Jarrid; lifters genrally wear on their base. When installing a new cam if
the old non flat lifter is reused it can cause a cam lobe failure,
particularly if extra strength valve springs are used or if high lift cam
is used.
For everyone to hear....the lifter to lobe contact point is the highest
degree of pressure normally found in any engine. Perfect surfaces, proper
steel tempering , proper lash settings, proper load pressures and above
all...proper quality motor oil will assure long life and non failure.
Yes Isky lifters were the best I ever obtained but hear this...
Most valve grinding machines have adapters for refacing the tips of rocker
arms and also refacing the base of lifters !!!
When the lifter base is touched up with a suitably fine grit stone the case
hardening will not be penetrated. If you had to go more than say .005" to
clean it up I would have the base rehardened using a cyanide powder or
Caseinet powder (base only...not entire lifter).
Therefore you never should need to buy lifters. Wear on lifter sidewalls is
virtually nonexistent and tolerences are loose anyhow, even if there was
some wear on the sides. The flood of oil around this region and also the
splash action which lubes them really prevents lifter wear on the sides.
--------------------
Chuck and Tony; Thanks for compliments. I understand what you people are up
against with an old car and particularly an orphan car with no factory
alive. I will try to give some of my time when possible. Young and old
alike have need for experienced advice and I choke sometimes when I read of
the problems, errors, damage, expense etc. etc. incurred by owners all
because they had no proper advice or info available.
-----------------
The Mole; cardboard gaskets supplied for oil pan are poor as you found.
Modern methods is to clean block and pan nicely and apply Permatex Silicon
Rubber sealant (Blue Glue or Black Glue as you prefer). Blue is just fine
and handles the heat OK.
Most modern car, truck and vehicle makers now dispense with paper gaskets
in favor of this silicon product.
It completely solves the Sunbeam leaks around front and rear main bearing
caps, timing cover and oil pan !!! Use it on every part of the car to
obtain true oil tight sealing of metal joints. DO NOT use silicon on
exhaust manifold or other high temp areas. You can use the Blue on carb and
intake joints OK as the temps are mild. I believe the Black is the one
which has a higher temp rating in case you feel the need for it.
On intake manifold and carb joints we would however continue to use the
std. gaskets supplied but give them a thin coat of the Blue to assure zero leaking.
-----------------------
Bill Lewis; glad to hear you solved the cooling OK..Youre welcome to the
advice. Now your next step if to get the engine up to proper coolant temp
and full HP . Your reporeted 165 deg is too damned cold ! No reason you
cannot put in a 190 deg stat now !
Power timing with a mild knock heard when lugging is a very good setting
but because your lugging is likely below 2000 rpm, you actually do not know
what is happening at say 2700 and higher.
Also, if you get a load of fuel which is below your expected octane, you
may have more knock than expected and won't be able to even hear it due to
other noises.
Until you can truly measure spark advance (as related in prior messages to
others) I would back off the present setting by about 2-3 deg. to be safe.
------------------------
Sergio; almost every mechanic fails to properly test compression with a hot
engine, all plugs out and throttle AND carb pistons propped open at least
1/2 their travel.
How can you expect a max reading when you are NOT letting in a full gulp of
air during the intake stroke.
I bet your 130 psi would jump up to 150 or more when done as required above.
Also, to have true comparisons, the number of compression strokes must be
the same on each cyl.
Do cyl number one and count how many strokes it takes to just max the
needle. Use this same count on other cyls.
Then, with a trigger gun, squirt no. one cyl with say 4-5 good sized
squirts. Spin engine for 1-2 seconds to spred the oil nicely, then repeat
the comp test. Record all data. Repeat this on each cyl.
Normal new engines will increase psi when wetted and the amount will be
approx 10psi. Anything more than 10psi indicates "some" ring wear and
professional evaluations must then be made to see what may or may not be
justified in the way of repairs. A worn engine will show a jump when
wetted, of perhaps 20 psi or more.
As long as "dry" test gives readings within 10 psi between highest and
lowest cyl, the engine WILL idle smoothly. Larger variations will be felt
as roughness in idle.
You also mentioned "breaking in the valves" before adjusting. There is
actually NO break-in of valves. When valves and seats are freshly ground,
there is a microscopic surface irregularity present, When the engine is
first started up after overhaul, the valve action (slamming shut on the
seats) immediately pounds down such tiny surface roughness and the hard
valve face and even harder valve seat become mated perfectly and DO NOT
sustain further settling or change of positions. Therefore when a rebuilt
engine is started and run up for say 30 minutes or more, it is ready for
it's FINAL valve adjustment. Acutally it is ready probably after one
minute of running (which would be about 1000 valve closings at 2000 rpm).
You also mention using 20w-50 oil in carbs. This is way too thick.
Carb dashpot oil is used to prevent too rapid lifting of the needle but
something around the thickness of 5W oil or auto trans. fluid works much
better and gives snappier accel. The bottled oil supplied for the CD carbs
is very thin stuff. On the race cars we used NO springs and just Dexron
type fluid.
-----------
Dick T.
This archive was generated by hypermail 2b30 : Tue Sep 05 2000 - 09:55:51 CDT