New 700cc Outfit

The Front end is largely built, needs a couple of supports for the lower shock mounts, the top triple made and a few other odds and ends.
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Started laying the major components out on the table and fixing them into position.
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The exhaust spigots have been tacked together and fitted to give us an idea where the frame rails can run. Made a start on the front engine mounts and side wheel axle support.

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Fitted a stock RD cylinder and new Chinese cylinder to a stock engine case to work out the port timing and how the ports need to be adjusted.

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The Chinese cylinders are made to the Ranjoot specs and from all accounts the performance of the Ranjoot was pretty abysmal. The exhaust gasket cut outs in the cylinders was also not concentric and the flanges need a lot of filing to get them to fit nicely. Luckily I was aware of this problem when I drew out the flanges for water jet cutting.
 
The aim is to have it on the track in October. Boxing day cemetery circuit is the race we really want it for, but also would like to have it for the Mike Pero Southern Classic in early December. The MPSC organisers are making sidecars the feature this year and we are trying to get a large contingent of North Island outfits down there at Timaru.
https://cemeterycircuit.co.nz/
https://www.cams-racing.org.nz/mike-pero-southern-classic-2016

It will probably debut without a fairing or paint job. Things will appear to move quickly as the frame comes together, then slow down again as the peripheral stuff gets done. Making the pipes will take a lot of time as we have to fit them on the bike somehow and still have the platform front exit.
 
We have had a busy time in the workshop the last few weeks.

The frame is mostly made and tacked together. The engine mounts and additional bracing in the head and swing arm pivot is still to be done.

The swing arm is almost done just a small amount of welding to do.

The rear brake and gear change mechanisms are well under way.

Last night I finalized the expansion chambers design, nothing fancy just followed the two stroke tuners guide. Years ago when fiddling with 2 strokes I had good results following his method and at this stage they will be good enough.

I have a friend with a large printer who has agreed to develop the cone patterns and print them for us. I will then test the patterns with cardboard and if all is good get the parts water jet cut neither of us fancy cutting that many cones by hand.

Also found out some troubling news regarding the Chinese barrels we are using. I have seen a forum post where the lining has moved in the casting. We have devised a way to pin the sleeve in the casting to help prevent this. The Chinese liners are inserted from the bottom rather the top.

The really time consuming work of making brackets and working out where to mount things is just beginning, but we have out sorted spots for the coils, CDI’s and the fuel pump. The fuel tank will mount on the platform.

We need to contact the local technical steward to get a ruling on the amount of oil containment we must have. The rules are written for 4 strokes to avoid oil being dumped on the track should a motor have a catastrophic failure. Two strokes are not mentioned and the minimum size of containment is 5L. We only have 1.5L in the gearbox.
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Starting to bend and notch.
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Rear shock mounts and platform taking shape
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A little bit of welding and fettling and it will be done.
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Bracing is cut but not fitted for the head area
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Thanks guys for the positive comments.

Gary: yes it is very much make it up as you go along, although there are some design parameters that if you deviate too far from you could end up in trouble.

MaxPete: I will post a video of it running. So far as what it will sound like we don’t really know. I am sure we will have a shed full of visitors when we have its official start up day. It is only right that we have a bit of a celebration.

Mailman: We both enjoy the challenges and problem solving involved with building these things. Building these machines is much less drama than building custom road bikes as we don’t have to go through the Government transport department certification process. The racing to me is the icing on the cake.
 
Time for an update.

The tyres have been mounted and wheel hubs refitted with discs. All buttoned up read to go.

The rear engine mounts have been made and the front one is nearly done. Still on the hunt for some 8mm steel rod to make the through bolts out of.

The gear shift shaft has been extended and the linkage made, need to remake a couple of mounts for the pedal but nothing major.

The test patterns for the cone development for the chambers worked well so they can be cut.

Started finishing the front end, making the top plate machining some large bolts to hold it on.

Not a lot to show but we have been pretty busy, but that’s how it goes.
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I am certain your bike is not only going to be functional but is true ART.
The purpose or goal of most art is to create an emotional response in the people that are exposed to it.
Your project simply takes my breath away ... leaves me speachless. What talent ! How do you do that ?
 
Scripto Vu I don't really know what to say other than thank you for compliment.

Also there are two of us working on this and its a lot easier solving problems when you can bounce ideas back and forth.
This weeks update:

The top triple plate is made this turned into a bit of a drama as I measured the distance between the two fork tubes without the front fork or wheel in.

Distortion from welding pulled the tubes together at the top meaning that when assembled the distance between fork tube centres changed and the top pate I made did not fit.

This was fixed by boring the holes bigger using the right centre to centre distance in the mill and turning some steel bushes to press into the top plate.

The front end steering shaft has been made to the correct length now.

With the top plate in situ work can start on mounting the master cylinder reservoirs and tacho.
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The front engine mount is finished and the through bolts have been made. The motor is properly mounted now.

The fuel pump is fixed in position under the right hand side engine cover, with that done the fuel rail / header tank can be sorted.
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The barbeque saw some more action this weekend and now 5 cracked heads are welded ready for fettling. When “vee-ing” the cracks out my friend noticed some porosity in the factory castings. The cavities had some become pockets for oil like substance to collect.

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The rear brake set up is almost there just need to make a stopper for the lever and get a clevis pin. The first lot of AN3 brake fittings arrived just waiting for the line and some other angled banjos to come.

Brackets to mount the CDI’s have been made.

The water jet cutting for the chamber patterns hit a small snag when the drawings I took on the memory stick would not open. With luck this is sorted now and we should have some cones to roll up soon.

