[net.auto.tech] MGB valve troubles.

jeq@laidbak.UUCP (Jonathan E. Quist) (10/07/85)

Okay, technical question #1:

I've got what I thought was excessive valve noise in my 1972 MGB.
The noise varies a bit with revs.  It quiets down while accelerating,
but gets quite loud while revving down to idle from anything over
1800 rpm.  It's kind of a clakety sort of noise, and seems to
be coming from the top end of the engine.
I just replaced the rocker arm shaft because the old one
was badly worn, making it difficult to set the valves.
I did a complete rebuild (except the original rocker shaft)
a few years back, so I don't suspect the rod bearings,
although I have overheated a few times.
In spite of the overheating, the old rocker shaft was still clean,
i.e. no evidence of oil varnishing from the heat.

After installing the new rocker shaft, and setting the valves,
the noise went away.... until I had driven half way around the
block.  It's a little quieter, but still there.

Ok, who's seen this before?
Do I just need to learn to set my valve properly?
(I've been setting them cold (.015") for convenience,
would I be better off setting them hot?)
Or, have I got something silly like a stuck timing chain
idler?  (This was replaced at the overhaul.)

And, while I'm at it, has anyone got advice for
replacing the shocks?  (For the non_British_car types,
the MGB has lever action shocks, the front units being
part of the suspension.)  I just hear a rumor
of $45 each for new units; I've seen prices listed
as high as 2/$190 front and 2/$160 rear.
I'm told the original Armstrongs aren't worth the cost.
Any suggestions?

Jonathan E. Quist
ihnp4!laidbak!jeq

saltiel@cdstar.UUCP (Jack Saltiel) (10/09/85)

In article <240@laidbak.UUCP>, jeq@laidbak.UUCP (Jonathan E. Quist) writes:
> I've got what I thought was excessive valve noise in my 1972 MGB.
> (I've been setting them cold (.015") for convenience,
> would I be better off setting them hot?)
> 
Here you *MUST* follow the manufacturers recommendations. I have
two cars by Porsche, one requires the valves be set on a stone
cold motor, the other requires the motor be warm, with the oil at
80C to set the valves. I don't know what your MG requires, but it
makes a *big* difference wether it's hot or cold.
-- 
					Jack Saltiel
					Cambridge Digital Systems
					{wjh12,talcott}!cdstar!saltiel

	"Here's to plain speaking and clear understanding."
	"I like a man who likes to talk."

joye@gatech.CSNET (William Joye) (10/10/85)

I just replaced the front hydraulic dampers in my 71 MG Midget.
They ran $170 for the pair. I had it recommended to me to install
new units as opposed to rebuilt units. The new units were only a
few bucks more than the rebuilt units anyway. The new shocks made
such difference in the handling of the car. They are real easy to
replace if you have a hydraulic jack handy.