Saturday 12 October 2019

Everyday TR1 - V-star conversion (part 2)

Now the incentive to give building a V-star based TR1-engine a shot came from the fact that I managed to get hold off a BT1100 engine for approx. a third of the usual price, because allegedly it had lunched its gearbox in a rather spectacular manner.

The rear cylinder had come off normally, but unfortunately the front cylinderstuds are covered with some black plastic tubing and if rust forms underneath it, things become unpleasant. 


The angle grinder gave the stud its final haircut. 


The lathework on the BT cylinders was actually easier than on the TR1 test piece as these are made from aluminium and machine very nicely, when the correct insert tooling (or sharpened HSS) is used.



A quick fit on an older TR1 engine case showed that they indeed fit nicely into the crankcase mouths now.


For reasons, which aren't fully clear to me either, I prefer an all silver engine in my TR1. So the cylinders had to be painted in heat-resistant paint.


While I was at it, I removed the breather hose on the camchain-tensioner cover. Originally I meant to reuse one of my old TR1 covers, but the bore-spacing is slightly different, so that wouldn't work at all. 



The fitting was helicoiled in M6 and a countersunk bolt used to plug it up.  


Next was to free the crankshaft from its current home and inspect it. In order to get the rotor's taper up to sufficient temperature, I used a jeweller's oxy-propane torch to heat it up in individual spots and make it distort ever so slightly, so it loses its grip on the taper.


A very satisfying moment, indeed. Also not the usage of one euro-cent coins to protect the crank end. (Also they are cheaper than buying little copper buttons to use...)


An almost new oilpump for the new engine. 


With the right crankcase-half off, it's time to inspect the gearbox and make some room inside the cases. 


Totally fried. 



Pushing the crank out, requires a special tool, which in my case is just some angle-iron with a few suitably spaced holes and a spacer ring to spread the load evenly on the outer bearing race. 


And finally the crank: already stripped of the oil-pump gear and the ball bearing, because it had a flat bearing ball in it and the conrods removed to inspect the clearances.


New bearing shells and pistons and rings have been ordered as the pistons had some marks on them, which made me ever so slightly uneasy and as such I decided not to reuse them. (Even though they probably are perfectly fine to use.) Once the parts the parts arrive, it will be time to take the engine out and dig into it.

15 comments:

  1. So I'm curious. I have a 2003 Vstar 1100. I'm rebuilding my top end due to a seized cam from improper oil filter installation. My question is, will a virago head work on the vstar?

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    1. Absolutely. But the combustion chamber is a bit different, so you would be better off swapping both heads. OR if you actually want to make some extra power, go for some XV700 or XV750 heads as those will bump up the compression and the smaller valves will help with low-end torque. (Which is what I am going to do on this engine.)

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    2. My apologie. Couldn't read this message before I replied. But that's fantastic news. I've been doing homework on the vstars. But cant pull up my on them, so I started doing homework on the virago. Hoping to squeeze more power outta my little xvs1100 bobber. So what I'm getting. Run the xv700 or 750heads? Should squeeze some extra power? Was also considering a port n polish since I already have the heads off. How you feel about a port n polish on my dirtystar?

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    3. A bit of dressing up the ports has never done any harm, but unless you really know what you're doing just remedy obvious flaws, like the casting protruding past the valve seat and seams from where the two halves of the mold were touching. Other than that the ports flow really, really well for what they are.

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    4. Both 700 and 750 heads are really good, I personally prefer the 700 heads as they have a nicer squishband all around, but I've run 750 heads in the past and if there is a realy benefit to the 700 heads, it's probably somewhere in the region of being academic. So if 700 heads are hard to come by, you're not leaving much on the table if you go with 750 heads.

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    5. Yea I was just gonna clean em up, focus on cast lines. Nothing crazy. But that's great news. Appreciate the knowledge. Definitely gonna try and hunt down the 700 heads. Finding them often as opposed to the vstar heads. And I feel like the virago heads will give It a very unique look. Tha is again

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    6. With regards to the look - I hope you will see it here first ;-) No really, the workshop move is coming to an end this weekend and I hope to finally continue the engine build.

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  2. this idea is complete blasphemy...BUT.... could one take what you are doing, a set of heads from something like a Yamaha Bolt (XVS 950) and a fuel injection setup from that bike and bolt it into a 1st gen XV920R (TR1 in your part of the world) frame?

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    1. Personally, I think you wouldn't ned the EFI from a bolt, but could use some other more generic setup, i.e. some MS-variant. I have no idea about the bolt pattern of of a XVS950 head, but I doubt it would fit. I would much more have a look at those integrated throttle bodies from a modern scooter or dirtbike. As these are usually meant to connect to the cylinder head via a normal inlet rubber, circumventing the whole head-swap malarkey.

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  3. Well I got a Yamaha dragstar, Vstar, or xvs1100. Bent valves. Because cam seizure. Can I bolt the virago 1100 heads complete to my Vstar bottom end? Will it operate correctly?

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    1. Yep. But see tonight's post about the looks. You will have to stick with frame mounts of your XVS1100 in order to make it work.

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  4. Hello and Greetings from Thailand from a German who left his country 20 years ago. I love your knowledge and would like to get to know you and follow your posts. I have a 1995 direct import Virago, 1100 cc, with the engine and frame number 4 -PP 0045......I guess sit's a 1995. Any idea about those bikes and how to check when they were built? Enough for today, waiting for your reply.

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  5. Oops, forgot to mention how I got to your website. Szekelda, the Admin of the best Virago forum in the world had mentioned you in one of this fantastic videos. He spoke very well of you and that means a lot to me. How can I keep in touch with you, bro? My e-mail is mikelmersi@hotmail.com it would be great if you can drop me a line. Best of all from Thailand. Mike, the German English teacher who's been teaching for the last 17 years. Pretty much the only thing you can do here legally. I'm married to a cool Thai woman and it's been 20 years now with her. And guess what? We are still in love. Wish you all the best, f...the rest. Ride to Live- Live to Ride. Mike, Sisaket/Thailand.

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  6. May I post a question about my bike, had a series of weird stuff going on. Thanks in advance. Mike

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    1. Hi Mike - just drop me an e-Mail (address on the top of the right column) and guess what, if you fancy, we can even write in German.

      4PP is a type-code I am unfamiliar with, but I am pretty sure that's a localized version of sorts, the regular type-code would be 3LP.

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