camshaft axial play

[wollimann]

Hi,
on my spare engine (this piece of metal don't run for 4 years) many things are
worn, i thought it would be in better shape.
Chains, tensioners and guides must be replaced, compression is ok.
I pulled the heads off and all exhaust valves take a lot of carbon.

The 12 lifters are cleaned and i think they are still useable.
But now i have recognized a axial play at both ends of the camshaft.
I don't measure the exact play, but for my sense it's too much.
Unfortunately two new heads would kill my budget.
Could someone please told me the maximal up/down play of the camshaft?
If too much, it's possible maybe to recondition the caps?
thanks in advance

Wolfgang

 

[shucker1]

I don't think you can recondition the caps without line boring the bearing saddles themselves.

How do the bearing shells them selves look?

Are the cam journals under size?

 

[wollimann]

Hi,
the bearing shells are looking good, no scratches, smooth surface.
The shaft itself looks good to
I am not a specialist, but as i pull off the four caps, the camshaft has no
side to side play. So i guess the journals are not under size.
But for the specific oil support i think there must be a litte gap
for the oil to come out.
Only the two outer caps torqued down to specs 11-12,5 lb/ft
you can see an feel the play on the rh head.
The lh head cam shaft don't have soo much play.
The play seemed to be only up and down.
I have to order a micrometer gauge to measure the play,
then i maybe have some more information.
But i can't find any information about maximum play for this stuff.
The only hint i found was service limit: 0.152 mm (0.006 inch)
could that be true?

kind regards Wolfgang

 

[shucker1]

Your not really looking for the oil to come out.

Metal rotating parts in bearings actually float on a thin film of oil while turning.

(.006) sounds about right off hand. The only way you will find a factory spec is from the service manual.

Best way to check it would be something called "Plastigauge".

In short you apply a small piece of the material between the bearing face and the journal, torque to spec and then remove the cap and bearing. You then compare the smashed plastic to the gauge for your reading.

It can be done with a dial indicator (Starrett Model 196 Kit) but your set up would be kinda complex.

If the bearing 1\2 shells look good and the journal faces look good I do see much need to worry.

A hot bearing would show up as a slight blue color. If you have metal transfer from the aluminum bearing to the steel camshaft it would almost look like speckles on the journal face.

P.S. Do Not mix up the cam caps! They need to go right back where they came from in the same direction. (Forward, Aft, Inboard, Outboard)

 

[wollimann]

Hi and thanks for your answer!

I took the heads to a Ford dealer and talked with a mechanic about the play.
He said everything is ok and totally normal for an engine with more
than 200000 km on it. If i wish to do a total rebuild i have to order new heads,
hone the engine block, oversized pistons, new crankshaft bearings an so on.
But this is too much for me, it's only a car but i like it for the past 20 years.

After reinstalling the lh camshaft (not mixing cam caps!) and torqued down to specs, the play
seemed to be nearly gone. Do not understand this behaviour.
What should i say, at this point i don't worry anymore, it's ok for me.

I am hopefull that everything will come to a good end, with a new oilpump,
regrinded valves, cleaned lifters, new timing chains and new fuel injectors
the engine should run for some more miles.

The heads are on their place again, hope the new head gaskets do a good
job. They looking different to the oem gaskets, comes from a complete gasket set.
Next step is to do the timing job with a buddy, who has the tools.

thanks so much!

Wolfgang