billthe3

How in the hell is a v-band clamp supposed to do anything towards sealing the exhaust?

I have a LR 2-piece crossover and the v-band clamp is leaking exhaust as if the two pipe pieces were held together with band aids. The copper gasket is in there, it is all lined up correctly, and the v-band clamp is tightened down as far as the bolt will travel, yet there is still a large amount of exhaust escaping out the connection. To the extent that you can simply hold your hand near the pipe and feel all the exhaust coming out.

I plan on calling lindsey about it on monday, but figured I'd post on here as well incase there are any fixes anybody knows about.

Thanks!

tedesco

did you check the v-band flanges for flatness? when I welded my exhaust it was necessary to surface the flanges after welding them to the exhaust pipes. Anyway, I would not expect the V-band so seal perfectly, that´s why I also just used it on the exhaust (low pressure) and not infront of the turbo. For my two piece crossover I used conventional flanges.

Ski

try adding a couple of flat washers to the long bolt, that should do it, it did mine.

special tool

You must have relatively consistant alignment before you even place the clamp on the joint.
When you do, you do not need copper washers with vee-band.
Loosen every single bolt on the exhaust system and try again.

tjbreen

I had the same experience with the LR two piece.

It is like the clamp is too big. I was down to the last thread on the bolt when mine stopped leaking. I was thinking either a new/different clamp or shimming it with an additional copper gasket.

dand86951

I agree with Tool, try loosening all other bolts in the crossover and then get the V band to clamp first. Then tighten the others, that worked for me.

billthe3

When I put the clamp on the most recent time I had loosened the entire crossover/header system before I tightened the v-band clamp down and it still is leaking. I will try tightening down again and if that doesn't do anything will try adding some washers to see if that helps. The two mating surfaces were as aligned and flat as I could get them to be before I tightened the clamp down.

Can you usually buy smaller v-band clamps at car parts stores?

dand86951

Don't know about auto parts stores but some of the performance shops would carry them. When you have the clamp as tight as it will go is there any room left between the ends of the clamp or has the clamp compressed all it is going to?

I don't know what different sizes they come in but doubt you would be able to get one just a hair bit smaller. Hate to say this but if the OD and the taper on the crossover pieces are machined just a bit off then the clamp won't seal it. You should measure the OD and the individual thickness at the outer edge of the pipes and then call Lindsey and ask what the dimensions should be. I don't doubt they will help you trouble shoot the problem.

billthe3

When the clamp is tightened down as far as possible the clamp does not have any room to tighten further. The bolt is as far down the threads as it can get because the clamp is fully compressed. I loosened all the bolts on the crossover last night and the piece still wasn't able to completely line up correctly. The only other nuts I'd be able to loosen are the header bolts, because I have the turbo fully rapped in header wrap (so I'd have to pull it back out to get at the bolts on that). Is it possible that the turbo is somehow mounted incorrectly and causing the up-pipe section of the crossover to be out of alignment with the bottom? I can't see how that would be possible without the whole turbo mount/engine support mount being out of alignment.

Matt Sheppard

It is possible that the turbo impeller housing is clocked slightly wrong on the center secton, but highly unlikely unless you messed with it.

How close to "flat" are these pieces before you go to town with the clamps?

I've had issues with the stock crossover not really alligning properly and it just takes patience and a strategic order of final torque on the hardware. Bummer, I thought these things were supposed to make life easier.

dand86951

If the clamp is coming metal to metal prior to tightening the exhaust pieces tightly then you definitely need to get some pictures and measurements taken and get back to LR. If the clamp has even a 1/16 of an inch left to compress but the nut is already all the way then as someone above said try putting some washers on and see if that will help. If these are new pieces, and you can get them on the heat of the exhaust will likely make everything conform so the next go around wouldn't be so bad.

BlacknRedGT

The only thing that took the longest time on my project was that damn V-Band clamp.... Dont ever try doing it alone is the only think I can say that might help. Remember that once you drive around for a bit it will start conforming a little more to the exhaust. You will prob need to retighten it after driving around for a day or two if you want a perfect seal.

billthe3

I did not mess with the turbo housing. It is the 27/6 I bought from Roger(Andial951) when he upgraded to his lindsey or whatever he has in there now. I originally screwed up and put the bolt for the AOS heat shield in before I put in the turbo forgetting about that stupid tab on the down pipe, which caused the turbo and piping to be severely misaligned. I took the turbo back out and placed a stud in the AOS heatshield/downpipe piece, but the pipe still seems to be off by a 1/4 in or so. The pipe piece flanges also do not mate up all the way either. It seems as though the crossover is maybe 1/4 in too low, because even with the copper gasket in there the passenger-facing side of the connection still seems to have a gap between the pipes.

Aside from this clamp issue, it does make installing the turbo and exhaust a hell of a lot easier. Once this clamp issue is solved this will be great.


I think I still have the pieces assembled from my last attempt at installing it, so I'll go take some pictures.



I suppose if worse comes to worse I can pull the steering rack out of the way and loosen the turbo mounts to see if I can get the pipe to line up that way. I don't want to have to actually pull the turbo and undo the header wrapping though. Being itchy from the fiberglass for one day was enough for me.

ibkevin

Damn that's a crappy spot to be in Bill.

BTDT x2 with the two screwed up Turo Performance 27/6 conversions. 2x turbo swaps, 2x wrapping, 2x SS banding = one pissed off ****! Plus I had to wrap and band the final turbo install.

Moral of the story, I nuked out the clocking of the hot and center sections to ensure I had NO problems down the line and Laust made it painfully simple. Make sure the bottom mount and hot inlet are perbendicular! Then I set the cold section outlet clocking.

With all the angles and joints in the turbo's plumbing, you could easily have something slightly out of alignment.

I started by bolting the downpipe to the block, left the top section of the 2pc slightly loose, the exhaust side slightly loose, and clamped the band flanges down tight. The proper way to tighten a V-band is to tap around the circumference in between turns to get the proper seat. If your band is bottoming out, get a new/smaller band and I'm sur LR can take care of that for you.

I've had mine apart twice and still seals well.

I feel your pain!

billthe3

Pictures pictures pictures.

It seems as though if it were not for the pipes being out of alignment and the v-band clamp would be large enough that it would be able to freely spin around the pipes. The one with red lines is trying to show where the edges of the pipe are compared to the v-band clamp - it seems like the clamp doesn't even hold part of the pipe currently.


Anyway, after I go have breakfast I'm going to call lindsey.