Stainless branch manifolds blowing

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Scimfancier
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Stainless branch manifolds blowing

Post by Scimfancier » Fri May 22, 2020 1:19 pm

I’ve just fitted some SS stainless manifolds to my Gtc. Whilst being generally delighted with their quality and the way they fit, I’m just wondering what people do to stop them blowing on the knuckle joints.


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Stainless branch manifolds blowing

Post by scimmy_man » Fri May 22, 2020 3:33 pm

send them back, they shouldnt blow


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Stainless branch manifolds blowing

Post by efi_sprintgte » Fri May 22, 2020 4:43 pm

I’ve had a few sets over the years with that knuckle joint that leaks, ended up welding the knuckle a few times to be honest.


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Stainless branch manifolds blowing

Post by Scimfancier » Fri May 22, 2020 5:41 pm

Jc, did you put many miles in after you’d welded them


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Stainless branch manifolds blowing

Post by scimjim » Fri May 22, 2020 6:26 pm

I’ve only had a couple with the knuckles (2.9i was the first about 20 years ago) and they leaked badly from fitting - a line of weld around them sorted it but I wasn’t impressed at all.


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Stainless branch manifolds blowing

Post by efi_sprintgte » Fri May 22, 2020 7:15 pm

Scimfancier wrote:
Fri May 22, 2020 5:41 pm
Jc, did you put many miles in after you’d welded them
About 75k over the last decade on that car. Agreed it’s a PITA that you have to.

Another set on a different car didn’t blow but “clicked” every time you took up drive or hit a bump. Again welding cured.


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Stainless branch manifolds blowing

Post by Scimfancier » Fri May 22, 2020 9:37 pm

The garage that’s fitted them has suggested cutting the joint out and welding in a modern flexible joint in its place.
They said they thought just welding the Knuckle joint might In use put too much stress in the system and cause fractures, but you’re experience is telling me different.

I’ve rang the supplier this afternoon and they’ve offered to exchange the manifolds and fit another pair In their workshop, which is probably the best outcome but that comes with the problem that they’re 1hr an 1/2 up the road and how durable is the design in the first place.


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Stainless branch manifolds blowing

Post by efi_sprintgte » Fri May 22, 2020 9:47 pm

A decent flex joint is a good idea and probably the best solution.

Don’t forget the original exhaust and many of the tubular sets that have been available over the years didn’t have flex joints.


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Stainless branch manifolds blowing

Post by scimjim » Fri May 22, 2020 10:37 pm

Flexible joints have a life though, how about welding on flanges and fitting bolt on flexis?


Jim King

SECURE DRY STORAGE FOR YOUR SCIMITAR

Current: SE5 (8Ball), TI SS1 (snotty), 1600 SS1 (G97), 1600 SS1 (C686CCR), 2.5TD SE5a (diesel 5a), 6 x random other SS1s.
Previous: SE5, 3 x SE5a, 2 x SE6a, 3 x SE6b, GTC, 2.9i GTC, 3 x 1600 SS1, 1300 SS1, Mk1 Ti Sabre, Mk1.5 CVH Sabre
Chief mechanic for: 1400 K series SS1 (Megan3), 1400 CVH EFi SS1 (Grawpy), 1300 SS1 (Number One) & Sarah's coupe.
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Stainless branch manifolds blowing

Post by Scimfancier » Sat May 23, 2020 6:44 am

Thank you. All good suggestions, I’ll put them to the chap at the garage, he’s a reasonable bloke and might not cost me anymore than the fuel required and time off to drive up to have them swapped.

At present though it wouldn’t pass an mot with it blowing like it is doing, the drivers side in particular.
Why does something that should be so simple and gratifying turn out to be such a PITA


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Previous GTCx2 SE6ax2 74 SE5a 74 SE5a 72SE5a
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