Author Topic: Salt Racer CB 750 OZ style (Read 169748 times)

johno · « **Reply #1100 on:** February 25, 2015, 11:21:36 PM »

Made up a bike stand, same as all my brackets, pegs, coil mounts, rear swing arm etc its out of stainless steel 316 , trying to beat the salt

johno · « **Reply #1101 on:** February 25, 2015, 11:25:11 PM »

Well the ol girl is now in finished road test trim, just waiting for the right day and conditions to give a fair crack on the road.

After the run I will change it to salt track mode with different back end , struts, swingarm etc ready the the speed week.

johno · « **Reply #1102 on:** February 25, 2015, 11:28:48 PM »

This is a shot of the electrical protector that Den reccomends, bit old school my son said but hey I am old school.
cover cost me the same price as a set of good pistons at $400.

alll velcro easy on / off

johno · « **Reply #1103 on:** February 25, 2015, 11:40:45 PM »

Just got off the phone from Finny my suzy waterbottle man, he spent the whole day today on the dyno with some interesting results.
When he set the record he dynoed at 112 HP with 17 : 43 sprockets at 8,300 rpm ( same as I have ) and run 149 mph.
3 engines later and many mods he run to 112 HP today at 8,300 but it revved to 9,000 but lost hp. I think he is experimenting with power jets tomorrow as it appears to lean out after 8,300 and make less hp.

Evan though I am hoping for only 90 hp and I still believe the big diference is the frontal area, his bike is big fat wide and low , his radiator is huge like a big flat billboard out the front .

Jim F · « **Reply #1104 on:** February 26, 2015, 05:03:31 AM »

Is the salt smooth enough to run struts or is that an aerodynamic thing
I have only walked on the salt once and it sure looks smooth but at speed
I would think that shocks would be the way to go.
From someone that does not know a thing about land speed records

Jim

bwaller · « **Reply #1105 on:** February 26, 2015, 05:56:45 AM »

At a buck fifty my back would like a little give in the rear too!

From someone else who doesn't know squat about salt!

Old Scrambler · « **Reply #1106 on:** February 26, 2015, 09:15:48 AM »

Can't speak for the salt in Oz.............Bonneville salt is groomed fairly smooth but still has a few dips to be found. A lot of bikes are set-up with rigid rears but I prefer to run suspension. I reason that the springs will help keep the tire in contact with the salt if I hit a small bump or 'toothpick' when at speed. My springs are rather stiff and adjusted for added tension. I have nylon stoppers added to the shock-rod to reduce overall travel to about 2-inches. I only have about a half-inch of sag when I sit on the bike. With tires filled to 50-psi, you can't expect much 'forgiveness' from the tire.

Johno............nice bib..............the FLAMES are

90+ hp at the rear wheel may be modest. I would think your motor will have better potential to keep gaining speed (Mike's head) by using revs after peak power..............it won't drop off as fast as the water-buffalo. I've been listening to the runs made by a GSXR rider............he gets into the high rpms in second gear and stays there through 6th. Based on how my motor 'cleared' at 7,000+ rpms and very rapidly climbed to 9,500 r's in 3rd gear, I anticipate my shift point to be 10,000 or higher from 4th to 5th in order to pull a few more mph from 8,500 rpms. I'm running 17 - 45 for cogs to start. Have 18 & 19 plus 43, 41, 39 & 37 to adjust as needed.

Here's hoping you show me the way................

.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #1107 on:** February 26, 2015, 11:42:51 AM »

Ahhhhh Peter Frampton fan, huh LOL

MRieck · « **Reply #1108 on:** February 28, 2015, 07:06:43 AM »

Looking forward to your dyno work Johno....hope everything went well.

Greg H · « **Reply #1109 on:** March 01, 2015, 01:17:43 AM »

Nice job with the stand mate

. You know johno I thought I'd done with the LSR game , but the more I read about your build the more I'm thinking of getting my hands on another frame and building a sohc Honda based LSR bike .
All our venues over here consist of dissused WW 2 airfields with the maximum length available being around 2miles . You need something that accelerates like a drag bike, has the speed and stability of a LSR bike , and stops like a WSB racer to go really fast over here .
I don't think a bike based on a 750 sohc Honda could meet any of the aformentioned criteria, but who cares , it would still be a lot of fun , even if we'll probably be spending most of our time explaining to all and sundry why we've chosen to go down the sohc Honda route , rather than running the ubiquitous Busa or ZX12/14

. Regards Greg "H".

johno · « **Reply #1110 on:** March 04, 2015, 04:05:30 AM »

So....creepstreet, getting confused like most people swapping parts on the rear end, easy done mate.

