Exhaust Clamps

[Richardtr3a]

I have found Mikalor exhaust clamps which are wider than the usual U clamps. Are they more effective and does the slot in the pipe have to be wider than the clamp.   Any advice please ?  Richard & B

[Nigel Triumph]

I've been using Mikalor for clamping exhausts and hose connections for a while.

As a band clamp, on exhausts the Mikalors exert a more even clamping pressure around the joint and can be done up tight to prevent leaks without crushing the pipe in the way an over tightened U-bolt clamp can do. Recommended!

Nigel

[NigelH]

Hi

As you appreciate, the clamp is only providing the strength to the joint, the sealant creates the glass seal, so the clamp needs to close the outer pipe down, generally a wider clamp does give more stability, but the fit/sizes of the two pipes do most of that.

Ideally the slot needs to be wider than the clamp to do so,  

You may of course be able to clamp with a shorter slot than U clamp, but it may not be as strong and may allow a rocking of the joint.

The bridge piece should be a snug fit or slightly smaller than the pipe did when offered up to the exhaust as you want it to close the pipe radially (that's its main purpose), not just top and bottom points.

Nigel H.

[NigelH]

Glass seal? Gas seal 

Slot comments are same for band type clamps..

Nigel H.

[jerrytr5]

Make sure you get the stainless steel ones. I always use them where possible.

Jerry

[Rodbr]

At the risk of repeating myself wrap the male part of the pipe with 3-4 layers of Plumbers PTFE tape.

Use Mikalor clamps fit and forget till you need to split them and you will see why you should use PTFE tape. It's a doddle as there is a barrier between the pipe sections.

Works really well on mild steel pipe.

Rod.

[Nigel Triumph]

3 minutes ago, Rodbr said:

At the risk of repeating myself wrap the male part of the pipe with 3-4 layers of Plumbers PTFE tape.

Use Mikalor clamps fit and forget till you need to split them and you will see why you should use PTFE tape. It's a doddle as there is a barrier between the pipe sections.

Works really well on mild steel pipe.

Rod.

Never tried PTFE tape on an exhaust joint but it makes perfect sense... It seals, it's non-stick, and it's thermally stable to at least 250 degC.

Next time I refit an exhaust I will ditch the usual sealing paste and use PTFE. Thank you Rod.

Nigel

[peejay4A]

Doesn’t the ptfe tape get scraped off when you slide the joint together?  Is there a technique to it?

[ianc]

Yes, Pete, the PTFE will get scraped away on assembly.

Stuart recommends use of Copperslip ( a.k.a. Copaslip) in the joint - stuff I have been using for years. 

Makes it easier to assemble and, later, to dismantle.

Ian Cornish

[Rodbr]

Hi Ian C,

Have you actually tried the technique, or do you just shoot from the hip without any knowledge backed up by fact?

Equally I have used the technique on Rally exhausts and my TR ones with equal success so why do you think you are any more authoritative on this?

If you are ham fisted and screw the joint together yes you might scrape some of the tape away. perhaps might like to suggest to a plumber of your choice to use snake oil instead of PTFE tape.

It is an alternative that has equal merit. Having tried both I found a tendency for Coppaslip to bake on with the intense heat of competition use. Try changing out an exhaust on a 12 minute service halt as well as fluid change, diff check, change all four wheels.

The worst thing you can do is use traditional exhaust clips as you end up with a localised compression which requires the use of a heavy persuader which in turn damages expensive exhaust boxes to separate.

Pete.

There is a technique which includes preparing the mating surfaces and removing sharp edges with a file to avoid such damage and you can also use grease to assist easing it on. The grease burns off leaving a non sticky barrier layer that does not rust and fuse together.

Rod

Edited June 27, 2020 by Rodbr

[Richardtr3a]

8 hours ago, Nigel Triumph said:

I've been using Mikalor for clamping exhausts and hose connections for a while.

