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MG MGB Technical - @#%%&! Side Covers!

The front one is leaking again! Has anyone used Mopar "form a gasket" stuff instead of the @#$#@! gasket?

rn
RN Lipow

It's been a while since I was into this, but I seem to remember that the cork gaskets work far better than the rubbery ones. I may also recall that you should use the cork gasket on the front side cover and the rubber one on the rear side cover. Liberal application of silicone helps.
Chris

My all-time (racer secret) cure:

I took my tappet covers and used a steel center punch and hammer to make a series of small dimples,
every 3/8", all along the gasket flange. These dimples provides a "tooth" to grip the gasket and helps prevent it from shifting out of place later on. Do not whack the tappet cover so hard as to knock it
out of flatness. Better that this is done against a steel workbench.

A smear of automotive grade silicone sealant (not household silicone) on both sides of the gasket fills
in any small surface irregularities and assures a tight seal. Both surfaces must be absolutely clean of
oil and old gasket material, and dry.

After installation, do not drive the car for 12-24 hours to allow the silicone to fully set.

Although I prefer the rubber gaskets, this works with cork, also.
Daniel Wong

RN. We are assuming that you are referring to the tappet covers. As a lawyer, you should be well aware of the importance of proper terminology. If, as most have assumed, you are referring to the tappet covers, I use the "hard setting" Form a Gasket to glue the gaskets to the covers. Even then, they tend to loosen somewhat and must be tightened down. Friends tell me that this is not uncommon and the bolts will develope a patina of rust, after which, the tappet covers will be held in place. Do not know whether this is true, or if the gaskets "take a set", but, using the hardsetting Form a Gasket, followed by periodic tightening seems to be the rule. Les
Les Bengtson

Les, I don't know if RN practices criminal law or not, but if so #$%^#$ is common and proper terminology. Unless you're actually on record, but sometimes then as well if you're quoting someone.
Wade Keene

Hmmn, do you guys use the cork or rubber gasket for the front tappet cover (Les, I was so p*ss*d when I saw the oil dripping again that I couldn't even think of the word "tappet"). I believe that I used a cork gasket the last time.

rn
RN Lipow

In the archives someone suggested exchanging the tappet cover bolts for studs and then using a lock nut to hold them in place. I had considered doing this but was unsure if the temperatures generated in this region might melt the nylon. Any thoughts?
Frank

Use cork on the front, rubber on the rear. I was able to get the things to seal and hold easily! Oh, the engine was out of the car. I share your frustration. It is one of the jobs I dread. Not as bad as changing out the heater/defrost cable , though!

I did use non-hardening Gasket sealer though. Of course, now that I know I should have used the hardening type, they will immediately start leaking! Thanks Les!!!! If you didn't mention that they would have held forever!
Mike Wish

RN,
I failed to mention that the reason the studs were used is because the problem sometimes with getting the bolts started on their threads can allow the gasket to move out of position on the tappet covers and therefore not seal properly.
Frank

Use gasket sealant (the shellack stuff) to stick 'em in place on the tappet covers. Once that was well set, and they weren't going anywhere, only then did I install on the engine.
baxter

My solution to this problem was to buy the one-piece
tappet cover from www.mgbmga.com. This is an
aluminum piece which requires changes to the engine
breathing, but it works fine on my 79.

The front tappet cover on my car was warped, and no
amount of gasket sealant would stop the leaks.
Ronald

RN. I almost consider tappet covers leaking to be a standard part of a rebuild. Everything seems to loosen up and require tightening for several months after a rebuild. The tappet covers and the sump seem to be the biggest offenders for me. I have used both the cork and the rubber gaskets on the tappet covers and, sometimes, use one of each. Do not know why, but some tappet covers seem to "like" a particular form of gasket and will work best with that type. Other tappet covers seem to work with whatever is used. I believe the rubber gaskets were introduced because the heat of the cat was damaging the cork seals and allowing leakage. As Baxter mentions, and I should have, part of the secret seems to be installing the gasket to the cover, off the car, and using a hard setting compound. Makes it much easier to get a good seal, using the non-hardening Form A Gasket, when you apply the gasketted cover to the block. I like Frank's idea of using a Nylock nut and a stud, but would like to see how it works on someone else's engine before trying it on mine. Les
Les Bengtson

Nobody has mentioned the bolt seals.

These are the little cup washers and rubber seals that go on the securing bolts.

Replace them and they will stop the bolt working loose and put a tension on the gaskets. Also do not overtighten the bolts - this pushes the gasket out of shape.

Both cork and rubber work - I usually use the cork ones.

Do not use silicone - it is too slippery. Use a non setting sealant like Hylomar - this will stick the gasket in place on the cover - use more sealant run round the inside of the gasket to seal it to the metal.
Chris Betson

I used the rubber gaskets, with a thin smearing of silicone, tightened the bolts up just snug, no leaks in over a year. The covers and engine were thoroughly cleaned of all grease and oil prior to application of the sealant. The sealant was spread on one side of the gasket then applied to the cover, set aside overnight to dry, then applied to the engine.
Randy Olson
1977 MGB
randy olson

Thanks all for all of your responses and advice. Yes, it's the last act for the rebuild...the engine is broken in, powerful, smooooooth and responsive. One of my friends commented that it seemed almost Japanese...hmmm, I told him that i always believed that those rice burners felt British...


rn
RN Lipow

I want to jump in here with a diferent side cover problem...replacement. My front cover has several loose pieces of that coarse steel wool stuff rattling around inside of it. As I'm putting a new engine together, I do not like the idea of this stuff fallling down to the new tappets and cam right below. I can't find a replacement, Moss lists it as NA! Is there another source, or have folks cut these open, cleaned and repacked the inside?
Thanks, Tom
Tom Lennon

Tappet cover, tappet cover, tappet cover...I remembered RN's use of "side cover". You all know what I mean!
Tom
Tom Lennon

We did know what you meant Tom, and we know what RN meant. Some of us on the BBS tend to be a bit too pedantic.

There's been some discussion here before about the use of a heavy duty stainless steel scrubbing pad to replace the factory stuff, I seem to remember the brand name "Chore Girl" was used, but that's probably not too important. Take a look in the archives, and be sure to use both side cover and tappet cover in your search, as that is commonly used, if not quite correct, terminology.
Paul K

How do you spell FEEEWWWW! I am really glad I read this thread, I thought I was the only one that couldn't get the side covers to stop leaking. Thanks everyone!
James Headley

Well, to follow up, I read the archives and found the info under "chore girl". I followed the procedure, and cut open the inner portion of the box. I removed the steel pad and found almost two tablespoons of grit and powdered metal also. This is rather startling, as I had backflushed the chamber rather thoroughly, I thought. Having found this, I would now think that any engine rebuild should include this procedure, to eliminate any chance of this years-old accumulation and debris getting down onto the cam and tappets.
Tom
Thomas Lennon

After re-reading this thread and reviewing Original MGB it seems to me that given the original design our efforts to stem the tide of leaking oil seeping from leaking tappet covers is misplaced. I am now of the opinion that a leaking front tappet cover is a "design feature" to protect the engine from infrequent oil changes.

For support of this thesis one has to only refer to the owners' manual which in no uncertain terms directs the operator to regularly check the vehicle's oil level. There is absolutely no reference to correction of engine or transmission leaks. The ancient tradition of "if its' British, it leaks" originated with the circumnavigational voyage of Sir Francis Drake and this fine tradition is carried on to this day in our garages and driveways.

Accordingly, our efforts to stop the drip is to go against the tide of centuries of engineering and tradition.

