So, I got my block/case back from the machine shop. It was worth every penny to have a professional with a CNC milling machine do the work of drilling out the two broken studs. His work was incredible and he went as far as to countersink the holes slightly for the TimeSert barrel inserts. Nice, clean and straight holes, important details:
With that done, it was time today to tackle installing the TimeSert barrel inserts that will make up the replacement threads for the head studs on these two holes. I've spent more hours than I should have pondering this critcal step, but it wasn't nearly as difficult as I allowed my imagination to believe it could be.
TimeSerts are an elegant solution for replacing damaged in-hole threads in a variety of materials. They are in my opinion much better than Helicoil wound wire inserts. I ordered the TimeSert install kit from Clark's Corvairs and the recommended length (0.75 inch) TimeSerts from a local industrial supply shop. The kit contains all the tools you need to install these:
First step, drill out the hole to the correct size. The importance of having this hole straight can not be understated. Although drilling aluminum is easy, best to use a drill press:
The brand new bit that came with the kit was very sharp and made short clean work of the holes.
Next up, the shoulder countersink bit. The countersink the machinist put in was quite deep enough. The bit has a cutter which creates a countersink shoulder for the top end of the TimeSert allowing it to sit flush on the surface. Again, the drill press is the only smart way to do this:
Careful application of preasure on the very sharp cutter results in a nicely formed shoulder.
Next up, threading this aluminum hole with the tap provided in the kit. This tap (also brand new) has four cutting flutes and a flat nose to ensure the hole is completely threaded to the bottom. This is delicate work that is only done by hand, so it was important to make it perpendicular to the case, ensuring straight threads in the hole. I used lots of 3-in-1 oil to ease the tap through and keep the threads clean from debris. The secret is to cut 1/2 a turn, back out 1/2 a turn and repeat:
Once both holes are tapped, it's important to ensure they are cleaned out of any cutting debris. A blow gun and compressor is perfect.
At this point everything looks good. Next up is the insert mandrel.
What makes TimeSerts so effective, is their engineering. The bottom couple of rows of the insert are formed in a way that allows the insert mandrel to cold-roll the threads, pushing them outwards and into the surrounding material, locking the insert in place:
First, a couple drops of oil on the mandrel to ease the insert forming the new threads, then thread the insert partly onto the mandrel:
Once placed in the newly cut holes, the insert threads in easy, up to the shoulder stop. Continue moving the mandrel forward (in) until it bottoms out:
Back the mandrel out and the TimeSert stays in place, now permanently attached to the aluminum walls of the hole. Looks perfect!
Was it really that easy? YES!
After cutting the matching threads on the two upper (long) studs that will be used with these inserts, I test fitted one. A good clean fit that will be made real strong with LocTite 620 as per the conversion manual.
I can't explain how relieved I am to be past this part of the head stud saga. Next steps will be fastening all the studs in permanently with LocTite 620. Before that, I need to clean the block completely as there are still areas that can use some detail attention. The suggestions are to either hot tank the block at a tranmission shop, use varsol with stiff brushes and 3M pads or maybe media blast it. Ron has a sandblasting machine, maybe that would be easiest. More food for thought.
The other task I completed was the removal of the oil pick-up assembly. It is press fit into the aluminum:
A little gentle tapping from the oil passage end of the block witha pirce of dowel, and it came right out:
Overall, a very productive 3 hours. I'm tagging this blog entry as a milestone because it has been bugging me for months to get past it. Barring any further surprises, this will be my airplane engine.
Now back to making other airplane parts :)
First off, I ordered my plans set today! Hopefully it won't take long to be shipped from Zenair. Once I have them, I'll have my very own serial number and I can start going down the road of endless inspection paperwork that needs to be on file with Transport Canada. I'm trying to decide if I want to reserve a good registration (call letters) or wait and see what they assign..... but that's a bit premature.... ha!
Four more hours in the shop today. Continued to open up the salvaged 701 wing. Wasn't too surprised to find damaged structure inside. This is the top of the wing at the root where it attaches to the fuselage. It likely got twisted back from the impact out on the tip of the wing. Lots of rash damage, probably from improper handling after the crash.
