Can it be welded (while it's still installed on the engine)?

[John Gervais]

I suspect my 1½ year old Freeflow exhaust manifold has developed a small crack at the point where it's bolted to the gearbox bracket.  My gut feeling is that when the upper engine stabilizer bushes wore, the engine rocked a small amount and even though the upper half of the manifold is secure, and the pipes under the car are securely mounted to the car, the elbow portion of the manifold has flexed and a crack developed.

I noticed when I pulled into the garage last Friday evening after a long highway drive (in horrible weather) that the car was running a bit louder than when I took off Friday morning.

My plan is to remove the sumpguard tomorrow and try to wiggle myself, a mirror and flashlight) under the car tomorrow, slide the clamp down and take a look for soot, but won't be able to remove it from the car to have it welded if necessary.  The mini has become my daily driver, and I haven't welding capabilities; I own a small MIG welder, but the garage doesn't have 'enough' electricity to use it - only enough amperage for (dim) lighting.

Another factor is that my wideband bung is slightly incorrectly placed, requiring that the RH pot joint gets popped out of the diff to allow the bung to come clear of the power unit.  The next exhaust system will re-locate the bung onto the short pipe just after the Freeflow.  Live and learn...

So, if it's possible, maybe I can drive the mini to an exhaust shop and they can weld a bead, given the tight space between the pipe and gearbox.


Otherwise, why would the mini sound really grumbly-loud after a long highway drive???

[MiniDave]

I think your assumption is correct, and I would think any decent muffler shop should be able to fix you right up......

[John Gervais]

Thanks Dave, any tips or suggestions you could give?  (unplug the wideband or electronic ignition?)

[Willie_B]

and the pipes under the car are securely mounted to the car,

The pipes under the car should all be rubber mounted to allow for some flex in the whole system.

[John Gervais]

Oh, they are - I guess I meant to say that I hadn't used coat hangers or bungee cords.

These are the rear bobbins/cotton reels:  HRM01

And the center mount:  C-19G3257

The center mounting strap is situated right in the middle of the rear box's skid plate, so can't be seen, and the standard rear bobbins were changed to the heavy-duty rubber ones that Maniflow sells.  I thought it best to change them, as this big rear box weighs a heckuvalot more than the RC40 it replaced. 

I could always re-insall the std. bobbins and loosen the center mounting's bolt to 'soften' the rubber block (but it's not 'tightly squished', only 'firmly squished').

[MiniDave]

You shouldn't need to do anything except find where the leak is, if they can see it they can weld it......

[John Gervais]

Fingers crossed then - hopefully it's not leaking, but I can't think of any other reason why it would be sounding significantly louder after Friday's excursion. 

It may be that the muffler guy might need to bend his welding rod at the tip to get the forward edge, but I'll examine it first.

I do recall hearing a 'clunk' prior to changing the stabilizer bushes, and really haven't used it too much this past year, so I hope this is an easy fix.  Otherwise, what would be a relatively simple job in the summer months will become a torturous affair in the unheated garage.

Oh, and another question -

As can be barely seen in my photograph, the Freeflow is bolted directly to the diff bracket.  In the event that there's a bit o'weld there, I'd need to shift the collar down the pipe a tad.  I wonder how effective will the little strap be, having 2 'joints'.

[MiniDave]

That bracket is just a stabilizer, moving it around a bit to clear a weld won't affect it's performance at all.

[John Gervais]

Super - glad I saved it!  Thanks -

[John Gervais]

Well, I took the sumpguard off today and couldn't see anything.  Dragging a finger around the pipe yielded zero soot.  So, I took it for a drive and it sounded 'normal'.  I have no idea why it sounded so loud when I got in on Friday evening.

I pulled into 2 different exhaust/tire shops, and they rejected me immediately upon hearing that I wanted to put it on a lift and take a look.  Their lifts won't take a car 'this small'.  Unbelievable.

I drove back to the garage and installed the one-piece engine steady bushes (http://minispares.com/product/Classic/Engine/Stabilisers_mounts/Stabilisers/KKF101320EVO.aspx?100201&ReturnUrl=/product/Classic/Engine/Stabilisers_mounts/Stabilisers/KKF101320.aspx|Back%20to the blue-poly are back in a box for eventual replacement of the lower stabilizer bar bushes), did some fuel economy calculations (31mpg US/37mpg UK), installed a clutch spring retaining tab on the alternator bracket (will install a spring to help prevent the oil dipstick from potentially lifting upwards), dug out a collection of carb dampers for measurement and consideration (more on this later), and forgot to reinstall the sumpguard.

So the plan is to drive it as is, keep looking for soot, install the FIA/ECE/DOT approved safety harnesses (need to find a few 1½" long 7/16UNF HT screws (bolts), but should be good for 2 or 3 horsepower once they're installed) and possibly enjoy driving it. 

I might even give it a bath and take it fishing.