Thorp Air Command - T18.net

I'm disappointed. I thought we had the drawing thing fixed. I e mailed a follow up two weeks ago and did not hear back. Sorry about that. I'll try him again.
The firewall just has three vertical structures. You can see their placement by observing the rivets on the engine side. Of course every airplane is different.
Cubes

Not your fault Cubes. I will take the measurements when I am at the shop and have time. I have a couple of customers eager for me to finish work on their planes before I do recreational maintenance on mine.

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson

I can't say about the 580 cause mine has gone awol, i.e. it's not in it's assigned folder and I can't find it in the other stacks of stuff in my office. That said 604 firewall shows the center two stiffners and 528 Fuel tank cradle inst shows the outer stiffners and 515/516 shows the main gear inst.

_________________
Bruce Finney
N18JF T-18C #262
Yelm, WA USA

Thanks Bruce. I looked at a cradle drawing but I don't think it was the installation. I will have to go back and check. I didn't think about looking at the gear drawings. I am at the shop now and am about to go take direct measurements.

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson

I pulled the top cowl this morning to take serious look at what I need to move the battery but got distracted.


That stack of lead was hitting a nutplate on the nose bowl and starting to cause damage so I removed the lead and did a w&b revision. When I went to put the cowl back on I learned the engine hoist loop had to be removed as well to keep the top cowl from resting on it now that the nose bowl had proper clearance.



I am kind of ashamed of myself for not catching this sooner. I had that cowl off several times over the last year but I guess I never really looked at the installation because it hadn't given me any trouble. Anyway, the aircraft lost another 4.4 pounds today and, since the engine is no longer hitting the cowl, the aircraft feels smoother in flight too.

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson

My hoist loop resides in my fly-away tool bag for the same reason.

_________________
Bob Highley
N711SH
SN 835
KLAL

Wow, Jeff... I've never seen a stack of lead like that on an engine. The builder must have been planning to help Bill W. haul some Model T engines in that bird. The hoist loop on my engine can be stored rotated enough to clear with plenty of room... it looks like maybe your case doesn't allow that?

_________________
John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE

Unfortunately it does not rotate enough. It now lives in the glove box. There is another stack of lead on the front baffle. My desire to lose the lead is why I am moving the battery.

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson

I finally got around to moving the battery to the firewall. After removing the starter solenoid I pulled a cover attached to the airframe expecting to see a master solenoid but found this instead. If it is a master solenoid, it is different than any I have ever encountered. It looks like an old school voltage regulator without the factory cover to me but that doesn’t make sense because that would make 2 on the airplane and the starter solenoid would have been pulling double duty. The two 8 gauge wires at the top were connected to the hot side of the starter solenoid. Any thoughts?

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson

Hummm ? I saw that relay in the Smithsonian when we toured the Thomas Edison exhibit !

RB

That's a DPST relay, we used these for years in the Xray machines as power contactors. Probably was used in the builders home air conditioner. I guess necessity is the mother of invention.
It's not a sealed contactor and if you had a fuel leak , I think the first thing you would remember is a loud noise.

I had one similar to yours, since been replaced with one from B & C.

_________________
Bruce Finney
N18JF T-18C #262
Yelm, WA USA

Thanks guys. A local heating and air guy identified it for me a little bit ago. I will pick up a heavy duty battery solenoid from the National Airplane Parts Association on my way through town in the morning.

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson

Has anyone used one of these light weight batteries?
Recently saw one on an experimental Cub.

Shorai LFX21A6-BS12 Lithium

We've all heard or read about the potential safety issues with Lithium batteries in general, as well as some horror stories like when they were first used by Boeing. That being said, LiFe (Lithium Iron) is purportedly one of the safest Lithium types. I know this isn't answering your question, but FWIW I would not consider anything but an EarthX brand battery at this point in time if I wanted to save weight, etc. with a Lithium battery. They have specific ones that are advertised for use in Experimental aircraft, and detailed technical specifications are readily available for their batteries, much more so than the Shorai for instance. They are made in the USA, here in Colorado. This is from their website:

Our ETX battery series is fully protected by an integrated battery management system (BMS) that protects the cell’s from over discharge, over charge, short circuit, temperature, plus cell balancing to ensure charge levels are equal. Additionally, our ETX Hundred series aircraft batteries have redundant electronic circuits and battery fault indication. The fault indicator can be connected into your EFIS or wired to a 12volt LED light on your control panel to alert you to the state of charge and state of health of the battery.

Their ETX680C has similar specs to the Shorai (just a little more "punch"), but it is also more expensive. They have been pretty well proven in Experimental aircraft now. I don't think I would consider any Lithium-based battery for my airplane unless it had a similar built-in protective BMS. You may already be well aware of all this, but thought I'd just chime in with some food for thought.

_________________
John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE