Sunday, 13 May 2018

The new TR1 engine - welding up and skimming a test piece (part 19)

The more observant and knowledgeable amongst the fine readership of this blog will instantly notice: This is not a XV1000 cylinderhead - and you're absolutely right. But just as with walking, you first have to walk, before you're able to run, it was necessary to ruin an already broken XT500 cylinder to try out my hefty flycutter and more importantly to figure out the potential pitfalls, when it comes to welding up cylinder heads.

The biggest issue I found was heat. Even though I put the cylinderhead on a hot plate and got it to well over one hundred degrees, it would cool down within minutes and basically just soak the heat away from the weld.  Next time, I'll go with the hot plate and the real XV1000 heads only need to be built up in one spot, I'll heat that spot up with a propane torch.

 Second was cleaning action. Even though a I ground about 0.5mm deep into the material, there is still quite a bit of peppering in the welds. As skimming showed it was mostly only cosmetical, yet still, it kind of bothered me.

That's the head in a different light, when put on the mill's table and you can see some of the inclusions a lot better. 

Still after running the flycutter over the whole thing, it becomes obvious that the peppering was superficial and nothing to worry about. A lot more worrying is the gap on the right side of the combustion chamber, as the weld didn't fuse all the way round with the base metal. (Mind you, this was at 200 amps...)

As usual, any input of knowledgeable folk is greatly appreciated. I tried out 4047 (AlSi12) filler, which crystalized instantly, so the rest of the welding was done with 5336 (AlMg5), which wetted out nicely and if the metallurgical handbook is to be believed, will work harden after a few heat cylcles.

Things worth considering for the next attempt: Try grey ceriated tungsten electrodes (I used golden ones and they stood up to the task nicely, white and blue failed rather quickly), maybe get a bottle Helium-Argon mix to get more heat into the head and heat the work area with a propane torch. Additionally, I will look into getting a digital TIG in the future as there's no way of playing around with frequency-settings on mine, when in AC mode.

Wednesday, 9 May 2018

The Turbo TR1 - GT15-turbo build (part 1)

"Auferstanden aus Ruinen" used to be the national anthem of the former German Democratic Republic and pretty much the same goes for this turbo setup. (Guess what, I haven't been working on the turbo for no reason...)

As I am a dedicated believer in recycling, I took an older set of turbo-headers, which I built for a TD04 and cut the flang off, as the waterjet-cutter messed this one up ages ago.

Turns out, with a bit of wiggling around you can fit a GT15 flange onto a TD04 flange, even when the whole flange came out roughly 10 percent too small. 

Drilling 10mm stainless steel, which has already work-hardened due to welding, is no fun though.

Not perfect, but it seals up good enough and it meant reusing some older headers. 

Fitted to the bike. It's just incredible, how much smaller the GT15 is compared to the T3 that was on there before. 

Next up on the list is to build a new 2in1-inlet-manifold and make an exhaust-flange from some stainless plate. As this is a bit of a side project, please be patient, this will take the backseat more than once against other projects like building the new everyday TR1 engine.

Saturday, 5 May 2018

Tooling up for the TR1 engine build - fly-cutter

Amongst the things I need to get the new hopped-up TR1-engine working, is a means to re-surface the cylinder heads after welding them up. As I don't own a large surface grinder, a fly-cutter is the means to an end.

First up was a chunk of 110mm diameter tool-steel, that was squared up on both sides and then center-drilled.

The future-shaft was made to a hefty press-fit and then, as the thought of a roughly 5kg fly-cutter arbor flying off through the workshop gave me a "slightly" uneasy feeling in my stomach, I decided to additionally TIG-weld it. 

Once it was welded up, it was put back in the lathe to turn it down to final dimensions and also decrease the amount of potential wobbles. 

After some thinking, I decided to decrease the overall mass by milling both sides flat. (Which incidentially also made tapping for the set screws quite a lot easier. 

The result is pretty acceptable, especially when considering that this was done on a flimsy RF-25 roundcolumn mill. 

Tuesday, 1 May 2018

The XS Triple Sidecar - modifying flatslides to work (part 3)

If you thought we were done last time... well, think again. 😏 The whole setup is pretty much alright by now, except for a somewhat leaky middle carb.

So first things first: Find out where the leak is. I used some tyre chalk, because that's what I had at hand.

Now that was no good news, mainly because it wasn't leaking at the flange, but to the left of it.Time to paint the sidecover and do some thinking.

As it was absolutely impossible to spot, I took the carb out and hooked it up to a fuel bottle and ... see for your self. The mother of all hairline cracks, but only visible under the right lighting.

Copious amounts of metal-powder-reinforced epoxy raisin should sort that out. With that sorted, I should finally be able to focus on jetting them correctly now.

And a day later, it's finally sorted, the raisin has cured and there's no leakage (but lots of pollen!)

Oh and while I was at it, the old girl now sports a lovely taillight of a Guzzi V7 Sport from the 1970ies.

Thursday, 26 April 2018

The new TR1 engine - a fresh start ... again (part 18)

I admit this project has:
  • taken quite a break
  • taken more turns than an Alpine road built by the Romans.
Additionally I`have to admit, that I had sort of given up the hope of finding a suitably priced BT1100 engine again, after I sold the last two.

As luck had it a bit of chatting with some people revealed a slightly parted out BT1100 engine for the right price with a bent shifter fork.

Saturday, 21 April 2018

Getting Dre-XT-Stück ready for its roadworthyness inspection (and making her mine)

As some may (or may not) remember, I was given the Dre-XT-Stück as a Christmas-present and also somewhat for fixing up the pretty one. Truth is, life aside from what you see on the blog is keeping me quite busy, so in reality I haven't done much to her.

In an attempt to "make her mine" and get some other stuff dialed in, I changed the gear-lever position to fit with my boots.

Fitted some new and some not so new sidecover rubber grommets...

... and installed an auto-decompressor cable to make kickstarting a bit more comfortable. 

Lest I forget, there's also a new horn hidden underneath the tank, which is obnoxiously loud. (Or in other words PERFECT!)

Additionally I swapped out the stock carb for one out of a later XT600, as the carb that was installed was overhauled with an XT600 43F jet kit, which meant every single jet in there was too big. As my dad and me plan to do some rideouts and only I will have panniers on the XT, it also leads to the convenient situation, that we only have to carry one set of throttle cables. (As the ones from a 43F are ever so slightly shorter!) Unfortunately this carb is also jetted a bit rich as it has got bigger mains in both carb bodies, which probably works brilliantly in a 600, but in the 500 not so much... but still these jets at the very least are still available. I also have to make a new choke cable, because 90 Euros for a choke knob is a but much for my taste.

Wednesday, 18 April 2018

The XS Triple Sidecar - spring clean

Now I admit, I am not the great cleaner, when it comes to my bikes. Unfortunately with Winter usage of bikes comes exposition to salt. A lot of salt. Now over the years I've tried quite a few things, but two years ago I tried some protective spray wax, as used on new cars to prepare them for oversea shipping.

As a sidenote, it comes off very easily with hot water and soap.

I'll let that result speak for itself.

Yes it truly is this shiny. 😎