New 700cc Outfit

Oh great..... just what I need..... another thread that I just 'hafta' follow... :rolleyes:
Nice work Signal!! Are you gonna set the crank up for 90deg. firing?
Last weekend 1000 cc Nortons were finishing at least the length of the start finish straight ahead of us.
I returned to this bike with new energy.
That's the spirit. :D
 
Last edited:
Gary, Mailman and Jim , thanks for the kind words.
Jim the crank will standard two up two down, like a TZ700. I think a cross plane crank would be turbine smooth but the ignition would be another problem that would need to be sorted.
Trueing the crank will be an act in itself.
Stage two once the initial motor is running well is water cooling the top end , that might be the time to build another crank. However this depends on anticipated rule changes to our class.
 
but the ignition would be another problem that would need to be sorted.
Since lean angle isn't a problem.... you could hang something the size of a VW distributor off the end of the crank. Direct drive would give you 4 pops at 90deg's per rotation. Imagine that exhaust note. You'd think you'd died and gone to heavan... :rolleyes:
Trueing the crank will be an act in itself.
That's gonna be true no matter the timing. I don't envy you that task...
 
Last edited:
I have been able to put some time into the 700 lately so a small update.

Decided to go straight to O rings to seal the heads and made a cutter to fit in the boring head. It works but chatters badly so will cut the grooves by hand, luckily there is only four to do.

Started sorting through the motor top end trying to match heads and work out what needs to be repaired. They are in a sorry state but are repairable. If worse comes to worse I don’t think it would be that hard to make a head.
2018_1211fireplace0002.JPG

Used a DTI and the mill DRO to measure the spark plug heights in the heads and how much to remove from the cylinders and it worked out really easy to do. Milled the spark plug holes of the heads in pairs to the same height also helicoiled a stripped spark plug hole.
2018_1211fireplace0001.JPG 2018_1211fireplace0009.JPG 2018_1211fireplace0008.JPG

Now that the heads are in pairs I used a burette to measure each heads volume to let us know what we are starting with. This will need to be adjusted. From what I understand you set the squish then machine the combustion bowl to get the CR you want.
By using the measuring set up in the lathe the head can be left chucked up and if further cuts are needed it’s already to go. I still need to make a bowl radius cutter but luckily won’t need it for some time.
2018_1211fireplace0005.JPG 2018_1211fireplace0007.JPG



Got some 38mm tubing bent at the local exhaust centre for the rear swing arm, normally exhaust tube benders make horrible distorted bends but these guys’ race cars and have a proper bender for doing the roll cages in their cars.

Also started making the swing arm pivot bolt and the pivot mounts. I will post some photos when it is tacked together. Once that’s done I can start on the outrigger rear shock mounts.
 
The output shaft will be extended and supported by an outrigger bearing. A simple means to mount and change the front sprocket needs to be devised.
This outriigger bearing - how far out will it be? About 75 mm or 100mm away from the RH case?
It occurs to me you could utilise the existing unused LH hole and pass a tube down throught that, and the outrigger bearing, that would abut directly on to the end of the ouput shaft. The OP shaft itself can be extended by say, 25mm and have a parallel nose on it that will insert into a needle roller bearing in the end of the extended support shaft.
The support shaft itself needn't necessarily be free to turn, but I'd think it would be best if it does, because if there's the slightest binding of the needle roller, the whole thing can turn and you can keep going rather than fry the needle bearing. Even if the shaft does turn, it's securely held by two decently-sized bearings.
To replace the sprocket, you unbolt the LH bearing retainer, slide the whole shaft out and bingo, there's your sprocket.
Details like the securing of the sprocket, I leave to you.
 
I have been able to put some time into the 700 lately so a small update.

Decided to go straight to O rings to seal the heads and made a cutter to fit in the boring head. It works but chatters badly so will cut the grooves by hand, luckily there is only four to do.

