'Ticking' engine

[cmdrew]

I'm afraid i will be asking many questions as I try to build up my knowledge of my car! I have the 4.2 roadster and took it out for the first time today and it seemed to go well. However the engine does sound rather noisy from the top end. Sounds like tappets to me as there is a distinct ticking which is pretty loud but I am unsure what is 'normal' for this engine. Should it be pretty quiet or do they all sound rather tappety?

[mgcjag]

Hi Chris.....not unusual to here a tappy xk engine but its not correct.....you shouldnt here a tap.....could just need the tappets adjusted useing shims so a measure, dismantle, fit new shims, etc.....but it could be loose tappets etc,.....Steve

[Gfhug]

Chris, what year is your car and engine? The later S2 have different cams and are more tappety sounding when cold and tick over. That may explain some of the sound, but as Steve says have a good check of the engine, clearances, etc.

Geoff

[TheMadBadger]

I also have a ticking noise in my 4.2 E-type. It has an early head with small valve clearances and the first thing I did was check valve adjustment. If the car had lifters I’d swear that is what it sounds like. The cam bucket guides on the exhaust side have had the retainer plates installed. After a few hundred miles of ownership I don’t think it has gotten any worse, but maybe I’m just getting used to it. My ‘71 coupe doesn’t make this noise.

Mark

[christopher storey]

Mark : the tappets have a tendency to become barrel shaped and this allows them to rock in the tappet guide which is often the cause of the ticking noise . If you take the camshafts off you can then remove the tappets and check them for uneven shape with a micrometer

[cmdrew]

Measured all of the clearances and across the board they are between 9 and 10 thou. As such according to what I have read they should be 4 and 6 thou for inlet and exhaust respectively so they are all rather large more so on the intake side. Bit of a surprise as clearances usually wear to be too tight not slack. Next task then is to get the cams out and measure the existing shims and check the buckets for ovality. Not easy to access the front of the engine though as the bonnet is still on...

[christopher storey]

Your car is a S2. As such, it will have the parabolic cams which require a much greater valve clearance than the earlier camshafts. From memory the recommended clearance is between 12 and 14 thou, ( with no difference between inlet and exhaust ) so your clearances although a little on the tight side sound to be pretty much in line with the recommendations

[mgcjag]

As christopher says above.....should be 12-14 on a series 2...check your cams .....Steve http://www.georgiajag.com/Documents/Camshafts.html if your tappets are worn (barrel shape) you can fit long skirt tappets

[Gfhug]

Not all S2 had the larger clearances, as per my comment above. Mine were 4+6 thou, though now changed to a later head. Hence the cams need to be checked as Steve points to and then set correctly.
The change came in Nov 69 engines from 7R8688 and 7R38855.

Geoff

[cmdrew]

I guess mine is a pretty early engine 7R2258 which matches the data plate which states the valve clearance should be .004 and .006. Now I guess its possible the heads have been changed at some point in the past but the main reason I am doing this is because it rattles quite badly, especially when hot so my guess it that someone previously has set them to the wider tolerances in mistake. I have taken pictures of the cams and will see if I can work out which they are - they certainly are the 2 bolt sprocket type.

[mgcjag]

Each camshaft should have a small flat machined area with a number stamped.....on the main shaft

[Gfhug]

Chris, the bonnet can be quickly taken off by one person if you follow the advice given by Andrew Bowie here:
https://www.projectetype.com/index.php/ ... 2&modid=77

I've done this several times and it will help you get easy access to the engine.

Geoff

[dlgis]

It doesn’t show how one person on their own can get it back on

[Gfhug]

Well it does assume anyone with the nous to remove the bonnet should have the common sense to reverse the process.

[christopher storey]

I can't see why he needs to remove the bonnet to do any part of this job : access to any part of the valve gear isstraightforward, including to the locknut and tensioner behind the front dome - although a mirror helps with seeing what you are doing

Note that the locknut is one of the very few on the car which is a whitworth fastener, from memory 1/2 whit

[Simonpfhc]

I can't see why he needs to remove the bonnet to do any part of this job : access to any part of the valve gear isstraightforward, including to the locknut and tensioner behind the front dome - although a mirror helps with seeing what you are doing

Note that the locknut is one of the very few on the car which is a whitworth fastener, from memory 1/2 whit

I totally agree - bonnet does not need to be removed for any of this work. However, it make access easier if you put some cushions under the bonnet nose and simply remove the two bolts that hold the spring bonnet supports. The bonnet can then be tilted forward a lot more and access is a breeze.

[Gfhug]

I wasn't advocating removing the bonnet just showing how easy it is to do as the topic author commented about it being in the way. And there will be times he'll find it useful for other work.
For the later S2 cars the bonnet strut is very easy to disconnect, too.

Geoff

[abowie]

it make access easier if you put some cushions under the bonnet nose and simply remove the two bolts that hold the spring bonnet supports. The bonnet can then be tilted forward a lot more and access is a breeze.

You need to be incredibly careful doing this, as I learned to my chagrin when the bonnet on my newly painted 3.8 coupe overbalanced and fell right forwards while I had the car on my hoist.

Fortunately it hit my toolbox which stopped it at 180 degrees (upside down but parallel to the ground) and the car didn't fall off the hoist onto me. It did move about 6" diagonally though.

Needless to say it did a lot of damage to the bonnet.

What I have done is make a pair of 1" flat steel pieces the correct length so that when one end is bolted to the trapeze and the other end to the bonnet it has the bonnet virtually upright but still with the balance to the back, so it tends to close.

I also now ALWAYS use my piece of rope as a secondary failsafe, especially while installing and removing the steel pieces which was what I was doing when I dropped it.

If you're a bit arthritic like me having the bonnet out of the way when doing things on the front of the engine makes it a lot easier. Especially for annoying jobs like trying to scrape off cam cover gasket without dropping it into the oil.

[Simonpfhc]

Andrew - you’ve scared the living daylights out of me!

I will never tilt a bonnet forward so relaxed ever again!

[cmdrew]

Well cams are out after many attempts to remove the correct cam bolt so leaving the one I could access when the engine was at TDC! No idea why it took me 3 attempts to get that right! I've measured the existing shims and will order new replacements today.

I would welcome advice on torque settings however as they are absent from my Haynes and also from my copy of the factory service manual - perhaps my version is just rather poor. Specifically -

timing chain adjuster nut
Camshaft cap nuts
Camshaft to sprocket nuts

In the case of the latter, rather than using lock wire would medium strength loctite be suitable? Seems to me that things have moved on a little and usually you would expect to use loctite rather than wire these days...