Separate names with a comma.
Discussion in 'Announcements & Open Forum' started by kopcicle, Oct 23, 2018.
all I can say is , it isn't radio .
78-80 XT/TT 400 turned flatracker/scrambler?
A '79 Yamaha XS650 2FO . I have modified the rear to accept the KZ750B LTD M1 twin 18" disc brake hub . At the moment the front is stock with he the exception of the second brake . The rear is modified only by way of spacers to center the disc in the caliper and turning down the drive hub center to accept more common KZ650 #530 sprockets . The disc itself is a Honda CB200C turned down .200" to fit inside the caliper . The bearings in the rear had to be changed to accept the Yamaha axle .
I found a WM4 2.50" 40 hole rim attached to a Sportster hub and a WM3 2.15 19" 36 hole rim from some dirt bike for the front . Both rims are vintage Akront .The angle of the spoke holes is well within limits for adaptation to the Yamaha and Kawasaki hubs . All I have to do is polish replacement hubs and rims and deliver to the Wheelmaster .
The engine is at present a stock bore XS650 with a 277/83 crank . All else other than a stock XS2 left cylinder decompression valve remains either stock Yamaha or modified Yamaha parts .
I have an alcohol engine in development for the bike . Probably next summer for that project .
Red ? That deserves an explanation . The frame was going to be painted because of 20 years plus of abuse so down to the metal it came . first in a hot tank and then by hand . I'll say this for Yamaha , whatever the paint or process what paint remained was removed by nearly a week in the hot tank . Commercial stripper wouldn't touch it . I had to resort to old fashioned elbow grease to get the remainder.
So where were we ? You wanted to know about red . I had gone the extra mile for a customer several times and he had access to powder coat . The original intended owner wanted red so red it was . A week after it had returned to the shop another customer shows up with the tank , painted rustoleum red .
The rear wheel shows up the next week in the hands of my machinist . The off side caliper was on my lift when I came to work days later .
Yet another customer heard of the project and donated some hoarded engines and goodies like the chrome engine covers and a couple piston sets .
Red it is save for a not very original but appropriate crossed tuning forks logo done in gold leaf destined for the tank . The one other embellishment will be a brass plaque in plain view . So many donated their time effort and parts to this build over the years that I can not in all good conscience let their efforts go unnoticed . Nearly 3/4 of the outside labor was donated . A fair half of the bright work was donated . The rear wheel complete was donated and created untold hours of modification to get it to it's simplest form here . The heavily modified front forks were returned to me after nearly 20 years by a fellow racer . The seat may need replacement even though it looks intact it belongs to a RD250C . A parts bike donated the tapered needle roller bearings for the neck .
An experienced Honda parts guru sifted through seals to get the rear axle assembly finished . A customer taught me 135 x 18 degree split point drill bit sharpening that made going through brake discs near painless . The Wheelmaster has offered to do the wheels . I know the wheels will cost me but just what yet I don't know . For those of you in my corner of the country that know Morrie and Jim I'm sure you'll understand that whatever the cost I'll gladly pay . Having done near daily business with Morrie for 25 of the 40 years I've known him I just don't ask any more .(yes I was part of the tide flat clientèle in the '70's ) I close my eyes , sign the check and have never regretted it . For those of you out here that don't know Morrie it's time you did . All those names and a few more will be on that plaque .
Okay so I avoided it till now I guess I have to answer . Yeah , it's red . Red and chrome to be exact . She wanted it red . Eventually she didn't want me, or the bike, but wanted the bike red . So red it is .
It's a xs650 limited by it's combustion chamber and center crank pin .
The best thing about the over bore was gaining room for quench area and even at that some careful welding to fill in some obvious voids in the chamber .
Some facts .
Alcohol has approximately half the BTU's by volume than that of good gas (not pump)
Alcohol has a greater latent heat of evaporation
Alcohol has a stoichiometric mix 6.5:1 as opposed to 14.7 for gasoline .
Most CV diaphragms and rubber parts as well as the carb bodies won't put up with straight alcohol.Even intake port erosion can be a problem .
The combustion chamber is steel on top and sides while the piston top is aluminum .
Alcohol burns much slower and it's behavior near relatively cool combustion surfaces is way different than gasoline .
toss the BS36-38's
Drop a significant sum on carbs and jets from Sudco (real good people)
Use an old Axtel mag or equivalent
Be prepared to get it wrong a bunch of times possibly torching a piston or two and get used to tearing into it on a weekly basis .
Fixed advance as much as 40 degrees
Jets you can see big screen TV through
Pistons running so close to the deck that at temperatures below 40 degrees the engine has to be heated just to provide enough deck clearance so it will turn over .
Over advancing the timing without enough fuel and "banging" the tune up and having the rod bearings "peen" the crank .
Having to carefully start the bike on gasoline then switch to alcohol .
Freezing the carbs in high humidity .
