250 engine runs terribly

I know you marked the locations that the head bolts came from but I'm not a
real fan of re-using head bolts.


Bill


"azazel scratch" <warlock RemoveThis @ispwest.com> wrote in message
news:fsgcgb01bue@enews2.newsguy.com...
>I had my head professionally machined at the auto machine shop. The valves
>and springs were removed, inspected, and cleaned. The seats were reground.
>The head looked brand new. I installed the head, new gasket, and rocker
>arm assembly. This is the first time I ever removed the rocker assembly
>and cylinder head. I've replaced the exhaust manifold once before and
>removed every other component several times (carburetor, smog pump,
>alternator, radiator, all vacuum hoses, etc). I labeled every head bolt,
>every rocker arm bolt, all the pushrods, and put them back exactly in their
>original positions. I torqued the bolts in the correct sequence and to the
>correct foot- lbs. I also labeled every vacuum hose to make sure I put
>them back where I removed them from. I installed new spark plugs, new oil,
>and new water/antifreeze. The engine started after a few crankings but
>there is smoke coming off the carburetor, manifold, head, and valve cover.
>The engine sounds different and there is no power. I'm going to run a
>compression test on the 6 cylinders but could I have overlooked anything?
>I didn't move the distributor and can try adjusting the timing. I
>rechecked the torque on the exhaust manifold bolts and the rocker arm bolts
>and half of the head bolts and they were all tightend to specs. The valves
>are not adjustable as far as I can tell. I've rebuilt VW engines
>completely with new crankshafts, bearings, camshafts, shells, pistons,
>rings, and heads with no problems.
>
 >> Stay informed about: 250 engine runs terribly 

azazel scratch wrote:
> I had my head professionally machined at the auto machine shop. The valves
> and springs were removed, inspected, and cleaned. The seats were reground.
> The head looked brand new. I installed the head, new gasket, and rocker arm
> assembly. This is the first time I ever removed the rocker assembly and
> cylinder head. I've replaced the exhaust manifold once before and removed
> every other component several times (carburetor, smog pump, alternator,
> radiator, all vacuum hoses, etc). I labeled every head bolt, every rocker
> arm bolt, all the pushrods, and put them back exactly in their original
> positions. I torqued the bolts in the correct sequence and to the correct
> foot- lbs. I also labeled every vacuum hose to make sure I put them back
> where I removed them from. I installed new spark plugs, new oil, and new
> water/antifreeze. The engine started after a few crankings but there is
> smoke coming off the carburetor, manifold, head, and valve cover. The
> engine sounds different and there is no power. I'm going to run a
> compression test on the 6 cylinders but could I have overlooked anything? I
> didn't move the distributor and can try adjusting the timing. I rechecked
> the torque on the exhaust manifold bolts and the rocker arm bolts and half
> of the head bolts and they were all tightend to specs. The valves are not
> adjustable as far as I can tell. I've rebuilt VW engines completely with
> new crankshafts, bearings, camshafts, shells, pistons, rings, and heads with
> no problems.

I wonder if the timing is off a few degrees (like a tooth on timing gear).

Jeff
 >> Stay informed about: 250 engine runs terribly 

"azazel scratch" wrote (250 Engine)

I had my head professionally machined. Valves and springs were
removed, inspected, and cleaned. The seats were reground.
I reinstalled the head, new gasket, and rocker arm assembly.
I replaced the head bolts, rocker arm bolts and pushrods in their
original positions and torqued them in the correct sequence to
the correct torque. I installed new spark plugs, oil, and coolant.

The engine started after a few crankings but there is smoke
coming off the carburetor, manifold, head, and valve cover.
The engine sounds different and there is no power.

I didn't move the distributor but I can try adjusting the timing.
The valves are not adjustable as far as I can tell.
I've rebuilt VW engines completely with no problems.

I'm going to run a compression test on the 6 cylinders.

