MG Drivers Club Deutschland - Forum

Hallo alle zusammen , ich hab da mal ne Frage .
Auf meinem Zylinderkopf ( MGA 1500 ) steht eine 15 eingegossen , heißt das nun 1500 so das beim 1600 und 1622 jeweils 16 und vielleicht 162 eingegossen ist und wo gibt's noch unterschiede bei den Köpfen ?
Auf eure Antworten bin ich schon gespannt .
Gruß Armin

Hallo Armin,
hier die Antwort des MGA Gurus, von dem ich das auf meine ähnliche Frage wegen verschiedenen Köpfen, die ich vorrätig habe, gemailt bekam (leider nur in Englisch, sollte aber klar sein):

All of the "B" series heads will physically fit on all of the "B" series engines (except the Twin Cam). The 16 and 18 heads have larger combustion chambers, so you need to watch out for change of compression ratio if you have a mismatch with heads and pistons.

The 15 heads come in a wide variety, with small valves for single carburetor engines (like Nash Metropolitan) and larger valves for dual carburetor engines (like MGA). The small valves are no good at all for the MGA. What are the sizes of the valves? The MGA 15 head (used on 1500 and 1600 engines) had 1-1/2 inch intake valves and 1-9/32 inch exhaust valves. This wouild be detrimental to the performance of an MGA 1622 engine.

The 15 heads may have round intake ports for early heads and larger rectangular intake ports for later heads (round at the gasket surface but rectangular farther in). One thing all 15 heads should have in common is a 38cc volume combustion chamber, with one exception.

When the 1622 engine was installed on the MGA it was given a larger combustion chamber (43cc), and one size larger valves and better porting. The MGA MK-II then had 1-9/16 inch intake valves, and 1-11/32 inch exhaust valves (same as the MGB to follow). The new 16 head was apparently not ready in time, so the first 300 or so 1622 engines for the MGA 1600-MK-II were fitted with heads special machined from "15" type castings. These few hundred heads have the "15" casting numbers, but were machined out to the specifications for the new 16 head with 43cc chambers and larger valves. These odd heads should only be found on early MGA MK-II cars with 1622 engines.

After this the new special 16 head became available and was used on the rest of MGA production 1622 engines. The 16 head is nearly identical to the early MGB 18 head, except for a small difference in the Weslake promentory (the heart shape between the valves). To have the appropriate compression ratio with the larger combustion chamber the MGA 1622 engine was built with flat top pistons. Pistons in the 1800 to follow were slightly dished. The early 18 head would be more suitable as a replacement for the MGA 1622 engine.

As far as I know, the 16 head was unique to the MGA MK-II. There are a lot of other variations of the 1622 engine used in other cars (often with no tachometer drive), but generally using the 15 head. Those other applications nearly always use valves the size of the MGA 1500/1600 engine, or smaller in some cases, but seldom with the larger valves seen in the MGA MK-II. Keep in mind that the 15 head has smaller chamber than the 16 head, so a 1622 engine with a 15 head should have dished pistons.

Gruss Edi

Hallo Edi
vielen dank für die schnelle Antwort , mein Englisch ist zwar nicht so gut aber das habe selbst ich verstanden.
Gruß vom Bodensee Armin