Camshaft wear....photos...

[Tobs]

I've just spent the morning stripping down the top of my engine to take a look at the camshaft and followers. I've been suspecting the camshaft needs changing as I’ve been getting tapping sounds from the rocker area at 2000-3000rpm (I've ruled out the exhaust gaskets as I have recently changed these, and the sound is a lot more 'mechanical'). However I am still unsure if the wear is excessive. The car is a 400 and has done about 70,000 miles, and I don't believe the cam has been changed (although I have a couple of years of receipts/invoices missing so I can’t be sure).

All followers have a circular wear pattern (which I believe is normal), with the ones nearer the front of the engine appearing more worn than those to the rear. The most worn follower has a slightly 'dished' appearance when you look at it with light reflecting off its surface - if you get what I mean! (see the photo below)

The camshaft shows some wear on the lobes - the main 'point' shiny all over, with the remaining part of the lobes shiny on one side, and a brown/yellow on the other. Should the 'point' of the cam also be like this as I know they are ground slightly on the slant, so the follower turns as the cam rotates. Also some of the lobes are showing slight wear on both sides of the lobe - See the photos below.


What I want to know is if anyone can advise if the cam/followers etc needs changing soon or will it last a few more miles yet.....

Cheers,

Toby

Here are a couple of pics I took:
(For larger versions click on the text link and wait 'till the image loads!)




For bigger version click : - http://img422.imageshack.us/my.php?im





For bigger version click : - http://img342.imageshack.us/my.php?im




For bigger version click : - http://img54.imageshack.us/my.php?ima


>> Edited by Tobs on Saturday 6th May 15:34

>> Edited by Tobs on Saturday 6th May 15:41

[GreenV8S]

I'm no expert, but there was a nice clear description of good/bad wear patterns in, I think, one of the Haynes books. See they are good for something after all! As far as I can remember, the wear on the shoulders of the cam is a sign that the follower is getting too dished and is on the way out. The fact that there is a noticeable variation also strikes me as a bad sign.

[tahiti450]

Unfortunately the photos dont really give much useful info, very difficult to judge from the angles shown. The pic of the tappets is probably the most useful but again because it is taken perdendicular to the bases one can't see any dishing, on the photo the bases look pretty flat. Really need an oblique / skyline view. Both tappets appear to be rotating normally which is good. Really the only way to check the cam is with it out and with a micrometer, straight-edge etc.
The lobe tips will be shiny because this is the point of maximum pressure / friction and the leading ramp will tend to be polished too as this is doing all the work of opening the valve and overcoming the inertia of the valve train at speed, the trailing side will logically tend to show less signs of burnishing as it is just controlling the rate of closure under less than spring pressure (increasingly less at increasing rpm) as the profile is trying to 'outrun' the tappet.
If there is anything more than the slightest dishing of one or more tappets then the cam is gone since this indicates substantial wear and the valve lift is reduced, the profile compromised and will be uneven between lobes, so lost power, uneven running etc. If the trailing edge of the lobes are looking slightly stained with oil deposits that is probably a good sign since worn lobes tend to be bright and polished all over, and possibly show signs of surface fissuring. Once a cam starts to wear measurably then it is likley that the surface hardening will have been breached and further wear will be rapid and terminal.
In view of the sounds you are getting have you checked the rockers carefully for loose or missing pads / pushrod-end inserts as this is a common cause of isolated ticking and much easier to rectify than a cam change.

>> Edited by tahiti450 on Saturday 6th May 17:21

[Tobs]

Thanks for your comments, yes I have checked the rockers for missing pads/pushrod seat damage - I did this a month or so ago and didn't see any problems. There is a bit of wear on the pads, and on the shaft, but doesn;t look too bad.

The tappets did have a small ammount of 'dishing', I could see this with the tappet at an angle - it was very difficult to get a photo of it though...

If you look at this site, about halfway down the page, there is a photo of three tappets, my worst one looked similar to the middle one:

www.rpiv8.com/faq-gen.htm#fitting-tappets

Toby.

