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[tom]

I recently had my head rebuilt plus new rings.

At 400 miles, plugs look very clean, light tan. No more oil soaking
Mechanic wants a 500 mile breakin before I can open it up and check
power against prior performance.

But:

My compression reads

155 155 155 180

Valves are very noisy and will be readjusted at 1000 mi.

Question:
After valves are readjusted, would compression normally even out
closer top the 180 range?
Is this a matter I should take up with the mechanic now?

Thanks,

Tom

[Guest]

[tom]

Thanks for the reply Pete.

Cylinders were rehoned, but not rebored. I checked compression with
engine stone cold. I was not looking for actual numbers, but rather
comparative compression. Engine runs fine, but as I said, I have not
pushed it up to full power yet. I'm using low revs in all gears.
Doing most driving at under 55 on back roads so as not to bother
other drivers.

The big thing is that there is no visible exhaust smoke any more, and
the plugs look clean. I had high mileage and a broken ring.
Since you say the parts could still be settling in, I'll give it a
little while. As long as I am not harming anything by driving with
the noisy valves (and one properly adjusted cylinder), I'd rather he
not know that I tested the compression. In the unlikely event
anything should go wrong, I don't want him to be able to blame me for
foolng with his work. Although if the noise really gets to me, I may
do a slight valve adjustment to bring them more in line with specs.

When I bring it in for final valve adjustment and head retorque, I'll
have him do a compression test as a benchmark for me. I hope that the
cylinder at 180 does not have too tight a valve setting.

Thanks again,

Tom
===========

On Tue, 11 Oct 2005 04:33:47 GMT, cselby@mts.net wrote:

[quote]

155 155 155 180

Valves are very noisy and will be readjusted at 1000 mi.
Not trying to start trouble between you and your tech guy,
but:

Valves should have been adjusted - again- after the engine
heated up - before it left the shop. There is no logical reason to
have sloppy valve lash.


Question:
After valves are readjusted, would compression normally even out
closer top the 180 range?
Does the engine run fairly smoothly - and if so - don't lose
sleep just yet. It may be that valve lash or it could be the rings
are not yet seated in what could well be cylinder holes that are out
of round (you said a ring job with no mention of a rebore).

Compression is done with engine warm, throttle wide open, all
spark plugs out and read the compression after 4th compression stroke
consistantly for all holes. More or less will skew the results (3
strokes on some holes and 4 on one hole make no sense) .

Is this a matter I should take up with the mechanic now?
Yes. Take it up with the mech - the valve lash part.

Pete

Licensed automotive mechanic - red seal
Licensed heavy equipment mechanic - red seal[/quote]

[Mike Romain]

What are you driving?

500 miles chewing up valve lifters is total BS. The engine should just
have been heated up and set.

'Retorquing' the head is total BS. Today's head gastkes won't allow it
'usually'. Once compressed, they don't allow a second one. The head
should have been torqued in stages and at the 'worst' heated up and done
again immediately, but to leave it loose is BS. If you blow that head
gasket in 3 cylinders (like the numbers imply) with the head loose,
'nothing' short of replacement will fix it.

Valves too tight will burn out and/while drop(ing) the compression way
down. Valves too loose will beat the parts up and lower compression a
bit.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

tom wrote:
[quote]
Thanks for the reply Pete.

Cylinders were rehoned, but not rebored. I checked compression with
engine stone cold. I was not looking for actual numbers, but rather
comparative compression. Engine runs fine, but as I said, I have not
pushed it up to full power yet. I'm using low revs in all gears.
Doing most driving at under 55 on back roads so as not to bother
other drivers.

The big thing is that there is no visible exhaust smoke any more, and
the plugs look clean. I had high mileage and a broken ring.
Since you say the parts could still be settling in, I'll give it a
little while. As long as I am not harming anything by driving with
the noisy valves (and one properly adjusted cylinder), I'd rather he
not know that I tested the compression. In the unlikely event
anything should go wrong, I don't want him to be able to blame me for
foolng with his work. Although if the noise really gets to me, I may
do a slight valve adjustment to bring them more in line with specs.

When I bring it in for final valve adjustment and head retorque, I'll
have him do a compression test as a benchmark for me. I hope that the
cylinder at 180 does not have too tight a valve setting.

Thanks again,

Tom
===========

On Tue, 11 Oct 2005 04:33:47 GMT, cselby@mts.net wrote:



155 155 155 180

Valves are very noisy and will be readjusted at 1000 mi.
Not trying to start trouble between you and your tech guy,
but:

Valves should have been adjusted - again- after the engine
heated up - before it left the shop. There is no logical reason to
have sloppy valve lash.


Question:
After valves are readjusted, would compression normally even out
closer top the 180 range?
Does the engine run fairly smoothly - and if so - don't lose
sleep just yet. It may be that valve lash or it could be the rings
are not yet seated in what could well be cylinder holes that are out
of round (you said a ring job with no mention of a rebore).

Compression is done with engine warm, throttle wide open, all
spark plugs out and read the compression after 4th compression stroke
consistantly for all holes. More or less will skew the results (3
strokes on some holes and 4 on one hole make no sense) .

Is this a matter I should take up with the mechanic now?
Yes. Take it up with the mech - the valve lash part.

Pete

Licensed automotive mechanic - red seal
Licensed heavy equipment mechanic - red seal[/quote]