Installing front crossover shims

[tmcafe]

Just got the Aaron Bard made steel shims (the crossover has become loose and leaks around the joints, with classical symptoms like exhaust popping at lower revs, running rougher and more vibey, etc). Now I'm looking forward to installing the shims.

 

Sorry for the dumb question, but what's the best way to do it? Gracias!

[savagehenry]

I'd loosen up the clamp to the right exhaust pipe/muffler and right side of the crossover, pull the right head clamp away from the head. Don't take it all apart, just loose. See if you can slightly rotate the pipe away from the bike. The cross over will come out, and then put your cross over back, with shims in place, rotate the pipe back, and re-snug it, from the head back. I've done mine this way with no problems.

[tmcafe]

I'd loosen up the clamp to the right exhaust pipe/muffler and right side of the crossover, pull the right head clamp away from the head. Don't take it all apart, just loose. See if you can slightly rotate the pipe away from the bike. The cross over will come out, and then put your cross over back, with shims in place, rotate the pipe back, and re-snug it, from the head back. I've done mine this way with no problems.

Thanks SH. The crossover was pretty loose but I ended up removing the right header to clean/scoop out whatever was left from the fiber gasket. Had to do the same with the left header. Strange that I couldn't see the fiber gaskets that are supposed to go in the compression chamber--maybe there were the dark gray smooth rings inside that looked like they were part of the rim before the opening to the comp. chamber.

 

The problem is that I snapped the screw when I tightened back the left clamp on the crossover (though I didn't tighten it too much, definitely not more than the one on the right). For now it's tight enough just from the new steel shims and the tight clamp on the right. The rest of the screw with the head can't be extracted from the clamp, so I'll need a new one. Hope they're available.

 

 

 

[Scura R]

For some reason my right headpipe cracked all open, about 3 cm from the end(the mounting on the engine), using these steel shims. I changed them in July or August, and rode it very few kms until this happened. Maby more tension on the pipes using these solid shims?

 

It happened in September, some miles before I boarded the ferry from Gothenburg to Kiel, on my way from Norway to Mandello. Not the best start on my trip! It was late and no garages open, and also I had no time for repair before boarding. I really made some noise inside the ferry.

 

I had planned to visit Polo in Kiel to buy a new rainsuit, and there was an auto garage just next door, "Stop and go". I was lucky, they could weld, so I went and bought the rainsuit, and the pipe was fixed when I returned! And he absolutely refused to take my money!

 

The weld is holding up just fine. And the steel shims are still in. And my engine is now completely cured of any sneezing, rough running and is all smooth, also +-3000rpm. What a bike!

 

Anyone else had problems using these shims? Maby one should wait with the hard tightening of the pipes until after running the engine for some time.

[tmcafe]

For some reason my right headpipe cracked all open, about 3 cm from the end(the mounting on the engine), using these steel shims. I changed them in July or August, and rode it very few kms until this happened. Maby more tension on the pipes using these solid shims?

 

It happened in September, some miles before I boarded the ferry from Gothenburg to Kiel, on my way from Norway to Mandello. Not the best start on my trip! It was late and no garages open, and also I had no time for repair before boarding. I really made some noise inside the ferry.

 

I had planned to visit Polo in Kiel to buy a new rainsuit, and there was an auto garage just next door, "Stop and go". I was lucky, they could weld, so I went and bought the rainsuit, and the pipe was fixed when I returned! And he absolutely refused to take my money!

 

The weld is holding up just fine. And the steel shims are still in. And my engine is now completely cured of any sneezing, rough running and is all smooth, also +-3000rpm. What a bike!

 

Anyone else had problems using these shims? Maby one should wait with the hard tightening of the pipes until after running the engine for some time.

If you mean the pipe cracked near the cylinder head that's strange. Nice to get old-school help fixing it at the shop.

 

I noticed that the shims were very tight as I inserted them. However, the exhaust is still leaking a little, I can feel the engine pulses if I hold my hand near the crossover joints. But less noisy than with the loose crossover before.

