In the early 60s, Dytch upped their game and introduced 60,000 psi grey iron cylinders. The overall castings are heavier than stock 900 castings, but not so much so that they are immediately noticeable. These cylinders were also cast by MOCASCO and are easy to spot by the “60” cast on them – and usually because they have thicker fins and cylinder bases. These cylinders were available in 3-3/16 or 3-1/4 with the latter being the most popular option. Many of these cylinders also have 3/8 instead of 7/16 head bolts. This allows for slightly more clamping surface at the head gasket to help prevent blown gaskets.

Cylinder lengths were customizable and it is not unusual to find cylinders that are over-length. This allows the cylinder to be mounted directly without a stroker plate in some applications. These cylinders are also .060 longer than stock at 5.390 inches. This means that we may not need to use stroker plates depending on our stroke length. You can also see the major difference in the fire ring’s outer diameter. This means the cylinder heads must be counter-bored to suit.

Above: notice the smaller head bolts . . .

Above: measuring the OD of the fire ring on a brand new cylinder

Above: measuring the OD of the Dytch big bore cylinder -- notice the difference?

Above: to accomodate the big bore cylinders; both the heads and the engine cases must be suitably bored. Please ignore the "egging" of the head bolt holes -- we'll be fixing that poor piece of machine work later in the series.

Above: the "over length" of the cylinder -- this extra length means we should not need stroker plates for the motor Chuck is planning.