Thorp Air Command - T18.net

My oil dipstick sits about a 1/4" under the top cowl. And it sits exactly where the side cheeks attach to the top cowl. So, I cant remove the dipstick without removing both the side cowl and top cowl. Obviously not an ideal situation. I tried to massage the tube in order to put a slight bend in it, but that didn't work. Ended up buying a new tube.

So, does anyone have any ideas? I don't look forward to the idea of cutting an oil door in the overlap of the top and side cowl. The dipstick actually sits directly under one of the camlocks that hold the side cowl to the top cowl.

Ryan,

Would a shorter dipstick tube help. I made this one recently for David Read but as it turns out he needs something a little different. It should accept a factory lycomimg dipstick just figure out how much shorter it is than the original cut that much off the stick and remark it.

Wow that picture is really bad. This one may not be any better.

I cut mine down and "spliced" in an inner sleeve . Cut down the dip stick rod to match the full oil level . BOOM !

You can by a "short Lycoming" tube . I've seen them on E-Bay .

RB

Derek: That is one fine piece of metal turning ! I could use a new front door knob !

Yep, I've also cut down a tube so it fits as well. I have to cut the tube to where it is only about 4" long, otherwise my motor mount is in the way.
I have cut a tube down, but I didn't like the way it came out, but that may be my only option.

Derek, I would be interesting in buying that if its David doesn't need it. That's looks much nicer than my splice job. I'll shoot you a message.

Ryan, I had the same problem when I built my T-18 many years ago. I was fortunate to be able to use the templates in Johns shop for all the layout of my skins and bulkheads. I also bought one of his aluminum cowels. When I installed the engine I discovered that the oil filler tube was directly under the cheek/top skin joint with all the doublers and cam locks. I scratched my head and did a lot of thinking. I wasn't about to butcher that beautiful aluminum. I cut a small access door in the top skin as close as I could to the join area, just large enough to get my hand in with the doubler installed. This was great but now the oil tube was to long and even worse, out of alignment with my door. I cut about 2"out of the plastic filler tube and put it back together using an interior sleeve and three pop rivets above and below the cut. I also slathered some sort of epoxy adhesive between the plastic and the aluminum. Looked great but now the solid dip stick would not "make" the angle. I solved that problem by making a flexible dip stick. I removed the solid dip stick, drilled and threaded a hole of appropriate size and cut a piece of Bowden cable the same length as the original stick and screwed it into the threaded hole. I was a little concerned about what would happen if the cable came loose and dropped down into the innards of the engine when I was over the swamp full of alligators so I drilled the side of the cap and installed a set screw. I thought a little more about the alligators so I took a piece of the steel wire that came out of the Bowden cable, inserted it and bent both end over 180 degrees. Added 4 quarts of oil and at the mark installed a double wrap of .016 SS safety wire, doing this for each additional quart up the 8 mark.
Been working well for 34 years and 1500 hours!
Steve Hawley, Bull Swamp, SC. N9008Z
,

I originally cut down the plastic one like Rich, but I found no glue that would hold up under the heat/oil environment. I used some small P/K screws through the outer and inner tubes and put up with the attendant leaks. Later, Bill Williams machined a unit similar to the one Derik made and have used it ever since. One word of caution, however. The paper gasket called out by Lycoming for the plastic unit doesn't hold up to the heat an vibration of the metal unit. I have had best results with an "O" ring of the proper size.

_________________
Bob Highley
N711SH
SN 835
KLAL

My "tube" is aluminum and I cut it down and put in an inner aluminum "splice" . I think I used "JB Weld" or some other high temp epoxy upon assembly and the used cherry max round head rivets to hold it all together . On the exterior seams I put a small bead of high temp silicone . Bob is correct , the paper gasket does not hold up . I think it may "shrink" over time like most of us ! I did some research on the gasket and it seems most every one is using an O-Ring in place of the paper gasket . I even put a bit of Fuel Lube on the tube when I assembled it with the paper gasket and it still "seeps" a bit . Time for the 50 hour oil change and I may put in the O-ring and see what happens ?

In hind sight a one piece unit is the way to go and I'll keep checking E-Bay for the little bugger !

RB

I appreciate all the tips. I figured out I can jiggle and finiggle my dipstick gauge out of the tube with no cutting of the cowling. So, I'm going to leave well enough alone. On a side note, I just buttoned up my plane today and I am going to do the short ground runs that Lycoming calls for in their Service Bulletin tomorrow. I can not wait to get this thing in the air.

Ryan: Limit the ground runs to the minimum . If this a "new" or rebuilt engine the manufacturers recommend as much power above 75% as possible to seat the rings . This was the recommendation that Aero Sport Power gave me .

RB

I hear you Rich. I've been talking to the build shop about how to ground run it before flight. Basically just a few short runs at different RPMs. I should have it in the air this weekend!

I had a similar problem, & machined a new tube out of 2024-T3. Then I also made a new dipstick assembly with an extended handle to make it easy to grab & use. Then I chromic acid anodized both in my own home-made anodizing tank. I used an o-ring on the dipstick & cut my own silicone rubber gasket for the engine to tube joint, which has worked well for 23 years. This picture was taken when I had "P-Mags". I've since reverted back to conventional mags.

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

that's a pretty elegant solution, john. I especially like the extended handle because the short tube makes it difficult to reach.

Good Grief John!!, that thing looks like it was built in a sterilized surgery room with purified air abounding,a team of polish and shine folks fast at work, dust collectors running full blast and the floor continuously being mopped with anti bacterial solution so as not to get the Lyc dirty. Ive seen some clean engines before mostly at car shows, you need to go on tour and show em how its done this thing puts to shame the best of em in a heartbeat, don't you guys have dirt and dust in Colorado!! Dan

Dirt and dust is not allowed in Colorado ! John lands at an airport prior to his scheduled arrival and has the engine detailed ! BOOM !

RB