Author Topic: Exhaust pipe almost touching shaft coupling  (Read 165 times)

Offline Armycook

Exhaust pipe almost touching shaft coupling
« on: May 12, 2017, 12:33:04 PM »
I just noticed there is almost a few thousandths gap between the coupling and the exhaust pipe. Is there an easy way of making this gap bigger as i figure vibration may cause these two to touch.

Picture may look like it's touching but it's just the angle of the camera phone.

Offline Armycook

Re: Exhaust pipe almost touching shaft coupling
« Reply #1 on: May 12, 2017, 12:38:00 PM »
i see that there's that black stain on the pipe already maybe they are touching and it was melted on the pipe

Offline Armycook

Re: Exhaust pipe almost touching shaft coupling
« Reply #2 on: May 12, 2017, 12:43:20 PM »
took more photos and yes they're touching.

Offline MPlayle

Re: Exhaust pipe almost touching shaft coupling
« Reply #3 on: May 12, 2017, 01:00:56 PM »
That is a commonly reported problem with the LCB style headers (which yours seems to be) and the 'Yoke' style outputs (which you have).

The two "solutions" I have read about are: 1) ensuring the LCB has the lower support clamp/bracket going forward to the case such that it pushes that branch of the LCB header backward enough to provide minimal clearance; 2) denting a flat spot in that branch of the LCB header enough to provide minimal clearance.

Also, ensure all of your engine steady bushings and mounts are in good condition to minimize engine rocking.

Edits: I rechecked the second picture and the clamp/bracket is present - on the other branch.  It may not be able to be moved to the offending branch of the LCB.  (Also updated the instructions in #1 above as the LCB needs to go the other way from what I thought.

« Last Edit: May 12, 2017, 01:06:46 PM by MPlayle »

Offline MiniDave

Re: Exhaust pipe almost touching shaft coupling
« Reply #4 on: May 12, 2017, 01:05:07 PM »
3) different header.....

Engine steadies shouldn't make any difference, the header and yokes move together with the engine.
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline Merlin

Re: Exhaust pipe almost touching shaft coupling
« Reply #5 on: May 12, 2017, 01:11:00 PM »
Not a joke. A hammer.
Engineering the Impossible

Offline MiniDave

Re: Exhaust pipe almost touching shaft coupling
« Reply #6 on: May 12, 2017, 01:22:35 PM »
Squishing the pipe down has a negative effect on it's ability to flow.....I think I would take the header out, heat it with a torch cherry red at the 90* downward bend at the top and try to bend it slightly for clearance.
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline MPlayle

Re: Exhaust pipe almost touching shaft coupling
« Reply #7 on: May 12, 2017, 01:40:41 PM »
Won't changing the bend at the manifold end result in a significant change in the position of the other end of that branch where it has to go into the 'Y' pipe? 

Offline MiniDave

Re: Exhaust pipe almost touching shaft coupling
« Reply #8 on: May 12, 2017, 01:56:18 PM »
Yep, you'd have to probably bend it in a couple of places, that's why I said "different header" - the one that was OEM on my 62 Cooper S had only one pipe to join to the pipe under the car, not two, so there were different styles available even then.

The easy way is to bash a dent in it, but then why have a free flowing header if you're going to constrict half of it?

Truth be told, most people buy them for looks, they don't really get any real improvement in performance because the rest of the engine isn't turned properly to take advantage of it.

One like this would work vs. the second pic, which is what he has now.....I just wanted to illustrate the difference in pipes.
« Last Edit: May 12, 2017, 02:05:39 PM by MiniDave »
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline Armycook

Re: Exhaust pipe almost touching shaft coupling
« Reply #9 on: May 14, 2017, 09:14:46 PM »
i'm replacing the headers i think. but it does clear now.. that's because it grinded and chewed out the chunks that was hitting the pipe.

Offline Merlin

Re: Exhaust pipe almost touching shaft coupling
« Reply #10 on: May 15, 2017, 08:52:56 AM »
Squishing the pipe down has a negative effect on it's ability to flow.....I think I would take the header out, heat it with a torch cherry red at the 90* downward bend at the top and try to bend it slightly for clearance.

Not entirely true.
https://www.youtube.com/watch?v=azPKIjxmmdU

Agreed that can cause some effect, but the gas velocity is low enough that you do not develop choke-flow.
Engineering the Impossible

Offline Armycook

Re: Exhaust pipe almost touching shaft coupling
« Reply #11 on: May 17, 2017, 01:04:23 PM »
any noticeable difference between an LCB and a Freeflow manifold?

Offline Armycook

Re: Exhaust pipe almost touching shaft coupling
« Reply #12 on: May 18, 2017, 09:10:00 AM »
i meant noticeable power differences