Started sorting through the motor top end trying to match heads and work out what needs to be repaired. They are in a sorry state but are repairable. If worse comes to worse I don’t think it would be that hard to make a head.
View attachment 131317

Used a DTI and the mill DRO to measure the spark plug heights in the heads and how much to remove from the cylinders and it worked out really easy to do. Milled the spark plug holes of the heads in pairs to the same height also helicoiled a stripped spark plug hole.
View attachment 131318 View attachment 131319 View attachment 131321

Now that the heads are in pairs I used a burette to measure each heads volume to let us know what we are starting with. This will need to be adjusted. From what I understand you set the squish then machine the combustion bowl to get the CR you want.
By using the measuring set up in the lathe the head can be left chucked up and if further cuts are needed it’s already to go. I still need to make a bowl radius cutter but luckily won’t need it for some time.
View attachment 131322 View attachment 131323



Got some 38mm tubing bent at the local exhaust centre for the rear swing arm, normally exhaust tube benders make horrible distorted bends but these guys’ race cars and have a proper bender for doing the roll cages in their cars.

Also started making the swing arm pivot bolt and the pivot mounts. I will post some photos when it is tacked together. Once that’s done I can start on the outrigger rear shock mounts.


G'day from across the dutch,

Mate you have all the great toys and also the ability to us them.

Chose, Bro !!!

GW
 
Managed to deck the barrels and cut the O ring grooves then went on to start to centre and dowel the heads to the barrels.
2018_1212fireplace0002.JPG 2018_1212fireplace0003.JPG 2018_1212fireplace0004.JPG

Needed a smaller drill bit so didn’t get that far but I did devise a way to do it.

The funny the thing is the job I thought I would have the most trouble with (cutting the O ring groove) was easy once the tool was ground and set up, the job that I thought would be straight forward (dowelling the heads ) is taking some time to sort.

Then went on to work some more on the swing arm pivot, pivot bolt and bearing mounts and this turned into a giant cluster fuck.

I have a few days leave left so will be back at it tomorrow and will hopefully be able to correct my mistakes.
 
Been a while as we have been busy racing and repairing our running outfit as well as doing other stuff.


I have port matched the cases to the barrels sorry lost the photos of this. I have read there is little or no gain from doing this but as I could not find anyone who said it was bad I decided to do it. Also we had a bit of a BBQ in the shed.


First the weld faces on the cases were chamfered and cleaned.


The internal faces where the cases meet was bead blasted to give the surface some texture. This is an insurance as if we need to fill the cavity with some form of epoxy it will get a better hold onto the cases. We probably won’t need to do this but once they are together these areas are not accessible.


Then I took the cases to a local powder coater and asked him to put them in his degreaser tank overnight. He didn’t charge for this but I gave him a box of ice blocks (popsicles) for his trouble. It is summer here and pretty hot.


Rebolted the cases together and preheated to 130 degrees C in the old BBQ I have been keeping for just this job. The BBQ is clearly labelled not for inside use and don’t use all four burners with the lid down .Ha what do they know.


The welding was done using 4047 12% silicon filler rods. The welding went without drama and then the cases were put back in the BBQ and slowly the temperature was taken down to room temp over about 3 hours.


The ideal thing for this job would be a glass blowers lare I know some glass artists but I didn’t ask to use their gear as I know they wouldn’t be keen on it.


Also made some progress on the swing arm. It won’t be long and we will be able to start laying things out on the table.



2019_case welding comp.jpg


2019_0211case welding comp2.jpg

case welding comp1.jpg
swing arm comp.jpg
 
I have port matched the cases to the barrels sorry lost the photos of this. I have read there is little or no gain from doing this but as I could not find anyone who said it was bad I decided to do it
I always did that to my RD's... mighta' just been wishful thinking, but it always seemed to help...:rolleyes:
Looking good!!!
You guys come up with a plan to true the crank yet?
 
Jim, trueing the crank will boil down to perseverance.

I had a hell of a time trueing the crank in our XS outfit it was bent like a banana at the joining pin. I suspect it was bent before it was rebuilt.

I had no clue why this crank was being so stubborn until my mate put it in a set of cases and you could see the centre bearings lifting out of the cases.

I made a tool to straddle the cam drive sprocket to press the pin straight. After that was sorted it was straight forward.

I hope this crank is not as challenging as that, luckily my co-conspirator on this project is a bit of a whizz at trueing cranks.
 
Got some work done on the outfit since the last update.

