17 replies to this topic

[Milo07]

I check the forum but I don't find clear answers about if is possible to fit an A cylinder head on an A+ engine.

Someone told that is not possible.
And another man told me that it is with some changes, but didn't specified.

Would you please help me on this.

Thank you

[nicklouse]

there is no real difference.

 

But there are many A and many A+ some may not work correctly as for instance a S 11 stud head on a 9 stub block would leak if the block was not drilled to suit.

 

big bore heads do not readily work on small bore engines without some block machining. 

 

as you see it come down to specifics.

 

so yes the will fit. but some will need some form of work.

[Spider]

The later A+ didn't have a by-pass set up but that wouldn't prevent one from the other being used.

 

In fact the A+ engines up to about 1985 - 86 were fitted with the same heads as the A series.

[Midas Mk1]

there is no real difference.

 

But there are many A and many A+ some may not work correctly as for instance a S 11 stud head on a 9 stub block would leak if the block was not drilled to suit.

 

 

 

Where does it leak? I've not had any loss in coolant or leaks AFAIK... 

[nicklouse]

and then there is the MPI and SPI(?) that have the water temp somewhere else so no drilling in the head. and the MPI alternator mount on the head.

 

they will still work but solutions will need to be worked out.

 

but again it all come down to details.

[Turbo Phil]

An 11stud head on a 9 stud block will not leak. They're stud holes, whether the studs are present or not will make no difference.
To answer the original question, yes an earlier A series head can be fitted to a later A+ block.
 

Phil.

 

[Milo07]

Thank you everyone.

[limby2000]

On some small bore,s you may find putting an A head on an A+ will cause a clearance issue if your using the standard bigger pulley. If so you will have to fit the small clubman pulley.

[Milo07]

Can anyone tell me what mods do I have to do at the Cylinder head (A) to fit on the A+ Block?

[gazza82]

Depends which Cylinder head you are talking about .. any casting part numbers on the head you are thinking of fitting and to which engine?

[nicklouse]

Can anyone tell me what mods do I have to do at the Cylinder head (A) to fit on the A+ Block?

If like for like they just bolt on.

[Spider]

Can anyone tell me what mods do I have to do at the Cylinder head (A) to fit on the A+ Block?

 

Many A+ didn't have a by-pass, so you may need to block that up (but IMO should as a matter of course).

 

Otherwise, as the other guys have already said, just fit it.

[gazza82]

But that's not the only problem. if you try and fit a 12G940 head to a 998 you could need to machining the block. Some heads may be completely the wrong comp ratio. Yes they may fit but would it work? Which is why I was asking what head and what block. Keith Calver's site has a list of heads which migtht be a good starting point.

[Milo07]

Sorry, we are talking for a 1275 A+ block
I'm looking for a 12g940

Edited by Milo07, 19 July 2016 - 08:55 AM.

[nicklouse]

not an issue other than the bypass hose and mentioned.