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[mmaki]

My cylinder head, shown here:  https://imgur.com/a/HIQnm1m has 4 7/16 UNF bolts sticking out of it. As these are covering passages to the exhaust outlets I figure these must be ports for a air pump.

 

As I don't think smog pumps became a thing until maybe late 70's or 80's, it must mean this head is not original to my '67 998?

 

In google searching other A series heads I haven't even found a image of another with these ports.

 

Edit:

 

It is looking like the block isn't original to the car either although the gear case may be.

 

Block number 99H83V-H3011 on this site: http://www.guess-wor...NO=&EN_NO=h3011

 

Comes back as:

 

Source Vehicle :   Mini
Engine type & CC :   A Series 998 cc Transverse mounted
Fueling :   
Engine features :  
Exhaust emission control
Mechanical petrol pump
Gearbox features :  
Std. Ratio Rod Change gearbox with Pot Joints
3.44:1 final drive

 

Currently it has u joint driveshafts, magic wand shifter and a electric pump

Edited by mmaki, 24 July 2021 - 11:27 PM.

[weef]

These ports were part of an early emisions control system. There is a section relating to this system in the Mini Black Book repair manual. 

This was why the radiator top outlet was to the rear leaving space for an engine pump to be mounted above the dynamo. The system injected compressed air into the exhaust ports on the engine over run controlled by a "gulp valve" operated by inlet manifold depression. 

I believe it never was a great success consuming too many engine HP making the small bore engines performance somewhat lacking.

The Leyland Moke of Australia had this system and it was discontinued when the Moke was reclassified as a commercial.  

Probably this system was removed from many vehicles and lie in the back of sheds in Australia, and a complete fitted working unit will be quite rare.