Noise in engine

[Johnty]

Hi All

I have recently changed the timing chains and tensioners but when finished and I started the car I am getting and fairly loud tapped like sound under the right hand bank cam cover.

This noise wasn’t there before I changed the timing chains. I have checked the inlet and exhaust valve clearances on the cam and they are within spec. Can anyone tell me what this is likely to be and how to solve it.

On another issue can you tell me if the air valves on the carburettor should rise after the engine fires and is idling as only the left hand bank carb is doing this, the right hand bank carb is rising when the engine is revved. The carbs are Stromberg 175CD 2. The carbs are not fitted with by pass valves.

Lastly can anyone tell me what the plunger valve is for which is operated by the tab immediately above the throttle stop screw.

Thanks for anticipated help.

[wilf]

Alternator fan hitting the hose clip?

[Lingen]

Johnty.
Both pistons should be seated when the engine is just idling, and only rise when you rev it up. It may be that they need balancing if one is open (rising) more than the other.
As for the ticking noise, it might be that the r/h bracket that supports the cam sprocket when it is disconnected from the camshaft, is fouling on the thread of the bolt that holds it.
Mike.

[DJT]

Lastly can anyone tell me what the plunger valve is for which is operated by the tab immediately above the throttle stop screw.

It operates a vent valve. The plunger is spring loaded and should move in and out, following the lever.

[Chris01573]

When you changed the chains did you make sure the hydraulic tensioners were correctly fitted with the plastic shim in place that you then remove to allow the tensioner to "set" correctly ?

[Mark S]

Is the tap at cam, crank or jackshaft speed? Is it there from cold start or does it develop?
I had similar issues with a 10,000 mile engine that started as a tick and it turned into a clack.
I wrote a series I-V on the issues and what I found.
Clacking Engine IV - The Autopsy - Stag Owners Club Forum (socforum.com)
May not be the same on your new timing chains but I believe mine was a chain slapping on the guide.
I really struggled to find the issue and couldn't pinpoint the noise with a stethoscope.
Are you sure you removed the spacers under the tensioners? did you push the tensioners in afterwards to reset the spring mechanism?

[dasadrew]

Just a tip if you start off on a hunt for carburettor anomalies, the LH Bank carburettor doesn't serve the left hand cylinders etc. Both carbs serve different cylinders on left and right banks

[stagforum-moderators]

Someone posted a handy guide for that,,,https://socforum.com/forum/forum/sta...or-tips-tricks