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Cylinder head decode
Posted: Thu Mar 17, 2016 4:13 pm
by Pastypearce
Hi all, I just came upon a (supposedly) 1298 head ( unleaded) and, separately, a very nice cast rocker shaft.
I'm planning to swop the head for the one on my 1969 convertible. I've bought a ( good) gasket set and have read
the manual! What I don't have are any studs or nuts to fix the shaft onto the head.
The head is marked 2A3 AF1 AS3 with another set of numbers 22-4-5 between two screw heads in the casting. It also has MOWOG in the casting.
I realize that the "old" head will have the studs but I want to have a complete head ready for "unleading" and probable sale.
Any tips about any of the above will be much appreciated.
Happy St.Pat's day to all.
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 4:14 pm
by Pastypearce
Apologies, I should have said 1098 head.
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 4:24 pm
by philthehill
Whilst the studs are available from the likes of MOSS personally I do not see the point in purchasing the studs.
If you can obtain free of charge that is different.
Whoever purchases your old head will have their own studs to complete the job and if they are wise will fit new studs as over time the old studs become stretched / waisted.
If you are going to purchase new head studs I would purchase the later 'A' Series cyl head studs as they can be torqued up a bit tighter.
They can be identified by either a dimple, a taper top or a 'P' on the top.
Use the improved studs and sell your head, rocker shaft and old studs.
All the rest of the studs are available from the likes of MOSS.
Phil
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 4:33 pm
by Pastypearce
Thanks Phil, certainly food for thought! Terry.
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 5:23 pm
by bmcecosse
I assumed it was the 4 studs (2 short/2 long) that hold the rocker shaft pedestals..... Don't worry about 'unleaded' - it's really not necessary unless a very hard driven car used for Mway work. Do however set the exhaust valve gaps to 15 thou.
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 5:31 pm
by Pastypearce
many thanks. Are you able to point me at a decode of the serial numbers on the head?
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 5:41 pm
by bmcecosse
If it's a 1098 head it will clearly have 12G202 on the casting....(or perhaps 12G206 or 12G295 if you are lucky) between the centre two rocker pillars. Never known one not to have these marks. Does it have the thermometer pocket in the side below the thermostat housing - usually plugged with a large hex headed screw, and not used in the Minor as standard? Valve head diameters will also give the game away. It's likely with the 'cast' rockers that it is an old 803/948 head. Pictures would help us!
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 5:54 pm
by Pastypearce
Thanks again. The rocker shaft was bought separately. I'll have a look tomorrow for the temp sensor.
I bought the head from this site some time ago and have just had it refurbished with new valve seats and new valves, springs
and other fittings.
I think that you could be right about the smaller engine. However, the refurbisher did increase the valve seats so as to fit valves
for the 1098 engine.
Does that help?
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 6:12 pm
by philthehill
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Re: Cylinder head decode
Posted: Thu Mar 17, 2016 6:37 pm
by Pastypearce
Thats very interesting, thanks. It seems that the 1098 head I bought is no such thing!
So the question is, will it fit on my 1098 engine?
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 6:41 pm
by philthehill
A photo of the head would be appreciated and would throw more light on what you actually have.
Phil
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 6:42 pm
by bmcecosse
It will 'fit' - but you will lose power. Ok in an emergency - or while you 'do up' your own head, but not ideal really.
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 6:49 pm
by bmcecosse
Increasing the seats is no use - it's the bore of the port throats, and the shape/size of the ports that matter. He really should have asked you about it before barging ahead. It 'can' be upgraded with a lot of work to the 202 standard - but it's really really not worth it when you can pick up a 202 head for ~ £30.
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 7:04 pm
by philthehill
Before jumping to any conclusions - a photo of the inlet/exhaust side of the head, the top of the head, the plug side of the head and the combustion chamber should confirm what head you have.
Phil
Re: Cylinder head decode
Posted: Thu Mar 17, 2016 7:11 pm
by bmcecosse
Let's see the rockers too...
Re: Cylinder head decode
Posted: Fri Mar 18, 2016 8:53 am
by Pastypearce
Morning all. I've taken some photos but my ipad can't upload them to this site.
Could I send them to someone's email address who's able to upload them?
Re: Cylinder head decode
Posted: Fri Mar 18, 2016 10:43 pm
by philthehill
Photos of the head in question:[frame]

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Re: Cylinder head decode
Posted: Fri Mar 18, 2016 10:44 pm
by philthehill
Photos of the head in question:[frame]

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Re: Cylinder head decode
Posted: Fri Mar 18, 2016 10:45 pm
by philthehill
Photos of the head in question:-[frame]

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Re: Cylinder head decode
Posted: Fri Mar 18, 2016 10:46 pm
by philthehill
Photos of the head in question:-[frame]

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