Step by Step: Assemble the Short Block
Step-01: Inspect the Block
Last-minute detailing is done on the block mating surfaces. A razor blade is used to debunk deck surfaces contaminated with paint and rust. Close inspection of the coolant and oil passages is good measure prior to assembly.
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Step-02: It’s Ready for Assembly
The small-block Ford has five main bearings, with the thrust bearing at the number-3 journal. Small-block Chevrolets, by contrast, have the thrust bearing at the number-5 rear main bearing. Obviously, the main caps will have to be removed to install the crankshaft.
Step-03: Install Oil Galley and Freeze Plugs (Important!)
Screw-in oil galley plugs are installed at this time prior to block assembly. We do these first to avoid any chance of forgetting. Teflon sealer or Permatex is used on these plugs to ensure a tight seal. There are three plugs at the front of the block behind the timing set. Freeze plugs also go in using silicone sealer around the perimeters. Don’t forget the oil galley plug at the top of the block. There is no need for sealer here; just score the edges for security.
Step-04: Wash the Cam
The camshaft should be installed first because the crankshaft tends to get in the way of easy installation. Wash the cam thoroughly in solvent to remove all machining debris.
Step-05: Lubricate the Cam Lobes (Important!)
When you are installing a conventional flat-tappet camshaft, you need to use two different types of lubrication. The journals get engineassembly lube. The lobes get the molybdenum grease shown here. Do not get the molybdenum on the journals.
Step-06: Install the Cam
The camshaft is carefully inserted into the cam alley, taking extra care to ensure that the journals are not nicked by the lobes.
Step-07: Install the Thrust Plate
The camshaft thrust plate is installed next using Loctite on the bolt threads for security. The oil passages on the thrust plate face the camshaft.
Step-08: Bearings into Caps
Main bearing halves are seated in the main caps. Bearings are installed in the caps dry, with no lubrication between the bearing and cap. Note proper positioning of the bearing tang or tab, which retains the bearing.
Step-09: Remove Rope Seal Pin
Originally, older small-block Fords had rope seals for rear main seals. Those old rope seals were retained with this pin. Replacement rubber seals don’t need this pin. Unless you’re using rope seals (which is not recommended), remove this pin. This pin will distort the rubber seal and cause an oil leak.
Step-10: Thrust Bearing into Cap
The main thrust bearing (number-3 saddle) is installed as shown in the main cap. This is called the thrust bearing because it keeps the crankshaft from “thrusting” fore or aft. It keeps the crankshaft centered in the block.
Step-11: Bearings into Block Thrust
Main bearing halves are installed in the block next. As with the main caps, bearings go in dry for a firm grip.
Step-12: Thrust Bearing into Block
This is the thrust main bearing installed. Note the proper location of oil passages.
Step-13: Install Rear Main Seal (Professional Mechanic Tip)
The rear main seal is next – installed as shown. Use a light film of silicone sealer between the seal and block. Don’t use too much sealer – just a light touch. Note how the seal lip faces. It must be on the inside to ensure a positive seal. The seal tab should be outside. Jim Grubbs Motorsports positions the seal gaps away from the main cap gaps, which prevents leakage.
Step-14: Lubricate the Rear Main Seal
The rear main seal gets liberal doses of engine oil or engine assembly lube. Put a dab of silicone sealer at the seal gaps before crank and bearing-cap installation. Don’t forget to use plenty of engine assembly lube on all main bearing surfaces.
Step-15: Set the Crank in Place
The 1M 2.87-inch stroke cast-iron crankshaft is lowered into place.
Step-16: Prevent Leaks
Silicone sealer is used here at the rear main seal gaps to prevent leakage.
Step-17: Lubricate the Main Threads
Main bolt threads should be lubricated with engine oil to ensure an accurate torque reading.
Step-18: Install the Caps
Main bearings are lubricated with engine assembly lube and the caps installed as shown. Hand-tighten each cap, then snug with a socket wrench until the cap seats with the block.
