What does this blueprint show?

It shows the front face ('Block Front') of a Small Block Ford engine block, with dimensioned locations of bolt holes and two dowel/locating circles referenced to the vertical centerline and the crankshaft bore centerline.

What is the reference point for the vertical dimensions?

The crankshaft bore centerline, which is explicitly labeled with an arrow pointing to the lower large circle.

How far are the two large side circles (dowel/hole locations) from the centerline?

Both are 4.0000" from the vertical centerline, at a height of 5.7800" above the crankshaft bore centerline on each side.

Where are the lowest bolt holes on the block front located?

The lower-left hole is 4.5600" left of centerline and the lower-right hole is 4.4600" right of centerline; both are 0.9200" above the crankshaft bore centerline.

What are the highest bolt hole positions shown?

The upper-left hole is 2.0400" from centerline at a height of 7.7800", and the upper-right hole is 2.4800" from centerline at a height of 7.4200".

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Small Block Ford Block Front Bolt Pattern Blueprint - Dimensions & Hole Layout

CAD dimensioned drawing of engine block front bolt holes and crankshaft bore centerline

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Dimensioned CAD blueprint of the engine block front showing bolt-hole locations and crankshaft-bore centerline measurements.

AI caption December 2010 · Photo 150 of 156

This document is a CAD-style blueprint drawing titled 'Block Front' showing the front face bolt-hole pattern of a Small Block Ford engine block. It depicts the locations of the threaded bolt holes and two dowel/locating circles on the front of the block, dimensioned relative to a vertical centerline and the crankshaft bore centerline (explicitly labeled with an arrow). Two large red circles represent the camshaft bore (upper center) and crankshaft bore (lower center). Horizontal dimensions from the centerline include 2.0400", 2.4800", 4.5800", 4.6300", 4.0000" (both sides), 3.5700", 3.5000", 3.4400", 2.9000", 1.7800", 4.5600", and 4.4600". Vertical heights above the crankshaft centerline include 7.7800", 7.4200", 6.4300", 6.3800", 5.7800" (both sides), 4.6000", 4.6700", 2.8000", and 0.9200" (both lower holes). A reader can use this drawing to locate front-cover, water pump, and accessory bolt hole positions when fabricating brackets, adapters, or front plates for a Small Block Ford engine. The drawing is undated and does not state specific model years or displacements.

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Frequently asked questions

What does this blueprint show?: It shows the front face ('Block Front') of a Small Block Ford engine block, with dimensioned locations of bolt holes and two dowel/locating circles referenced to the vertical centerline and the crankshaft bore centerline.
What is the reference point for the vertical dimensions?: The crankshaft bore centerline, which is explicitly labeled with an arrow pointing to the lower large circle.
How far are the two large side circles (dowel/hole locations) from the centerline?: Both are 4.0000" from the vertical centerline, at a height of 5.7800" above the crankshaft bore centerline on each side.
Where are the lowest bolt holes on the block front located?: The lower-left hole is 4.5600" left of centerline and the lower-right hole is 4.4600" right of centerline; both are 0.9200" above the crankshaft bore centerline.
What are the highest bolt hole positions shown?: The upper-left hole is 2.0400" from centerline at a height of 7.7800", and the upper-right hole is 2.4800" from centerline at a height of 7.4200".