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MG MGB Technical - Manifold gasket

Hi,

I'm replacing the gasket on the front tappet chest cover and want to remove the intake manifold in order to improve access.

My question is, will I also need to renew the manifold gasket (which implies removing the exhaust manifold too) or can I leave the manifold gasket in situ and re-use it?

There is a sense of one thing leading to another here!

Thanks
T H Brearley

I'd just struggle on getting the cover out without disturbing the rest, it'll come out ok
When refitting make sure you have a good leakproof seal on the bolt like a fibre washer or rubber o ring style seal or it will leak oil from there-
If you really want to remove the inlet, IF your gasket is one of the perforated metal type you will be ok, but if it's one of the black cardboard style then you'll be lucky to get it off clean meaning pulling the exh. manifold back as well

willy
William Revit

I'd have thought it was the exhaust manifold that was more in the way than the inlet, but I just removed the carbs and heat shield. The only tricky bit is getting the cover back, avoiding the cork gasket and sealant touching anything on the way.
paulh4

Thanks chaps. It's a perforated metal type. I think removing the intake manifold will provide much improved visibility to check the chest gasket is making a good seal all the way round.

Incidentally, the cork gasket I received from Rimmer Bros is too small. Currently awaiting one from Moss.
T H Brearley

It was my rubber gasket that was too small for the recess, it wouldn't stay in unless I clamped it in position overnight on the bench, and didn't hang about between unclamping it and fitting it.

Whilst the cork didn't reach the edges of the cover there has been enough overlap to give a good seal - with non-hardening sealant - for five years now.

paulh4

Yes, mine was much smaller than that Paul. It rode up on the shoulders of the cannister.
T H Brearley

Probably old stock, if you soak it in some warm water for a few mins. it will swell up
William Revit

There are two thicknesses of cork gasket. The thicker one works well if sealant is properly applied and the bolt is not over tightened but is tight enough.

I have tried the silicone seals and they are working well.
Glenn Mallory

According to John Twist if you're ordering a front side cover gasket you want the thin cork one from the MGA. See at 2:38 on this video -
http://www.youtube.com/watch?v=xH_h44FQdXE

The gasket also fits earlier a-series engines.

Moss, MGA Gasket, tappet cover [thin] - http://www.moss-europe.co.uk/gasket-tappet-cover-12a1139.html?assoc=121200
Nigel Atkins

Thanks Nigel. I did check that John Twist video before getting stuck in. The same part number is quoted for the MGB (as well as a thicker version) so that's the one I got.

William, thanks for the tip. I would try it if I hadn't covered the first gasket in glue in misguided attempt to get it in place!
T H Brearley

We always fit those gaskets dry, and never get a failure if aligned correctly. Which is the biggest challenge because.....

Size is an issue, yes most around are too small. I have optimistically fed photos of current and original gaskets back into the wholesale supply chain... Probably wishful thinking but worth a try. (they ate currently on back order would nice to think we might get a batch the right size)

For best result on the bolts use the 12A1176 and 12A1177 cup washer and o-ring fitted to the later Bs. Cup washer is well shaped to compress the large section o-ring in onto the bolt as it tightens.
Paul Walbran

Even ordering the same part number with the same supplier doesn't always guarantee getting the same part as previously or each time as their source(s) can change.

Often you can get an alternative part to factory original without being told so, I remember decades back, ordering a couple of short, small-bore, shaped hoses for about a fiver and what I was given was two very short off-cuts from a reel of hose.

Paul,
remembering your previous comment on genuine parts quality, only recently I dealt with a part from SU that was wrong, I rang them to let them know and got through to a right miserable b*gger, answered the line with "Urgh" and this was 'Sales' that I'd been put through to (I'm not joking), no initiative or even helpfulness. I previously thought I might have had unsuccessful dealings with them before many years back, and a mate said they were uncooperative with his company despite the volume of purchases his company made of their products, which they found more successful to source via one of SU's customers. So it isn't just me, there's at least one other. We all make many mistakes, some of us more frequent than others, it's how the mistake is handled, or not, that matters.

