Muffler/Ground Clearance

[Alan W.]

I have approximated 2 1/2" clearance from the muffler to the ground and was curious if there is a thinner profile muffler available. Car is a 59 bn6 (not lowered).
Thanks,
Alan

 

[DerekJ]

2 1/2 inch seems lower than normal. I think it’s normally more like four inches. Sagging springs?

 

[nevets]

The muffler ground clearance on my BN6 is about 3 1/2”

 

[BoyRacer]

On my 1960 BT7 I have 3-7/8" clearance. My muffler is a stock replacement Wagner muffler. I am running Michelin XAS 180 HR 15 tires.

 

[Alan W.]

Thanks for your responses. On further inspection it appears that the flex pipes from the exhaust manifold are too long and results in the front of the muffler being low. If I adjust the flex pipes then the mounting brackets don't line up. I will attempt to shorten the pipes. There is a welded-on solid end.
Alan

 

[Michael Oritt]

Like Richard (Boy Racer) I have been able to increase normal clearance to right about 4".

1. I run Michelin XAS 180's which are a bit taller than most others commonly used.
2. I reworked the manner in which the muffler is hung, so that it is as tight as possible to the underside of the driver's floor (after adding a layer of heavy Dynomat).
3. I also reworked the manner in which the pipe passes below and beyond the dogleg frame member--which is usually the tightest ground clearance spot on our cars.

I had planned to attend Conclave in Florida in 2020--which of course was cancelled due to COVID--possibly taking the AutoTrain down (to increase my odds of arriving without issue or drama) and then leisurely driving back up to Maryland afterwards. To guarantee the car's admissibility onto the AutoTrain--whose requirement is, I believe, 4" minimum with its driver at loading (even allowing for a pessimistic inspector and a fat guy driving)--I installed a short SS coupling or cuff at the exit of the muffler that allows me remove the tail pipe ahead of the rear tire and put on a side exhaust, thus eliminating the "knuckle" under the dogleg which results in a solid 4-1/4" to 4-1/2" clearance with driver aboard. The section of tailpipe will just fit into the car even with the hardtop in place. I hope to attend Conclave in 2023--again planned in Florida--next Spring.

I'd attach photos now, but am still recovering from pneumonia. We'll probably be blabbing about this for another week or two so I'll post some pics when I feel better.

 

[Jerry]

I just put these tires on my project. Full 80 profile and good ground clearance. I think the taller tire also helps with suspension. Seems softer than my other BJ8

https://www.performanceplustire.com/products/ts:tiresizeshort-185-80-15:ty:Tire/

Galaxy R1

 

[Bob McElwee]

Hope you are feeling better soon Michael.

 

[BoyRacer]

Alan, check the orientation of the front muffler mount that is bolted to the floor pan. This can be reversed. If it is reversed, the tab that the muffler is bolted to will be too far forward - by about 1-1/2" - and would make your down pipes too long.

Michael, Sorry to hear you're ill. Bummer.

Tail pipe swap solution for a 6 cylinder car? I decided to drive 400+ miles down to Califoria last month to a Healey meet. Since I had side pipes that would be too uncomfortable for any long drive, I swapped everything out for new fabricated down pipes (I have headers), a new Bell muffler and new tail pipes. After I slipped my new tailpipes into the muffler outlets ( I think they went in about 3") and bolted up the tail pipe mounts, I thought to myself, why should I put clamps on those unions? What if I want side pipes for next summer's driving around town? I really do like side pipes - just not on long drives. So I didn't use any clamps and everything seems to be fine. Nothing loosey goosey. Next summer I should be able to slip out the tail pipes and slip in some new side pipes for that around-town driving. And vice versa for the long drive to that Healey meet up in Canada next summer.

 

[Alan W.]

Richard, I will check the clamp orientation. Thx. The car had a total restoration (kind of), and this is the type of thing that happens when a restoration is done by shops not familiar with AHs.

 

[Alan W.]

It appears that the non flexible part of the front pipe off of the exhaust manifold comes down too low, I don't see a fix except proper replacement.
Alan

 

[BoyRacer]

What does the motor mount look like on that side?

 

[Alan W.]

What does the motor mount look like on that side?

Motor mounts look fine, they are relatively new.

 

[AUSMHLY]

It appears that the non flexible part of the front pipe off of the exhaust manifold comes down too low, I don't see a fix except proper replacement.
Alan

I had the same issue when I got my mild steel ones from Moss. Where the pipe bolts to the manifold, 1" down, I cut about 1" off, had it welded back together. Don't see the modification. That fixed that issue. If you choose to do this, measure what's needed.

I don't believe remanufactured exhaust systems are as well fitting or sounding as the original.

Some modifying or changing of the mounting parts can also help raise the system. Example if a stock bracket is 1 1/2" and you have space, make it 1" (unless concours minded)

Just ran out to take photos, sorry, cars on jacks.