I have overlooked anything?
_____________________________________________________

Smoke coming off the head and from nearby components (valve
cover, carb, and manifold is may be surface oil burning off from
an overheated engine. Extremely retarded ignition timing, a
too-rich fuel mixture, or burned/unseated valves will cause this.
The compression test will show if the valves are the problem.

When valve seats (and valves?) are reground there is a possibility
that the increased valve stem projection will prevent valves from
fully closing. The valve lash must be adjusted to compensate:

1.) Mechanical adjusters: Reset valve lash to specs.
2.) Hydraulic lifters w/Sphere nut: Back off nut and readjust.
3.) Hydraulic lifters No-adjust: Install perforated shims under rocker shaft posts.

Good luck.

Rodan.
 >> Stay informed about: 250 engine runs terribly 

"Rodan" <Rodan.TakeThisOut@verizon.NOT> wrote in message
news:BWXGj.5880$Pc2.1731@trndny06...
> "azazel scratch" wrote (250 Engine)
>
> I had my head professionally machined. Valves and springs were
> removed, inspected, and cleaned. The seats were reground.
> I reinstalled the head, new gasket, and rocker arm assembly.
> I replaced the head bolts, rocker arm bolts and pushrods in their
> original positions and torqued them in the correct sequence to
> the correct torque. I installed new spark plugs, oil, and coolant.
>
> The engine started after a few crankings but there is smoke
> coming off the carburetor, manifold, head, and valve cover.
> The engine sounds different and there is no power.
>
> I didn't move the distributor but I can try adjusting the timing.
> The valves are not adjustable as far as I can tell.
> I've rebuilt VW engines completely with no problems.
>
> I'm going to run a compression test on the 6 cylinders.
>
> I have overlooked anything?
> _____________________________________________________
>
> Smoke coming off the head and from nearby components (valve
> cover, carb, and manifold is may be surface oil burning off from
> an overheated engine. Extremely retarded ignition timing, a
> too-rich fuel mixture, or burned/unseated valves will cause this.
> The compression test will show if the valves are the problem.
>
> When valve seats (and valves?) are reground there is a possibility
> that the increased valve stem projection will prevent valves from
> fully closing. The valve lash must be adjusted to compensate:
>
> 1.) Mechanical adjusters: Reset valve lash to specs.
> 2.) Hydraulic lifters w/Sphere nut: Back off nut and readjust.
> 3.) Hydraulic lifters No-adjust: Install perforated shims under rocker
> shaft posts.
>
> Good luck.
>
> Rodan.


Ask here.
http://fordsix.com/forum/viewtopic.php?t=49720
 >> Stay informed about: 250 engine runs terribly 

im wondering what year and vehikle you have.if its the 250 inline 6 with
the intake manifold made onto the head, its critical for the valves to
stick out of the head at specified hieght or the valves wont close.
grinding seats and valves causes the valves to stick out further. lucas

http://www.minibite.com/america/malone.htm
--------------------------------------------------------------
Beer is proof that God loves us and wants us to be happy. --Benjamin
Franklin
 >> Stay informed about: 250 engine runs terribly 

