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About smithy09

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    Ball Peen Hammer

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  1. Yes. It was all OK, but just had that dip in the middle. In real life on the track it was a little annoying as you would be hard over mid corner, just exiting the corner when you came out of that dip in power and got a big rush, which wasn't good for rear wheel grip! The twin plug arrangement lessened that considerably but it was still there. Once I went to the big bore though, it completely disappeared. I was dreading riding a 150hp GS1000 on the track, but actually it was much easier to ride than the small engine. All was good until the crank broke!!
  2. I can't remember, and I'm away from home so I don't have my notes, but it was enough that we had to file extra length in the slots of the Dyna 2000. The HP gains were amazing. We did a run, advanced a bit, got a gain, advanced some more, another run, more gains, and so on until the hp stopped increasing. Found the dyno graph on my laptop! Advance was 40 degrees. These were with standard Wiseco 1100cc pistons, 10.5:1 before I went bigger. Unfortunately I never got a print out of the 150hp runs.. I will next time. Notice how the dip around 5500 rpm is less pronounced with the twin plug h
  3. When I say we retarded the ignition, this was compared to the massive advance we had pre twin plug head. You cannot say "Don't" to apply across the board. All my timing mods were done on the dyno with back to back runs. Advancing the timing with a single plug head and around 11.5:1 compression made a massive difference. We gained 10-15 hp, might have even been more. However the heat generated must have been substantial and like you say, the chance of detonation is also there. When we went to twin plug, the timing was dialed right back, probably to around standard timing, yes. I have no experie
  4. Here are the pistons I used. They were custom made by Wiseco to fit the Combustion chamber and valves I was using (Can't remember exact sizes of valves). I had to re-sleeve the block and bore the cases slightly. My head was sourced from the states and was a small port but well ported by Buzz from Dynoman. I fitted the Yoshi style cam tensioner system to control cam chain issues. Seemed to work OK. I hear you on selling parts for peanuts! You kick yourself right? That sounds like it was a good engine. I'm so glad I didn't sell my race bike when I stopped racing in 2009, and I'm looking for
  5. Here is an article on the XR 69 engine.
  6. The main reason Pops fitted twin plugs was to reduce flame travel. When the spark goes bang, the flame has to travel from one side of the chamber to the other. This takes time, and when you go high compression, you find you have to advance ignition big time to get the bang to happen at the right time. With my first gen motors we actually had to slot the Dyna 2000 back plate to get enough advance. The hp on the dyno just kept going up every time we advanced it. (I think we gained around 10-15 hp just on timing..) The problem is that because ignition takes a long time, the engine runs
  7. Great series of posts and love your bike Yann. Really nice to read the story and evolution... Tres Bien.
  8. Great story. Loving watching this build. Keep it coming! I'm still working offshore and currently in 2 week quarantine in Malaysia. I know the parts ordering madness that goes on!!
  9. Excellent choice! Runs cooler and spark can be retarded big time..
  10. Has anyone ever bypassed the oil feeds around the studs and fed oil to the head direct like the GSX1100 kits? Those damn oil feeds can be hard to seal..
  11. Great mod! Big difference!
  12. I fitted new liners when I went out to 78mm. Had no issues. I used custom Wiseco pistons bought through Dynoman.com. 150 hp at the rear wheel. Very nice power too!
  13. I like the weight saving on the mounts. I might have to take that route as well... I agree on the Katana swingarm. Easily strong enough, and you can always brace it a bit. Something I would also like to do is make a fibreglass mould of the seat and tail fin and make a one piece fibreglass seat along the lines of the Katana versions on offer. That and either an alloy or fibreglass tank. I want to keep the bike looking like a GS thou though, not a bitsa. The current engine managed 150 rear wheel hp which is enough for me. If you want any engine photos, let me know, as I went through q
  14. What engine and running gear you going to use? Progress photos as you go please!
  15. Love the jig. I might build one myself!! Are you changing the steering head angle? The rear geometry change is a good one. I guess you copied Pop's dimensions from the period? I did the same on my race bike and it works well. You have to move the lower shock position as well, but it works. I reckon you went over the top on bracing. In my experience it's just not required and simply adds weight. When I get my bike back together, that's what I will concentrate on; weight reduction. Nice work though mate. I look forward to seeing progress!
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