 

 

 

[Mike Stewart]

There have been quite a few reports of the exhaust pipes cracking at the crossover location. I feel having the crossover rigid at that spot from having the crossover shims installed could put added stress to the joints, mainly due from expansion and contraction of the exhaust system and engine.

 

I installed my own shim just on one side of the crossover and used the stock Guzzi graphite crossover seal on the other. At least this way, there is still alittle give on one side and hopefully it will prevent any cracks from forming.

 

Mike

[tmcafe]

There have been quite a few reports of the exhaust pipes cracking at the crossover location. I feel having the crossover rigid at that spot from having the crossover shims installed could put added stress to the joints, mainly due from expansion and contraction of the exhaust system and engine.

 

I installed my own shim just on one side of the crossover and used the stock Guzzi graphite crossover seal on the other. At least this way, there is still alittle give on one side and hopefully it will prevent any cracks from forming.

 

Mike

I guess that might be a problem. In retrospect I should have kept the original sleeve/gasket on the left, where it was almost fine (the pipe would still spin in the sleeve though). I just didn't want to feel like it was patched.

[savagehenry]

I'm currently running without the front cross over pipe. As a test, I turned some aluminum plugs, and put them inside the two nipples and used the clamps to tighten them in place. I have'nt noticed any difference in how my bike runs, and will probably cut them off and have a stainless patches welded in place.

[Mike Stewart]

My gut feeling is that the front crossover might only be really helpful on the stock exhaust system

 

A manufacture would not be adding cost to a product if they thought it did nothing. I have only seen dyno reports on bikes with aftermarket crossovers, mufflers and pcIII's which the front crossover just showed a hint of a hp increase.

 

When my Rosso Corsa was bone stock (the first week I owned her), I went out with some Ducati guys for a ride. Well there was a long straight and their tail lights were becoming smaller, me in a tight tuck read 137 mph on my speedo. Later on in the ride, we came to a tight, narrow, steep road, I passed 4 of them inbetween two turns, coming out of a tight turn, my front wheel lifted, I never thought this bike could do that. The Ducati guys were scratching their heads after that.

 

Now, the next week, I changed out the crossover and mufflers plus installed a PCIII. Yes, it has a bunch more top end, but my wheel lofting days are over because the bottom end grunt is gone. Something to be said for the stock setup.

 

Mike

[tmcafe]

My gut feeling is that the front crossover might only be really helpful on the stock exhaust system

 

A manufacture would not be adding cost to a product if they thought it did nothing. I have only seen dyno reports on bikes with aftermarket crossovers, mufflers and pcIII's which the front crossover just showed a hint of a hp increase.

I should have done my homework better. I vaguely remembered a discussion where Greg said that the crossover does have a role. In the same post, I found their shop's cure for the loose crossover joints:

 

http://www.v11lemans...72entry140272

 

After all, there must be a logic to the fiber/graphite gaskets that prevent too much vibration in the headers and joints.

[Skeeve]

My gut feeling is that the front crossover might only be really helpful on the stock exhaust system

 

A manufacture would not be adding cost to a product if they thought it did nothing. I have only seen dyno reports on bikes with aftermarket crossovers, mufflers and pcIII's which the front crossover just showed a hint of a hp increase.

 

Well, Guzzi may have been doing a styling exercise, trying to better tie in the new LeMans w/ the original, which had a hard-welded front x-over [that was a source of complaint due to the tedium of removing the one-piece header system]?

 

I postulated on Guzzitech once that the front x-over would have had some f/x on the 4k rpm dip, & Todd's reply was that with a better collector & a PCIII it was unnecessary & more reliable to go w/ no front x-over. Not exactly my point [mine being a path of frugality], but the better solution, no doubt.

[tmcafe]

My gut feeling is that the front crossover might only be really helpful on the stock exhaust system

 

A manufacture would not be adding cost to a product if they thought it did nothing. I have only seen dyno reports on bikes with aftermarket crossovers, mufflers and pcIII's which the front crossover just showed a hint of a hp increase.

 

Well, Guzzi may have been doing a styling exercise, trying to better tie in the new LeMans w/ the original, which had a hard-welded front x-over [that was a source of complaint due to the tedium of removing the one-piece header system]?

