Droaning noise with sports manifold

[engineman]

imported post

Russ,

I have fitted four Exhaust clamps two per side to various positions between the manifold and the silencers without success, I have also experimented removing the exhaust support brackets from the automatic gearbox to reduce the rigidity in the system, I have also inserted foam into the rear suspension chassis to eliminate any vibration at the rear of the car, the manifold in definitely not touching the steering mechanism, I am beginning to run out of ideas any further thoughts.

Regards


Peter

[stustag]

imported post

engineman wrote:

Russ,

I have fitted four Exhaust clamps two per side to various positions between the manifold and the silencers without success, I have also experimented removing the exhaust support brackets from the automatic gearbox to reduce the rigidity in the system, I have also inserted foam into the rear suspension chassis to eliminate any vibration at the rear of the car, the manifold in definitely not touching the steering mechanism, I am beginning to run out of ideas any further thoughts.

Regards


Peter

Hi Peter

When you fitted the new 4 branch manifolds do you also fit a new exhaust systems or did you keep the one currently fitted?

If you kept the original one did you disturb it (take it off) in anyway? If you did or fitted a new system did you use the correct brackets and rubber mounts that support the exhaust through the rear sub frame? This is the most common area for any Stag/200/2500 exhaust to HUM when fitted incorrectly.

Second have you tried the steering on both locks to make sure it is definitely not fouling on the lower steering column?

Last check to see is the all the sub frame bolts are tight and gearbox mounts just in-case the prop is dropping slightly when on part throttle and touching the silencers?

Also check the rear gearbox mounting rubbers if these are damaged you will get this cause and effect as well.

Stuart:dude:

[Kevin Garrod]

imported post

engineman wrote:

Kevin,

I have a Holley 4150 fitted to my Stag , the Holley is fitted to the inlet manifold via an adaptor plate and an additional 7 degree wedge, a shallow Edelbrock Air Filter is fitted, the air filter touches the bonnet insulating pad, the overall height of the Edelbroch is about 2 inches, I am interested to know why you should have a small clearance between the pad and filter and I do not? I have recently fitted new engine mountings maybe my engine sits higher than yours? I notice that Monarch stags sell an adaptor assembly that has been machined to have the 7 degree tilt incorporated into the design, maybe the overall height of the adaptor is smaller and would allow the Holley and air filter to sit lower?

I may have to purchase the Low Rider air filter does it have a provision for the Camshaft cover air breather pipe to connect to it ?

Regards

Peter

Hi Peter

My adapter plate was sourced from Tony Fox in Canada and has the 7 degree angle like the Monarch one. Maybe the addition of a wedge plate is too much:?

The Low Rider airfilter made by Mr. Gasket has provision for the breather pipe, but you have to make the hole yourself, it is marked out for this.

Hope this helps!

Kevin

[mjheathcote]

imported post

I have a holley, adapter plate, wedge plate, and K&N recessed filter.

I only have about half inch clearance to the underside of the bonnet without insulating mat, so would clash ifstandard mat was fitted.

Currently I have no mat fitted though so no problem.

Cheers,

Mike

[engineman]

Resonators

I have finally received the two stainless resonators from Double-S, they measure 220mm in length with the centre section
measuring 120mm long by 75mm in diameter, they are in effect small straight through silencers, I will be fitting them in a few
weeks time when I return from a short vacation. I have not been looking at the forum for some weeks so not picked up on additional
comments posts made by members, I will have a look at these areas when I install the resonators.

[KOY 23]

Peter.

Did you want to post this in this 8 year old thread? as there was a recent one.

I wait your answers with interest as my next job is fitting tubular manifolds.

John.

[engineman]

I have closed this thread see later 2016 problem.