Manifold studs - two lengths?

[Napoleon Boot]

My manifold gasket is blowing, so I'm replacing it, and in the process I should really replace the studs and nuts as they are looking a bit past it.

Watching videos and searching the forum, it seems that a 1098 engine should have four longer studs in the middle, and two shorter ones on the ends, but looking at ESM's site, they only stock one manifold stud for OHV engines. I've also seen reference to four double length nuts for the centre studs, though it's a tight fit underneath the manifold and I'm not sure they'd fit?

At present, the car has six studs the same length, large washers on the four middle studs and the stud nearest the bulkhead, and a spring washer on the stud nearest the front. I'm pretty sure this is not how it's supposed to be!

I've looked at parts diagrams but am no clearer - can anyone advise what hardware I should be using on a late (1971) Traveller with it's original 1098 engine, so that I can get it right?

Thanks in advance,
Seb

[les]

I don’t see why the studs should be of different lengths, if you can see some of the thread protruding from the nuts on your manifold, then you’re ok.

[Bill_qaz]

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Stud
Inlet and exhaust manifold 53 K 487 quantity 6
All the same

[svenedin]

Have a look at this kit. There are 6 studs all the same length and 6 brass nuts (these do not seize at the high temperature on the manifold). 4 larger diameter thicker washers and 2 thinner smaller diameter washers (these go at each end).

When you fit the new gasket, pay attention to the correct torques (15 Lb ft; 20 Nm) as the manifold expands with the high heat and could crack with overenthusiastic cold tightening. Tighten the nuts gradually avoiding fully tightening one whilst the others are loose to spread the load. A universal joint for your socket extension makes the middle ones easier.

https://www.morrisminorspares.com/engin ... s-p1238183

Stephen

[geoberni]

I don't know where you've been looking, but as Bill said (although he has the wrong illustration )
53K 487 qty 6
.

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[Bill_qaz]

I don't know where you've been looking, but as Bill said (although he has the wrong illustration )
53K 487 qty 6
.
Studs.JPG

No I posted the illustration and parts list for the nut and washer part of the query and just used the text for the head stud without the illustration. CBA posting another picture

[philthehill]

There were originally three lengths of manifold stud:-

Pt No: 53K486....Short..Qty 2.............Studs at ends of head.

Pt No: 53K487....Medium..Qty 2 or 6....Studs between inlet port and outer exhaust ports. Can be used for all studs.

Pt No: FH2513....Long..Qty 2.............Studs between centre exhaust port and inlet ports.

The nuts Pt No: BNN105..Qty 6 were all originally brass with spring washers. There is less chance of the manifold nuts giving trouble if they are all brass.
There is no requirement for sealant on the manifold gasket. All that is required is a light smear of general purpose grease on both sides of the gasket.
Tighten progressively to avoid straining the manifold which could lead to cracking and failure.

[Bill_qaz]

Interesting Phil, why does the parts manual for 1098 show all six studs the same, was there a change point?

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[philthehill]

Bill
There is a change point quoted.
The part numbers given above were taken from parts list AKD559 third edition. Morris 1/4 ton van so the change point will not be relative to the saloon.
Phil

[geoberni]

Change point was during the 948 (9M) engine.
As always with BMC, there are a few exceptions.... but with the list of 'significant' engine change points in Original Morris Minor giving 353449 as Sept 1959, and 441410 as May 1960, I would estimate 437662 as being around New Year 1960.
.

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[Bill_qaz]

OH, sorry Phil & Berni if I've confused the issue. I thought the OP was asking about a 1098 engine in a 1971 traveller and thought I was looking at the correct parts manual section. I don't understand the references to earlier versions, but
I know you guys have a lot more knowledge about Minors.

[Napoleon Boot]

Thank you all for the comprehensive help you've given me! I'm glad I wasn't imagining the different length studs, but reassured that I just need six the same length.

Having cleaned up the faces of my manifold this evening, I can now see how chipped and pitted the exhaust ports are, it's no wonder that the gasket blew in so many places. I'm now going to look for a reconditioned manifold that I can use instead, which should hopefully improve the car's performance no end. The manifold is one of the few bits I've not looked at since getting the car seven years ago, and it's showing every one of its fifty-five years.

Best wishes,
Seb

[svenedin]

Thank you all for the comprehensive help you've given me! I'm glad I wasn't imagining the different length studs, but reassured that I just need six the same length.

Having cleaned up the faces of my manifold this evening, I can now see how chipped and pitted the exhaust ports are, it's no wonder that the gasket blew in so many places. I'm now going to look for a reconditioned manifold that I can use instead, which should hopefully improve the car's performance no end. The manifold is one of the few bits I've not looked at since getting the car seven years ago, and it's showing every one of its fifty-five years.

Best wishes,
Seb

The standard 1098cc manifold is easy to find as a used part. 12A1141

There is also a type with a tapped hole for a PCV valve stub pipe (often used for a servo vacuum connection instead) and another smaller tapped hole for the PCV valve bracket stud 12A1097 (these are quite rare).

For a 1971 the correct one is 12A1097 with the tapped PCV valve stub pipe hole blanked off with ADP210 and a fibre washer. The engine breathing having moved on to a hose from oil separator to breather type SU HS2 carburettor by that stage.

Just depends how much of a stickler you are for originality. For reference see AKD3541 parts book.

Stephen

[Napoleon Boot]

Thanks Stephen,

I'd assumed the 12A1141 that was on the car was the original from the factory, so that's interesting to hear. I have a brake servo vacuum connection on the carb spacer already, and the current engine breathing setup is working effectively, so I'll just go for another 12A1141 manifold and not bother looking for a 12A1097.

Best wishes,
Seb

[svenedin]

Thanks Stephen,

I'd assumed the 12A1141 that was on the car was the original from the factory, so that's interesting to hear. I have a brake servo vacuum connection on the carb spacer already, and the current engine breathing setup is working effectively, so I'll just go for another 12A1141 manifold and not bother looking for a 12A1097.

Best wishes,
Seb

That makes sense. 12A1141 is much easier to find and cheaper.

Stephen

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