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Head Swaps

Cylinder heads are a complicated and simple at the same time!

All 1300 and 1500 heads are interchangeable in that they will all bolt on, and all manifolds fit as the inlet/exhaust port arrangement is always the same. However it is vital to get the compression ratio correct for the fuel available. 





515573 13/60 Herald

small inlet valve

figure 8 valve retainers


515973 Spit Mk3

small inlet valve

twin collet retainers


218139 1500 forward

biggest inlet valve

8:1 (on 1500)

218140 1500 forward

biggest inlet valve


218141 1300 Toledo

big valves


218142 1300 Spitfire IV(not US market)

big valves


TKC1156 Dolomite 1300

slightly smaller inlet valves

no water outlet in RH rear corner


TKC1155 Spitfire/Dolomite/Midget 1500 (not US market)

slightly smaller inlet valves

9:1 on 1500

There is a variety of USA heads with/without valve seat inserts, with/without air injection, and some at 7.5:1 with dished pistons or 9:1 (1976) with flat. Physically they will all bolt on.

Problems occur with 1300 heads on 1500 engines as the compression is too high, but a 1300 head at 8.5:1 is fine with the 1500 dished pistons (low compression pistions)! Torque of an engine is really related to its capacity, the BHP can be increased by making the gasses get in and out easier and faster but this is always at the top end. The most important thing normally is to get what is there working correctly.