Flipped the wing over and with some drill effort, off comes the wing root fairing, fuel cell inspection cover and lower wing skin. Whomever built this wing wasn't much of a craftsman (or craftsperson). Lots of rivets where they shouldn't be, and lots of rivets missing from where they should be. We also discovered the rear spar channel is way under gauge from what the plans call for. Seems like someone decided to take a shortcut.
Next step was to drill out the rivets holding in the incorrect rear channel:
It came out easy, but it too has holes in all the wrong places.
Easy to fix/replace, but after seeing this, we are truly wondering what else we are going to find.
Next up, straighten the inboard main wing rib (on the left in the above picture). It will require another strip of aluminium (called a doubler) to reinforce the damaged area after we straighten it.
I just two afternoon sessions, I've learned a ton thanks to Ron but I've got a ton more to learn yet!
It took some time, but I finally got back into the shop. The last few weeks have been real busy between work and family commitments, and I'm trying to keep moving forward.
This afternoon, I took another crack at removing the last two head studs. Unfortunately, they continue to be stuck half-way out of the block, and by stuck I mean they don't seem to want to go either way (all the way in or all the way out):
Next, I'm going to try something suggested by some on the interwebs - make a penetrating oil with equal parts acetone and automatic transmission fluid. So far PB Blaster hasn't worked, so why not? It apparently works very well in exactly this situation. So add acetone to the shopping list and check the shed for ATF, I'm certain I have some.
Rather than dwell on this, I thought I'd take the steps to separate the case halves. If you recall, I mounted the block sideways on the engine mount to prevent the crank and cam from falling out of the block as it separates. They came apart surprisingly easy with some light tapping on the non mating surfaces with a rubber mallet:
Getting a good look inside now! Crank is likely trash, way too much rust and pitting on the connecting rod throw bearings. The cam? Hard to say, but it looks bad too and maybe it can be salvaged but probably not. Disappointing, but I already have two good cores for exchange form the 110hp core engine, so no big deal. Found more rodent debris and I think this core has been sitting dry (without oil) for a long time:
Also conspicuously absent are any bearings. Looks like someone decided they didn't need to be replaced yet. That's okay, I'll need specifically sized new ones once the crank and cam are serviced.
Carefully removing the old crank and cam reveals some surface rust on the block bearing surfaces. I think this is more of a transfer of rust staining from the crank and cam and hopefully they should easily clean up:
I was a bit worried about the bottom edge of the block, but then realized that this mating surface is inside the engine (above the oil pan), so small leaks here although not ideal, are not an issue. A close look at it looks like this is the spot someone previous used to pry apart the halves:
They look better once I used the shop-vac to clean away the last of the mouse debris. The inside of this block seems pretty clean otherwise:
One final thing I did while putting away the crank was to try giving it the "ring test". It's something I learned from the FlyCorvair.com DVD. A simple test used to check a crank for cracks (especially hidden ones) is to hold the crank from one end and give it a light tap with a hammer. A good crank will "ring" for up to 20 seconds once tapped lightly.
I tried this.... my cranks rings, but not consistently. The first time it rang for a few seconds, the second time a bit longer but the third? "Clunk". Perhaps I'm not striking it consistently. Either way, this crank is likely junk with all the rust pitting. Just wanted to try it.
But at least it's all apart and I'll be able to start moving towards assembly of my new power-plant!
Next up.... taking out the oil gallery plugs (if they will come out!), start power-washing and hand cleaning everything....
Completed a milestone today with inventory. All parts catalogued, numbered and tagged using the numbering system from the conversion manual. Similar items placed in totes, totes numbered accordingly. All stacked and awaiting cleaning, measuring and disposition:
From top to bottom:
I've also got a bin full of associated hardware bolt, nuts, old gaskets etc.:
All of these were loose items in a pail and are typically filthy and rusty as to be expected from a 50 year old engine. They will need to be cleaned and assessed before making a decision on keep or toss.
Next step will be to build a parts cleaner.... stay tuned :)
So here is a first look at some of the highlights of my find.
There are a LOT of parts to go through and inventory, but I can't begin to explain how stoked I am about my acquisitions.
Most of everything is either salvageable as is, prime for exchange as a core for re-manufacture, or trade-worthy for other things I will need.