Honda changed the sprocket output shaft length longer on some models to allow chain clearance for bigger tyres

They started doing that on 75 F models on and the K models 77 and 78

If you swap parts around you need to be aware of what model parts you have.

the main points to focus on are;
Engine wise ....type of front sprocket output shaft, early narrow type had the two 6mm screw retainer

Frame wise ......the length of top shock mount stub on the left ( chain) side of frame ( long output shaft models have the left top shock mount 10mm longer on the left side. ) and so need the 10mm wider swing arm on left side.

Sprocket carrier had to be cast 10mm wider to match the 10mm longer sprocket shaft

Swing arm wise.....to identify the swing arm the F models had the rear disc torque arm mount on top , the drum rear K models is a bit harder to tell the difference at a glance but the earlier drum K models rear axle distance is 10mm less than the later K7 or K8 which are 10mm wider than the early drum models. ie short output shaft swingarm measurement at axle is 255mm wide the later wider swingarms to suit longer output shafts are 265mm .

while the wheels are both on the centreling of the bike but the wheels may or may not be centered at the rear axle depending on the front sprocket shaft. an example is my salt bike, I have two frames , 75 F and K8, both had the longer front sprcket shaft but I want narrow rear end so I use the shorter front output shaft from early K, for raod test and dyno I use the 10mm wider K8 swingarm cos thats all I got but put in a 10mm spacer on the left side and I use the narrower rear sprocket carrier from an early K. to keep the chain alignment.
On my longer salt swing arm I made it narrow as possible back to early K axle specs 255mm and adjust the left lower shock mount to match the longer top shock mount on left side.

So summarising , match the front output shaft to the rear sprocket carrier, then 10mm spacer on left side depending on which swing arm your running.
WAR and Peace BABY, hope your not more confused than I am,
cheers Johno

creepxstreet · « **Reply #1111 on:** March 04, 2015, 06:12:04 AM »

I appreciate you writing this all out and explaining the difference for me. But I'm not using a stock swing arm or a stock wheel. Right now I can run it with the rear wheel offset or take it all apart and machine the cush drive/sprocket carrier down on the cbr sport bike wheel I'm running. What I would rather do is try it with the offset then if that doesn't work I can take it apart and machine it down and run a spacer on the right side. I'd rather not machine the wheel if I don't have to. I understand that the wheel is not supposed to be offset stock though.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #1112 on:** March 04, 2015, 11:36:01 AM »

Johno,

AFAIK, The 75F/76F/76K used the same length output shaft as the earlier K's but did away with the chain oiler hole. That is their only difference outside a double row bearing and I'm not sure when that happened. They changed the length after that when they went to the 630 chain on the 77's. I have done recent research into this as I will be using a 75/76F shaft in my 78 K 1000 engine going into a 75F frame. At least I hope so

Retro Rocket · « **Reply #1113 on:** March 04, 2015, 01:07:13 PM »

Quote from: creepxstreet on March 04, 2015, 06:12:04 AM

I appreciate you writing this all out and explaining the difference for me. But I'm not using a stock swing arm or a stock wheel. Right now I can run it with the rear wheel offset or take it all apart and machine the cush drive/sprocket carrier down on the cbr sport bike wheel I'm running. What I would rather do is try it with the offset then if that doesn't work I can take it apart and machine it down and run a spacer on the right side. I'd rather not machine the wheel if I don't have to. I understand that the wheel is not supposed to be offset stock though.

From reading your posts i think you are confusing the rear sprocket offset with the wheel centreline, the wheel should sit dead center in the swingarm, then what you need to do is work out your chain line to suit the wider wheels, hence the machining some material off the sprocket carrier, you may still have to use a 3/8 offset front sprocket to make everything fit, CycleX have the sprockets.....
The K7 K8, F2 F3 have a 10mm wider chain line, 10mm longer out put shaft and 10mm wider sprocket carrier....

johno · « **Reply #1114 on:** March 04, 2015, 01:28:41 PM »

Ditto

creepxstreet · « **Reply #1115 on:** March 04, 2015, 01:36:36 PM »

When I say offset I mean not centered. I get that it should be centered. It wasn't before. It rode normal. Didn't pull either way. Didn't turn different in either direction. I'm gambling that adding 3mm more total wheel offset from center will not ave much of a change then previously when it was fine. I would rather try that before I start machining the wheel. I would need to machine the wheel to bring it left in the swing arm to center it and add a spacer on the right to make up the difference. Currently the cbr wheel and brake mount fit in the swing arm with nothing more than stock cbr spacers. Again, I appreciate your interest in this and I don't want to seem like I'm ignoring sound advice for no reason.

bwaller · « **Reply #1116 on:** March 04, 2015, 02:29:38 PM »

Bear with me for a moment creepxstreet.... I once made a rake change to a frame and ignored addressing the trail in turn. It didn't seem to have any ill effect, until it did! Big time, and it destroyed the bike and beat me up badly in the ensuing tank slapper/crash.

