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View Full Version : Outboard engine crankshaft center main split outer race search



OUTBOARDER
07-21-2013, 11:54 AM
working on the project and need a Bearing with Split Outer Race.
Looking for 1.625" - 1.5" O.D. Split Race.

PART # & Dims of AVAILABLE SPLIT OUTER RACE bearing you know of would help.

OUTBOARDER
08-06-2013, 05:20 PM
220 grams , found centermain sleeves to use for custom 56, 49 or 45 rod

Powerabout
08-06-2013, 06:03 PM
are you saying you can create a custom aluminium rod and use a centre main as the big end...
clever!!

OUTBOARDER
08-06-2013, 11:34 PM
Spoke to Second Effort Tech who develeped Mod 50 Porting for the Engines sent to Europe back in the 70's.
From our many discussions he said the short coming of the engines were the cast steel connecting rods, which he said limited the rpms of his engines to 8,800 rpms. He knew there was room to make more power but bottom end limited his mods. The rod vendor has made custom outboard engine rods BUT there is a relatively large min order to produce rods with "fractured" big ends for use with split roller bearings.

The 220 gram total includes the Split Bearing Outer Race for the Big End and Sleeved Small End opens up use of Titanium with ARP Rod Bolts. will also bring engine into balancs without adding mallory metal to crank.
My next step will be to have FEA performed by rod vendor , refine design and get a set made of Ti Rods for use with a set of custom forged aluminum pistons and lightweight connecting rods to correct rod/stroke ratio to reduce piston side loading and max acceleration. Two stroke with 2.344" stroke doesnt reach peak rpms untill 10,000 rpms or piston speed of 4,000 ft/min based on calcs from modern two-strokes.

I am not implying that this is the only concern in making more power but are some of the parts needed to get there with a more acceptable reliability factor.

OUTBOARDER
08-08-2013, 06:45 PM
There are some relatively new Aluminum Alloys and Processes out there one vendor has succesfully made rods that are used in small block V-8's on the street with reliability . the down side is they end up weighing about as much as a Titanium rod with the split race. Would help stuff crankcase of two stroke though................