Lotus 51C Engine Help

[kmrk]

I am trying to understand more about the motor in my 51C and have searched the web high and low and cannot find what the block marking FoMoCo 37 represents? Is this a Kent block? The motor has a Minister Power head and a Hewland H6 gearbox. Any help would be greatly appreciated. Many thanks, Ken.

[bob darcey]

Check out this http://www.lotus-cortina.com/library/block/blocks.htm for a good explanation of the various Ford blocks. Also, some history here http://www.thekentlives.com/thekentengine.htm.

Not sure of the "FoMoCo 37" designation, could that be a "2737"? Basically, the earlier FF's used what is called the "Cortina" or "original" (SCCA/GCR-speak) 1600 crossflow motor, and the appropriate blocks had casting numbers 681 and 2737. These engines had the smaller, roundish main caps, a kidney-shaped recess in the head and the small diameter lifter bores. In 1971, Ford updated the motor slightly to what the GCR calls the "uprated" motor, a.k.a., the Kent, with a 711 casting designation. The 711 has larger, more squarish main caps, a flat cylinder head (but valve reliefs in the pistons), larger diameter valves and larger diameter lifters. Otherwise the engines are very similar and most parts will interchange. In an attempt to equalize the motors, the GCR allowed Cortina motors a 10:1 compression ratio, whereas the uprated is allowed 9.3:1. Today, a few vintage cars still run the Cortina configuration, but piston availability is a problem and the old Cortina generally doesn't make as much power as the uprated config. A couple of people have developed competitive Cortina motors with some success, based on the 10:1 allowance as well as a lighter minimum car weight allowance.

A true Contina configuration should have a 681 or 2737 block, a chambered head, pistons with no valve reliefs, the earlier intake manifold (no linkage mounting bosses on the rear) and a Weber DFM 32 (or Holley 5100??) carburator. A good resource for the crossflow engine in all its incarnations is the Dave Bean Engineering catalog.

[kmrk]

Bob,
Many thanks for the education and direction. Most appreciated. Ken.