• If you log in, the ads disappear in the forum and gallery. If you need help logging in, send request for help to: webmaster@southernairboat.com

Oil Leaks Are Normal - Curtiss Jenny & A Lycoming Angle Valve (AV) IO-540 Tear Down

Slidin Gator

Well-known member
If I get lucky my Teslong (perfect name) Chinese borescope will take a charge by tomorrow and I can get some close up shots.

I got to wondering where it was this morning, first I thought my boy had it, but after a full coffee I remembered who I loaned it too. These things are cheap (under $100), looks like I'm gonna be taking mine apart, testing the battery, finding out I need a new battery, ordering a new battery, putting it in and then finding out I could have bought a later version for less than the battery.

Hey look, the primer is dry:) Back to work.

Teslong Borescope.jpg
 

John Fenner

Well-known member
Yeah, I would address those for sure, either send the stick out to Daniel at Powell Machine Inc, 412 Wilson Creek Rd, Iva S. Carolina 29655
He can regrind it.
Or find another stick, the H-290 grind is the profile of the 636878 continental stick, now, being a late model unit, it is likely an integral geared unit, getting the 10° advance in it is a great move as well.
Send the cam followers as well, have them refaced but not too deep, a slight pass and polish is all that is needed, go too deep, you get past the rockwell hardness of the face.

Here is a comment about the cam rotating in same direction as crankshaft but at 1/2 the rotation, the firing order of a Lycoming 6 cyl is 145236, a continental 6 cyl cam is opposite rotation of the crankshaft, firing order is 163254.
So if you take #1, put it on the end and read it right to left you get the same order but reversed.
 

Slidin Gator

Well-known member
Yeah, I would address those for sure, either send the stick out to Daniel at Powell Machine Inc, 412 Wilson Creek Rd, Iva S. Carolina 29655
He can regrind it.

Thanks for the info John, we will be talking more for sure (start looking for a set of jugs). It's going back together now, if I get 200 more hours of run time I will be satisfied. This tractor needs to get back to making hay while I build the next tractor. In the meantime I will collect parts for this tractor.

Last year I had a vine cut the pinion seal on my Dana 60 front axle on the buggy, letting in swamp water and sand. All it takes is 1 piece of sand to jam up the roller bearing and the bearing will wear down and spin the carrier. I run a Detroit Locker in that axle and last year they were showing something like 6 months, 1 year, who knows lead time (I see now they have gone from $550 to $850, but are back in stock). So, no time to waste, pull it apart Monday night, I need it running Friday. I decided to make the carrier stub big enough to get a press on the bearing again. I put a new bearing on with Green Loctite for bearing seating. Gotta love a hydraulic press.

We always running with something about to break, or already broke!

Dana 60 Carrier Repair.jpg
 

Slidin Gator

Well-known member
Here is a comment about the cam rotating in same direction as crankshaft but at 1/2 the rotation, the firing order of a Lycoming 6 cyl is 145236, a continental 6 cyl cam is opposite rotation of the crankshaft, firing order is 163254.
So if you take #1, put it on the end and read it right to left you get the same order but reversed.

It is funny you say this, a buddy called me the other day, he is looking at buying another boat, but it has a Continental on it. I told him don't be scared of the Continental, they have some advantages for sure. I told him basically, whatever Lycoming does, Continental does the opposite, so they are pretty much the same. 🤔
 

Slidin Gator

Well-known member
I'm surprised, the catalog spec cam (LW-19340) is available for around $1,700 new, I was expecting something like $8K or so (price of a new O360 crank these days). New Tappet Bodies for $88 each. Add cam bearings and it looks like around $3K for brand new parts. A $300 yellow tag cam and tappet set would be just the ticket here.

LW-19340 LYCOMING CAMSHAFT ASSY - Aviation Parts Inc.
SL72877 Superior Air Parts Aircraft Products BODY HYD.



LW19340=30_920.JPG
 

Slidin Gator

Well-known member
I hit a wall with this project, the ole exhaust studs are still haunting me. Out of 6 cylinders, I got all the exhaust studs out except 2, on 2 different cylinders, both the inner. The first one I was able to drill out successfully and Hellicoil (along with 10 other threads). One cylinder didn't come out so good. At this point I got her cleaned out for welding. In the meantime, it looks like I blew up the lawn mower today pushing it too hard in wet grass while thinking about all the other blown up and broken stuff I gotta sort out.⛈️

Lotsa folks around here don't talk about their blown up stuff (you know if I'm calling you out☄️). I got no issue hanging out my dirty laundry. Guess like I'm looking for a good man on the tig and/or a P10 cylinder.

IMG_0680.jpg


IMG_0682.jpg
 

Slidin Gator

Well-known member
Moe money and UPS fixes things again. Got in a fresh cylinder today, just after the welder called to tell me my wollered out cylinder thread is filled, come get Tuesday.

