A1D. No mention of the O-340. Maybe they offered that too, but not in this one.

I'm was concerned and skeptical how efficient an oil cooler will be mounted against the firewall like that. I mounted mine on the firewall but in a "downdraft" configuration with an 3" scat tube air intake off the back of the engine baffles. To my way of thinking this also made good use of the negative pressure within the cowling to enhance airflow through the oil cooler as well. All that said a Canadian OM C of A allows for bit more "leniency" than a standard C of A.

asa wrote:

hotrod180 wrote:It was my understanding that the Doyn conversion used the (uncommon, and unsupported) Lycoming O-340.
It only makes sense to substitute a 360, but I'm curious if there was a field approval or something done to allow that change?

Nope, the Doyn conversion paperwork I has says O-360-A1A or -A1D. This is the -A1D. No mention of the O-340. Maybe they offered that too, but not in this one.

This piqued my interest, so I did a little research:

The Doyn conversion I referred to is STC # SA3-13, to install a Lycoming 340-A1A on a 170A or B.
This STC is now held by D'Shannon Products Ltd in Buffalo MN.
https://drs.faa.gov/browse/excelExterna ... pened=true

There is another Doyn conversion, # SA421CE, to install a Lycoming O-360-A1A or A1D on a 170A or B.
This one is now held by the (infamous) Bob & Barbara Williams of Udall KS.
https://drs.faa.gov/browse/excelExterna ... pened=true

hotrod180 wrote:

asa wrote:

hotrod180 wrote:It was my understanding that the Doyn conversion used the (uncommon, and unsupported) Lycoming O-340.
It only makes sense to substitute a 360, but I'm curious if there was a field approval or something done to allow that change?

Nope, the Doyn conversion paperwork I has says O-360-A1A or -A1D. This is the -A1D. No mention of the O-340. Maybe they offered that too, but not in this one.

This piqued my interest, so I did a little research:

The Doyn conversion I referred to is STC # SA3-13, to install a Lycoming 340-A1A on a 170A or B.
This STC is now held by D'Shannon Products Ltd in Buffalo MN.
https://drs.faa.gov/browse/excelExterna ... pened=true

There is another Doyn conversion, # SA421CE, to install a Lycoming O-360-A1A or A1D on a 170A or B.
This one is now held by the (infamous) Bob & Barbara Williams of Udall KS.
https://drs.faa.gov/browse/excelExterna ... pened=true

So now you have piqued my curiosity. Given the challenges in contact the Williams, could D'Shannon Products applied for a deviation that would allow an 0-360-A1A or A1D to be substituted for the 0-340 in their STC.

Let's call it an "alternate means of compliance" is this something the FAA might be open to considering.

I am just starting the Avon/Williams conversion on my 170 B but the STC doesn’t come with the drawings. Do you have a copy? I am wondering about the oil cooler mount and the fuel pump. I was going to mount the cooler on the back side of the baffling and I hear there is an approval to eliminate the fuel pump. I too am going with the Sensenich prop, did you already get the field approval? I am needing an air box if you know where one is available also. Thanks for any info you have.

WY sage hopper wrote:I am just starting the Avon/Williams conversion on my 170 B but the STC doesn’t come with the drawings. Do you have a copy? I am wondering about the oil cooler mount and the fuel pump. I was going to mount the cooler on the back side of the baffling and I hear there is an approval to eliminate the fuel pump. I too am going with the Sensenich prop, did you already get the field approval? I am needing an air box if you know where one is available also. Thanks for any info you have.

An old friend of mine got field approvals to eliminate the engine driven and backup electric fuel pumps on Avcon converted 170 and 172s. The only reason for the pumps is that the original fuel line from the fuel selector to the gascolator/engine installation was too small to flow max fuel for an O-360. So, he replaced that line with a larger diameter line, which then provided adequate fuel flow at max power.
| don't believe there was ever an STC for this mod, but a bunch of them got done in Fairbanks area. Someone up there might have some paperwork, if you can get a FA. The fellow who got these field approvals ran the A & P program at the Community College. I never had my 170 done, since it was a lot of thrashing around to lose a couple pounds of weight. That said, if I was doing this mod and had to purchase the pumps, etc.....

As to that oil cooler, I too would mount the cooler such that air flowed DOWN through it. With it up against the firewall like that, it's not going to flow much air.....but maybe enough, unless you're in Texas....

MTV

WY sage hopper wrote:I am just starting the Avon/Williams conversion on my 170 B but the STC doesn’t come with the drawings. Do you have a copy? I am wondering about the oil cooler mount and the fuel pump. I was going to mount the cooler on the back side of the baffling and I hear there is an approval to eliminate the fuel pump. I too am going with the Sensenich prop, did you already get the field approval? I am needing an air box if you know where one is available also. Thanks for any info you have.

Swing by and look at mine anytime. It’s a Avcon conversion. I believe I have a copy of the drawing around somewhere. I’m in Powell.

Greg

WY sage hopper wrote:I am just starting the Avon/Williams conversion on my 170 B but the STC doesn’t come with the drawings....

Did you buy the stc from Bob Williams?
Hard to believe that (even) he would sell an STC without the necessary documentation to install it.

My customer bought the doyn STC from Williams, really just an n number transfer, 3 years ago for $450 and it came with exactly one piece of paper. The STC.

Here is the process to modify the airframe fuel to a gravity flow setup.

Mapleflt wrote:Here is the process to modify the airframe fuel to a gravity flow setup.

Yep, that either IS Fred Dyen's mod, or a copy of same, word for word.

Definitely worth doing if you don't already have an engine driven pump and an electric back up. Save some money and a few pounds.

MTV

I heard there was someone in Powell with 180hp 170. I would like to come over and check it out if you have time. I will be home the week of 12/17-12/21. I have been flying the Bearhawk with Mike Bond so I make it over there every couple of weeks.

I did get it from Bob but it was just the STC paperwork with a parts list. He said he doesn’t have the drawings. It’s to bad that the person who owns this conversion doesn’t want to really do anything with it and is very hard to get a hold of. It took me about three months to get the STC because he will only reply to your emails about once per month.

Awesome! Thanks. I will let you know how it turns out with the FA.

Well after a winter of coming and going, this 170 project is out of my life for now. Completed the panel, everything powers up, all the switches are active, etc. Engine is about 70% hooked up I'd say - needs airbox, exhaust, a couple controls hooked up, cowling, starter, alternator. Obviously the rest of the airplane needs to be assembled too.Customer is waiting on wing repair and his finances come and go so nothing is going to happen for a bit. Here's how it left me...







There's plenty of things I would've done differently had it been mine, but I think it'll be a good plane for him. He's big into the retro panel style, didn't even want digital engine gauges. Behind the left yoke in that pic is a GTR205 and txp.