I have heard back from the local Technical Steward regarding oil containment and he said the rule was written for four strokes and we do not need a catch tray. That is a big bonus as catch trays are tricky to fit and very time consuming to make.

Work will slow down a bit for the next two weeks as we both have work commitments.
 
Thanks Skull.

The water cut cone patterns worked out well and have had a preliminary roll. The smaller ones were a bit tricky but will be ok with a bit more massaging.

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However the material is too thin and knowing that early TZ 750’s cracked chambers at an alarming rate we have opted to stop and get some thicker patterns cut.

One has been tacked together to give us an idea on routing them.

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Turned up some fuel line spigots (8) for the fuel rail and tank and ordered some spring clips for the fuel line.
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Bought a piece of ply for the platform and painted the underside to seal it. It is construction ply , marine ply would be ideal but was going to cost $100 and the construction ply was $20. The platform will have 10mm foam carpet underlay and topped with Butynol roofing material. Most people don't bother with the foam but it makes the passengers ride much more comfortable.

Mounted the controls and made mounts for the reservoirs they still need some tweaking. This took ages as everything impacts on everything else.

While mounting the controls and checking clearances I realised we had forgotten about steering stops so need to make a couple of those. The CDI holders need to be positioned as well as they are going to mount on the front down tubes.
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Had a frustrating day making the brake and clutch lines the AN3 fittings are made for non-covered hose and we prefer covered hose as it doesn’t get as dirty. Anyhow they are made and hopefully no leeks when we bleed and pressurise them.

Work has started on the mould for the seat and kneeler troughs. The seat mould at this stage reminds me of the frames fitted to camels to enable the camels to carry cargo. We don’t usually go to that much trouble but a mate of ours is building a XS powered outfit and with a few mods the mould will do for him.
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Under the seat is a small fuel tank (9 L) not big enough really so we are in the throws of deciding where to mount another tank. The obvious thing is to make a small tank that sits above the motor but this needs some thought as we need to maximise the airflow over the motor. Another mate suggested making a mini TZ style tank.

My mate will be away for a while so I will make a start on pinning the cylinders and bringing the transfer porting up to RD specs and roll up the new cones. There is so much to do and its less than 6 months to boxing day. Yikes.
 
Thanks Skull.

The water cut cone patterns worked out well and have had a preliminary roll. The smaller ones were a bit tricky but will be ok with a bit more massaging.

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However the material is too thin and knowing that early TZ 750’s cracked chambers at an alarming rate we have opted to stop and get some thicker patterns cut.

One has been tacked together to give us an idea on routing them.

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Turned up some fuel line spigots (8) for the fuel rail and tank and ordered some spring clips for the fuel line.
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Bought a piece of ply for the platform and painted the underside to seal it. It is construction ply , marine ply would be ideal but was going to cost $100 and the construction ply was $20. The platform will have 10mm foam carpet underlay and topped with Butynol roofing material. Most people don't bother with the foam but it makes the passengers ride much more comfortable.

Mounted the controls and made mounts for the reservoirs they still need some tweaking. This took ages as everything impacts on everything else.

While mounting the controls and checking clearances I realised we had forgotten about steering stops so need to make a couple of those. The CDI holders need to be positioned as well as they are going to mount on the front down tubes.
View attachment 144751

Had a frustrating day making the brake and clutch lines the AN3 fittings are made for non-covered hose and we prefer covered hose as it doesn’t get as dirty. Anyhow they are made and hopefully no leeks when we bleed and pressurise them.

Work has started on the mould for the seat and kneeler troughs. The seat mould at this stage reminds me of the frames fitted to camels to enable the camels to carry cargo. We don’t usually go to that much trouble but a mate of ours is building a XS powered outfit and with a few mods the mould will do for him.
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Under the seat is a small fuel tank (9 L) not big enough really so we are in the throws of deciding where to mount another tank. The obvious thing is to make a small tank that sits above the motor but this needs some thought as we need to maximise the airflow over the motor. Another mate suggested making a mini TZ style tank.

My mate will be away for a while so I will make a start on pinning the cylinders and bringing the transfer porting up to RD specs and roll up the new cones. There is so much to do and its less than 6 months to boxing day. Yikes.


This thing is shaping up to be a real beast! Super impressive!
 
Work has slowed down a bit and we were both able to put some time into the bike this week.

The cylinders have been pinned and I have started matching the transfer ports to RD specs. The inlets have been opened up and the exhausts are now raised to 1mm higher than RD specs.
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The liners below the main transfer port have been trimmed back to increase the catchment area and the bottom of the liners chamfered. Still a lot of works to do but the barrels were needed on the bike to allow the pipes to be fitted.

Started cleaning the repaired heads up, and trued them in the lathe. Still need to check and recut squish then set compression ratio.

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The pipes have been made and after a fair bit of thinking and tossing ideas around we have gone for two out each side. My partner in crime has made a great job of the pipes; the headers look like a plumber’s nightmare but actually go on and off easily if you use the correct order.
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Making the parts for the mufflers took a bit of work. First the outer skins which are aluminium but don’t look it in the photos were cut to length, then the end plates were cut using a hole saw and turned to a close fit to the ID of the skin.
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Then using 4 endplates pushed into the skins for support the skins were squared up in the lathe. Then the end plates were bored to fit over the stinger and muffler outlet pipe. Some flat perforated stainless sheet was rolled into a tube to make the core. The whole lot is held together inside with hose clips.
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The muffler skins are cut from an out of hour’s helicopter tail rotor drive shaft it’s an ideal OD. Still more work to do on the pipes but they are mostly done.
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