Extra “tappety’ noise to engine after re-build

[265bhp]

Hi all

Having rebuilt my 3.8 engine and got it test running the other week all seemed good but there is an additional mild clattering/tappety sounding noise

I left it overnight, removed the cam covers and then measured the gaps, which were around 7/8 thou on the inlet and 8-9 thou on the outlet side...so around 3/4 thou over spec

I am waiting for a reply from the guy who built the head, but in the meantime wondered if you might have some thoughts as to what is making this noise (hopefully you can hear it) and if it could be anything else other than the gaps

Thanks
Jonathan

[mgcjag]

Hi Jonathan....i cant hear anything unusual on the video. ....but thats probably just my tablet....another recent engine noise problem here...Steve http://forum.etypeuk.com/viewtopic.php? ... a0c78f069e

[265bhp]

Hi Steve
What do you think about the clearances though...pretty well out of tolerance range...?
All the best
Jonathan

[splosh]

IF the cams have been turned without the cam sprockets fitted with the chains on then possibly a bent valve.
It's quite an easy mistake for the unknown as the cams must be set and not rotated without being timed.

[mgcjag]

Hi Jonathan. ...i cant hear the noise from here....yes the gaps are out of spec......let us know what your engine builder has to say....when was it done......has the noise just started?.....Steve

[265bhp]

Hi Steve
I am hopefully going to speak to him tomorrow
He did all the machine work and assembled the head, I did everything else

Engine was built up around 2 years ago and has sat waiting for me to build the car up around it

The first start up and short run around the lanes here was 2 weeks ago


Jonathan

[mgcjag]

Hi Jonathan....are you confident that you set up the valve timeing and chain tension correctly..and you do have plenty of oil in there......Steve

[abowie]

A tappet 3 thou over will be noisy. All of yours are well over, and the engine sounds like it.

Some people advocate setting clearances slightly loose (maybe one thou) based on the observation that newly cut seats may close up a little once the car is driven. Personally I'm not an advocate of this; when I set up heads for customer cars I aim to have the valves spot on 4 and 6. I have also done this on all of my own cars; they do not have tappet noise.

So were it my engine I'd redo the shims to set it up to factory.

If you haven't already done it, retighten the timing chain too.

[Series1 Stu]

Hi

It is noisy but it will quieten down quite a bit if you fit the air filter. I would say correcting the gaps will certainly help.

Is the engine fully warmed up?

Regards

[265bhp]

Thanks all

The engine was correctly filled with oil, but partially warmed

Mike (engine man) is coming over a week on Saturday so we will hopefully adjust and space within the day..

I’ll let you know

Best
Jonathan

[christopher storey]

I hate to say this, but that engine sounds to be firing on at best 5 cylinders and some of the time on 4 . Perhaps a longer video with the engine fully warmed up, and with the air silencer trunk replaced, would give a better guide

[Mich7920]

[265bhp]

If heat on the exhaust manifolds is an indicator that a cylinder is working fine then the engine was firing on all 6..it ran smoothly as we did a couple of short runs up and down the lane I live on

It’ll let you know once the gaps are re-set next week...as they are certainly not good as they are so it’s best to rule them out and see if any other noises remain

Best
J