Exhaust fit

[czakky]

I just picked up an FBF X-over from a member here, very happy btw.

Fitting the piece is more of a pain than I thought it would be. I know the idea is to "relax" this exhaust system so everything slides on nice and easy fits tight to help with expanding/contracting and hopefully reduce cracking. I have a couple questions here.

When loosening the collar at the head to header should I replace the gasket? It doesn't leak but looks to be aluminum?

The only way I can get this thing remotely close to lining up is stressing the headers a little, the gap between the studs on the collars is a little uneven about 1/8" difference top to bottom. Is this considered relaxed?

Last up how far (guesstimate) do the stock mufflers slide on the aftermarket x-over? Seems much less than stock about 2" or so?

[JRD]

Czakky- I don't think you need to replace the gaskets but it certainly wont hurt, Im sure they have already been compressed and run thru enough heat cycles that they have probably lost all their compression and sealing ability.

As for the alignment issue- you might need to remove the header and try "adjusting the bend" to get everything lined up properly. It shouldn't take much pressure. If the header isn't centered at the cylinder head it could possibly be blocking the exhaust port.

[czakky]

Ok, was hoping I wouldn't have to bend the headers... I'll try one more time front to back, thinking relaxed as Bob Marley in a hammock factory.

[GuzziMoto]

I also like to use anti-seize on the pipe joints, so they can slide in and out as required. It also makes it easier to take apart later.

[czakky]

Tried it again using some anti-seize. Made it easier didn't gain much though. No leaks just resting hard on the left muffler bracket.

 

My experience with the performance of the new FBF x-over mostly echoes what others have said about it. Maybe a little gain on the top end and seems to help the "4k torque dip" a little too. I'm happy don't think I'd pay retail for it but it works. Let's hope this one doesn't crack....

[Gmc28]

thread revival...

the lack of overlap on my header pipe and crossover (agostini) has been gnawing at me, though perhaps for no good cause.  i have the mistral on the other V11 (goldie), and am tempted to pull it off and put it on Red, to confirm that it has the "correct" amount of overlap, at least to satisfy my curiosity, and partly then to hide the scarred header pipe on Red where the stock crossover left its marks.  i'd also gain the crossover mounting bracket which the mistral has for Red that the agostini crossover does not have (but then goldie loses it, though Red gets all the attention and riding these days).

The other night i loosened just the front crossover pipe connections on the agostini crossover (all newly installed as of a month or two ago), as well as the rear-most muffler hangar, so that the muffler and crossover could somewhat "swivel" forward and slide more onto the header pipe (just got more overlap onto the header pipe).  That required some effort, but just a little pressure from underneath with my arms, nothing mechanical and no rubber mallets.... But still i ended up tightening the clamps while holding some (20 lbs?) of pressure on the whole thing to keep it lined up the way i wanted.

any of you out there experienced with exhaust work believe that its a bad idea to do that?  my goals are as described above, and to help assure i have good snug exhaust joints.  have also considered using some exhaust compound, though i have not been a fan of those in the past.

most likely i'll just move the mistral crossover from goldie onto Red, and call it good, but then ultimately i'll end up with same question for Goldie (though maybe things will line up differently with goldie with its stock exhaust).  i've also noticed clear evidence of exhaust joints that are NOT tight on goldie with the mistral crossover.  I did not install that system, and don't know if it was user error, or a mistral issue, or if its not really an issue at all.  any mistral users have comments on that?

[po18guy]

I see it stressing the headers where they exit the cylinder head. 20 pounds pressure one direction means 20 pounds the other when you let go. As I understand it, the headers are double thickness for 30 mm or so where they exit the head, precisely because of stress cracks. And we hear enough about crossovers and X-pipes cracking. I would think that the best solution (do you have rear pegs and their hangers?) would be to slot the various mounting holes as needed so as to eliminate the stress. Then, only a few pounds to counteract gravity when installing and you should be good. Eliminating the rear muffler-peg hangers gives you a lot more freedom in mounting. Something like a stainless closed body turnbuckle would suspend the mufflers while allowing fore and aft movement depending on the amount of pipe overlap you want.  If the ends do not work, SS rod ends (Heim joints) could be substituted.

 

 

[Gmc28]

good thinking on the slotting.  the rear muffler hangars have the single bolt which doesn't need to be over-tightened (lock nut), and is how I "swing" the mufflers and x-over forward to slide onto header pipes more.  but the notion of slotting one or both of the two muffler mount bolt holes, the ones on the muffler itself, might be the ticket to create the desired slack.

i am concerned about cracking, but was under the impression that our headers without the forward crossover (the one on the header pipes that some bikes have/had), are less susceptible. either way, agree on wanting to minimize stress.  want to make this agostini setup work, mostly on stubborn principle,  but in reality i'll likely change over to the mistral crossover, which appears to have just enough extra length that it should fit together more naturally than using the agostini crossover, and make this all a moot point.

