Author Topic: Salt Racer CB 750 OZ style (Read 169651 times)

johno · « **Reply #50 on:** July 19, 2012, 05:27:57 AM »

Re the missus, Dont worry boys, I got a plan, she rarely enters the shed zone so she wont see it just yet and she probably wont go to play pot plants until spring if and when she does I'll score a heap of browny points when I tell her I'm jazzing it up for a XMAS present. Hopefully the motor is finished by christmas.

FuZZie · « **Reply #51 on:** July 19, 2012, 04:39:04 PM »

hahaha.... Just make sure she don't find a motor on it or the jig is up!

johno · « **Reply #52 on:** July 24, 2012, 05:20:30 AM »

This definately the not so glamourous side to a project, cleaning thinking cleaning and more thinking more cleaning , I'm wrestling with the disc bolts, loctited in and very secure.

Just in case you didnt notice its still bloody cold, best thing about tonight was a hot cuppa tea and a slab of dark chocolate.

ciao Johno

johno · « **Reply #53 on:** July 24, 2012, 05:33:23 AM »

The front, Using these Yammy XJ 900 rims cos they are from my son who got them from my dad, bit of a nostalgia trip thing. Trying to impress my dad who is up there somewhere watching with interest I'm sure . He was a hard core bike adventurer, touring, racing, showing off, what ever he could get from a motorbike he took. he was on this Yam at the end so be good to show these wheels who's boss hey !

I'm planning to run two sets of wheels, these alloys and the standard Honda cb 750 rims. I have a preference to run the honda rims as I'm keen to make this bike look as stock as possible in the class and to leave no doubt as to what it is. I do however think the colour scheme ( bright ferrari yellow ) frame and tank would look better with the black alloys for a bit of contrast ( sorry Sam) ciao johno

johno · « **Reply #54 on:** July 24, 2012, 05:41:49 AM »

The back wheel is going to be challenging, not sure if you can see but its a shaft drive, so got this splined drive that I have to convert to holding a light motocross type sprocket and 520 chain. Cos I'm going light on the drive I wouldnt mind keeping the rubber cush drive. the splined drive is case hardened and would be a bugger to drill and tap, could use the axle bolt to locate, tensione by axle bolt swing arm nut, HMMMMM
not sure, another cuppa and more dark chocolate me thinks.

Ciao $:-\$ Johno

johno · « **Reply #55 on:** July 24, 2012, 05:58:05 AM »

The first engine I stripped down was pretty bad and I thought ooooo this could get ugly with not enough parts but this is the second engine and it turned out great, the old girl was almost like new . Got no idea of the history but apart from the valve stem seals being hard and cracked the rest of the motor was first class. I think the leaky valve stem seals additional oil left the bores and pistons like new. Must have been reconned or something as the primary and cam chain and chain guides were soft and new unlike the guides

? First crank was too worn but this one is as new. So will package up for balancing.

Not sure why ?? but I have changed my mind on the lightening, will just tidy up the weights a little and leave it at that, clean out the plugs, flute journals, get it crack tested, peened and balanced only.
I was all fired up until I spoke with a couple of superbike dudes who werent keen cos it is a salt race bike and then thought I can always do it later when I do the big motor.
ciao Johno

johno · « **Reply #56 on:** July 24, 2012, 06:02:13 AM »

Cleaning , more cleaning

johno · « **Reply #57 on:** July 24, 2012, 06:09:16 AM »

all cleaned , measured and packed away

last thread for a couple of weeks I'm off to Singapore for business 1 week , then chill out ( should say warm up) for 1 week, gonna try the big ferris wheel, and swim in the boat pool on top of the three skyscrapers, I'll take a snap to share in case it sounds weird.

Should be going to the states for some duty free shopping on HP bike parts, trouble is Id come back without a wife and bankrupt.

ciao boys catch ya soon

johno · « **Reply #58 on:** September 04, 2012, 05:42:42 AM »

Been foolin around with a few bits , decided to do the crank tonight , Not sure about what the heck I'm going to do with it, lighten it to buggery or tidy up and radius the leading edge only with a nice aerodynamic round edge , leave the trailing edge as is. !