Having to nearly redesign the clutch or just spend the bucks at Heiden tuning . Might as well change the primary ratio while you're at it .
Adapt XV 700-750 valves , Buy Manley stainless valves or keep an eye out for the titanium valve guy on fleabay .
Hoos racing for the exhaust . They just get it .
Fishead brakes .
A stack of rear tires ,
And on ...
About 75 miles on a tank which drops drastically if you wrist it .
About 78 hp and nearly as much torque in one of the most sensitive to state of tune compilations I've ever owned .
I couldn't keep the thing together as a 360 degree crank . I had to twist the crank and cam . Crank is 277 degrees , You do the math for the cam I'm tired .
This was an outgrowth of the 70's Yamaha ,Shell Thuet , race program with the same caveat as then . Even with the odd crank (the object was to have one piston at or near max acceleration while the other was at minimum ) The center crank pin and it's fit to the counter weights becomes a loose pin in a hand grenade waiting for a place to happen at power levels over 80 hp . Shock load it a lower levels and see the same result .
Was it smart ? No,
Was it fun ? Not really the engine development was a drain on my time and resources .
Was it difficult ? Not really , it's just nutz and boltz .
How close was I at first get ? Left field ( more like Landsdown Street . If you savvy baseball if not nevermind )
Was it worth it ? heh heh heh . Well ok some days yes . Other days it's wtf was I thinking
So here we go again ....
The rear caliper is bone stock 2F0 . I was careful to leave as much of the conversion stock as possible . With the un-modified KZ750B LTD M1 twin 18" disc brake hub and rim the Honda disc centers in the caliper once .200" is taken off the diameter . Now one caution , the disc was "marked" CB200C but I did not take it off myself so I won't swear to it . I'm told that the KZ305 is very similar also so ya pays yer money and takes yer chances . I did turn down one side of the rear hub and I believe it was the sprocket side . I'll know more in a week or so . As the project stands the disc is centered in the caliper and the sprockets are so nearly in alignment that I may be able to let it go . I did have to futz with spacers for hours but it fits . I should say almost fits . I'll have to pull the wheel toward the drive side about .250" to put it on center line but with all else falling into place I'm far beyond complaining. I had considered the modification of the front hub to carry sprocket and disc but going without the dampener was more than I or the gearbox and transmission could tolerate .
No one asked but it's my thread so read it or don't.
So other than 5 X 5 there arn't any other gear heads here? An electrocuted rat got more traffic than custom bike build. Sick fsckers .
I have been riding bikes since 1963 and have built a few bikes in my time. I remember when those XS650's came out. BSA and Triumph bike were bedeviled by those new Japanese twins. A lot of those British bike owners started souping their bikes up because they did not want to be out run by the Jap bikes. I bought a basket case Yamaha XS-850LG.(Midnight Special) Not a true basket case, it was rolling stock with carbs off. 45 minutes after I got it home I had it running. Good bike but a bit weird as a three cylinder engine.
Now I rebuild boat motors. Want some serious HP for your Chevy? I can do that.
454 CID .400 tall deck BBC
Modified 348 CID crankshaft
L88 heads with lightweight valve gear (old skool, Today I'd use Dart products)
Sheet metal manifold
A "REAL" Powerglide with external trans-brake
10" torque converter
and someplace to put it
A 1966 Chevy Malibu would be good. You could go and race the 405 in Oklahoma with it.
I built a destroked short rod 454 for alcohol and a blower, they took it for dyno testing and ran it up to 10,000 rpm and it did not blow up. Thanks to Kiel machine shop for the dynamic balancing job.
1971 LS6 beefed up.
The bike you put that in will put EJ Potter to shame.
PS: The electrocuted rat fan community is actually quite a bit larger than most people would believe.
Elon was my kind of nutcase but no, that rat will never find it's way into a bike.
Ahh go fast,looks a work of fun in progress kopcicle.nice clean work.
Go fast cars i had a 68 chevelle ss 396 engine died bought a 475 hp 427 with tripower. Then to a 72 hemi cuda. Wish we could buy new stuff like they were in late 60s early 70s. Thank your insurance n government for killing geat machines
I had a 1967 Firebird that was on of those special order jobs. Tri-Power 400 cuin, rock crusher transmission and functional hood scoops. I put a Ford 9" with 4:11 posi-trac. My EX-brother in laws still talk about that car, 51 years later. They said it was the fastest car in three counties.
The car paid for itself, It was the most expensive car I ever bought, $7500 dollars. That was 1 and a half Cadillacs back then. I had one guy wanted to race for pink slips at the end of the run he blew by me and kept going, I never did get his pink slip.
I could have used a new Dodge Charger back then.
dang we sure cant buy much muscle now maybe a roush mustang or a gss modified mopar .
Speaking of gss i went to chicago to gss with a friend.we drove a new hemi charger home that gss reworked into power.ghosts at grand spaulding street now