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Sunday, November 14, 2010

A little bit of DRZ and alot of stripping in Ypsi

Well, first the not so fun stuff, the endless stripping continues, one wall done:

One wall to go:

Now, something a little more fun, the DRZ motor back together.  It had been a stock stroke, 95.5mm bore (447 cc) engine with +1 mm valves and Hot Cams, now it is a +4mm stroke, 94mm bore, for 461 cc's, stock size valves, Hot Cams intake and stock 'DRZ 400E' exhaust cam.  I also threw in Web Cams valve springs and titanium retainers, in case I go to something like the RHC 187 cams or something else in the future. 

Bottom end coming together, the piston is JE, skirt coated by Swain Technologies.  I have done their Gold coating on piston tops in the past, but I've seen more than a few SAE papers now that measured a slight volumetric efficiency loss due to the additional heat in the chamber as a result of the coating (perhaps too effective?).  So we'll give this a try as is:

Head is from a spare motor, stock sized Vesrah valves (nitrided), mild clean up work in the ports, chamber opened up slightly to unshroud the valves with the bigger bore:

Checking cam timing.  Not adjusting, but just making sure, they were both at 106 deg:

Got the bike buttoned up and took it for a ride today, and did some accel/decels to seat the rings.  Feels very nice and torquey, over a small hump at an intersection it pulled the front wheel up in 3rd inadvertantly doing an accel : )  Changed the oil, nothing to note, so now the bike can sit for the winter : (

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