Anyway I sleep on it tonight and be like a naturapath in the morning I'll put my hand on the crank close my eyes and say , you need to lose some kilos OR baby you feel fine to me stay the way you are. I got a decent lathe to tidy up the outside radius if need be but I have this notion that a standard type weight my be an advantage at full throttle for extended periods with fluctuating surfaces, puffs of varying wind speed etc the inertia might be a good thing ... yeah talked myself into it , a tidy up will do, grub screw the galleries with a balance and journal polish. Johno

johno · « **Reply #59 on:** September 04, 2012, 05:46:34 AM »

Grub screw the gallery.
I havent done this on the Honda yet but I read the thread that some nice bloke posted and followed his instruction to the letter, was worried about punching the balls deeper like he did on his first try, however his thread was spot on. johno

johno · « **Reply #60 on:** September 04, 2012, 05:50:07 AM »

Grind down until there is no black line around the ball and its difficult to see where the ball is.
Is that a crappy camera or bad photographer ?

johno · « **Reply #61 on:** September 04, 2012, 05:56:44 AM »

Forgot to mention I took his advice and taped the journals, just in case !

To try and spin the ball rather than punch it in I used 3 punches before I found one to do the job comfortably.
first I tried a new centre pop , nah tended to spread the metal with its point , then I tried a skinny 2mm pin punch and that bent like a bannana, then I tried a 3mm punch and ground a slight taper on the end but left it blunt. PRESTO evey ball just spun beautifully by hitting on the edge of the ball ring.

johno · « **Reply #62 on:** September 04, 2012, 06:01:34 AM »

Check out the crud everyone talks about when the half balls are removed, had to drill the crud out.

just tapped the holes to suit a 1/4 UNF grub screw which I'll buy tomorrow.

These cranks act like a centrifuge, I'm amazed at how much sh#t gets past the filters

johno · « **Reply #63 on:** September 04, 2012, 06:04:56 AM »

got out a couple of grinders and put a radius on the leading edge of both sides of the counter weight,
ordinary pic , Ill take some decent pics when I get it back from the balancer.
ciao Boys

Blitzburgh207 · « **Reply #64 on:** September 05, 2012, 12:52:47 PM »

Subscribed!

Old Scrambler · « **Reply #65 on:** September 05, 2012, 04:21:48 PM »

J......I'm with you on the crank weight. My plan for the salt-build is to remove the left end and run with a total loss system from a well charged battery. That will help the crank to stay harmonized. Cutting about 4-inches from the left case will help areo. Electronic ignition is lighter than the points plate but be sure to true the screw into the crank.

I am collecting rods, bolts, pistons, etc for a Production Class motor build. It has to "look" stock, including the exhaust and carbs, but what you can't see is allowed to be tweaked.....as long as you stay within the production motor cc category. I am still looking for clarity on the 736cc vs. upto 750cc. I started to gather parts for a K build but have just switched to an F model because I think the 4-1 exhaust will be good for more power. I have the motors and a header......looking for a stock muffler with no internals.

Enjoy your time away from winter........ours is fast approaching now that the first signs of colorful leaves are showing. My actual 750 sohc/4 build will not start until next year becasuse I have a new Cub motor to build and a couple of 305 twins to build into complete bikes.........and I could use a few thousand bucks in my pocket. The travel to and from Bonneville costs me about $2-grand.

johno · « **Reply #66 on:** September 05, 2012, 09:48:01 PM »

Cheers D. great comments

much appreciated as its a form of motorsport so different in the detail and operating conditions to anything Ive done nice to hear from someone who has been there and done it.

Your motor plans all sound sane to me , The ozzy regs are based on the California regs whth oversize piston is Max . 050 and why I'm using the JE 12.5 pisons 1mm os as the max allowable bore. I agree you shopuld check as there are so many classes and organisations.

I noticed on a LSR site your comments on a technical formula thread, you absolutely nailed it mate. So easy to go with the fairies and hypothetical world , you are obviously a practical bloke
cheers Johno

johno · « **Reply #67 on:** September 06, 2012, 02:45:30 AM »

seeing as your such a practical bloke D

I have a couple of things to run past you.

