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Old 01-24-2011, 11:33 AM   #31
AliBaba
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Quote:
Originally Posted by supershaft View Post
Academic interests??? I have SEEN it work! As have MANY others!


Yes it works, and if you check out Farmers link you can see some dyno-graphs. They are in the range I described. Be sure to read the right graphs...


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Originally Posted by supershaft View Post
Different solutions to big bore kits?? The one solution they need and no one has done is moving the cylinder studs out to make more room. They ALL have the same issues as long as the studs are where they are. Of course, moving the studs out would require completely re-casting the heads AND cylinders.


So multiple Paris Dakar on a single set with cylinders or 200.000 km doesn't count?
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Old 01-24-2011, 11:57 AM   #32
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I didn't read his charts. I have seen the results myself with a dyno.

Who is trying to WIN Paris Dakar on wrung out cylinders and pistons? Over and over again? Was the class wide open or 1000cc?

Just about anything will work. How well is the question. Big bore kits do work but I expect my rings to seat better and my gaskets to not leak oil. I am just going on what I have seen myself. No googling.
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Old 01-24-2011, 12:37 PM   #33
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Originally Posted by supershaft View Post
Who is trying to WIN Paris Dakar on wrung out cylinders and pistons? Over and over again? Was the class wide open or 1000cc?


Raymon Loizeaux, he started in at least 18 Paris Dakar rallyes so I guess he knew what he was doing. I never said he tried to win.

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Originally Posted by supershaft View Post
Just about anything will work. How well is the question. Big bore kits do work but I expect my rings to seat better and my gaskets to not leak oil. I am just going on what I have seen myself. No googling.


It isn't that difficult. After all I've managed it.

One thing I find strange is that you say you have a lot of experience with big-bore kits but not modifying clutches. Is there a trick here? I got clutch-problems with my lightly modified Siebenrock 1000ccm-kit.

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Originally Posted by supershaft View Post
Thanks R12B!!! I didn't know they existed for the later clutches! It's not through BMW as far as I can figure. I can't see ever needing one. The late model clutches just don't slip in my experience with the standard spring.



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Old 01-24-2011, 01:56 PM   #34
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I don't have that much experience with high mileage big bore kits but the ones that I have experience with had big issues. Looking at the almost non-existent gasket surface sealing area and the distorted cylinders explained the trouble to me.

When I was working for Chris at San Jose BMW with the very late Wrecking Ball in road race trim, it had basically a stock K75 clutch in it and Chris told me that in hindsight the mod needn't had been done. I am willing to bet that that bike was making WAY more power than your setup.

More than likely you have a warped cover plate and pressure plate. I have quite a bit of experience with the late model clutches handling quite a bit more power than stock with NO problems other than the ones they SOMETIMES have anyway. NO clutch is perfect that I know of.

What about the class rules? Who said he was running the same top end year after year?
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Old 01-24-2011, 03:06 PM   #35
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Originally Posted by s.c.m. View Post
Did I get it right - this guy believes in a more than 20% gain in torque/performance just by increasing rod length?

Kind regards
Sven

the Seibenrock kit is 1070cc and has a modified camshaft, so it's not just rod length that gives the power.
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Old 01-24-2011, 03:13 PM   #36
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thx!
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Old 01-24-2011, 03:29 PM   #37
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A longer rod is not going to do a damn thing by itself.I believe most of you are thinking that it increases CCs which it doesn't. That would be a longer stroke which means a shorter rod is needed so the piston doesn't hit the head or the wristpin moved closer to the crown as mentioned.In some cases a plate between the jug and cases will alleviate the problem but also requires redegreeing the cams for optimal results.
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Old 01-24-2011, 03:42 PM   #38
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Originally Posted by baloneyskin daddy View Post
A longer rod is not going to do a damn thing by itself.I believe most of you are thinking that it increases CCs which it doesn't.
I'm not thinking that. Richie says his rods are 15mm longer and he makes the shorter piston to counter that. The gains come though higher compression pistons and more efficient thrust angles.

The guys having work done by him seem really pleased with the results and he seems like a genuine open guy.

Rob Farmer screwed with this post 01-24-2011 at 03:59 PM
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Old 01-24-2011, 04:22 PM   #39
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the clutch problems started for me at about 60ftlb at the wheel and about 75bhp you could open the throttle in 4th or 5th at about 70mph and just smoke the clutch. my 980cc sidecar race engines have about 100bhp at the wheel thats over 110 at the crank and the standard clutch with a heavy spring has no hope. the longer rod with moore dwell at tdc helps the power with the high top piston. i have spent more than a month on the dyno trying many things and long rods work on this engine.
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Old 01-24-2011, 04:40 PM   #40
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I have seen stock clutches hold up behind engines that turn about the same numbers. Then again, I have seen stock hp smoke many a clutch as well. I bit more spring pressure might help at some point but remember that all the later model bikes with way more power stock have about the same exact clutch. K12's for instance.

Rob, most in the know including Yunick attribute most longer RLR's gains to the increased piston dwell at TDC and NOT more efficient thrust angles. Yes, longer RLR's do have a slight advantage in not trying to cock the piston quite as much but they have a distinct disadvantage as far as thrust angles at the rod/crank are concerned. Dr. Curve explains it pretty well.

supershaft screwed with this post 01-24-2011 at 04:49 PM
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Old 01-25-2011, 12:06 AM   #41
Rob Farmer
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Supershaft,

It looks like the man himself is the latest noob. You can ask him yourself.
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Old 01-25-2011, 12:13 AM   #42
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Originally Posted by Rob Farmer View Post
Supershaft,

It looks like the man himself is the latest noob. You can ask him yourself.
I am not following you rob? Ask who about what?
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Old 01-25-2011, 12:21 AM   #43
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Post 39 above is Richie Moore. I was implying you could ask him where the extra performance comes from with the long rod engine.
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Old 01-25-2011, 04:02 AM   #44
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Originally Posted by Rob Farmer View Post
Long Con rod with a shorter piston. Send Richie an email and ask him about it.
Thanks, Rob.

I was being cheeky.


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Old 01-25-2011, 04:08 AM   #45
Airhead Wrangler OP
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Originally Posted by supershaft View Post
Of course, moving the studs out would require completely re-casting the heads AND cylinders.
...and the block too.
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