Mixture/Prop/Throttle replacement for 180hp 170B

[Wxbee]

Hello all!
Still loving the new to me 170! But while the wx has been garbage I keep digging into items I probably shouldn’t ! I have reached out to a few members, but thought I’d get some last minute advice before I purchase new cables. I have been doing the leg work so my mechanic doesn’t have to, and exhausted the search function, so here we go!

I have a 170B with a very old Avcon conversion 1982 I believe. All of the cables look quite rough and the propeller cable has a loop in it at the firewall?
Is this normal for these conversions.? My Mx and I don’t think so and are ready to replace. So, what size and how are guys routing it that have the conversion and have replaced it?? It seems like a very tight bend to do without the loop?
We are pretty confident the that the throttle and mixture are easy replacements as McFarlane pmas are for airframe not engine. (Not that that matters to me or my Mx) just like the mcfarlane stuff.
Thanks all!

[redacted]

If you pull the old ones just measure and get equal length replacments from McFarlane and you're good to go. The loop in the prop cable is a service loop, rather than cutting it down. Sometimes it's easier to do the loop.

[cessnut]

I would not install an engine control cable with a 360 degree loop in it. Measure and order the correct length.

[Wxbee]

Thanks all! I agree the loop doesn't seem right. But if that is normal I don't mind replacing, I guess I'm just reaching out to see if anyone has a loop on there's. This 170 seems to be a little wonky, perhapse it's the wrong bracket attached to the prop gov? Or it seems like the prop cable may be coming out of the wrong hole on the firewall? Lots of variables, I appreciate all of my virtual hangar neighbors who chime in!
Thanks again

[c170b53]

I think it makes sense that there’s a loop in many 170 conversions. The governor (at least on my Lycoming is mounted on the rear case close to the firewall) operating lever to which the cable attaches is at right angles to the dash panel hence the push pull (inline with respect to the longitudinal axis) action of the cable has to operate a lever which swings parallel to the firewall. Apologies if my description leads to a sense of vertigo to the reader, Rereading previous entries the definition of what is a loop might be misconstrued by a reader without a pic; 180 degree loop seems correct whereas a 360 would be really just silly. Posting a pic tends to help understand situ-a-tions.

[Wxbee]

Thanks Jim! So you do have a loop? 180? As well? Your description doesn't give me like trying to upload a Pic on this forum! . First Pic is "the loop" second Pic is just the firewall pass through and the prop gov attach point. Thanks again for the help!

[c170b53]

Mine is very similar, i’ve routed it a bit more forward and away from the engine mount ( mine a 0-320 Doyn not a 360 ). I don’t think you have a problem unless of course the control isn’t smooth. I believe the Del-Air conversion C/S control routing is the same.

[Wxbee]

Jim, thanks so much! Unfortunately yea cable is garbage, also 2 adell clamps have broke since I owned it. The Clamps attach prop cable to bracket that is on prop gov, so something is going on with it!

[sfarringer]

It's a little hard to tell in the photo, but if the cable is clamped to both the firewall and a component of the engine, and if the clamps are not fairly widely spaced, then something has to give when the engine moves around a little in its mounts.

[c170b53]

I thought the association might have the Avcon engine conversion docs in the library but when I found their listings the hyperlinks didn’t work, so Bruce or George might know the real story there. There’s purportedly a controls installation doc which might shed light but like some of early conversions much is left up to the installer as the instruction illustrations are not really blueprint like. I cannot see the bracket on your governor to make a comment on it but obviously the cable end sheath needs to be well anchored. The swaged end of the control should have a flat end that is captured in the bracket, after that clamping the cable need only be done to keep it from fouling on the engine mount in my opinion.
There’s a few Avcons out there, they might chime in with their installs.

[Wxbee]

I scoured the forum as well and couldn't find any avcon guidance. My mx has herd of guys using Vans RV parts, citing that there is no STC support anymore? Any avcon guys herd of this? Particularly prop and throttle brackets?

Found out how to resize pics on my phone so whatch out now!

[JohnNielsen]

My 1955 Super 170B with DelAir O-360 uses both of the brackets shown in the pics on this thread. They fit perfect and have continued to work for 400+ hrs now. We referenced a section of AC43-123 related to control cables as FAA Approved Data.
John