[po18guy]

Way too much hassle to TIG a one inch extension onto the crossover. But, if you know a talented welder who's not too busy...

[Lucky Phil]

1 hour ago, Gmc28 said:

good thinking on the slotting.  the rear muffler hangars have the single bolt which doesn't need to be over-tightened (lock nut), and is how I "swing" the mufflers and x-over forward to slide onto header pipes more.  but the notion of slotting one or both of the two muffler mount bolt holes, the ones on the muffler itself, might be the ticket to create the desired slack.

i am concerned about cracking, but was under the impression that our headers without the forward crossover (the one on the header pipes that some bikes have/had), are less susceptible. either way, agree on wanting to minimize stress.  want to make this agostini setup work, mostly on stubborn principle,  but in reality i'll likely change over to the mistral crossover, which appears to have just enough extra length that it should fit together more naturally than using the agostini crossover, and make this all a moot point.

Personally I'd start from scratch with new crush seals in the heads. Remember to remove the old head seals as I've seen a few with 2 seals fitted there. So remove the headers install new crush seals and re install leaving everything loose and nip up the joints that are causing the issues and then the headers in stages with the rest of the system.

I've fitted many many full systems over the years and Termi's on Ducati's can be an appalling fit that you need to wrestle into place. The Akra full Ti system on my 1198 is the only system I've ever fitted that fits perfectly everywhere with the most beautiful and highly accurate slip joints you could imagine and zero strain on anything. I couldn't believe a system could fit so perfectly until I experienced it. Mostly there will be stress involved OR some degree of poor lateral positioning. Sometimes both.

How much lack of engagement at the joints do you have? My system has at one joint maybe only a couple of mm past the clamping slot on one side and it creates a tiny black line on the pipe there after a while. Another 3 mm would be good but its about on par with what I expect from a system these days. You could always go to a decent exhaust place and get another 5mm of pipe welded on and linished back smooth.

Ciao

[Tomchri]

Not long since I put Mistral crossover and the titanium option cans from Guzzi on the greenie. New gaskets for headers, and tighten the bolts so I can turn them a little sidevice. The headers I think are the boss, the rest have to follow, and I use a lot of paste. I'm sure you know all this.  But I think the wear marks are nugging you the most  . You can put the Mistral crossover all the way into the headers for a nice fit, but then you are in trouble with the cans   Can take a picture tomorrw, to show my fit together and wear marks.     A few inches of piping woud have been nice, a few inches divided by ,,,, comes out in $. I woud have paid the full price.

Cheers tom.

[Gmc28]

2 hours ago, Lucky Phil said:

Personally I'd start from scratch with new crush seals in the heads. Remember to remove the old head seals as I've seen a few with 2 seals fitted there. So remove the headers install new crush seals and re install leaving everything loose and nip up the joints that are causing the issues and then the headers in stages with the rest of the system.

I've fitted many many full systems over the years and Termi's on Ducati's can be an appalling fit that you need to wrestle into place. The Akra full Ti system on my 1198 is the only system I've ever fitted that fits perfectly everywhere with the most beautiful and highly accurate slip joints you could imagine and zero strain on anything. I couldn't believe a system could fit so perfectly until I experienced it. Mostly there will be stress involved OR some degree of poor lateral positioning. Sometimes both.

How much lack of engagement at the joints do you have? My system has at one joint maybe only a couple of mm past the clamping slot on one side and it creates a tiny black line on the pipe there after a while. Another 3 mm would be good but its about on par with what I expect from a system these days. You could always go to a decent exhaust place and get another 5mm of pipe welded on and linished back smooth.

Ciao

Very good... that’s more or less the warm fuzzy I was looking for, that not a lot of engagement is ok (I probably have about 1.25”, so about half of what the stock system),  and that some stress on the system is not a cardinal sin.  
I did the new crush gaskets on the initial install a month or two ago, and this time just loosened a couple joints to achieve the better overlap. Thx Phil

[Tinus89]

Out of curiosity (I am not experiencing any netative effects from the exhaust system), do you connect up the crossover connections using a sealing paste/gun gum?

[Tomchri]

Very good... that’s more or less the warm fuzzy I was looking for, that not a lot of engagement is ok (I probably have about 1.25”, so about half of what the stock system),  and that some stress on the system is not a cardinal sin.  
I did the new crush gaskets on the initial install a month or two ago, and this time just loosened a couple joints to achieve the better overlap. Thx Phil

Not perfect, but.

Sent fra min SM-A505FN via Tapatalk

[Gmc28]

8 hours ago, Tinus89 said:

Out of curiosity (I am not experiencing any netative effects from the exhaust system), do you connect up the crossover connections using a sealing paste/gun gum?

i don't, and in the past on other systems have not found that work well for me, but i'm very much open minded about it, assuming that i may have been just using the wrong stuff.  maybe there's a good product out there that i'm just ignorant about.  tried using some product on a Cagiva exhaust system some years ago, and was a bust.  ended up shimming the exhaust joint, tediously, but came out well, and still holding up nicely.