Tim's XS project - 750cc rephased ported head titanium valve hot cam craziness

[Tim]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

Off to get a crank bearing puller. Sheesh. But it's the best way to get the end bearings off and I guess a nice pipe to bang them onto the new crank

Just gotta decide to completely disable the electric starter. Beyond removing the motor itself, there are internal gears I can leave out as well, saving more weight. Probably silly to leave them out as who knows, maybe 10 years from now I want an electric start on this thing again. Easier to skip the next donut.

 

[Tim]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

Upgrading the front suspension while I'm at it (details on the rear coming soon). Very light compared to the stock front end - will have to confirm the difference but I'd swear it's at least 10 pounds.

 

[Tim]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

For the record the GSXR front end weighs 21 pounds - no axle (which is also very very light). Trees and forks. Will have to weigh the stock unit when I pull it off.

 

[50gary]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST


I have a 2007 GSX-R 750 front end on my '78 CX500 Honda, it works super.
I think the overall weight is not that much different but the unsprung weight is less and the USD tubes are much shorter and therefore stiffer (as well as being much larger in diameter than stock. Back in '03 I did my XS650 with an R6 front end de-raked to 24 degrees, and mono shock. That bike also rides like a new bike. Keep up the good work fun build to watch.
Cheers, 50gary

 

[Swagger]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

Tim you'l want to brace your neck if you're going to hit it hard in the twisties. The last xs650 I rode had some R1usd on it and you could see the neck flex in the corners! That old frame just isn't up to the stresses that much improved front end will be putting on it.

 

[707racing]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

I have an 01 SV650 front end on mine with a 'Busa steering damper. It works fine without bracing, but the forks aren't upside downers. Put some tapered rollers in there while you're at it.

 

[Swagger]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

If you're not riding them hard then it'll likely never be an issue.
Pretty paint.

 

[Tim]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

See, always count on someone smarter than me to point out what I should have considered before hand

For the moment, my goal is a straight line as fast as possible. But I will give some thought to bracing the head at some point. I could do it under the tank and spray paint the damage - don't want to tear the entire bike down for new powder coat just now.

It will for sure be getting a steering damper as it's required for the run on the salt. Gotta sort out the mounts for my Suzuki 4LS brake stays. Might end up running the forks 'backwards' and trimming the caliper mounts down, just leaving the lower mounts in place for the brake stays.

Good news is the length of the forks from the bottom of the steering stem to the axle centerline is almost identical - might be 1/2" off which I can play with no problem.

 

[Tim]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

Quick update - some reading and discussions have swayed me and I've replaced my Taiwanese MikesXS crank bearings with Yamaha OEM Japanese units. Also bought all-new Yamaha OEM oil seals as well, even though I'm staring at the unopened pack of aftermarket ones on my desk. Want the engine to be tight and run forever after dumping all this $$$ into the rephasing / 750cc / titanium fun stuff.

Oil seals in hand, one bearing on its way to me via Sonreir in the US and another coming to my local Yamaha dealer. Should be assembling in a week or two. Patience will pay off on this one.

 

[50gary]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

I would not run a front brake at all for the Bonneville trials. Seriously, why carry the weight and frontal area wind resistance? You won't be going very fast and don't have to brake hard, just slow down. I'd pick up a pair of FZR 41mm forks/triples (bolt up to the XS with bearings) service them and hit the salt. Run a mag wheel without rotors. There's a guy on our CX500 forum that does the Bonneville speed trials, he hits about 145 - 150 without a front brake. I think his forks are also 41mm Katana.
Cheers, 50gary

 

[Tim]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

Remember I'm not going for any records (would be competing in the 750cc OHC class near as I can tell). Just going for fun and running the bike full out on the salt for shits and giggles

If my SR500 was running regular tires I could grab that front wheel (CB750 front hub - nice and small) loose the rotors and run that but it has Shinko dual sport rubber on it.

 

[Tim]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

Sheesh I'm slow as usual.

But, progress has been made. Just buttoned up the bottom end of the engine. After double triple quadruple checking all the bits were in the right spots, I spread the Threebond 1194 and bolted the bottom end on.

Now I can flip this beast over and start work on the top end which should go pretty quick.

 

[Cloyd]

Re: Tim's XS project - May 10 2010 - suspension improvements

Some new pics. Put new headers on it now that it's running nicely and the new pipes have been treated internally with ceramic coating to avoid discoloring.

Where is that seat from and where is your battery? I have a fiberglass seat but Im not necessarily going to use.

 

[hedrives]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

Tim, great looking build which I just saw for the first time.
Are you going to Speed Week in August?
My build is for this year's event, too.
http://www.dotheton.com/forum/index.php?topic=11466.msg101434#msg101434

Anyway, one thing I noticed was your fuel filters.
SCTA rules do not allow glass filters, need all metal.
You really should get a rule book if you haven't already.
First year out with a car, it took 8 hours to get out of tech, they are really picky.

cheers,
brad

 

[Tim]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

The glass filters broke long ago No filters at the moment.

I'm more likely heading for the BUB Speed Trials. Motorcycles only, less hectic than Speed Week and there's a Run-What-You-Brung class that I can just get an official time slip from.

I was going to buy the SCTA rule book but $10 for the book and $19 for shipping it to Canada seemed silly, especially if I'm not going to Speed Week.

 

[Tim]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

Where is that seat from and where is your battery? I have a fiberglass seat but Im not necessarily going to use.

The seat is a Manx replica from Clubman Racing, and the battery is under the hump. Just put a small Shorai in there and it's great.

 

[JRK5892]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

mna i really wish i could see thepics... for some reason this is coming up wiht "X" in the pics!

 

[Tim]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

They're just old pics of the bike Joe - nothing new.

The engine is coming slowly along. Buttoned up the bottom end and hope to flip it over and start assembling the top end this weekend. Will snap some pics.

 

[hedrives]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

The glass filters broke long ago No filters at the moment.

I'm more likely heading for the BUB Speed Trials. Motorcycles only, less hectic than Speed Week and there's a Run-What-You-Brung class that I can just get an official time slip from.

I was going to buy the SCTA rule book but $10 for the book and $19 for shipping it to Canada seemed silly, especially if I'm not going to Speed Week.

Lot easier to do BUB. You can wear perfed leathers, yada.
I'm an SCTA member, plus I love car stuff.
This will be my 5th trip.

Again, great build.
Cheers,
brad

 

[VonYinzer]

Re: Tim's XS project - ENGINE UPGRADES COMING - AUG 2012 SALT FLATS OR BUST

http://ecta-lsr.com/

Just drive to Ohio to set records Tim...