Engine tapping noises / Exhausts & chipping

[mike ward]

Hello all. Firstly what a pleasure to find this site and all you enthusiasts in the forum section. Educational in the least to a relatively new owner.

I have a 95' Chimaera 4L with about 36k on the clock which someone had rebuilt after it had been in a ditch. After a £2k service, wishbones, ball joints etc etc at Blackpool I still have an engine tapping to resolve. It's ok when cold but taps when warm on one cylinder, for all the world like tappets. I believe from a professional source that it will be a loose steel insert in one of the ally rockers and the best solution just to change the whole rocker / shaft assemblies. This seems an ok job (are they a standard Rover item?) but having no experiance of hydraulic tappets I'm a bit wary. Any advice from anyone?

Final question on Joospeed sports exhausts & chipping with Mark Adams. I read in fact putting a sports exhaust on reduced the back pressure and consequently dropped the power. Any truth? I guess having it chipped afterwards would resolve any problems. Having once owned a Trident Clipper with a 289 hypo I just want to get that true burble back again! The Joospeed item sounds, from earlier correspondence on here, the way to go. Thanks in advance for any help.

Mike

[Silver City]

In search of the ideal exhaust note I cut out the centre box and welded in two lengths of pipe. The result was an awesome sound, BUT what a drone on longer runs - no noticeable reduction in power though. Have now (today) fitted a JP Exhausts Sports system and the annoying drone has gone and the note albeit quiter is much sweeter and liveable with. I for one would not go for anything more extreme than a sports system.

[.Mark]

Can't help with the exhausts Mike, but the tapping could be exhaust manifold gaskets, it does sound remarkably like tappets.
If it is make sure you fit the metal version for longevity.

Welcome to PHead's by the way

[RichB]

I read in fact putting a sports exhaust on reduced the back pressure and consequently dropped the power. Any truth?

Hi Mike, from what I've heard this is true for smaller sized turbo engines (like Suburu's etc.) but on a normally aspirated 4.0 V8 it makes no difference, plus or minus. Rich...

[mike ward]

Thanks for the input guys - it probably will be a sports exhaust in the long run. The tapping sound is, I believe internal but, hopefully as I say, just the rocker(s). If you've any further thoughts on them, they will be welcome.
Ta
Mike