scoobyis2cool
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| posted on 10/8/05 at 12:23 PM |
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Is this camshaft worn?
Hi,
I've been having a bit of trouble with my engine (fuel economy, irratic idle) so have decided to give it a good check over. I've taken the
top off to have a look at the camshaft but because I've never done this before I don't know how to tell whether it's worn or not!
The pic below shows a few of the cams, you can see that the central area is a different colour to the rest, and there is a noticable, but small, ridge
if you run your finger over the area. It is noticable on the "high profile" part of the cam, but not on the "low profile".
Also, 5 out of the 8 rockers feel loose and I can wobble them fairly easily by hand, is this normal?
Any advice gratefully accepted!
Pete
 
Rescued attachment camshaft.jpg
It's not that I'm lazy, it's that I just don't care...
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JAG
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| posted on 10/8/05 at 12:30 PM |
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1) LOOSE ROCKERS; quite normal. Not all the valve springs are in compression in other words those valves are shut and the cam lobe isn't
touching. The Haynes manual should give a clearance value and this can be checked.
2) CAM WEAR; Yes there is some wear evident. Is it the source of your problems? I wouldn't think so, at least not on its own. Wear will occur
first on the highest point of the camshaft - as yours has. If you get wear on the rest of the lobe then the cam definitely needs replacing  Check
further.
Fuel economy and erratic idle is perhaps more associated with issues surrounding the ignition timing. Check all the connections and run a timing light
over the whole situation.
[Edited on 10/8/05 by JAG]
Justin
Who is this super hero? Sarge? ...No.
Rosemary, the telephone operator? ...No.
Penry, the mild-mannered janitor? ...Could be!
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MautoK
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| posted on 10/8/05 at 12:37 PM |
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Check the state of the induction side as well - inlet manifold gasket OK, nuts tight, carb-to-manifold, and any rubber on the engine side of the carb
such as servo pipe.
All worth a look as any of these can cause erratic running particularly at idle.
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NS Dev
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| posted on 10/8/05 at 12:38 PM |
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Depends on how much of a "ridge" is on the tips of the lobes.
That cam certainly is not completely knackered, but equally has seen better days!
For now, just adjust the clearances back to where they should be (they always need pretty regular adjustment on pinto's, especially with higher
than std lift cams) and change the oil, it'll be fine.
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scoobyis2cool
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| posted on 10/8/05 at 01:32 PM |
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Thanks for the help guys, going back out now to check valve clearances and the inlet manifold/carb for any air leaks. I haven't got a timing
light but want to buy one, I'm sure I'll use it enough in the future to make it a worthwhile purchase.
Pete
It's not that I'm lazy, it's that I just don't care...
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mookaloid
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| posted on 10/8/05 at 02:50 PM |
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I have a Mild road Kent FR31 cam and followers (as new - done less than 1000 miles) which you can have cheap if you want. It would be better than a
standard one and a lot better (and quieter) than what you have just now.
Cheers
Mark
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scoobyis2cool
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| posted on 10/8/05 at 04:35 PM |
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Mookaloid - thanks for the offer of the camshaft but I think I'll see how I get on with this one first.
I've just been and set the valve clearances, another first for me  Thought I'd got it all spot on then realised I'd got the inlet
and exhaust clearances mixed up, so had to do it all again!  Still, at least I noticed it before I put the engine back together again!
Now to find myself a nice (and cheap) timing light...
Pete
It's not that I'm lazy, it's that I just don't care...
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NS Dev
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| posted on 10/8/05 at 04:40 PM |
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Worth looking on ebay for a used heavy duty professional timing light with an advance knob on it, rather than a "Gunsons" cheapo one,
these don't tend to last very long (mine broke pretty quickly!)
Worth taking up mookaloid's offer too, these Kent cams are great, same as the std one in terms of idle etc, but LOADS of torque (much
enhanced!!) and rev out better too, a real win-win camshaft, the 32 is great too, used that on the old road rally car!
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scoobyis2cool
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| posted on 10/8/05 at 04:46 PM |
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OK I'll keep an eye on ebay, what sort of price should I be looking at for a decent light? Any brands that are particularly good/bad?
Mookaloid - a U2U is on it's way re: camshaft
Cheers,
Pete
It's not that I'm lazy, it's that I just don't care...
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mookaloid
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| posted on 10/8/05 at 06:06 PM |
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Timing light
This looks ok
http://cgi.ebay.co.uk/Professional-variable-advance-timing-light_W0QQitemZ7991775503QQcategoryZ72205QQrdZ1QQcmdZViewItem
Cheers
Mark
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alfasudsprint
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| posted on 10/8/05 at 07:51 PM |
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scooby...scuse for hijack...I dont having a timing light, will get the timing and carbs set up by an experiencede pro...but for now, is it correct
that roughly the best timing point is where I get the highest rpm, at idle???
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Stu16v
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| posted on 10/8/05 at 08:59 PM |
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quote:
Originally posted by alfasudsprint
scooby...scuse for hijack...I dont having a timing light, will get the timing and carbs set up by an experiencede pro...but for now, is it correct
that roughly the best timing point is where I get the highest rpm, at idle???
Very doubtful.
You can get the timing somewhere near right by warming up the engine first, and then bringing the engine revs up to about 4000rpm. First retard the
timing and get the revs to drop noticably, and then advance the timing, and let the engine revs climb. There will be a point where the revs do not
climb any more. Go a little further, and you should hear the engine just 'cough', and falter occasionally. This is too far. Turn the
distributor back until the revs are *just* starting to drop again, at this point you shouldn't be too far away.
The above is only a guide (although I can honestly say that I have never used a timing light for actually timing the igniton - but they make a great
diagnostic tool), and assumes that the dizzy actually suits the engine tune.
HTH Stu.
Dont just build it.....make it!
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NS Dev
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| posted on 10/8/05 at 09:48 PM |
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quote:
Originally posted by mookaloid
Timing light
This looks ok
http://cgi.ebay.co.uk/Professional-variable-advance-timing-light_W0QQitemZ7991775503QQcategoryZ72205QQrdZ1QQcmdZViewItem
Cheers
Mark
Yup, that's just the sort of thing, though the £50 buy it now is a tad optimistic, worth £35 though I'd have thought, and it'll last
many more projects then!
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alfasudsprint
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| posted on 10/8/05 at 10:00 PM |
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thanks stu, i'll give it a go!
no major probs with the motor as is, but a bit difficult to start sometimes, like its getting locked up...
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