Exhaust band clamps, general (fitment) question

[KevinK7]

Question on band clamps, specifically SUMMIT brand if anyone has used them. Do they normally go on easy?
I've never used them before, and wasn't expecting to 'fight' with them to get over the pipe ; )

Since there doesn't appear to be dropdown pipes available for a 396 with factory manifolds (and no local shop with a mandrel bender) I'm starting to gather exhaust parts for my truck (68 C20 Utility, 396 w/ factory manifolds).
I'm planning to go with 2.5" system, I placed an order with Summit for a pair of FLowMaster FlowFX mufflers, some 2.5" (lap joint) band clamps, etc.
Link to band clamps: https://www.summitracing.com/parts/SUM-681250

The parts arrived and it was nearly impossible to get the band clamps on the muffler. I had the nuts backed out to all but 2-3 threads and still could not get the clamps in place.
Eventually by removing the bolts, spreading the band around the muffler/pipe, 'clamping' it with large pliers, I was able to get it.

This may be normal, I don't know, but hoping others can shed some light.


Thanks,

Kevin








Apparently I'm not the first person to run into this...

[TotallyHucked]

That's pretty normal. I've got them on my '85 at the headers and that's how I have to get them on, even after 35k miles on them

[72c20customcamper]

Not from Summit I got the 3” x pipe exhaust for my Chevelle from Pypes. Same issue I just went and bought longer SS bolts . Been 10 years no leaks

[KQQL IT]

Clamps are for slip fit junctions

[LS short box]

They make the clamps shown above for slip fit and also non-stepped type for butt connections.
I used to use the wide type on my hot rods for years but now I use the 1" wide clamps like they use on late model vehicles. You just need to make slots in the exhaust or muffler tube so the clamp can clamp down.

[KevinK7]

Thanks for the replies guys...
The more I ask around (and from your responses) it does appear this is normal.... editing that "normal" may not be the correct word, but 'expected at times due to variations with brands/pipes' ...might be more accurate ; )

Thanks again,

Kevin

[72SB]

I used the same ones on my 2 1/2" FX mufflers to OTA pipe, no problems. Slip fit which they call lap.

[MikeB]

We know that the muffler pipe ID is designed to slide on a 2.5" exhaust pipe. But the OD depends on pipe wall thickness. Could be that your mufflers' 2.658" OD is a bit on the large size. FWIW, I've bought them from a few different vendors, but haven't had the problem you've described.

[KevinK7]

Mike, Thanks for your reply. A buddy of mine locally stopped over and (as you) said he definitely didn't have this issue. On the other hand, he noted, "well, at least they won't slip..."
I was on the fence of returning these Summit ones and trying another brand, but with the thought in mind that they won't allow the pipes to slip/turn, I'm going to go with them.
I may not get into this for another month or so, but I will update when I do.

Thanks again,

Kevin

[jerry moss]

exhaust tubing is always measured O.D. the muffler neck is measured I.D. that way the pipe will slip inside the neck of the muffler. that's how it's been as long as i've been working in a muffler shop(39 years and counting)

[MikeB]

Originally Posted by jerry moss

exhaust tubing is always measured O.D. the muffler neck is measured I.D.

Yes, that's what we said above.

The muffler pipe is meant to slide over a 2.5" OD pipe. There may be some kind of standard for its OD, but its ID is the critical dimension, whereas OD is a function of wall thickness. In this case that's .079". I'd bet some muffler pipes have thinner wall thickness (.0625"?), which would have made for easier clamp installation.

To the OP: I have leaned to torque the heck out of the clamp bolts, or you will see some condensation drip out. Also, those clamps will be easier to reinstall once they take the shape of the pipes.

[jerry moss]

Originally Posted by MikeB

Yes, that's what we said above.

The muffler pipe is meant to slide over a 2.5" OD pipe. There may be some kind of standard for its OD, but its ID is the critical dimension, whereas OD is a function of wall thickness. In this case that's .079". I'd bet some muffler pipes have thinner wall thickness (.0625"?), which would have made for easier clamp installation.

To the OP: I have leaned to torque the heck out of the clamp bolts, or you will see some condensation drip out. Also, those clamps will be easier to reinstall once they take the shape of the pipes.

sorry Mike I misunderstood how you worded it-besides that it was too early in the morning when i read it you are correct in wall thickness variations, the thin wall tubing has a tendency to kink when bending and will split when you expand it. we only use thick wall aluminized tubing at work, here in commifornia it last a loooooooong time.

[MikeB]

Originally Posted by jerry moss

sorry Mike I misunderstood how you worded it...

Yeah, I can see how that happened! When writing both my posts above, I had to double check my OD and ID numbers for exhaust pipe sections and mufflers.