I should be ashamed of myself for starting this thread! God save the Queen, pass the oil drip-pan!

rn

RN Lipow

Another consideration for using the studs and locknuts that I referred to above is the fact that the set-up shouldn't loosen as opposed to the other setup which has a cup and fiber/rubber washer but no lockwasher.
Frank

So much for lawyers! The tappet cover is the one on the top that contains the tappets. (Tappets are the things you adjust to set the valve clearances).
The side covers you are discussing cover the cam followers - so I suspect side cover is a better name.
On the subject of the breather filter in the front one, it is important that it is renewed when re-building an engine, or you can get very high oil consumption due to inadequate engine breathing.
T Green

No, rockers are the things you adjust. tappets are cylindrical things between the cam and pushrods, and the most direct way to the tappets is via the tappet cover AKA side cover AKA that damn leaky thing.

By the way, when I was in the navy, we worked on huge deisels that had something like 20 side covers. Every one of them leaked like sieves.
Baxter

Ahoy Baxter, what kind of diesels? I ran a GM 8-268A EDG (Emergency Diesel Generator)on one of the boats. Chasing oil leaks was a full-time occupation. Were you an Engineman?

Tappets and and cam followers are the same thing, it's one of those British/American translation things. IMO either tappet cover or side cover could be used.
Paul K

They're known as lifters around here. When RN said sidecover the first time, I could think of nothing else he could have been talking about. I figure since the car was built for the American market (as were the vast majority of MGs), the car spent at least the last 31 1/2 years of its 32 year existence in America, I'm an American, I bought the car in America, from an American, buy replacement parts from American companies, and so on, I'll use the American terminology :)
Wade Keene

Ah well I guess we must be talking about the difference between sidewalks and pavements then! I'm sure that in the UK you adjust a tappet which is on the end of a rocker which is pushed by a pushrod which sits in a cam-follower which is moved by the cam.
What happens in the states if you don't have rockers?(Many overhead cam engines don't have rockers) I suppose you still adjust a rocker even when you don't have one!
T Green

"Main Entry: tap·pet
Pronunciation: 'ta-p&t
Function: noun
Etymology: irregular from 3tap
Date: 1745
: a lever or projection moved by some other piece (as a cam) or intended to tap or touch something else to cause a particular motion"

Does seem to refer to the bit between the pushrod and the valve i.e. the whole 'rocker' not just the adjutable bit. And where Americans get 'rockers' from to describe the sills I can't imagine. Just like the Russians having derived their alphabet from a can of Heinz Alphabetti I think the Americans must have got their first car in bits in a big box but all the labels had fallen off in transit.
Paul Hunt

For a dictionary of automotive see, click on T and scroll down to tappet
http://www.motorera.com/dictionary/car-dic.htm
We are an international group so I think it's interesting to learn automotive terms from places
other than the USA. FWIW, Clifton
Clifton Gordon

I like this discussion as I have been confused in the past. Different terms, different books, different countries.
Perhaps thinking logically down here in the upside down world compared to UK & USA who at least face the same way.
To start I think we can all agree on some things :
One end = A camshaft, has lobes and goes round.
Other end = A valve, is round and opens/closes a hole.
Middle = A Pushrod, describes it's self.
Now for the others :
Camshaft/Pushrod interface = Converts rotating cam lobe motion to linear pushrod motion called a cam follower by definition or lifter by it's action (if vertical).
Pushrod/valve interface = Converts linear pushrod motion to reverse linear motion to push the valve called a rocker by it's action or tappet by definition.
Some engines have manual adjustments on the rocker/tappet and others have automatic adjustments by way of a hydraulic cam follower/lifter.
So a pavement, sidewalk or footpath are places all over the free world where pedestrians are forced to commute as not to present a safety hazard to automobiles/cars etc with all these mechanical moving parts which may become injured by human interferance.
A spade is only a spade when it is not a diamond, club or heart.
my 2 bits worth . . . . . henry
henryo

I just use the cork ones (for some reason they tend to fit the covers better than the red rubbery ones I have gotten) and some of the Permatex Ultra Blue gasket sealing compound, another of the family of sealants that are similar to Hylomar that Chris favors (Hondabond being another good one).

