Technical Exhaust split from flange - repair or replace?

[Noah500]

After successfully overcoming the carb/fuel hose issue I had recently, I went out for a short run and I thought it felt slightly down on power/ Today I went on a slightly longer run, including 5 miles on a motorway and it started sounding like I had a sports exhaust. When I got home and let the engine cool down, I loosened and retightened all the manifold and elbow joints and started the car up again - same issue. Shining a workshop lamp in the engine bay I could see that the flange on the far side of the engine (by the firewall) had become disconnected from the actual pipe. I assume the welded joint has given way. I;ll take the whole thing off to have a proper look but is it worth getting someone to weld up the flange again or do I bite the bullet and get a new exhaust (slightly gutting since this one is only 2 years old and a thousand or 2 km... ).

If I do decide to get it welded, any advice on marking it so that it gets welded up in the right position and orientation?

If I decide to replace, standard or 'sports'? Any recommendations for either?

For non-standard exhausts, I found these, for example - opinions? (I don't want anything too noisy, though a few extra fractions of horsepower wouldn't go amiss )

Record Monza' Sports Exhaust Chrome Twin Pipe

Brand New Made in Italy Black finish Small Twin Reinforced Chrome Pipes 30mm Diameter to fit: Classic Fiat 500 all models with standard 499cc Engine Fitted If you have any questions please contact us for help

www.ricambio.co.uk

https://autobellaparts.com/products...33728&pr_ref_pid=8820756381952&pr_seq=uniform (looks the same as the one above)

Classic Fiat 500 499 Sport Abarth Exhaust 499cc Single Chromed Pipe Br

CLASSIC FIAT 500 F L SPORT EXHAUST FOR 499cc ENGINES ONLY Fits all Fiat 500 with 499cc engine. This exhaust with a sport note was hand made by Italian artisans that have been in the trade for decades. Sounds and looks amazing on an original Abarth or Replica. Single chromed exhaust pipe with a...

autobellaparts.com

(standard 499cc engine, btw)

 

[fiat500]

After successfully overcoming the carb/fuel hose issue I had recently, I went out for a short run and I thought it felt slightly down on power/ Today I went on a slightly longer run, including 5 miles on a motorway and it started sounding like I had a sports exhaust. When I got home and let the engine cool down, I loosened and retightened all the manifold and elbow joints and started the car up again - same issue. Shining a workshop lamp in the engine bay I could see that the flange on the far side of the engine (by the firewall) had become disconnected from the actual pipe. I assume the welded joint has given way. I;ll take the whole thing off to have a proper look but is it worth getting someone to weld up the flange again or do I bite the bullet and get a new exhaust (slightly gutting since this one is only 2 years old and a thousand or 2 km... ).

If I do decide to get it welded, any advice on marking it so that it gets welded up in the right position and orientation?

If I decide to replace, standard or 'sports'? Any recommendations for either?

For non-standard exhausts, I found these, for example - opinions? (I don't want anything too noisy, though a few extra fractions of horsepower wouldn't go amiss )

Record Monza' Sports Exhaust Chrome Twin Pipe

Brand New Made in Italy Black finish Small Twin Reinforced Chrome Pipes 30mm Diameter to fit: Classic Fiat 500 all models with standard 499cc Engine Fitted If you have any questions please contact us for help

www.ricambio.co.uk

https://autobellaparts.com/products...33728&pr_ref_pid=8820756381952&pr_seq=uniform (looks the same as the one above)

Classic Fiat 500 499 Sport Abarth Exhaust 499cc Single Chromed Pipe Br

CLASSIC FIAT 500 F L SPORT EXHAUST FOR 499cc ENGINES ONLY Fits all Fiat 500 with 499cc engine. This exhaust with a sport note was hand made by Italian artisans that have been in the trade for decades. Sounds and looks amazing on an original Abarth or Replica. Single chromed exhaust pipe with a...

autobellaparts.com

(standard 499cc engine, btw)

Tricky...ideally, you'd want it welded, (or at least tacked), in position, which is nigh on impossible.
It might have been under strain, depending on how it was fitted. The exhaust should really be secured to the elbows whilst they are loose on the head.. This is also nigh on impossible on a 50-odd year old car, especially as the securing bolts for the elbows are a dodgy area prone to seizing and stripping.

 

[porta]

If there’s decent metal there then weld it

 

[Noah500]

OK... I've got the exhaust off (at least on these cars it's not a big palaver!). As I had seen, the top pipe has sheared off the flange but additionally the joint between that pipe and the silencer has cracked.., possibly/probably caused by one of the half brackets having cracked. With the general vibration of the engine, that seems likely to be the cause.

Anyway, aside from new brackets, I don't think it's worth trying to patch up the exhaust so I need to get a new one.

So, standard replacement or one of the 'sports' ones?

 

[The Panda Nut]

Definitely weld that. The metal looks 100%

 

[Noah500]

Well, I would have to find and pay a welder to do it, and a new standard exhaust is not too pricey. I had a previous exhaust welded up where it had cracked at the silencer joint and it eventually went in the same place

 

[fiat500]

Maybe non-500'ers aren't aware of how fussy the exhaust setup is. It looks simple enough, but there is very little scope for error in alignment between the carrier brackets, the pipes to the elbows, and the elbows to the head. For instance, even if the brackets were useable I wouldn't recommend just expecting a new, standard exhaust to sit correctly in them, (although it might).

