TZ250/350 Landspeed bike

[EE]

So.... I retired bike 254 my RD250 landspeed bike after the last race of the year in Nov of 2020, cleared out a nice spot for it against the back wall of the shop, cleaned out the fuel system and parked it.. Then I went to the first race of 2021 to work in MC inspection and all.i could think about all day was man I should be out there lol!!!! So it didn't take much arm twisting for a friend to talk me into one last Landspeed bike.... This time the goal is to see how fast I can get the old TZ250 and TZ350s to go :) I also have a TZ700 cylinder I'll run as a 350. So this should be fun! To stay period I'm using a TZ250G frame that I'm modifying right now. The G was the last TZ250 to use RD based engine cases so this is able and I'm setting it up to be able to accept, RD250,350,400,TZ250,350 and half TZ700/750 though the plan right now is just to run the TZ based engines and my current RD250 engine. Well here we go!!!
Start with one TZ250G frame but you'll notice the subframe is all wrong. One of the reasons for switching to the G frame is to have room for anything on the intake side that I want to do and that means getting all that subframery out of the way and starting over.

[SoCal250]

 

[m in sc]

 

[Czakky]

 

[Chris V]

EE  are you thinking BMST at end of August

[teazer]

Interesting project. How about a 3G3 barrel modified to take large reeds? Reportedly they were a lot more powerful than any other 350 or 375cc combo up to the OW31 which IIRC had 3G3 ports and small reeds.

Following along.

[EE]

Hi Chris, No I only run at ElMirage (well and the 2 years we got to run at Muroc again). At (intentionally unmentioned speed) mph I can be at El Mirage in an hr and a half, theses bikes like the shorter course there, and I don't have to deal with salt corrosion..
Teaser oh I've got some fun things with reedvalves planned :) :) :)

[pdxjim]

Go go go!!!!!

... and proud to mention your porting feels super strong on my LC!  Thanks so much for your help 👍

[EE]

Ok a little update: For those of you that know me you know that my mo is "Hard work and Good science" on a shoestring budget.. So to save time and money I'm borrowing the front end off bike 254, alot of time went into it and it works great, it's a mix of 250,350 and 400 parts. So I'll use a 400 lower triple clamp because that's what I used on bike 254, they come with an undrilled boss for a steering dampener. RD250 drum brake triples would have been slightly narrower (narrow is good) but that one doesn't have the boss. I can't use the TZ triple clamps because their 35mm as opposed to an RD's 34's (except Daytona at 35 of course), and the TZ's are wider and the offset is less. At the same time I wanted to convert to a TZ style stem (No male threads and nut right there at helmet height..). So a bent Daytona lower triple for the stem and a 76-78 lower triple got chucked up in a lathe cut the stem out of the one pressed it into the other, welded and bingo. The lower factory tapered roller bearing on this TZ is bigger than the aftermarket replacement pieces were used to So i cut a piece of cardstock the size of the lower headstock od (see pic) and slid it on and off of the lower triple trimming the steering stops until it cleared. Next I checked the degrees of steering, some classes limit this, so i checked and then added material to the frame stop to get the desired number of degrees of movement.

[teazer]

Cool project. 

FYI, on our RD350 drag bike, I had the OEM stem machined out and pressed in a slightly modified GSXR750 stem I had lying around. Weight may not be as critical on the salt as at the strip, so your priorities are probably different.

Can't wait to see how this project develops.  Thanks for sharing.

[EE]

Alright progress is great. I relocated one brace and added another, and built the upper subframe, fuel tank and steering dampener mounts. i'll run bike 254 once more this weekend and then start swapping things over, then i'll be able to build the lower subframe ect.. I'll run the new bike with my RD250 engine first and then switch over to the TZ combinations.

[EE]

Alright were on what I call "Bonneville break" while the bonneville guys go to bonneville in Aug i get 2 months to make changes before the next El Mirage race in Sept, so the day after the July race things get busy...or bussier.. Bike 254 has been torn down and the new bike is being assembled still lots to figure out, fabricate and weld but I really like how this build is going!

[Czakky]

 

[busa1300]

Cool project. 

FYI, on our RD350 drag bike, I had the OEM stem machined out and pressed in a slightly modified GSXR750 stem I had lying around. Weight may not be as critical on the salt as at the strip, so your priorities are probably different.

Can't wait to see how this project develops.  Thanks for sharing.

Speaking of drag bikes....Martin 131 Dragway 2 stroke meet is coming up.
Think you might make it this year with one of your bikes?
I'm hoping to be there with a stroker....to watch

[bostontrackrat]

Yep! I'm interested!