Gear ratios for datsun 720 street truck

[datzenmike]

Z22 with KA24E head????

 

The E head has a very large combustion chamber and coupled with a Z22 piston dish of 9.32cc the compression is in the basement @ 7.68. Over bore to 89mm and swap stock KA24E 2.8cc dish pistons in and you have a big bore 2300. KA-E pistons on Z22 rods stop 1.55mm below the deck so milling 1mm off will remove over 6cc of volume from the combustion chamber giving you a compression of 8.26. If you remove the full 1.55mm the compression is 8.6.

 

If there are high compression KA-e pistons you want a dome volume of at least 10cc to get 8.6 and mill the block surface for more.

 

A KA24DE head volume is very close to an L series head so on a Z22 block the compression is 9.59 but there's the sorting out of the timing chain and gears. 

[dew]

Thanks Mike. Probably your umteenth time repeating that, but most concise I’ve ever read. Haven’t had it confirmed but read on old forum that Toyota R series timing (or crank?) pulley makes KA24de head timing match the Z bottom, plus upper part of timing cover?

[datzenmike]

The KA24E cam sprocket is identical to the L and Z series sprocket.... except that it's a single row chain. Pretty sure a Z or L cam sprocket will fit. Chain length is another matter. Depends if cam on the KA is higher or lower to the block than the Z series.

 

 

[dew]

Just sayin’, all you guys here are an awesome (and patient) resource. Learned SO much on this forum. Perhaps I can find a Canadian/ Mexican/JDM KA20de to play with....