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Last night I worked on mounting the MONSTER ZDZ-180. This is probably 1.5x the engine this airplane really needs, but it'll make it that much more fun. The one thing with the ZDZ180 is that it is a rear carb design so a hole will need to be cut into the firewall.
Joe Mitchell provided a template for the ZDZ180 that gives the proper shape for the cutout for the carb, and gives drill hole locations too. I ended up using both the supplied template with the Laser and the ZDZ template to mark my holes. Terry Wiles (you'll find I go to him for advice quite often) suggested I trace the hole out and then drill a number of holes using 1/16" drill bits. It is tedious work trying to get the holes as close together as possible without having then walk into each other, and the 1/16 bits are FRAGILE! I'm glad I bought a 10 pack because I killed off 3 of them doing this, this plywood is THICK and STURDY, good aircraft grade ply!
The theory is that if you drill them all close enough together that you can just punch out the wood. Well I seemed to have failed, and resorted to a cutting bit on the dremel to open the hole up. Nice and clean...
OK so not exactly my best work. The ply is thick and the cutting bits were walking all over the place with this wood- it's definitely not the cheap chinese wood that cuts easily! I spent a little more time with the cutting bit to clean it up some. I will spend more time with the dremel and sanding drums to smooth it all out. With the firewall being as strong as it is, there isn't any compromising the structural integrity, even with the beastly ZDZ180 yanking it around.
I ended up test-fitting the motor by drilling the upper right hole out as it was market. Then run a bolt through it and position the motor in place using the spacers- I wound up using a 3/4" spacer to get the proper spacing out from the firewall. The spinner will fit tight, I might even space it a little more. When the bolt is snugged down, put a 2nd spacer on the lower left hand side so that the engine will press it into the firewall. This way the entire weight of the engine isn't hanging on one bolt, and your engine will be sitting roughly how it will be when all of the bolts and spacers are in. Once you have done this, bolt your cowl up to see how it fits around the engine.
Pretty much perfect!
I ended up getting 3 of 4 holes just spot on, the lower right hole I had to elongate SLIGHTLY to get the holes to all align up. Once I got all of the holes squared away I bolted the engine up for a final fit.
Tonight I'll pull the engine off again, clean up the hole for the carb, drill another hole for the fuel line to fit into the carb, and get to work on getting throttle and choke servos installed and setup.
Joe Mitchell provided a template for the ZDZ180 that gives the proper shape for the cutout for the carb, and gives drill hole locations too. I ended up using both the supplied template with the Laser and the ZDZ template to mark my holes. Terry Wiles (you'll find I go to him for advice quite often) suggested I trace the hole out and then drill a number of holes using 1/16" drill bits. It is tedious work trying to get the holes as close together as possible without having then walk into each other, and the 1/16 bits are FRAGILE! I'm glad I bought a 10 pack because I killed off 3 of them doing this, this plywood is THICK and STURDY, good aircraft grade ply!
The theory is that if you drill them all close enough together that you can just punch out the wood. Well I seemed to have failed, and resorted to a cutting bit on the dremel to open the hole up. Nice and clean...
OK so not exactly my best work. The ply is thick and the cutting bits were walking all over the place with this wood- it's definitely not the cheap chinese wood that cuts easily! I spent a little more time with the cutting bit to clean it up some. I will spend more time with the dremel and sanding drums to smooth it all out. With the firewall being as strong as it is, there isn't any compromising the structural integrity, even with the beastly ZDZ180 yanking it around.
I ended up test-fitting the motor by drilling the upper right hole out as it was market. Then run a bolt through it and position the motor in place using the spacers- I wound up using a 3/4" spacer to get the proper spacing out from the firewall. The spinner will fit tight, I might even space it a little more. When the bolt is snugged down, put a 2nd spacer on the lower left hand side so that the engine will press it into the firewall. This way the entire weight of the engine isn't hanging on one bolt, and your engine will be sitting roughly how it will be when all of the bolts and spacers are in. Once you have done this, bolt your cowl up to see how it fits around the engine.
Pretty much perfect!
I ended up getting 3 of 4 holes just spot on, the lower right hole I had to elongate SLIGHTLY to get the holes to all align up. Once I got all of the holes squared away I bolted the engine up for a final fit.
Tonight I'll pull the engine off again, clean up the hole for the carb, drill another hole for the fuel line to fit into the carb, and get to work on getting throttle and choke servos installed and setup.
LOL Wish I had a nice field, a sexy van, and this wonderful airframe to fly like you bud.