This message is not archived
 >> Stay informed about: 250 engine runs terribly 

On Mar 28, 1:56 pm, lugnut <lug... DeleteThis @roadkill.net> wrote:
> On Thu, 27 Mar 2008 07:55:02 -0800, "azazel scratch"
>
>
>
>
>
> <warl... DeleteThis @ispwest.com> wrote:
> >I had my head professionally machined at the auto machine shop.  The valves
> >and springs were removed, inspected, and cleaned.  The seats were reground.
> >The head looked brand new.  I installed the head, new gasket, and rocker arm
> >assembly.  This is the first time I ever removed the rocker assembly and
> >cylinder head.  I've replaced the exhaust manifold once before and removed
> >every other component several times (carburetor, smog pump, alternator,
> >radiator, all vacuum hoses, etc).  I labeled every head bolt, every rocker
> >arm bolt, all the pushrods, and put them back exactly in their original
> >positions.  I torqued the bolts in the correct sequence and to the correct
> >foot- lbs.  I also labeled every vacuum hose to make sure I put them back
> >where I removed them from.  I installed new spark plugs, new oil, and new
> >water/antifreeze.  The engine started after a few crankings but  there is
> >smoke coming off the carburetor, manifold, head, and valve cover.  The
> >engine sounds different and there is no power.  I'm going to run a
> >compression test on the 6 cylinders but could I have overlooked anything?  I
> >didn't move the distributor and can try adjusting the timing.  I rechecked
> >the torque on the exhaust manifold bolts and the rocker arm bolts and half
> >of the head bolts and they were all tightend to specs.  The valves are not
> >adjustable as far as I can tell.  I've rebuilt VW engines completely with
> >new crankshafts, bearings, camshafts, shells, pistons, rings, and heads with
> >no problems.
>
> What you describe sounds like tight valves.  That is common
> where the head has been surfaced and/or the valves
> resurfaced.  Machining the head moves the head closer to the
> cam and resurfacing the valve moves them further up in the
> heads.  Both take up adjustment in the valve train
> effectively making the valves too tight such that they
> cannot close fully.  There are several ways to get around
> this and restore proper valve adjustment depending on thr
> valve train.  One way is the use of shorter push rods which
> is the case on several Ford V8's.  If the rockers are the
> pedestal style used on many Fords, shims are available to
> place under the pedestal.  The ideal way is to grind the end
> ot the valve while the machinist is doing the valve job to
> get the exact installed stem height which is specified in
> the FSM.  If the valve stems are too long, there may be no
> way to restore adjustment short of pulling the head and
> machining the valves for the correct stem height.  All that
> said, a compression test may not tell you which cylinders
> are having a problem.  You may be able to go one valve at a
> time turning the engine to get the cam on the base circle
> and collapse the lifter fully.  You can sometimes collapse
> the lifter by leaving it on the nose of the cam for a few
> minutes.  Keep in mind the lifters also have an internal
> spring to keep them expanded for quick takeeup on engine
> start.  You will have to overcome this spring pressure when
> checking clearance.  If these are pedestal style rockers,
> you can loosen them enough to get a feeler guage a bit
> larger than the max spec in and retorque it.  Wait a few
> minutes to check the clearance.  The valve spring will do
> the work of c=ollapsing the lifter for you.  Most Fords I
> have dealt with need 0.050-0.60" to be sure the lifter is
> correctly centered when running.   The lifters have
> 0.125"-0.150" or so total travel, IIRC.  Keep in mind that a
> hydraulic lifter is really just an automatic lash or
> clearance adjuster.  With the engine running, the engine oil
> pressure enters the lifter while it is on the base circle of
> the cam to expand it taking up any clearance. That position
> is maintained by a check valve inside the lifter.  To ensure
> the lifter does not overdo it's job, it is designed with a
> controlled bleed or leak.  If the lifter has not clearance
> when fully collapsed, it may not allow the valve to close.
> This is not an uncommon problem where a machinist may have
> cut the valves and seats a little too far in an effort to
> save the cost and trouble of installing a new valve or seat.
> In any case, he should have checked each and every valve
> stem height to make sure it is within specs.  I can't recall
> a competent machine shop that would not have access to these
> specs.  This will also affect valve spring pressures which
> are correct with shims under the valves.  If the machinist
> did this along with too much stem, you may also get coil
> bind on the springs which is undesireable and can cause more
> problems with cam and valve train wear or damage.
>
> Lastly, I would advise that you check each and every valve
> for clearance before you remove anything else.  If you do
> not have clearance, make sure you check each pushrod for
> bending.  A compression check would also be a good idea just
> in case there is a major *U somewhere- Hide quoted text -
>
> - Show quoted text -

if i was him i would not run the the motor to much with those valves
to tight it will wipe the cam and lifters
 >> Stay informed about: 250 engine runs terribly