I dont know what bolt seals in particular Chris favors, but I use the metal cup washers with a Flat cylindrical washer (like a section of hose) rather than rubber o-rings, even the fat ones. I don't know the dynamics of why they seal better and last longer, but if made of neoprene, the square cross section ones simply work better for me. A small detail to be sure, but put it under the heading of "these cars really don't have to leak if you find the right materials and have a bit of luck finding them". FWIW
Bob Muenchausen

While all of the above techniques for dealing with leakage are good ones, it’s best to investigate the major contributing factor in leakage: Warped mating surfaces. While today’s sealants are excellent and today’s gaskets possess greater compressibility than those of the past, they can compensate for warped mating surfaces only to a limited degree. During the course of an engine rebuild it’s common the find that the block is warped along its longitudinal axis, so we’re always prepared to line-bore the main bearing journals. However, we rarely stop to consider that this warpage should also extend to the mating surfaces elsewhere on the engine. The necessity of skimming them flat just as one would the deck of the block and the mating surface of the head should always be explored. Get the mating surfaces flat and you’ll go a long way towards having an oil-tight engine. To check for warpage in your garage, simply clean the mating surfaces and smear a very thin coat of petroleum jelly on them. In a smooth, perpendicular motion, place a clean plate glass or a mirror on the surface and then gently pull it away. Hold it up to a light and look for any gaps in the petroleum jelly outline. If you find any, you’ve got warpage. This technique will work with any mating surface.
Steve S.

Another terminology question out of curiosity - Why do the Brits call the trunk a boot? Here, a boot is something we put on our feet. Trunk derives from early cars, which didn't have an integral trunk, but instead used an actual luggage type trunk, like steamer trunks, mounted at the rear to put things in. I drive as fast as I can, and my MG's wings still don't get me off the ground.
Safety Fast
Wade

One boot on two feet makes walking a bit difficult ...

A 'boot' is where one keeps ones booty on the way home from a trip to the Calais hypermarkets.

If you had gone fast enough with the original 'wings' you *would* have taken off.
Paul Hunt

OK, So what does the British Term "Bespoke Parts" mean?
Devin

Well, I was going to offer the Leyland Manual terminology for our two sorts of 'covers'. Went through it and found the relevant references and THEN noticed the following under the copyright notice (1976): "This manual is based on the latest information available at the time of compilation. However, the right to make changes at any time is reserved."
So I thought I'd skip it!
Regards
Roger
Roger

Paul, sorry I'm late getting back to this party. Yes I was an engineman, can't remember what the deisels were, but an FFG has 4 of them, huge v-16 things, made by GM/Allison, and wholly unsuited to marine use. What a nightware.

And I still don't get what all the terminology fussiness is about. If someone says side cover OR tappet cover, doesn't everyone know exactly what they're talking about?

One final note... as an American, I have no idea where "rocker" came from to describe the bit under the door, but I agree, it's dopey.
Every other door has a sill under it, why not the ones on the car?
Baxter

Main Entry: bespoke
Pronunciation: bi-'spOk
Variant(s): or bespoken /-'spO-K&N/
Function: adjective
Etymology: past participle of bespeak
Date: 1607
1 a : CUSTOM-MADE b : dealing in or producing custom-made articles
Paul Hunt

Actually, "be spoke parts" is exactly what you have on a wire wheeled MGB- 240 of them- nipples and spokes. And where do nipples come from. .
Ken R
Ken Rich

Well you've only got to look at a grease nipple to see where that term comes from!
T Green

Steve S. makes an excellent observation and one which is too often not thought about when our cars age. It is a very good point about the warpage of a block, but consider too that most other metal objects subject to the repeating heat-cycles inherent in the usage of an automobile ALSO affect these other items too. Items like carburettors, manifolds, and most other cast metal bodied goodies we stuff under the hood. These small but present changes can and do affect the performance of the units themselves as well as their contribution to the overall running of the car.

