Recent content by SKmetal7

Nope, unfortunately I don't have a tapmatic. Everything is hand tapped. The orange thing is a high temperature o-ring.

Here's a render for you guys. You can see I changed the rear mounting brackets I think they look pretty sweet vs. the tierod linkages; and finally modeled a carb. And found a cad model of a prop online, it really completes the engine! I still need to figure out how to model wires...

Hmm, that sounds good. I have their buzz coil electronic ignition on another engine that I shelved for the time being. Maybe I'll use that. Anyone ever tried these EI systems from RcExl? http://www.prcmodel.com/modeng/name/onlinestore/category/25

What electronic spark ignition systems do builders use for engines that need a high spark count per second, like the Hodgson 9? The S/S Machine Multi-spark buzz coil is only capable of producing 80 sparks per second, and it's not capable of spark advance.... my engine will run (I hope :p ) at...

Ha! Thanks! Yea, I never explained that... It's basically a supercharger. It will pull in air/fuel and pressurize the cylinders on the intake stroke. I have it geared 2.56:1 overdriven.

pics include titanium pushrods and assembled engine.

The surface finish on the impeller is a bit rough. I'll probably try sandblasting it smooth. The pictures include making the rear sections of the engine, and the valve and lifter bushings.

more pics, continuing from the crank case.

CF, those gears look great! Did you cut them yourself? Well It's been a while since I've updated and the new site looks spiffy! Made a lot of progress.

The crank shaft should be strong enough, it's 7/16" stressproof 1144 steel. I can't really design a larger diameter shaft because of the cam gearing. I'm already at the maximum internal bore of the gear already. I'd like to see that 9 cylinder your designing. ;)

Thanks, guys! The mill is beefy, but the x-y table is stock and has some play in the dovetails, so it does chatter a bit when I push it. I have a question on the springs to use for the valves. What is a good spring rate for valves this size? (3/16 shaft diameter .45" valve diameter, .1"...

Wooo. Been a while, but I have been steadily working on this engine. Many CAD hours, and still have CAM programming to do. I started the cam/ main bearing and cylinder heads, then decided to upgrade my mill. I redid the z-axis on my HF mini mill to make it more solid, bought a treadmill motor...

Ok I've started to make some parts! I started with the rocker brackets, and rocker arms. I started with these since they are set in stone and will not change; and it was a good motivator part, something easy I could crank out many of. I made them out of Fortal Al. Very strong and hard stuff...

I'm going to use gas/ spark for fuel/ ignition. The compression ratio will be between 8 and 9 to 1. ~1% shouldn't make much of a difference in a model engine. This way I won't have to make different cylinder lengths. Its between the recommended CRs for these engines anyway. To get the master...

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