Casting numbers (T1208RH) on the dis-assembled core block indicate a 1965/66/67 110HP "automatic transmission no smog" block manufactured on December 8th in either 1965, 66 or 67.
The casting numbers (3878566) on the heads from this core indicate 110HP from 65, 66 or 67.
These are prime candidates for conversion. Two things I haven't found in the boxes yet are the camshaft (but that isn't a game-stopper as it will be replaced by a custom cam anyhow) and the push-rod tubes (cheap to purchase new). Everything else important seems to be there.
The original cylinders, pistons and rods from this 110hp core are in great shape and will be excellent core exchanges.
The crankshaft is the correct model (8409 cast iron) for conversion. It has already (as far as I can tell and was told) been drilled for the prop hub and safety shaft. I'm not sure if it has been nitrided or not, should be easy to find out. Huge savings having this already complete.
The new in box pistons I got with this lot have been superseded in the latest conversion plans with dished and forged aluminum pistons. Perhaps these can be traded or sold.
I paid a bit extra to obtain the prop hub assembly. It includes the machined safety shaft called for in the conversion plans. A new one from William Wynne costs over $500USD, I got it for $50CAD. Great deal!
The second core is still almost completely assembled and appears on the outside to be super clean. The valve covers even have some of their factory chrome finish left on them. The cooling fins are real nice and straight on both the cylinders and the heads.
Casting numbers (T1214RM) on the dis-assembled core block indicate a 1965 or 66 140HP "manual transmission no smog" block manufactured on December 14th in either 1965 or 66. It would be neat to know if both this and the other 110HP block were made within 6 days of each other!
The casting numbers (3878570) on the heads from this core indicate 140HP from 65 or 66.
This block is also a prime candidate for conversion. The heads however would have to be directly replaced with 95HP or 110HP heads. They will be of value to someone, probably a car rebuilder (140HP heads are rare). Of course the crank and camshaft are still inside and the push-rod tubes are there as well. I haven't looked inside this motor yet Everything else important seems to be there on this core too.
Although not pictured, Paul also included new in the box set of chrome piston rings and a David Clark headset (which appears new from the box!).
So, I think it's fair to say I've got a running head start on my engine project. A complete inventory is next. Time to buy some storage totes :)
On another note, I'd be remiss in not mentioning the support for this mission that has been given to me by my wife Brenda. She always seems to guide me away from to good to be true deals to hidden ones like these. Thanks - I love you.
What an AMAZING day Sunday was! Drove to Roseneath Ontario and met my new friend Paul.
Paul is a retired electrician who at one point in time had plans to build his own Corvair powered airplane. His plans got delayed for a number of reasons and he recently decided to sell his Corvair engine collection. Of course we could have talked for hours....
I don't have a complete list yet of what I obtained to post here, but I feel I got really lucky. Two complete core engines, several new parts and a custom work stand. I even picked up a billet aluminum prop hub and a bunch of technical manuals and drawings. More pictures to come when I get to inventory everything. It almost didn't fit in the truck (even the back seat was full):
A great day... sometimes things work out and I like to think somehow my mentor Barry had a hand in this.
Sunday was a combination of timing and a generous seller wanting to pay things forward. Something I will do as well.
What used to look like this:
Now looks much, MUCH better:
The biggest change is floor space. I'm no longer tripping over stuff to work on other stuff. Most of that is from better organization and better work surfaces. And a personal commitment to put stuff back where it belongs.... HA!
It's certainly not perfect. I still have some decisions to make on some of the smaller items and some stuff to get rid of (bonfire anyone?) I doubt it ever will be perfect, but it's a darn sight better than what it was!
On another note, I picked up a digital calliper on sale at Home Hardware during their no tax sale this weekend:
Like the dial indicator I bought a couple of weeks ago, this will be an invaluable tool to measure the engine components as I pull apart the core engine.
Off tomorrow to look at 2 cores that should be acceptable for conversion! Now I have space to work. Very motivating :)
Time until takeoff
Husband, father and 911 dispatcher. Long time pilot with a licence that burns a hole in my pocket where my student loan money used to be. First time aircraft builder. Looking to fly my own airplane.