As a band clamp, on exhausts the Mikalors exert a more even clamping pressure around the joint and can be done up tight to prevent leaks without crushing the pipe in the way an over tightened U-bolt clamp can do. Recommended!

Nigel

Thanks for the advice. I tried 3 sites on EBay and when I tried to check out they all said page not available. Where do you get yours??  Richard & B

[Nigel Triumph]

I haven't needed to buy any for a couple of years but had no problem buying them on eBay in the past. For example,  from here:

https://www.ebay.co.uk/c/1456969273?iid=302571910886

Nigel

[Andy Moltu]

Ceramic grease allegedly copes better with the heat than copper slip.

[Waldi]

I got SS Mikalor clamps from Moss.
The bolts are not SS, I think, though.

Waldi

[Spit_2.5PI]

Waldi, Mikalor also do their clamps with SS bolts, but the variety with hi tensile bolts are rated to a higher clamping force. Norma is another manufacturer of the same style of clamp.

I've also used a smear of copper grease on exhaust joints since my Dolomite days and can confirm it makes disassembly soooo much easier years later. (I've never done any track days.) So long as I only get the merest "puff" of exhaust from a joint (as felt with my finger), I can't hear it and the MOT examiner has always been satisfied.

Cheers, Richard

[Waldi]

Thanks Richard, 

I accepted them, and they fitted nicely. With my planned dry-no salt  driving I did not care much about it.

Waldi

[Xmas6]

Hi all Mikalor stainless clamps are listed in the Car Builder Solutions catalogue (a great read!!) , l think I got mine through RS a few years back.

cheers Neil

[Richardtr3a]

Thanks for the link ,  Who are RS and can you supply contact details please?

Thanks Richard & B.

[BlueTR3A-5EKT]

On 6/27/2020 at 11:16 PM, Andy Moltu said:

Ceramic grease allegedly copes better with the heat than copper slip.

Here is what we have use since the 1980's

http://www.brianhyde.co.uk/product/category/52/la-co-e-z-break-copper-grade-anti-seize/20274

Peter W

[Spit_2.5PI]

Richard, RS Hose Clips & Jubilee Clips link. Usually not the cheapest place to buy bits but ... !

Cheers, Richard

[BlueTR3A-5EKT]

One of these I suspect will do a sidescreen  exhaust - check pipe od before buying!

 

 

https://uk.rs-online.com/web/c/fasteners-fixings/clips/hose-clips-jubilee-clips/?applied-dimensions=4293500846,4294472193,4292085519

 

 

 

 

[Kevo_6]

Hi, I got mine from here. https://www.advancedfluidsolutions.co.uk/mikalor-hose-clips--clamps-w1-w2-w4--w5-116-c.asp

Edited June 30, 2020 by Kevo_6

[Z320]

I sadly destroyed some clamps like the Mikalor clamp by using them on the exhaust, so I never use them since.

They have been all not strong enough for a REALLY tight fit, the stainless strip is too thin and the ends are bended outwards

and are welded outside on the strip, some with a sharp bend (which I pulled very fast straight, then off).

If you want too use something like this on the exhaust I recommend to buy PA-RI clambs,  a small German producer.

Their strip is bended inside and holds more tight the more you tight them up.

I have one reliable supplier for them, all sizes cost about the same price (not cheap),

but this is a honest price because the effort to produce them is always about the same.

I modyfied a pair of them for the radiator top hose from ellen head to a more classic domed hex head.

I like them...

 

Edited June 30, 2020 by Z320

[Waldi]

Hi Marco,

the PA-RI clamps look to be even better designed than the Mikalors, I fully agree. If my clamps fail, I will change to these. But I hope they hold, they are and remain a much better design than the traditional U-clamps, although there is a ratio between pipe wall thickness (stiffness) and achievable clamp force.

Cheers,
Waldi

[Z320]

Hi Waldi,

today I found another pair of Pa-Ri clamps on my car, fitted by the previous owner.

Ciao, Marco