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MG MGB Technical - Running with Rocker cover off?

In order to diagnose which if any tappets are the main noise generators ( my engine sounds very tappety!) Can I run the engine with the rocker cover off?
How long for?
What risks?
Also If anyone uses a 'clickadjust' tool for th tappets how many clicks do you use?

Martin
Martin Gunn

No problem running with the rocker cover off
while you listen to the tappets. You might get a
little bit of oil spray. Don't drive with the cover
off however.

I have a clickadjust, but somehow couldn't get the
hang of it, so I've gone back to a feeler gauge.
Ronald

Martin-
Noisy tappets are usually caused by one of three things:

1) Improper gap setting. Proper adjustment is impossible with a feeler gauge if the rocker faces are grooved.
2) Worn rocker bushings, rocker shaft
3) Unevenly worn tappet faces which cause the gap to vary as the tappets rotate in their bores.

#1 can be dealt with by using a gunson's "Click Adjust" tool. When using the tool, tighten the valves to zero clearance with the engine cold, then back off nine clicks to arrive at a gap of .015". If your rocker faces are indeed seriously grooved, then chances are that you'll eventually be facing an overhaul as the case hardening on the rocker faces is only so deep. This is the case on #4 Son's 1973 Roadster the head of which I'll overhaul this summer after he enters the Marine Corps.
Steve S.

Martin-
I just reread your post. Running the engine with the valve cover off won't help you determine the condition of the tappets or the rockershaft/rocker bushings. You'll just get oil everywhere, so don't do it. Only disassembly can reveal their condition.
Steve S.

Running with the cover off is a good way to find *which* tappet/rocker combo is noisy though. Get a length of hose, stick one end in your ear and move the other end along the row of valve stems with the engine running until you find the noisy one.

Of course, you would find this if you carefully re-set all of your tappets, but we're after speed, right? :o)
--
Olly
Oliver Stephenson

You also can get a more accurate reading of the gap with the engine running.
George B.

Yeah but you've got to slide the feeler gauge in and out really quickly so you don't pinch it when the cam comes round again :o)

--
Olly
Oliver Stephenson

You might be able to narrow it down without taking off the cover. Start the engine, and place a large screwdriver on the cover over one of the rockers. Press your ear against the other end. The screwdriver will act as a stethoscope and let you hear the rocker. Move down the rocker cover until you find the one that sounds loudest. You'll probably not be able to isolate the noise definitively, but you can figure out better where to look. WARNING!!! -- if you have long hair, tie it back. Don't wear a tie or loose clothing whilst leaning over the engine. Common sense stuff, but it's worth repeating.
Rob Edwards

steve s.,
What will your son be doing in the Marine Corps? I have been serving our beloved Corps now for 18 years. This is a great opportunity and I am certain he will never regret it, whether he serves for 4 or 30 years!

Semper Fi,
GySgt Andy Heston
78 mgb
andy heston

Andy-
He hasn't quite decided just what he'll specifically train in for our beloved Corps. He still has time to decide. He'll be following in my footsteps and those of a lot of other good men who went before. When I see him in those dress blues for the first time I'm going to be the proudest father on earth!

Semper Fi, Mac.
Steve S.

wow,
a great lineage for your family. i was wondering with your location listing. i have a 16 year old son who has his eye on my B. so maybe he will also have his eye on my blues. tell your son good luck.

andy
andy heston

Martin:
All about the ClickAjust is here:
http://www.mgcars.org.uk/electrical/Clikadjust_0.html

Regards,
Jerry
Jerry Causey

To Gunny and all the others who have joined :

A _BIG_ THANK YOU ! for service rendered to our country ! .

Good luck and god speed for your son .

-Nate
NSH

You don't have to strip the engine to change the cam followers.
1/ Unscrew the adjusters, push the rockers along the shaft and then take out the push rods.
2/ Remove carbs, tie them together with string to stop the linkage disassembling itself.
3/ remove Tappet covers, fish out followers with pushrod, suck is enough to pull them out.
4/ replace worn or pitted followers approx £4 each.
5/ Reverse prceedure. You will need new gaskets for tappet chests and carbs.

Whole job probably takes a couple of hours. I run my engine with the rocker cover off and use a 4 thou feeler to detect the noisey rocker.
Paul Hollingworth

£4 each? Ow. I paid ~16 + vat for my latest set (from Jon Miller, Droitwich).

But otherwise yes, it's quite easy to change the tappets with the head on. If you can't get the tappet out with the pushrod, then sticking your finger in it will provide you with enough grip to pull the offending metal object out (assuming bucket-type tappets).

ttfn,
--
Olly S
Oliver Stephenson

Regarding finding the loose tappet: If you take the cover off, as you turn the motor to each adjustment position (TDC for me, rule of nine for others) wiggle the loose rocker up and down. The bigger the clearance, the louder the click. It's not exact enough you could forgo the feeler blades, but it'll give you an idea of who's loose.

As noted, if you adjust one and it's still loose, you probably have a grooved face. You might be able to loosen the adjuster all the way, slide the rocker sideways and then be able to flip it over for a visual inspection.
Matt Kulka

Oliver
Guess what, it was the same John Miller that charged me £4 each. Ive already bought 6 from him should have bought the set it would have been cheaper. He charged me exactly the same price that they were at the MGOC. He probably looked it up on their spares database like I did.
Paul
Paul Hollingworth

Looks like I got mine just in time!

It could of course be that I read my reciept wrong... I don't have it at hand so I shan't accuse Jon of doing anything nasty. He generally provides great service.

ttfn,
--
Olly S
Oliver Stephenson

And it won't be long before you are doing so again - new tappets on a worn camshaft last no time at all.... 8-(

Chris Betson

This thread was discussed between 18/05/2002 and 21/05/2002

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