Air leak and vibration?

[coaster]

Ha!

Just for 'balance' (as in " you pays your money & makes your choice") when it comes to ease of use & cost:

https://www.toolstation.com/connector-nut/p29740

So, £1.39 for ten off.
M7 tap (most of us will already possess) but, say, about four quid...
Lockwire or some stripped copper wire.

Change from twelve pounds to do five engines.

Hmmmm. I think i'll 'stick'

A good compromise ould be your re-tapped and cross drilled nuts but using an R clip instead of the lock wire, no need to carry wire, cutters and pliers

[Warkton Tornado No.1]

Ha!

Just for 'balance' (as in " you pays your money & makes your choice") when it comes to ease of use & cost:

https://www.toolstation.com/connector-nut/p29740

So, £1.39 for ten off.
M7 tap (most of us will already possess) but, say, about four quid...
Lockwire or some stripped copper wire.

Change from twelve pounds to do five engines.

Hmmmm. I think i'll 'stick'

A good compromise ould be your re-tapped and cross drilled nuts but using an R clip instead of the lock wire, no need to carry wire, cutters and pliers

You are right, of course.

i have always matched inlet & exhaust manifolds on my own engine builds & lock-wired as I have loads of the stuff & the pliers but also prefer to use heavy duty plain washers rather than a plain & spring washer. Matched manifolds can usually remain dedicated to particular barrels & left in place as, after all, they never, ever leak.....

However, what always mystifies me, is how do you get those clips to keep quiet? They either rattle or 'fizz' IMHO

[Danbretta]

Warkton, are you getting away without using a sealant on your exhaust manifold? On further inspection my manifold was slightly warped, I've filed it flat now hoping this would eliminated the leak but no, I think sealant is my only option here but as before I think this may blow out again. How are you getting yours fitting better?

[dickie]

Warkton, are you getting away without using a sealant on your exhaust manifold? On further inspection my manifold was slightly warped, I've filed it flat now hoping this would eliminated the leak but no, I think sealant is my only option here but as before I think this may blow out again. How are you getting yours fitting better?

I found soft gaskets allow/cause thinner manifolds to warp. Using a solid.copper gasket, or maybe no gasket at all stops them from warping.

[Danbretta]

I had been using a solid copper gasket, maybe the copper silicone I used helped the manifold warp. I filed the face flat today but was still getting an air leak with and without the gasket. Maybe the outlet flange isnt as flat as could be. A straight edge across the surface and feeler gauge didnt show anything up.
I'll take another look and see if I can get a better seal without the sealant.

[Warkton Tornado No.1]

Warkton, are you getting away without using a sealant on your exhaust manifold? On further inspection my manifold was slightly warped, I've filed it flat now hoping this would eliminated the leak but no, I think sealant is my only option here but as before I think this may blow out again. How are you getting yours fitting better?

Sorry, I've only just seen the question.

I use the Loctite copper silicone stuff only on the head joints.

For OEM type two fixing manifolds, besides the long nuts, thick plain washers & lockwire, I use the bathroom silicone sealant (the vinegar smelling type) with or without a solid copper gasket. The solid copper gasket, whilst being the only type to trust, can be left out & the bathroom silicone sealant relied upon entirely. The main reason I put them in the assemnly is that I use them to match the exhaust port & manifold & therefore the best place to keep them as they are also a reference.

[Danbretta]

No problem, thanks for getting back to me
I'll try the bathroom sealant, sounds like it may work better than the stuff I'm currently using, I'm also using the nuts you suggested, tapped them out and I'll use the wire method.
I'll see how this goes, sounds more promising.
Thanks again.

[Warkton Tornado No.1]

Just a thought.

Your engine is standard & the oil/fuel ratio might be excessive. It's a touchy subject, but I had to reduce the mix in my Rapido 71 x 61 (piston ported, home tune, 34 mm PWK, home made 'Clubman', points ignition est circa 25 BHP) to just 2% of Exol's Optima. I use the same mix in a TS 70 x 60 but may up that a tad after thinking about Scotty's advice. That said, it has no cylinder wall in line with the con-rod, so big end lubrication may be enhanced.

Anyway, I'm only stating the above for reference.

Might your OEM type exhaust be oiled up?'

[Danbretta]

I'm going to try it at 2% and see how that goes when I get it back up and running. The old original box was coked up and battered. I replaced it with a tutto standard one (recommended on this forum) last year, seems to be ok at moment.