Category: Firewall Forward

In light of my last post regarding the heat barrier, I realized I made a mistake in materiel choice for the patches I made for the firewall. I used aluminum sheet stock, whereas I should have used galvanized steel to match the material of the firewall. Aluminum melts at...

This kit uses a sheet of galvanized steel as the firewall and is further covered by a heat barrier to insulate the cabin from the engine heat (and noise). The galvanized steel is good as a fire protectant (per FAR 23.1191), however, I have seen several other builders dismiss...

One minor issue with my engine was that it came from the factory fitted with an optional cooling baffle. This baffle is primarily for installation in an aircraft with a pusher prop configuration, but since my plane is tractor config, I need to remove the baffle to ensure proper...

Continuing with mounting items to firewall. I had to make a decent-sized doubler (160x120mm) to cover all the holes originally provisioned for the 914 fuel pumps. Instead, the gascolator (fuel/water separator) gets mounted at this location near the bottom of the firewall. Meanwhile I’ve also started on all the...

I started mounting components to the firewall. There is a little bit of extra work for me to do since my firewall was pre-punched for a Rotax 914UL engine, but I’m installing a 915iS instead. This means I have some new holes to drill, some holes to cover up,...

My Airmaster propeller arrived! I now have all the parts needed to build up everything forward of the firewall, just need time 🙂 Thanks to COVID-related delays, including lockdowns and sea freight shipping problems, it took over a year for the prop to arrive (the normal lead time is...

When I bought the engine way back in December 2020, I planned to bring my plane to the airport to install the engine. I found space inside a community hangar at the Nashua airport, which I where I will perform final assembly. The hangar manager graciously allowed me to...

Last week I received the custom firewall kit I ordered to install the 915iS on my Sling 4. Shipping took a long time – almost 5 months – but I’ve read it’s a widespread issue in sea container shipping right now. Everything in the kit arrived just fine. I...

It’s been a little bit since I posted, but there are a few exciting developments to share. First, I got word that my firewall forward kit arrived in Torrance CA last week and is on its way to me! This is the long-awaiting custom kit that will allow me...

By request, here’s a breakdown of the technical and cost differences to equip my Sling 4 with a Rotax 915iS engine instead of the Rotax 914UL engine. As a quick reminder of why I’m doing this: +26HP at takeoff power (5800 RPM), +35HP at max continuous power (5500 RPM),...