Curtiss Jenny Restoration

Welcome! We hope you enjoy following the restoration process of a 1918 Curtiss JN4D Jenny. Once completed, the aeroplane will be flown and displayed at the Candler Field Museum in Williamson GA (30 miles south of Atlanta). You can contact me below by clicking on "VIEW MY PROFILE"

My Photo
Location: Peachtree City, Georgia, United States

Monday, August 10, 2009

Fuel Tank Cradle and Firewall Pattern

It was time to tackle the firewall. After studying the drawings for a while, and a frantic phone call to Paul Dougherty, I was able to patch together enough information to make a cardboard pattern.

I transferred all the dimentions from the Curtiss drawing onto the poster board with one exception - since the Hisso engine does not have any downthrust (as does the OX-5) I did not cut out the slots for the fuel tank cradle. The slots would be in the wrong location for this airplane.

Believe it or not, the firewall was a perfect fit. I have to pick up some galvanized sheet steel later this week to make the actual firewall. The plans call for 20 gauge (.035) steel.

I also made the two straps which hold the fuel tank. The material is 2 in. wide .090 strips. I found the dimentions on the drawings were very accurate. This was thick stuff, so bending took a bit of heat sometimes. The design calls for 3/8 in. strips of spruce and 1/4 in. strips of felt to screw to these cradles.

Here they are after a coat of primer. The holes need to be drilled yet, but I'm waiting for the spruce to be cut.
Interestingly - because the Hisso has no downthrust, the fuel tank does not need to be angled like the JN4 D with the OX-5. This theory was reenforced by two drawings I saw in the packet - one with the fuel gauge angled (labled JN4 D) and one with the fuel gauge straight up and down (labled JN4 D2).
The D2 was supposedly the "advanced" version of the Jenny with a Hisso engine, but never went into production. Unfortunately, a lot of the drawings are D2 prints. This frustrates anyone wanting to build a JN4D. The prints are close, but not the same as a straight D.
See, I'm building a JN4D with a Hisso, just like a barnstormer would have done in the 1920's - remove the OX-5 and drop in a Hisso - when they wanted to "soup up" their Jenny So, the firewall forward D2 information is very helpfull.


Post a Comment

<< Home