Hit er with some paint and let it marinade for the weekend.


IMG_0696.jpg
 
Last edited:

Slidin Gator

Well-known member
Here's the weld repair cylinder.

IMG_0717.jpg


IMG_0720.jpg

After some burr grinding work.

IMG_0722.jpg

IMG_0723.jpg


Finally, work in the JB Weld and let it set.

IMG_0724.jpg
 

Slidin Gator

Well-known member
Aviation engines for airboats are Bastards. Here is an example of why it's not such a big deal. 3 different piston part numbers. 3 grams max difference, including wrist pin.

As Removed Piston Arrangement.jpg
 

Slidin Gator

Well-known member
Valve installation is reverse of removal, just clean everything and coat with 50 weight oil is my standard.

The valve stem keepers are definitely different than the GM/Ford stuff, no long taper.

IMG_0579.jpg
 

Slidin Gator

Well-known member
So, time to load some cylinders. "Loaded" cylinder refers to a cylinder with a piston and rings already installed in the cylinder. A "Loaded" cylinder is installed onto the rod with piston rings still compressed in the cylinder. I like to keep a loaded cylinder in the truck when road tripping.

So 2 questions come to mind when loading pistons into cylinders, Orientation/spacing of the rings and orientation of the piston.

On the subject of the piston, the only thing I find in any literature about orienting pistons in the cylinders is this section from an old Lycoming manual.

Piston Orientation.jpg


Consider that and look back at the picture I show of the as removed condition of the pistons. Even the text on the pistons varies upside down, right side up etc. if this was followed. Just think, if you have a loaded cylinder on hand, it is only good for one side of the motor if you go by the above directions unless you twist the piston 180 in the bore before install.

I consider the above to be more of a standard to remember how it was taken apart vs. something worth slowing down a rebuild.
 

Slidin Gator

Well-known member
Once you realize that the piston can go in either of two positions, the next is ring position. The information is even less available, the answer is logical. The rings just need to be rotated 120-180 degrees apart from each other during installation. They rotate as the engine runs, sometimes they line up, compression drops, motor hick ups, then runs right and you think oh'well.

I set 1st and 2nd compression rings 180 apart with the oil ring 90 degrees from each. It's simpler than trying to do 120 on each.

IMG_0587.jpg



Lube is your friend.

IMG_0590.jpg



Note that I never removed the rings from these cylinders, just cleaned everything up.
 

Slidin Gator

Well-known member
As usual, I don't use the Lycoming tools to load the cylinder. Napa sells a good enough ring compressor that handles the 5.135"+ Pistons. Make sure the rings compress into the grooves when tightening.

IMG_0589.jpg


IMG_0591.jpg

IMG_0592.jpg
 

Slidin Gator

Well-known member
Keep things clean and oiled when loading cylinders. Use wood and just taps on piston to install. If it stops going, don't go large on the hammer, dis-assemble the ring compressor and start over.

IMG_0593.jpg


IMG_0594.jpg
 

Slidin Gator

Well-known member
Great thread, really enjoying reading through and picking up tips and tricks along the way.
Thanks man, always good to know I'm not just talking to myself.

I put stainless 5/16-18 helicoils in all my exhaust stud holes, I use the 5/8" length Helicoils so they extend beyond the end of the stud. I put the Helicoils in with red loctite and let it set for a few days. I've never had an issue with Helicoils walking out. In aluminum they corrode for sure, but the Helicoil adds years. Little known fact, Locktite is an anti-seize agent.

Monday we welded up a broken starter mount hole on my buddies 4.3 cast iron motor using torch and 99% nickel wire. Then we drilled, tapped and put Helicoils in with red loctite. Damn thing started smoother than I ever seen, makes me want to weld on my stuff.

So with SST Helicoils, I can run SST exhaust studs. That's the big picture here.

IMG_0732.jpg

IMG_0733.jpg


IMG_0730.jpg

IMG_0734.jpg

IMG_0731.jpg
 

Alaska viking

Well-known member
Very nice! You are an expert grinder!
I lost an exhaust stud, and need to helicoil it back. Alas, that is a project that must wait, for now. Boat has too much work to do, before winter.
 

Slidin Gator

Well-known member
What torque specs will you use on the exhaust nuts?

The manual calls for 40 in-lbs (3 ft-lbf) minimum for stud installation, then 17 ft-lbf for 5/16 nuts. I've never put a torque wrench on these things, it always takes ratchets and wrenches to tighten them all. I snugged up the studs and then usually just go as tight as I can with a 3/8" drive ratchet and/or wrench, close enough for me. The Helicoil makes the female thread the size (and therefore the strength) of a 3/8” thread. The stud will break before the Helicoil shears out.
 
Last edited:
Top