Step-19: Install the Rear Main
The rear main cap (number-5) is carefully seated in place. This one needs extra caution to ensure rear main seal security and smooth operation.
Step-20: Torque the Main Caps
Main bearing cap bolts are torqued in third values – meaning they are torqued to one-third their full torque valve, then another third, then the full amount, which is 60 to 70 ft-lbs.
Step-21: Check End-Play
Crankshaft end-play should be .004 to .008 inch, checked with a dial-indicator (not shown here).
Step-22: Install the Timing Set
The timing set is installed by sliding both sprockets and the chain on as a set. Timing marks in each of the sprockets are aligned at 12 and 6 o’clock to confirm proper valve timing.
Step-23: Install the Pump Eccentric
For small-block Fords equipped with a mechanical fuel pump and carburetor, you’ll have to install a fuel pump eccentric. Torque the bolt to 40 to 45 ft-lbs.
Step-24: Check Ring End Gaps
Compression-ring end gaps should always be checked, even when you have pre-gapped piston rings. End gap should be .010 to .020 inch on both rings.
Step-25: Second Ring
Compression rings differ from each other based on the conditions they face. The top ring is exposed to more heat than the second ring. This is the second ring, identified with a dot.
Step-26: Top Rings
The top compression ring is identified by the word “TOP” as shown. This varies from ring manufacturer to ring manufacturer. Check your instructions and the packaging for specifics.
Step-27: Install the Expander
Oil ring installation begins with the expander. Ends must meet as shown and not be overlapped.
Step-28: Install the Oil Rings
Walk each of the oil rings onto the piston as shown. Position the end gaps 180 degrees opposite one another.
Step-29: Install the Compression Rings
The compression rings are installed next. Begin with the second ring, then the top ring. Make sure each ring is right-side up. You may roll the rings onto the piston by locking one end of the ring in the groove and walking the ring around into place. Take extra care not to scratch the ring lands. Here we’re using a piston ring expander to install the ring.
Step-30: Remove the Rod Nuts
All connecting-rod nuts are removed at this time. Do not remove the cap until it is time to install the piston and rod. This minimizes the risk of mixing up the rod caps, which are each matched to their rod.
Step-31: Lubricate Bearings and Bolts
Lubricate the connecting rod bearing with assembly lube. Put a thin film of engine oil on the rod bolts.
Step-32: Lubricate the Cylinder Walls
Cylinder walls get either a lightweight assembly lube or 30-weight engine oil. Coat the walls with liberal amounts of lubrication.
Step-33: Cover Your Rod Bolts
Since you don’t want to nick cylinder walls or crankshaft journals, the rod bolts need to be covered with some sort of protection. Rod-bolt condoms prevent cylinder wall or crank journal nickage. Damage the crankshaft journal or cylinder wall and you can expect unnecessary time and expense machining out the damage.
Step-34: Install the Pistons & Rods
Piston-ring compressors vary in design. Seasoned builders use billet compressors that are bore-size specific, but adjustable ring compressors are cheap, easy to use, and perfect for the hobbyist. With the piston in the bore, guide the rod to the journal and carefully seat it in place. Hand-snug the rod nuts.
Step-35: Torque the Rod Bolts (Torque Fasteners)
Torque 5/16-inch rod bolts to 19 to 24 ft-lbs. When you are working with 3/8-inch rod bolts, torque them to 40 to 45 ft-lbs. Remember to use lubrication on these bolts prior to torquing.
Step-36: Degree the Cam (Professional Mechanic Tip)
It’s time to degree the short block. We degree an engine because we want to determine both valve and piston timing events. Using the information provided by the cam card, we determine valve timing events by running the crankshaft two full revolutions. With a top-dead-center indicator (a dial indicator), we determine true piston location. This helps us determine compression height.
Step-37: Check the Stroke
With the pistons and rods installed, we can confirm the 289’s short 2.87-inch stroke. The 302 has a 3.00-inch stroke. The taller-deck 351W and 351C have a 3.50-inch stroke.
Written by George Reid and Republished with Permission of CarTech Inc
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