[oggs]

While its apart wouldn't it be best to change it as a lot wear around 50k

[Tobs]

Its back together again now..... spent this afternoon in the rain re-assembling it!

It's my only car so I can't have it off the road for too long. I think I may change the cam/followers etc anyway in the near future as they are showing signs of wear and it's a good excuse for a bit of a performace upgrade! Which brings the question about which cam to go for - i've been looking at the 'tornado' camshaft - has anyone fitted/got one of these running? Whats it like compared to standard?

Toby.

Sorry I ment typhoon not tornado....

>> Edited by Tobs on Sunday 7th May 09:20

[oggs]

Have a look at the cam choice thread. I'm having a MC1 fitted at V8D and pick it up this week

[Tobs]

I was looking at the MC1, however it seems expensive compared to the other cams - £500 for the kit as oppsed to £250-£300ish for the others.....

[GreenV8S]

Make sure you are comparing like with like. You'll need a cam, lifters and timing set and I'd expect this to cost around £400-£500. The only real room for variation is whether you need a vernier timing set or a fixed one, but that isn't going to make a huge difference to the price.

[Tobs]

Here's a description of two kits i've found:

For the MC1 £595 (!) Not sure about VAT....
www.v8developments.co.uk/camupgrades.htm

For the typhoon kit (£329 inc VAT)

www.v8tuner.co.uk/product.php?id=525

The tyhoon kit would require some gaskets, and it does not have fully adjustable timing gear, but does have a fiex/adjustable duplex gear set.

So I can;t really see why the MC1 is so much more expensive (except the extra development time that may or maynot have gone into it.....)

Toby

>> Edited by Tobs on Sunday 7th May 14:49

[David H]

Tobs said:

For the MC1 £595 (!) Not sure about VAT....

It's plus VAT, so £700 on the dot.

[brummiewedge]

Typhoon from real steel are around £130 and the followers are £50, i run the typhoon in my 4.6 and i love the way the power is, was 296 bhp in my wedge, it pulls even better in the Chim, it must be the larger diameter header pipes.

[tobs]

The tornado kit also includes the valve springs - with 1 less coil.

Does anyone know if the valve spring retainer caps I currently have will fit the single springs - as my chim has the double springs fitted as std.

Toby.

[v8 racing]

tobs said:

The tornado kit also includes the valve springs - with 1 less coil. Does anyone know if the valve spring retainer caps I currently have will fit the single springs - as my chim has the double springs fitted as std. Toby.

Yes your caps will be fine, just to put the cost of the mc1 into perspective here because there is a big difference!! firstly the realsteel cams dont have the facility to fit a cam retaining plate so there is nothing there to stop the cam from floating, you also dont have the facility to time the cam in correctly, we do sell these kits so i am in no way slagging them off but i prefer the kent kit, also i can phone dell up at kent cams and he will just grind me a cam to my spec which i cant do with real steel, ps the price of the mc1 is listed incorrectly it should be £490 plus vat and out of interest the typhoon kit is £250 plus vat

[IPAddis]

v8 racing said:

tobs said: The tornado kit also includes the valve springs - with 1 less coil. Does anyone know if the valve spring retainer caps I currently have will fit the single springs - as my chim has the double springs fitted as std. Toby. Yes your caps will be fine, just to put the cost of the mc1 into perspective here because there is a big difference!! firstly the realsteel cams dont have the facility to fit a cam retaining plate so there is nothing there to stop the cam from floating, you also dont have the facility to time the cam in correctly, we do sell these kits so i am in no way slagging them off but i prefer the kent kit, also i can phone dell up at kent cams and he will just grind me a cam to my spec which i cant do with real steel, ps the price of the mc1 is listed incorrectly it should be £490 plus vat and out of interest the typhoon kit is £250 plus vat

... and you do want a cam retaining plate and you do want new valve springs. Been there, done that several times!

Ian A.