 

I postulated on Guzzitech once that the front x-over would have had some f/x on the 4k rpm dip, & Todd's reply was that with a better collector & a PCIII it was unnecessary & more reliable to go w/ no front x-over. Not exactly my point [mine being a path of frugality], but the better solution, no doubt.

I assume the PC and simple aftermarket headers work very well, though it's a more pricy solution than fixing the crossover.

 

Curious if anybody went back to the OEM crossover gaskets.

 

 

 

[savagehenry]

I did, and tried the same procedure in the thread you are refering to, it used a tie down strapped across the cross over during re-assembly, yes? Eventually the cross over started getting loose again. I tried a few different ways to deal with it. The OEM gaskets were $25.00 each IIRC. I'm happy at this point without mine at all, but as always, your bike, your call.

That being said, my local dealer is EXCEPTIONAL, and during a discussion on this topic, he said he could fix it and make it stay tight. Unfortunetly, with the way things are these days, my repairs will have to remain in my garage, since money is very tight, and my kids want to eat, like, everyday, etc... Otherwise, I'd hand him my bike in an instant

[tmcafe]

I did, and tried the same procedure in the thread you are refering to, it used a tie down strapped across the cross over during re-assembly, yes? Eventually the cross over started getting loose again. I tried a few different ways to deal with it. The OEM gaskets were $25.00 each IIRC. I'm happy at this point without mine at all, but as always, your bike, your call.

That being said, my local dealer is EXCEPTIONAL, and during a discussion on this topic, he said he could fix it and make it stay tight. Unfortunetly, with the way things are these days, my repairs will have to remain in my garage, since money is very tight, and my kids want to eat, like, everyday, etc... Otherwise, I'd hand him my bike in an instant

Thanks. What was the reason you switched back to the original gaskets? Leaks?

 

One thing I noticed after I installed the shims is that there's more vibration above 5k, I can feel it in the pegs. Maybe I should tighten the whole thing like in the example you mention. If the original gaskets are so $$, the shims are a better buy anyway.

 

 

 

[savagehenry]

After I started having the front cross over leaks, I tried different approaches, not wanting to disassemble my entire exhaust system back to the rear cross over. I made my own versions of gaskets to put in place, and even tried wrapping both front joints with exhaust wrap, figuring maybe letting it be "free", but pushing the exhaust down the path of least resistence might be better than an entirely solid system, thinking the isolating of vibes might be the solution. Nothing lasted more than a few thousand miles per fix. Finally I said "screw It", just drop the whole exhaust, fix it per "Greg's Thread". But that too did not last. And I dropped about $70.00 in gaskets, only to have it start popping and farting on deceleration, the sure sign I was loose again. So finally, I just removed the front pipe all together. Plus, I have had a slow oil leak at the Phase Sensor and timing case, so now this winter I can fix that without effing with that pipe during re-assembly when I'm done.

That said, I also have essentially the Fast by Ferracci Nuovo Thunder motor upgrade, (11:1 pistons, big Breva cam, open airbox and wire mesh filter, oversize intake and exhaust valves, heads ported and polished, rear exhaust cross over, CF slip ons, PCIII, re-mapped ECU, which then necessitated that I make a "Roper Plate, because I'm cheap, but stubborn...) so the "needs" of my bike may be quite different from yours. And when an apparently very knowlegeable MG mechanic, Major M/C magazine contributor, and accomplished racer (Ed Milich) says he's spent enough time dyno'ing these enough to state that the front cross over is not needed, I'm listening, and trying that out. I'm convinced.

Until MY dealer says otherwise, I'm good to go. He might feel the difference, but he's also way smarter than I'll ever be with motorcycles, and faster than I could ever hope to be (and, due to his knowledge, and connections, MY Ohlins don't fail prematurely!). Plus, I'm on public roads. My bike will pull the front wheel up on command, and bounces the needle off that "140 MPH" pin on the end of my speedo, and keeps pullin', no problem. That's good enough for me! Good luck with yours, S.H.