| Block Specs | ||
| DRCE2 | DRCE3 | |
| Part number - gray iron | 24502572 | 25534403 |
| Casting p/n | 24502572C | 25534402 |
| Bore spacing | 4.900 | 4.900 |
| Bore - as cast | 4.200 | 4.150 |
| - finished | 4.500 | 4.590 |
| - maximum | 4.700 | 4.700 |
| Stroke - maximum | 4.600 | 4.325 |
| Maximum displacement | 638 | 600 |
| Deck height | 9.525 | 9.250 |
| Deck thickness | 0.925 | 0.750 |
| Deck height - minimum | 9.100 | 9.000 |
| Cylinder bore length | 6.055 | 5.780 |
| Wall thickness | 0.200 | |
| Head studs - number | 6 | 6 |
| - size | 7/16 | 7/16 |
| Lifter diameter - max | 1.060 | 1.060 |
| Lifter bore angle - In | 45 | 48 |
| - Ex | 45 | 56 |
| Cam to crank | 5.751 | 7.067 |
| Cam bore | 2.308 | 2.672 |
| Cam bearings - number | 5 | 9 |
| - Journal size | 55 mm | 60 mm |
| - Width | 20 mm | 20 / 12 mm |
| - Type | Journal | Roller |
| Cam base circle | 1.105 | 1.302 |
| Lobe lift | 0.530 | 0.530 |
| Main bore | 2.681 | 2.682 |
| Main bearing journal | 2.750 / 2.500 | 2.500 |
| Main cap material | 8620 | 4140 |
| Main cap studs - size | 1/2 | 1/2 |
| - orientation | Splayed | Splayed |
| Main cap located by | Stepped block | Stepped block |
| & 1/4 inch dowel | ||
| Oil pan bolt centerline | 10.376 | 11.820 |
| Oil feed line diameters | ||
| - Main gallery | 0.562 to 0.413 | 9/16 |
| - Lifter gallery | 3/8 | 3/8 |
| - Main bearing feed | 1/4 | 5/16 |
| - Cam tunnel drain | n/a | 3/8 |
| Water and oil plugs | Pipe plugs | AN plugs |
Note the shorter stroke and maximum displacement specs of the DRCE3, and the camshaft relocation dimension (over 7-in. from crank centerline) and bearing journal changes. GM stabilized the valvetrain and gained 300-350 RPM (they will admit to).
Naturally GM Racing isn’t fast and loose with its racing budget allocation amounts, but from my sources on both sides, I think it is a fair approximation to say the NASCAR budget is about 10 times the NHRA one. No wonder Engel borrowed a few engine design items that had proven effective in other GM Racing programs – the IRL (back when GM raced there) and NASCAR. A tight budget can be a mother of engine invention.
This is how you minimize camshaft flex – sheath it in nine journals with roller bearings. This cam tunnel also keeps camshaft lubrication off the crankshaft. The small passages between the journals at the floor or the tunnel were originally for oil squirters and were included in the first DRCE3 blocks. They were found not to be needed, and were deleted from later versions.