Most classic car owners are tight-fisted and are more concerned about very low retail price (unless it's bling of course) than quality so suppliers have to supply them what the want and those of us in the minority just have to put up with it.
Nigel Atkins

In part, a true observation on pricing Nigel. But it also reflects on the sales approach. Where there is a choice of quality I ask people do they want to pay x for a cheapo or 2x (or however much more it might be) for one that will fit properly/not fail etc.
90% opt for the good one.
I still take that approach even if it means losing a sale, for example
people wanting a front bumper are strongly advised yes, we can do a new one, they are better than nothing but if you have an original then spend 50% more with the chrome players. And most do.
Paul Walbran

With respect Paul you're not dealing with thousands or tens of thousands of customers, many of whom are tight-fisted classic vehicle owners, the customers coming to you probably want and expect better quality and are happier to pay for it.

Just as one example, the famous unmentionable Spridget part (fwb), a good quality kit was made up to sell alongside the cheaper, not correct but might work for a short or longer time, kit widely available.

The initial batch of better quality kits sold out eventually and a second batch (of 100) was attained (I guess to complete the contract) and I see they are still not sold out after over a year so even if they sold out today that'd be sales of less than two sets a week. The cheap sets sell at many (many) multiples of this. The site gives heavy hints as to which set should be purchased but at about half the price the vast majority of buyers go for the cheap set.

When I returned to owning Triumph/MG classics I found the parts quality had become very poor, Triumph parts I found to be even worse than MG, and when I asked a couple of suppliers about getting better quality they explained their sales and I could understand their position.

When I had my previous Spridget I can remember being told by one of the big suppliers that I was one of the few Spridget owners who was happy to spend on functional parts.

B owners are prepared to spend a bit more presumably because of the value difference in models -they're especially happier to spend more on bling. For all models functional parts don't matter so much as the owners have vehicles that are mostly static year round.

I've worked on retail and B2B sales and service at shops, showrooms, customers' premises and exhibitions, attended classic car shows for about 30 years (not selling and I don't mean for unnecessary sales or costs, I was never into that) and I can assure you the classic car shows have the oldest most whinging, whining, tight-fisted attendees - and I've become one of them.
Nigel Atkins

We use cork on the front cover and rubber on the rear one. We superglue the front one onto the cover. The rear one is usually a tight enough fit it the later style cover to stay in place. A smear of silicone sealant to seal them.
I have seen a blob of built up weld on the front one to force the cork into a more rectangular shape where the cover is 'the wrong shape'. Fidgety but the front one can be done with ex manifold and carbs in place.
Peter Burgess Tuning

I have always done as Peter does - use rubber gaskets and glue them to the covers. I usually use a thin smear of silicone seal that I let set up on the engine side before installing them, but you probably don't need anything as the rubber will conform to the engine side.

One set I installed in the 1970s is still working just fine with no leaks.
Bill Spohn

Just seen in TD-TF section, this chap does some better-quality sideplate and other seals -

Declan Burns, Düsseldorf Germany, email (link) - declan_burns@web.de

. "Rocker cover and sideplate cover re-usable rubber seals. These side cover seals are thinner than the original leaky cork seals"

and

. "Fulcrum pin dust caps MG TD/MG TF/MGA set of 8. (MGB set of four)
These dust caps are fit for purpose being designed and manufactured by ourselves to the highest quality. They are made from a synthetic rubber which is oil and grease resistant and not subject to ozone cracking as some of the inferior products currently being sold. The last thing owners want to do is to frequently have to dismantle the front suspension due to the premature failure of a simple rubber seal".

See attached pdf.

No connection to me, just passing on what I've seen.
Nigel Atkins

Thanks for all the advice. The majority view seemed to be to use the thin cork gasket so that's what I went for (having obtained one that actually fits from Moss). My cover has some corrosion pitting so Red Hylomar was used on that side and Blue on the engine side.

So far so good.
T H Brearley

I've no idea what the differences are between Hylotyte red and Hylomar Hylotyte Red 100 but I've had good success with the later for sealing previous coolant leaks.
http://hylomar.com/hylomar-product-range/gasket-jointing-compounds/#hylotytered
Nigel Atkins

This thread was discussed between 15/07/2020 and 25/07/2020

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