Attachment 60988Attachment 60987Thanks to Dick for posting the text. Hopefully this image posts.
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Attachment 60988Attachment 60987Thanks to Dick for posting the text. Hopefully this image posts.
Definitely could make a cut on the sides of the rods to reduce weight. Lower is always better. Do some calculations and you'll see that cutting a notch on each side of the rod won't reduce the I value much but you can probably take 30% of the weight out of the middle of the rod.
Rods have been honed round to 1.137", pins were cut & fitted to links. Block clearancing and test assembly is planned for this weekend. If all goes well, pins might be tack welded early as Monday. Watch for pics through the weekend.
Tim
A couple hours were spent making room for the rods, basically duplicating the prototype cutout. Fitting this weekend will include making weld bosses for the bottom end cap, and slotting back-to-back crankcase take up bolt holes: The Mercury bolt pattern is not quite symmetrical. Provided there are no surprises, the plan is to complete first full-assembly mockup next weekend (complete except piston rings). Now we're cooking with gas - Avgas, that is!
BTW: Now that BRF is somewhat behaving, you'll see more images. TimAttachment 61009Attachment 61008
Tight turbo packaging made internal block watering risky, so bypass channels are fed externally. Two bolt bosses were removed from the bottom end cap, and a new one will be welded into place: There will be only two spaced 180 degrees apart. Finally, the carb to turbo adapter was machined. It's off to the welding shop tomorrow. Images of fitted accessories will be posted later this week. TimAttachment 61010
While the carb adapter and bottom end cap are at the weld shop, it was time to complete the cooling system, locate the ECU and methanol tank. Watering will be as Mercury designed it except the rear bank will be fed externally. There are too many fasteners in the turbo mount area to provide a sufficient water channel. Inlet side rear bank port covers will be drilled and tapped for primer nozzles, and ignition coils mount to the rear cover flange, so the only remaining spaces for the ECU are on top of the front bank, or over the upper exhaust cover on the front bank (not smart to position the methanol injection tank over the ECU and/or starter solenoid). Hard to believe, but I'm starting to run out of real estate!Attachment 61017Attachment 61018
What a really neat project this is turning out to be. Thanks for sharing and I'm looking forward to the completion of this motor.
Ignition will be provided by Matt Richardson who developed the "Firefly" capacitive discharge system for the Oregon river racers. He bench tested a version modified specifically for the 888 that fires in pairs (remember only four firing events per revolution, two cylinders at a time). To learn more, go to: http://southsidelabs.com/ignition.html
Attachment 61020Attachment 61021
Glad to see you opted for a more powerful starter. The stock one would have burnt up!
Jeff