Firstly one of our forum members VBled1 with a project thread called "CB750 drag cafe build" caught my eye with his longer wheel base by 650 swing arm and raked front end and the 21 inch wheels, kind of where I'm planning to go with the small engine (750) Our class regs allow a 10% increase in wheelbase and originally I was planning to split that distance 50 /50 between the rake and the swing arm. currently considering most from raking and minimal from swingarm in an attempt to get more weight on the back wheel ( although surely my 20kg of fat guts would apply enough down force over the back end) Normally I like a weight bias to the front to assist handling but I'm thinking the massive trail should make it directionally stable enough and let the rear weight work on traction. Any thoughts ?

Also do you know what the stock wheelbase length is for the later F models ?

The highest rated 3 inch by 21 inch Avon tyres come in H or V rating so the max speed is 149mph, doubting I'll get there but do you know of any higher rated Z tyres ? otherwise this small engine test bed frame wont be any use for the big motor next year.

Cheers Johno

Old Scrambler · « **Reply #68 on:** September 06, 2012, 05:36:46 PM »

Thanks for the 'practical' bit

I added 1-degree of rake to my T20 and extended the swingarm the full 10% (5.7-inches). The F2 in my garage has a 58.5" wheelbase with the rear axle about 1-inch back.

I like your thinking on the weight bias but too much rake may require stronger tubes which adds weight and decreases areo. I run 21-inch wheels and have a very stable chassis. I don't know how rough the courses are by you, but the salt-flats are not very smooth. Look up the Tom Mellor Triumph Trident on YouTube for a 'shakey' view of the ride.

I fully agree on the limits of tire sizes for faster speed ratings. Adding weight to the swingarm can be accomplished with hot lead INSIDE to stay stock appearing. To reduce mechanical drag I run used wheel bearings, light-weight single-row primary chain, half the amount of oil in the tranny and primary with added graphite, and the best 5-30w I can afford for the motor. I was also careful to direct the returning oil from the head away from the crank. I have a very large breather housing on the crankcase, and the tranny is also vented. The drive-chain was boiled and then lubed with Teflon & graphite. It gets sprayed after every run. Another trick is to spray the frame and inner fenders with Pam cooking oil so the salt will not stick and is easily removed. My extended part of the swingarm is angled to the axle so the original length stays at the same pivot angle. I added about 1.5-inches of hard rubber to the upper shock-rods to reduce overall travel and maintain rear tire clearance. Did you see the hole in the gas tank for the throttle cable? The real purpose was to have access to remove the top of the carb without lifting the tank.

More later........

Brookesy in Oz · « **Reply #69 on:** September 20, 2012, 01:16:46 PM »

I'll be keeping an eye on you lot...
Looks like a place I can learn some stuff I need to know.

Keep up the good work - I'm off to the shed

johno · « **Reply #70 on:** October 21, 2012, 04:27:37 AM »

Cleaned and ready for the bead blaster. Just going to bead them at this stage. I was going to get one case hydro blasted cos it looks sensational but after close inspection change of plans.
Got two bottom ends to choose from, or at least I thought i did.
Both are damaged in some way ( get what you pay for) one has one of 3 points plate mount lugs broken off the other has had the classic chain dump through the case. The repair looked OK for a flog across the lakebut I started poking around checking the Aryldite repair and YUK, it aint good

ciao Johno

johno · « **Reply #71 on:** October 21, 2012, 04:29:33 AM »

$:-\$ $:-\$ $:-\$ $:-\$ $:-\$ $:-\$ $:-\$ $:-\$ $:-\$ $:-\$

johno · « **Reply #72 on:** October 21, 2012, 04:31:19 AM »

johno · « **Reply #73 on:** October 21, 2012, 04:33:36 AM »

johno · « **Reply #74 on:** October 21, 2012, 04:36:59 AM »

Bugger , didnt passssss the ol screwdriver test, will use the set cases with the broken points plate support.
something to do when I'm bored.
ciao Johno

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Author Topic: Salt Racer CB 750 OZ style (Read 169651 times)