The rear wheel needs to be centered and both wheels aligned. It sounds like you're capable, I'd strongly suggest you do the right job while you're in "build mode". Don't tempt fate.

Sorry johno, didn't realise this was your thread.

Old Scrambler · « **Reply #1117 on:** March 04, 2015, 03:18:11 PM »

Whether for the Street, Strip, or Salt (high Mr. Johno) it all starts with alignment...........

Retro Rocket · « **Reply #1118 on:** March 04, 2015, 03:48:50 PM »

Quote from: creepxstreet on March 04, 2015, 01:36:36 PM

When I say offset I mean not centered. I get that it should be centered. It wasn't before. It rode normal. Didn't pull either way. Didn't turn different in either direction. I'm gambling that adding 3mm more total wheel offset from center will not ave much of a change then previously when it was fine. I would rather try that before I start machining the wheel. I would need to machine the wheel to bring it left in the swing arm to center it and add a spacer on the right to make up the difference. Currently the cbr wheel and brake mount fit in the swing arm with nothing more than stock cbr spacers. Again, I appreciate your interest in this and I don't want to seem like I'm ignoring sound advice for no reason.

You don''t need to machine the wheel..? Just the sprocket carrier where the sprocket bolts on and a couple of spacers to get the wheel centered, I've done it before with a GSXR rear wheel into a CB swingarm and its relatively easy and not expensive. You are getting advice from some pretty experienced guys here mate, center the wheel and go from there...

Old Scrambler · « **Reply #1119 on:** March 16, 2015, 08:16:01 AM »

Lake Gairdner begins.........One week from TODAY.........Carbs sorted?........Rider 'stoned'? Are you READY?

bear · « **Reply #1120 on:** March 16, 2015, 03:56:26 PM »

Quote from: Old Scrambler on March 16, 2015, 08:16:01 AM

Lake Gairdner begins.........One week from TODAY.........Carbs sorted?........Rider 'stoned'? Are you READY?

I'm with you Dennis,

C'mon Johno, how about a pre-meeting update.

Got a rider organized?
Bike ready?
Beer on ice yet?
My leathers required this year?.....................

Cheers,
Brian

johno · « **Reply #1121 on:** March 17, 2015, 05:38:56 AM »

sorry boys, been a very busy time , stressin out,

making progress, run on road last weekend, had dyno today, short notice drove 8 hour round trip to dyno, waited in a que , very busy man, paid two hundred for two pulls, was a start anyway

as the NGK air fuel meter wont work , had to go dyno.

johno · « **Reply #1122 on:** March 17, 2015, 05:41:35 AM »

notice the flames out exhaust at around 8,000. remember when looking at af ratio redline limiter set at 10,ooo

johno · « **Reply #1123 on:** March 17, 2015, 05:53:50 AM »

So boys, this is the af lines on the two pulls.
First pull red line main jet 115 Mikuni.......leans as at 16:1
I replaced the main jet with 130 ............good up until about 7,000 suddenly leans out.
so plan, would love to buy a dyno

but for now I will put in 135 mains and lift needle 1 notch for first run.
timing is retarded now I have it set a 33 deg , will increase to 35 for first run and see what happens

I havent shown the HP cos it sucks, real low. embarresing so. however the speed at 8,000 is high 168 mph ? who knows , we couldnt work out what was going on , thinking the tall gearing was making it strange. My gut instinct tells me I have a reversion problem at around 7,000 to 10,000 that I need to fix to get HP , exh and intake length me thinks ?
I always use Doc D 85 HP as the bench mark , but the numbers showed up less.

Anywa den , you were on the money for the jetting start you had,

FCUK it sounds real real horny, the guy doing the dyno has been around does a lot of superbike stuff like Giles etc, he said it was the first time ever the shed walls vibrated, he wasnt joking man, it was horny as.
still thrashing around trying to get organised, will relax a bit cos the HP is low so no records this your boys, sorry

johno · « **Reply #1124 on:** March 17, 2015, 05:57:57 AM »

Oops wrong screen, this is the AF runs, red first , jet change then yellow

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Author Topic: Salt Racer CB 750 OZ style (Read 169748 times)