180 horse conversion questions

[zero.one.victor]

I have a couple questions:
1) Is the battery relocated (for CG purposes) with the Avcon or DelAir O-360 conversion STC's ? (or with any other Lyc STC that may be out there)
2) What's a typical W&B after the conversion utilizing a constant speed prop? I realize every airplane is a law unto itself, I guess I'm looking for someone's real W&B figures- either weighed or calculated is fine.
Just for comparison, my 145 horse ragwing (empty, ready to gas & go)weighs 1,332 #, CG is 39.1".
Also curious what the weight of a c/s prop is versus a fixed pitch- the 170 TCDS sez the McCauley 1A170 weighs 33 pounds versus 60 for the old obsolete McCauley 2-speed controllable prop. I'm wondering if a battery relocation required by the c/s prop, might not be required if a fixed prop is used --if allowed by the STC, of course.

Eric

[N170BP]

You could always install one of those Odyssey PC680 GelCell batteries
+ battery box, which saves (I'm told) 17 lbs off of a stock
early 180 installation (no 12 foot long heavy cable running aft +
you get rid of the stock/heavy lead-acid battery).

The Odyssey has more cold cranking power than the Gill too. That
combined with short connections/leads to the starter makes for a
much more effecient start (less drain on the electrical system).

Would require a 337 though....

[Roesbery]

Don't know about the Del Air but on my 53', (done back in the early 70s') the paperwork says something like " no change in weight and balance" after the figures for engine and prop. You have a 4 cylinder engine replacing a 6 cylinder engine. The prop adds enough weight and moment to bring the overall weight and moment back up to the 6 cylinder engine and prop weight. That is for the O-360 A1A only, other versions of the O-360 have different weights. The battery box only needs to be modified so that the battery can be removed out the side instead of the top because of the motor mount. The ones I have, and the others I've seen have a hinge on the end of the box so that after removing the lower cowling the battery can be slid straight out. The Cont IO-360 and Franklin are totally different ball games as to weight and balance

[c170b53]

I could be all wrong here! I think the older steel hub propellers in the early conversions probably called for the battery to be placed aft. H.D. sells a STC to move the battery. His c/s alum. hub conversion does not need the battery moved but you might need a weighted flight bag in the cargo area to put you at the FWD limit. I put my battery in the back because I want to remove the back seat to give room for mountain bikes. The battery cable probably weighs 15 lbs. I'm not sure what a back seat weighs but I'm hoping I'm close. I havent done the weight and balance that's next on my to-do list.

[zero.one.victor]

The back seat in mine weighs 32 pounds at station 76". Removing it moved the CG forward 0.9". Then my (single) 180/185 jump seat installation added 10 pounds at 72", moved the CG aft 0.2".

Eric

[Dave Clark]

Eric you're in luck, my logs are here at home right now.

Mine, (Avcon) has the battery box on the firewall but moved to clear the motor mount. It's just below the top cowl and just to the left of center. The cg is at 39.21 and it doesn't seem nose heavy even with just two on board.

My weight, calculated for some time now, is 1330lbs. And I will NOT be weighing it!

BTW I use a Concorde RG-25XC battery.

[jon s blocker]

Eric, My '53 with a Del Air conversion does not require the battery moved back, that being said, I did it anyway. I have an 0360 narrow deck with a hartzell 80" C/S prop, w/dampner. I moved the battery back behind the baggage compartment, also I have installed a Javelin tank, which forms the floor of the baggage comp. These were all done on Del air STCs (not the tank), along with a Y yoke and new inst. pannel, (also Del Air STCs).All these things add weight, as my lead sled is testimony to. My empty weight is 1440. You start adding 13ft of 00 copper cable to the front, tail pull tubes, full IFR panel and the weight goes up fast. The good thing is that the CG from the factory was 39.0 inches, now it is 38.95 inches, so I have done a fair balancing act with the equipment on board. I would love to have a none painted A model with an 0360 and C/S prop with BASIC panel and NO frills. I guarantee it would be a rocket. on

[Jr.CubBuilder]

What RPM is the Lycoming spinning to get 180hp? It would be interesting to see torque charts for our motors rather than HP figures. I'm wondering how the torque curve compares between the Lyc. O360 and the Cont. IO360.

[jon s blocker]

The 0360 is rated at 180 hp at 2700 rpm, (usually limited to 5 min continuous max rpm at take off)

[c170b53]

Jon a change in the tread. Could you start a new tread about the new panel, dimensions and control wheel height and the like. Can you comment on Harry's instrument panel. Have a pic to share? I installed thr Avion panel but now of course I'm having issues with the certification. Should have waited for Harry's STC and may have to resort to changing it again.

[Watkinsnv]

Just weighed my 52 170B w/Del-Air & C/S conv 1324lbs @ 41.88 w/unuseable fuel and oil and every mod you could want. 180 gear was @ 21" Scott 10" tailwheel @ 255". L/H main 550lbs R/H main 652lbs T/W 106lbs with a 14lb tare wt bar between the main gear to subtract. Battery is on the firewall. My old w/b figured was 1301lbs @ 38.1 Lance

[zero.one.victor]

Lance, 1324# is quite light, especially for having weighed (not just calculated ) it. Great! Mine (with the bench rear seat) weighs 1,342 in the same condition re:fuel & oil, with the stock 145. The 41.88" CG kinda puzzles me, especially since your old CG was 38.1". Was the battery relocated aft? Your 180 main gear must be off an early (53-54) model with the arm at 21", mine is off a later model & the arm is 18.5". My Scott 3200 arm was 249.5", I see you call your 10 incher out at 255". Did you physically measure all these stations? I see you mention a 14# tare bar between the mains, sounds like that was for measuring the MLG arm? I guess the bigger t/w assembly could account for moving the CG back considerably, I don't know how much more it weighs than the stock 8 incher but it sure has a lot of arm - a little weight makes a biiiig difference way back there.

Eric

[jon s blocker]

Lance, just curios why there is such a large difference in the Lmain gear weight and the Rmain gear weight. Close to 100 pounds is quite a bit, or is that just a typo? Jon

[Watkinsnv]

I think with a light weight starter and using an alternator the mod came out pretty light up front.I moved the battery box to the top of the firewall. I measured the distances from the firewall to the gear and tailwheel. I used a type of elect scale that normally goes on the jack points of larger aircraft. since the 170 has none I used the tow hooks on the mains I just installed and a steel pipe bolted between them. I raised the tail to level the aircraft and marked the bottom of the pipe at both ends about 8 inches inboard. I then drilled two holes to install a small jack point at these positions, placed the strain gauges/elect scales on two floor jacks at these points and raised the mains about 1/4" off the ground. My 170 has paint only on the cowling I have a bird dog main tail wheel leaf spring and a Scott 3450-23 10" tailwheel. I installed 800.6 main tires, solid axles, Hooker shoulder harnesses, Bass tail pull handles more instruments, one piece windshield, bubble side windows and thicker rear windows. This moved my cg aft. Lance

[buchanan]

I have my ‘55 B torn apart for annual and was looking through the paper-work and just emailed my son in AK who also has a 170/180 bragging about how light I am. Then I clicked to the 170 site. 4339B is polished, vacuum pump with two gyros, plus electric turn and bank, two radios, transponder, intercom, 800 Clevelands ,Scott t/w, and Atlee Dodge jump seats which weigh 6 lbs. each.

I weigh without the jump seats 1278 lbs. with a CG of 38.47

This annual I’m installing a light weight starter which will more than compensate for the 80” CS prop I’m installing instead of the 76”.

Best………….Buck