LT1 Engine Build - Pull! Part 1

Mark checked the main saddles, crank, and bearings for proper dimensions and does a mock-up before final assembly. Mocking up a block makes more sense than to discover you have bigger problems later on. Mark had to notch the block some more to clear the rod bolts.

The bearings were installed bone-dry to ensure security, with absolutely no lubrication between the bearings and the block. Mark checked the oil holes for proper alignment. The bearings are lubricated with engine assembly lube when the crank is installed.

Main cap bolts were lubricated, installed, and torqued to 65-75 ft-lb for a main-bearing check. Mark later decided to go with ARP main studs instead of bolts for a more rigid package down under.

Mark checked crank main bearing clearances with a dial-bore gauge and micrometer...

...General rule of thumb is .002-.0035 inch for street use and .0025-.0037 inch for high-performance use...

...Mark opted for .0025-.0037 inch and carefully documented these numbers.

Before the crank was installed, Mark lubed and installed the COMP Cams 07-000-8 hydraulic- roller camshaft. Because this is a roller cam, the lobes and journals get the same engine-assembly lube...

...Check out the LT1-unique cam sprocket and chain package designed for the cam-driven water pump and Optispark ignition.

Mark gave both ends of the 4340 crank a whack to center the thrust bearing before torquing the main caps. Torque is 65-75 ft-lb. Begin at the center cap and torque in thirds-- first 25 ft-lb, then 45, then the maximum...

...Go back and check your work, marking each cap with a marker when torquing is complete.

Crankshaft endplay was checked next. Endplay should be between .004 and .007 inch.

Before we installed the pistons and rods, bore sizing was double-checked. Mark never trusts machine-shop work at face value...

...He checks --plus he rechecks his own work--twice.

Rods were fitted with bearings and bearing clearances were checked before pistons and rods were installed...

...Because rod journals run considerably hotter than main journals, clearances tend to run looser at .0017-.003 inch for street and .002-.003 inch for high-performance use.

Mark checked the ring end gap for proper clearance. Then he tailored the edges for smooth operation...

...There are two ways to install piston rings. You can roll the rings on like this or use a ring expander...

...We suggest the ring expander for best results. There's less ring distortion that way.

After Mark coated the cylinder wall and rings with 30-weight engine oil, he used this groovy billet piston ring compressor to install the piston and rod. You don't want much oil behind the rings. This causes carbon buildup behind the ring when the engine is fired. Just bathe the rings in engine oil before they're installed. That's plenty. If you are running a stock rod, remember to cover the rod bolts with rod bolt condoms to protect the cylinder wall and rod journal. It takes very little pressure to damage these surfaces.

In this 383ci stroker application, we have capscrews instead of conventional press-in rod bolts. Our 3/8-inch capscrews are much stronger and torqued to 45 ft-lb.

Mark slowly rotated the crank with one piston/ rod installed to check block clearances. You need to have a minimum of .050-inch between the rod bolt and the block. Our LT4 short-block is assembled and ready for completion. Next time, we're going to do some port work on the LT4 heads for remarkable gains in flow. Then we'll finish engine assembly and spin this guy on the dyno. We're going to show you what kind of power can be made from your own LT1 small-block on the Westech dyno.