Thursday, October 22, 2009

deja vu all over again

This picture probably looks a bit familiar -- both of my road bikes are in pieces, with engine work to be done, and frames to be painted. Two at a time seemed reasonable! The supermono frame and swingarm were locally sandblasted and then primed. I am going to leave the frame in primer for now, using the light grey paint to allow me to inspect for any stress cracks over the next few seasons. The rear swingarm will be sprayed black with "hammer" paint.

I was also able to get the cylinder on the 'mono honed, and it was installed on the case with the new rings, E base gasket, and a liberal coating of oil in the cylinders and on the piston. Waiting for the heads to come back from Sinceros Speed Works. Eddie emailed to say he had recieved the heads and cams -- he just needs to install the valves, new rings, and shim the cams on the bench and send it back. Oh yeah, and I need to give him some money.

This hammertone or hammerite paint is pretty good stuff. Needs a decent couple of coats to really do the job, but it is fairly durable for a rattlecan. About as good as you can get short of powdercoating. On an amazing side note, by using DRZ400 bushings and Aprilia Pegaso torrington bearings, I can do away with the bronze bushings I farted around with for so long last winter... combining the two allows me to use the 17" bolt that also works in the engine case. No more "slip fit" engineering -- the proper torque can now be used attaching the swingarm. More pics in the future will explain.

And speaking of powdercoating, the Ducati frame is off to get recoated gloss black. Meanwhile the engine is on the bench, getting ready to take a trip into Winnipeg. When all was said and done pricing out tools, gaskets, and opening and closing shims, I have decided to let the local Ducati dealer (Wildwood) do it for me. The labour costs will be cut down drastically because the engine is out of the frame. As well, the proper tools and shims are at their disposal, so the turn around time should be much quicker. And when they are done, they can re-set and re-tension the belts. I have been quoted "no more than 4 hours @ $80/hr". Hopefully they come in under the budget. If not, I will certainly make no bones about it!

Wednesday, October 7, 2009

Interesting Finds

As a part of the top-end service, I am dropping the engine out of the frame. This is by no means necessary -- the 999 series is known for its service friendly design... its just that in a few weeks, it will get bloody cold in the garage, and I wanted to take my time and work on the engine inside! Was able to remove the engine in pretty quick order, once I had a way to prop up the rear part of the main frame. A support base I originally built to steady a bike on a trailer was pressed into service, with the frame being steadied by bolts threaded into the rearset mounting holes. Put a jack under the engine and the unit dropped out. Hey, presto, and Robert is your father's brother! (Bob's your uncle...) Looking at the paint on the frame has got me thinking I might make a trip to the powdercoater's while I have it all apart... would look pretty cool in a gloss black.

On to the DRZ -- while I patiently wait for my cams to arrive, so I can send the heads off to Eddie Sinseros, I stumbled across an article in the most recent CycleWorld that talked about a DRZ400 built by Yoshimura for Kevin Shwantz. Of particular interest was the under-engine exhaust system...

Note how "short" the exhaust headers are -- not nearly as long as on other supermono designs. The muffler itself starts just aft of the rear part of the engine -- a tapered cone that extends onto the carbon-fibre bit. Interestingly, Yoshimura designed a 1-2 design -- there is a matching muffler exiting on the other side of the bike (just visible above the rear wheel) -- anyway, this proves that there is some merit to a shorter header design.

Detail shot of the LHS muffler. Very tasty looking, and eyeball engineering indicates these could be fitted to my 'mono without a lot of fuss. Then I looked at the price... $1100 'murican. Yikes! I think I can get a piece of stainless bent into the shape I want for a bit less than that!

Sunday, October 4, 2009

Engine Top End

As I mentioned in the last posting, I plan to work on the reliability piece with the engine. Again, its no powerhouse, but it is known for its reliability, especially when compared to 450 moto bikes. There are, however, 2 known issues when the engine is worked hard at high sustained revs. The camchain on pre-2002 bikes can slip due to a poor automatic camchain design. In the middle of the summer, I replaced mine with a manual camchain by APE. Sorted.
The second known issue is a bit more involved. The valves are weaker 2-piece design, and can come apart after lots of abuse. Again, for piece of mind, I have decided to get proper race valves installed, along with better quality springs. When I send the head down to Eddie Sinceros of Sinceros Speed Works, he will also shim the valves to whatever cams I have... and since I already have the cams out... I'll be sending down a pair of stage 1 hotcams for him to put into spec.
Again, the urge do go overboard is still quite strong, but I need to hold off for awhile and continue to develop the bike. Power is nothing without Control...! The big bore will have to wait.
I did take the cylinder itself off as well, and everything appeared to be in good condition. The cylinder will get a quick hone with a ball hone -- the cross-hatch marks could be seen, but there were a few streaks of increased wear in a few spots. Nothing major. I did check and the piston ring end-gap was well within specs -- not sure if it was the original piston or not inside. The piston is marked ART, which is an aftermarket supplier. However, sometimes when these companies grow they become OEM suppliers as well.

I did get in the necessary supplies to properly rebuild the top end. New base and head gasket, a piston circlip (got a couple extra while I was at it), an new set of rings (ouch!), and that's about it. I decided to get the thinner "E" base gasket, which will increase compression somewhat. Might add 1/2 a hp -- but I always put premium fuel in the bike at all times, so pinging won't be an issue. Haven't sent off the heads yet, as I am still waiting on the cams to arrive. Perhaps I can time the assembly for when Dad or brother Tim show up -- an extra hand threading the timing chain through the head would be helpful!

As promised, I bought the "rights" to the digital photos that Rob Bye took at the track. Again, a pretty weak angle of lean, but I am exiting turn 5 in this shot... I know I had the machine heeled over much farther than this! As well, I've spent a total of about 8 minutes on the bike on a track... excuses, excuses!

Lastly, I'm doing some research as to the "ideal" exhaust header length as I want to get a header fabricated out of stainless by my friends at Cycleboyz. I found an online header length calculator, and after doing some research, came up with the following specs...
Exhaust open BBDC: 65
Exhaust close ATDC: 29
Engine RPM: 7250
cc of 1 cylinder: 434
Results: 26" tuned length from valve head
Primary ID: 1.625"
Tailpipe Length: 22.967" (this is the muffler)

So, the figures above are for an E cam, which is similar to the hotcams. The RPM figure is based on where the HP peaks on these engines. The 434cc is anticipating a bigbore (eventually). The ID of the header works out to roughly 1 5/8" -- smaller than the 1 3/4" I currently use. And of course, the header length is quite short!

The final design might look something like this (quite popular on the showroom floor!)

But, I really don't want to creat a situation like this... even though it is a racebike, and I'm a MotoGPwanna-B... will continue to do some research. I'll see what the cycleboyz guys say. Right now, I'm leaning towards 1 3/4" tubing, and shortening up the whole assembly, although I don't think I can fit a 26" header and exhaust under the engine -- it'll be a bit longer, and attach to the right peg. This saves me monkeying with the rear seat subframe -- the muffler attaches to the peg assembly like on the Gixxer above. I think I can also shorten the TwoBros muffler I have to suit... and by shortening it in the right place, I can cut out the area that was damaged in the previous owner's crash. As always, stay tuned. The frame and swingarm should be back from the painter's in a couple of days.