Any tips for keep manifolds tight

[Rocket Ron]

Just wondering if anyone has any tips for keeping their manifolds from vibrating off the heads under extended “ street testing “

The engine is quite tightly supported with berg support bar, trapezium bars between the shocks and down to the frame horns,  updated  engine mounts and mid mount on the gearbox which I guessing results in a lot of vibration.

Its ok at blasts below 5k but any extended runs over 5k revs down the bypass results in  loose manifolds and missing because of air leaks

Any suggestions gratefully received

Regards Ron

[Lids]

ron, what nuts are you using?

[Rocket Ron]

11mm space saver brass nuts

[leec]

I seem to remember seeing a little brace bar that bolted to the nuts that hold the carb on top of the manifold and the other end bolted to the fan shroud

[nicolas]

I have tried to fit 12mm brass exhaust nuts and so far so good. they are tight, but not overly so you might damage something or pull a stud.
it is a brass nut with a washer on top.

a third stud between the two ports can sometimes be an option...

[Fastbrit]

Use stainless nuts with Schnorr washers. Brass nuts are soft and gradually wear.

[DaveN]

I use the washers KS mentioned on anything I don’t want coming loose CV bolts, manifolds,etc

My engine/box is solid mounted and tied to the roll cage too.

[Erlend / bug66]

10mm headed flanged nut. And a drop of thread sealer (not locker)

[BeetleBug]

Nord lock washers. Best there is!

<a href="http://www.youtube.com/v/cDlmbMV9ICU" target="_blank">http://www.youtube.com/v/cDlmbMV9ICU</a>

-BB-

[PPRMicke]

Nord lock  Washer and K nuts       (https://www.youtube.com/watch?v=IKwWu2w1gGk )
/// Micke

[nicolas]

Nord lock washers. Best there is!

<a href="http://www.youtube.com/v/cDlmbMV9ICU" target="_blank">http://www.youtube.com/v/cDlmbMV9ICU</a>

-BB-

great stuff. will not come loose.

[Rocket Ron]

Thank you guys I’ll give the lock washers a go 👍

[leec]

Have you got space for a full washer? I certainly don't on my Wedgeport big beef manifolds

Lee

[andy198712]

We use K nuts at work on helicopters so they must be good as we don’t add any locktite ect and in my line of work anything that can come loose in the slightest of chances is either lock wired, split pinned, tab washered or a combo of the above.....
so they can’t be too bad

I’ve just fitted those Allen barrel nuts to mine as it was the only thing that would fit....

[Rocket Ron]

Have you got space for a full washer? I certainly don't on my Wedgeport big beef manifolds

Lee

Will order some and cut if needed

[brian e]

Are you running a fiber gasket?  If so, they manage to compress over time and allow the nuts to get loose.  Myself and others have had really good success with a super flat manifold surface and then use Loctite 518 flange sealant.  No gaskets.  Two perfectly flat surfaces wont be able to rock or move and they tighten up nicely. 

Brian

[Rocket Ron]

Done about 100 miles with the schnoor washers and they appear to be holding fast now so thanks for the tip.

[Martin S.]

Ziegfried and Bly told me they ended up welding the manifolds to the heads at one point out of frustration lol

https://www.thesamba.com/vw/classifieds/detail.php?id=2010976

[181]

I had a problem with singleport Kadrons coming loose on my old 1500 engine. Imagine heavy carbs hanging on a length of steel tube, with small intake flange fastened by two tiny 6mm studs to the cyl. head!
So for my current 1835 I built small but very solid brackets going from cooling shroud to the inner side carb-to -manifold mounting bolt. I used stainless rivet-nuts for the shroud.