I would invest in a new, standard exhaust and brackets, but be sure to get the correct ones, and of good quality..

 

[The Panda Nut]

Well, I would have to find and pay a welder to do it, and a new standard exhaust is not too pricey. I had a previous exhaust welded up where it had cracked at the silencer joint and it eventually went in the same place

Worth repairing as a spare or sell it and someone else will probably repair it and use it.

 

[the hobbler]

Worth repairing as a spare or sell it and someone else will probably repair it and use it.

Personally, I would replace the exhaust---as you say, a welded-up exhaust is very likely to go at the same place. From personal experience, I definitely would NOT weld the exhaust bracket---they are not made of the finest steel!. Be aware---500 and 126 exhaust are different. Have you been abletoleave the exhaust "elbows" in place?---if you can, do so as removing the bolts that hold the"elbows" to the cylinder head can result of a fair bit of the thread in the head coming out with the bolt. Repairing that is almost always a "head-off" job.

 

[Noah500]

Yes, the elbows are still in place, though I've loosened the bolts so as to be able to tighten the exhaust to the elbows first, before tightening the elbows to the engine.

 

[lazylobster]

Grab yourself a cheeky little sports exhaust, will free approx 0.1 BHP but will sound a lot better. 500's are noisy cars anyway as the engine is about 2 feet from your eardrums. Let the public know you're there!

 

[fiat500]

Yes, the elbows are still in place, though I've loosened the bolts so as to be able to tighten the exhaust to the elbows first, before tightening the elbows to the engine.

Ideally.
The exhaust should be placed in the bottom bracket which should first be secured to the crankcase.
The flanges should be tightened to the elbows which are loosely secured to the head.
The top straps are tightened over the silencer, and finally, the elbows are secured to the head.
This procedure reduces the strain put on any part of the setup.
However, the threads in the head and in the crankcase are often stripped or siezed, and the threads of the original type of fixed stud on a 500 elbow are often corroded or broken.
It really pays back with reiability and longevity to spend some time getting everything perfect.

 

[Noah500]

Ideally.
The exhaust should be placed in the bottom bracket which should first be secured to the crankcase.
The flanges should be tightened to the elbows which are loosely secured to the head.
The top straps are tightened over the silencer, and finally, the elbows are secured to the head.
This procedure reduces the strain put on any part of the setup.
However, the threads in the head and in the crankcase are often stripped or siezed, and the threads of the original type of fixed stud on a 500 elbow are often corroded or broken.
It really pays back with reiability and longevity to spend some time getting everything perfect.

Thanks, Peter - that was the process I was intending to follow but it's useful to have it spelled out. You forgot the first part, though, which is to feed the exhaust up from underneath and hold it while trying to get the bottom halves of the brackets onto the studs

 

[Noah500]

I decided to go standard, btw, from Motobambino

 

[Toshi 975]

I decided to go standard, btw, from Motobambino

Good choice I think, both of supplier and type of exhaust. A sport exhaust would not do much if anything for power on a standard 499cc engine but would make it louder. The single big bore type being the loudest and the twin pipe a bit more mellow. With tuned engines I prefer he twin pipe but there is something sweet and wonderful about the sound of a standard 499cc engine ticking over

 

[the hobbler]

Good choice I think, both of supplier and type of exhaust. A sport exhaust would not do much if anything for power on a standard 499cc engine but would make it louder. The single big bore type being the loudest and the twin pipe a bit more mellow. With tuned engines I prefer he twin pipe but there is something sweet and wonderful about the sound of a standard 499cc engine ticking over

 

[the hobbler]

Whilst you may not be able to do this modification at this point in time, (because it is an "engine out" job) there is an "Abarth factory mod" which we carried out at Radbourne Racing, even on brand new cars, to ensure that the exhaust STAYS firmly in place. If you would like a copy of that mod, e-mail me direct [email protected] ) and I will patch it through to you.

 

[Noah500]

Whilst you may not be able to do this modification at this point in time, (because it is an "engine out" job) there is an "Abarth factory mod" which we carried out at Radbourne Racing, even on brand new cars, to ensure that the exhaust STAYS firmly in place. If you would like a copy of that mod, e-mail me direct [email protected] ) and I will patch it through to you.

Thanks, Tom. I've emailed you separately.

 

[Noah500]

@the hobbler Hi Tom - thanks for the document; a great source of advice

 

[Noah500]

All fitted and tightened up in the right order (though it was a hell of a job to get the top halves of the brackets on...) A quick run out to check and all seems good . I'll leave it to cool down and check the nuts/bolts (new deep brass ones for the exhaust to elbow joints).

btw, looking closely at the broken bracket, I could see that it had been welded previously... also the non-broken bracket had a weld on it, so I replaced both with new ones. It looks like the old ones had both given way at some time in the past, so well worth the peace of mind to replace them!