The rear hub has been drilled and tapped for the sprocket, a blank sprocket has been machined and lightened and fitted. Had a few false starts with the DRO PCD function but got it sorted now.
2019_0324RD7000001comp.jpg

2019_0324RD7000002comp.jpg

2019_0324RD7000005comp.jpg

The torque arm for the rear brake has been made; the rear axle nut has been welded.
2019_0324RD7000011comp.jpg


2019_0324RD7000012comp.jpg



The swing arm is largely finished apart from the shock mounts.

The final drive has been sorted thanks to a friend in the sprocket business who gave us the sprockets, duplex chain and a length of 4130 shaft.

The final drive coupling uses a modified duplex sprocket and chain that couples to the RD gearbox sprocket. The modified sprocket is keyed to the shaft and the drive sprocket in turn is keyed to the shaft. Hopefully we will be able to run two different sized front sprockets on the shaft and slide them along the shaft into service or out of service for faster gearing changes.

The outrigger bearing is held in place by a circlip and the shaft has circlips on either side of the bearing. The RD case only has a C clip to hold the gearbox bearing in place so I had to cut the groove in the other case half. This was pretty much at the limit of the mills capabilities but was able to get it done.
2019_0324RD7000006comp.jpg

Cutting the hardend teeth of the duplex sprocket with grinder and cut off wheel.
Old chain was to protect the teeth of sprocket that we want to keep.
2019_0324RD7000007comp.jpg

Further lathe work to tidy it up. The centre was machined to locate over the RD sprocket nut to add further rigidity.
2019_0324RD7000009comp.jpg

Test fitting .
2019_0324RD7000013.JPG

Test fit to see if I could centre the housing to cut the circlip groove. It was bolted down for the cutting.
2019_0324RD7000014comp.jpg

Detail of groove cutting at start.
2019_0324RD7000015.JPG

Test fit of bearing circlip and shaft.
2019_0324RD7000016comp.jpg

Shaft in place without drive sprocket, circlip grooves have been cut on shaft but not in photo. The hydraulic clutch slave cylinder I made earlier will need to be shortened.
 
Last edited:
More progress.

The clutch slave cylinder has been shortened and I put a circlip at the entry to the bore to retain the piston,

This is because often at the track we need to take the alternator cover off the XS and that holds the slave cylinder. Then inevitably the clutch lever gets pulled and the piston cocks over and jams . Just what you want when you are in a hurry.

The front end has been drawn up, in the photo see if you can spot the deliberate mistake.
2019_0420RD7000029 comp.jpg

Yes that's right the brake calliper will hit the fork leg when the shocks compresses. Easily fixed by putting the callipers under the swing arm. Lucky it was spotted before we got too far.

Started making the front end, the steering stem started life as a nose strut for a Cresco Top dresser. It’s a hard as anything and shown here after its dunk in hydrochloric acid to remove the chrome. Its an ideal size as it is thick walled enough to take a 47mm OD 25mm ID tapered bearing.

2019_0420RD7000031 comp.jpg 2019_0420RD7000034 comp.jpg

Finished making the steering stem through bolt and the front axle as well.

The big news is the crank is built and trued. My co-conspirator did it over two nights and a short morning’s work.

He started in the middle and worked his way out trueing as he went. First a set of RD 350 lowers were used to spin the crank as we didn’t have V blocks small enough. Then as the crank grew he used the 4 cylinder cases.

He did say next time he will start at the alternator end this is because if the wheels on that end where too close after pressing he would have to pull the whole other side off to correct it. He prevented this from happening by using two 18mm diameter steel spacers accurately sized to the desired space. It worked well.

It all went pretty smoothly and he made it look easy as only skilled people can. The crank is now oiled and wrapped in an old sheet and put in the airing cupboard to keep it warm and dry. Its just a shame some of the core cranks we started with were so corroded as they don't look that flash. However you wont see them when its on the track (hopefully).
2019_0420RD7000036 comp.jpg 2019_0420RD7000038 comp.jpg 2019_0420RD7000039 comp.jpg 2019_0420RD7000041 comp.jpg
2019_0420RD7000042 comp.jpg

Fitting on the last bearing with the crank vertical in the vice.
2019_0420RD7000043 comp.jpg
Our visitor
2019_0420RD7000037 comp.jpg
 
Back
Top