I mention this because I have thought for sometime that aging, metal fatigue, and other usage related issues are too often ignored by restorers and enthusiasts alike. It is easy enough to buy components to rebuild an item, but the relavant question before buying them is how old and how used is this unit and then, as Steve suggests, checking to see if the other parameters of accumulated wear and aging warrant a new starting place for this unit's performance or if a simple rebuild/refurbish is truly OK.

Several people have followed me down the path to replacing their SUs and been as amazed as I was that doing no more than a simple exchange was sufficient to clear up several small but irritating problems with their carburettion. I did my replacement out of sheer frustration, but the results intrigued me to think about this process of aging and I think there is room for its consideration when troubleshooting just about any system on a car that is more than a few years old. Our cars may still deliver great fun and reasonably contemporary performance, but that does not erase the 30+ yrs that many of them have been through and what that has done to a once fresh piece of machinery. FWIW.
Bob Muenchausen

Hi Paul,
Actually, my 2-year old has put both of his feet into one of of my boots and walked. Then again, he doesn't always do things the easy way.

"A 'boot' is where one keeps ones booty on the way home from a trip to the Calais hypermarkets." Hmmm, interesting... I think even you would have to admit that the American word "trunk" makes more sense in this application. By "original wings", assuming that you mean the style of fenders/wings generally used on T series MGs and others, that makes cycle fenders/wings make a lot of sense.
Wade

I believe that the word "boot" dates from the stagecoach days. That stowage area at the back of an English stagecoach was described that way, an I believe the same for a Wells Fargo one (you know, the kind in all the western movies). Whether it has a common etymological root with "booty" I don't know, but it sounds plausible.

We seem to have drifted away from "side covers": before anyone asks, no, I don't know what they were called on stagecoaches!
Kevin Kelleher

Greetings all,

It may be just me, but all this talk about greasy nipples, petroleum jelly, mating surfaces, etc.., makes me want to put down the Wrench, and go 'talk to' the ... Wife.

Seriously, though, I'm taking notes on the original subject matter of this post. Thanks to all, as usual.

Regards,

Steve
Steve

RN:

Respecting the subject of a leaking front side/tappet cover...

Some of these front covers have a rectangular pattern into which the gasket should fit...and some do not. In our experience, many were made with three corners in a standard rectangular pattern but the fourth "corner", the forward, lower one, has been "cut off" at an angle. The gaskets for these covers, however are all rectangular in shape with no corresponding shape for the "cut-off" corner.

When a standard rubber/neoprene gasket is placed on a cover with the "cut-off" corner, it will tend to follow the "short-cut" and not extend all the way into what would normally be the "fourth corner". Unfortunately, the section of the block which this cover is intended to seal does not have the odd shape this gasket tends to take, but instead, it's rectangular. So what normally happens is the gasket does not extend into the "corner" of the block in this area, thus allowing oil to escape no matter how tightly the bolt is torqued or how well the gasket itself otherwise seals areas where it contacts.

When we encounter one of these covers, our standard procedure is to cut a small piece of 1/8 in. flat cold-rolled steel the shape necessary to fully form the proper corner and TIG weld it in place. The cover then has four identical corners and when the gasket is in place, it then covers the corresponding mating surface on the block. We use Dow Corning DC-4 on both inner and outer rubber/neoprene gasket faces and these never leak and are easily removed at any time in the future.

I might also add the rubber/neoprene gaskets always seem a bit too tight for the area in which they are to fit. This can be a bit frustrating as the only way to make them fit properly seems to be to hold the assembly up to the block with some force, insert the respective bolt/seal/washer cup, and use this bolt to draw the cover and gasket into place against the block. However, once in place, as stated above, these never leak in spite of their proximity to the exhaust header. We've found the standard cork gaskets to eventually become brittle and leak in this area, presumably due to this very proximity to high exhaust heat, so we don't use them any more.

So if your front cover is of the "non-rectangular" type described above, you may wish to form it out properly before applying the gasket in the future.

Best regards,

Mike Brown,
Seven Shop British
Mike Brown

This thread was discussed between 02/10/2002 and 11/10/2002

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.