Engine exhaust and cowl internal baffles.

The next step in getting this engine ready was to fabricate new exhaust pipes. The twin pipes that came with my Casler engine were 90 degree pipes designed to stick out the bottom of the engine. That's pretty crude in my mind and a 1.5' diameter tube creates a lot of drag sitting 6 inches behind the prop in the prop wash. I needed these pipes to snake around inside the cowl and exit on the outlets of the side cheek cowls. I started the project by ordering some pre bent tubes from Columbia Mandrel bending. They did a really good job. I ordered some 180, 90 and 45 degree sections along with a straight section of tubing.

raw tubing from Columbia Mandrel bending

this took some time and a lot of cutting and fitting. the pipes were a 3 dimensional bend. I had to route the pipes under the push rod covers and along side the block. This required multiple bends.




















Here are pictures of the L/H and R/H pipes

Left hand Pipe

Right Hand Pipe






























the cowl was buttoned up and the clearances checked once again.

nice tight fit. I have good clearance to the fiberglass cowl. I will wrap these pipes in heat resistant insulating tape.




















After the pipes were fabricated, I started n the internal cowl baffles. The inlet air has to be forced thru the cooling fins. I started fabrication with a cardboard mock up.

This was time consuming. the shapes are just approximate at this stage of the mock up. have a needle contour gage that is very handy in creating offset curves. The baffle plates will be made from .020" 7075-T6 aluminum sheet. the seal edges will be lined with silicon rubber baffle seal. That will be pop riveted to the aluminum sheet.

here is the lower baffle with the cut out mocked up for the exhaust pipes. you can see the small bent flanges that seal the bottom of the cylinder fins.

I made the first one and them promptly bent the flanges in the wrong direction. Oh well practice makes perfect. I should have the baffles all wrapped up by this coming week end. After that, I can do the final trim and finish on the cowl, I will also install the final nut plates and then prime the cowl once more. The next step will be to finish the engine installation and then get a prop and try and start it!!!