Heater Installation and Firewal Sealing

Another builder, Dick G, also from Texas, did a great job spec'ing out his heater installation.  When I saw his pictures, I knew I would have to follow suit.  First order of business was to mount nutplates onto the heater unit, which consists of a small heater core mounted to 2 large computer cooling fans, as shown below.

Also appearing in the inlet and outlet barbs are some 1/4 inch aluminum tubing which I pre-bent before installation of the heater hoses.

After determining what I hope to be a good location with respect to the throttle cable and the as-yet-to-be-seen Skyview avionics, I installed the unit with #8 machine screws and aluminum tubes.

The next brilliant idea I also stole from Dick.  He had installed a small ball valve on the passenger side of the cockpit to regulate the effectiveness of the heater from completely off to completely on and everything in between.

Plumbing complete on the return side of the heater.

The return line comes up through the instrument panel shelf, adjacent to the map box (not shown) and exits the firewall via a brass bulkhead fitting, shown below this picture.

Return heater line exiting the firewall.

 The inlet side of the heater as it emerges from the firewall is shown below.  Again, a bulkhead fitting is used to manage the firewall penetration.

As usual, the strain relief for the hose via an Adel clamp.

Firewall side of the inlet heater line.

The proposed routing of the inlet heater hose that will run beneath the engine on its way to the pick up point on the head.

Shown below is the engine being pulled from the firewall, hopefully one last time, prior to sealing all rivets and unused Rotax nutplates.

  

I had reasonably good luck using some shop brushes cut down to about 1/4 inch to apply the Proseal.  I tried a new technique to facilitate spreading it around.  Previous threads on VAF addressed the use of a thinning agent to make for easier application of Proseal.  According to one poster, the manufacturer of ProSeal allows for the use of up to 15% toluene by weight to thin down the product.

After mixing my goo, I put a small bit of Toluene into the mixture and what a nice surprise, the Devil's Snot actually became downright friendly to work with.  Now, if it just cures like the unthinned product, I will be very happy.

Every rivet head and exposed nook and cranny got a dab, more like a brush, of Proseal.

Now we play the waiting game and see if it all sets up as expected.

Fast forward two weeks and the toluene-thinned ProSeal is finally cured...but it took a lot longer than I was hoping.  Nevertheless, it is all good and dry and the final install of the engine and its subsystems is under way.

Firewall Forward, Part 5 - Cooling System Upgrade, Oil Lines

 Jan at Viking has continued to develop and refine the baseline engine over time and since I took delivery of my engine over a year ago, there are a number of items I wish to upgrade.  First and foremost is the "tubing kit" upgrade, which circumvents the need for the coolant tank reservoir (not to be confused with the coolant overflow tank, currently mounted to the firewall).  Removal of the coolant reservoir affords greater space around the throttle body.  Freeing up this space makes it much easier to install the oil lines as well as provide for a clearer path of airflow into the throttle body.

First picture below shows the upgrade parts of the tubing kit.

Time to test the fit of the upgraded parts...and to my unpleasant surprise, I find that the new tubing was not fitting.  Shown below are the new parts overlaying the original ones.

 This picture shows the original system removed and replaced with the new, out of dimension upgraded parts - note the lower left portion of the picture and the tubing to radiator mismatch.

 A quick phone call to Jan at Viking revealed that I probably had the first of one hundred parts and the contractor probably threw an erroneous part on top of the lot....and guess who got it.  After putting a tape measure to the main tube, we indeed found that mine was about 2 inches too long.  Jan had me cut it down to the appropriate size and try fitting it into place.  I did and it fit like a hand in a glove.  Another call and Jan had a new one shipped out, with mine (in two pieces now) back to him.

Below is a shot of the offending part.  It should be a bit under 8 inches long instead of 10.

 

Now that the cooling system configuration was finalized, it was time to install the oil lines and associated fittings between the engine and the oil cooler.  Street elbows were mounted and marked for orientation as shown below.

Next the flared fittings were installed as shown below.

Next up was the customization of the stainless steel braided lines themselves.  As previously mentioned, with the ongoing development of the engine, specifically the configuration of the cooling system, has resulted in a different set of oil lines.  In fact, both lines are being shortened - one by about 12 inches and the other by about 2 inches.  With the engine's fittings in place and one end of each of the lines secured to the cooler, I could now measure for the length required as shown below.

Next, came the daunting task of cutting the existing line and installing a new fitting onto the end.  After some internet research, I arrived at the conclusion that the best tool for cutting the braided lines would be the Harbor Freight, 28 inch cable cutter.

With much fear and trepidation, I jigged up the hose, as demonstrated below, and committed cable cutting.  It is not clear from my photos, but a tight wrap of duct tape around the cut site is essential to guaranteeing a nice smooth (as opposed to frayed) cut end.

The pictures I took all came out blurry, so unfortunately you will have to take my word for it.  I was extremely pleased with the results.

First, shorter hose finished and installed temporarily in place.

Both hoses temporarily installed as shown below.

 Finally, a shot of the upgraded cooling system and with the oil hoses installed.

Views from the side and rear.