Nose fork tow-bar blocks

My mill is in the basement (heated) so I saved a lot of the small milling projects for the winter and this was a good day to start taking care of some of those things. Not that this was a hard project (nor does it require the mill) there was no reason not to have fun while fabricating.

I started by facing the blocks that were sent along from Vans.

I don't have a DRO on my mill (not yet) so Dykem and layout it was. I used a spotting bit to locate and start the 3/8" through hole.

You guessed it. I drilled a hole in the block. I did almost make a mistake here. I was about to counter-bore the hole to make it look a little more polished, but then I realized it is the actual bolt shoulder that the tow-bar (push-bar) is going to be attached to. 

After the through hole was in, I milled a set of parallel blocks to set the angles for the next four cuts. Complete.

MT Prop Governor

Not much to see here, other than my prop governor stud length... I installed the MT prop governor that I bought off of Todd. I have to do some digging to check on the length of the prop governor studs that came on my Thunderbolt. I know people typically have to install longer studs here, but I really feel like I would like to shorten mine up a bit. The gears lines up just fine, and there are threads a couple of threads into the governor flange so there is no need for my washer stack to be on there but I had other things that I wanted to get done today without rabbit holing into a broken stud. So I loosely installed this for the time being and will come back to address it later. I probably should have left it off, but I am in the mode of getting things out of boxes and onto the plane so I can clean up my inventory a bit.



Speaking of cleaning up the inventory, I ordered a top mount governor cable bracket with my show planes cowling. This lined up just as advertised. I did have to remove the fuel injector line to route it through the bracket, but other than that, everything looks great.

Brake and Fuel Line brackets

With the addition of braided stainless pressed fitting lines, the under seat hose management needs to be slightly modified. The original design calls for installing grommets prior to flaring the ends of the cut brake and fuel lines.

I originally had 3d printed some brackets for holding the hoses in place. I wasn't happy with the nylon print material and stepped it up to metal. I ended up using 3/4" by 3/4" 6160 1/16" aluminum and picked up the original 2 holes from the floor angle. I then put a couple #12 holes in for Adel clamps.

 

I then riveted the fabricated angles to the floor with 2 LP4-3 rivets and bolted two adel clamps to hold the fuel and brake lines in place.

MTV-12-B Spinner

I was making a spinner template last night so that I could start fitting my cowling. I didn't really think about it last night, but as I was laying out the board I had an issue with fitment. (don't mind the non-concentric circles, in the quasi-center of those dots are the real layout points)

The issue I had is that I started with the outer circle (15").

Thinking that I was just mis-remembering the spinner diameter I grabbed the spinner and laid out another line.

That went fine and everything bolted right up to where it should have been. But something still did not feel right. I went over to the show planes website and low and behold, the cowling is designed for a 15" spinner. So that is a bummer. I am not sure where the mix up was, but I think it all started with me assuming that all MTV-12-B spinners were 15".

I guess I have my first parts mix-up.

MTV-12-B Dimensions

One of the weekend tasks is creating a jig for the cowl fit up to take the place of the prop and spinner. I read a while back on the reliable internet that the distance between the spinner plate and the hub flange was 40mm. I did not want fit my cowling based on some internet numbers so I waited for my prop to arrive so I could take the measurements myself.

The first measurement I made was to the aft spinner cap. This looked to be 1.9". At this point I was completely assuming that the spinner itself was going to end flush with the aft plate.


Going to the manual, you will see that this is not a good assumption. When you fit the spinner onto the assembly you see that the spinner extends beyond the aft plate. With the spinner installed, there is ~1.55" between the aft most part of the hub flange and the spinner. I would really like all these numbers to add up, but having triple checked my setup, 1.54" (39mm) is the number.

Mounting the Engine!

With my parents in town and my dad ready to spend some time in the garage, it was finally time to hang the engine. The long story short, this was a lot easier than the stories I heard with the motor mount not lining up to the mounting ears. With the engine load leveler on the hoist, this is actually a one person job (its not like you are trying to get the engine bell housing bolts in place while laying under a car!)

I would say the thing that took the most amount of time was getting the lower mounting ear bolts torqued. Not that it was impossible, it was a bit annoying and I ended up taking the rear down tubes off of the sump to get at the nuts.

I am happy to say that everything fit first try. That said, I am going to pop the engine off and re-weld my cross bar on the engine mount. I previously lowered the cross bar in order to clear the sump. I will admit, that when I measured everything up, I never fully mounted the engine mount to the engine. I was looking for about 1/2" of clearance, which I did end up getting... And then I torqued the engine mounts and took the weight off of the engine. I ended up with about 3/32" of an inch when all was said and done. While that may be fine, there is no reason not to re-weld this because it is going to take me all of an hour to take the engine off and put it back on. Plus, since I have procrastinating some building I have been doing a lot of 4130 TIG welding to keep my skills up. 1/16" 2% ceriated tungsten with some 1/16" ER70S-2 does a much better job than my previous 3/32 setup.

Mounting Ear Torque

I have read a couple of posts on people not being able to get a torque wrench on the mounting ears. I figured I would go with the calibrated arm as well, until I uncrated the engine. All four of each of the mounting ear bolts are reachable with a torque wrench and some torque adapters. Just remember that torque adapters are to be used 90 degrees to wrench as not to multiple the length of the arm.



This was fine and dandy for the top ears. The bottom ears are another story. I ended up removing the rear intake tubes and torqued the forward facing bolts with a combination of an open-ended crow-foot adapter, 3/8 u-joint, and 6 inch extension.