This is the stage in the rebuilding process at which your Y-block gains a new lease on life. During the machining process, you’re truing all surfaces and components, so it functions like a factory-new engine. Allow me to impart the mantra of master machinist Gil Jordan to begin this chapter on machine work. It is simple and to the point. “Flat is flat, straight is straight, and round is round.” To rebuild an engine that provides years of service you have to pay careful attention to detail, clean and prepare properly, contract professional machine work, choose a combination of quality parts that work in concert with one another, and carefully follow proper assembly procedures.
This Tech Tip is From the Full Book, 4.6L & 5.4L FORD ENGINES: HOW TO REBUILD. For a comprehensive guide on this entire subject you can visit this link:
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It has always been a little harder to find high-quality parts for Ford engines, perhaps with the exception of the modern small-block V-8. Therefore, before you start rebuilding, you must find a reliable source of the correct parts. The availability of parts for the Y-block V-8 has increased tenfold. With the increased demand for these engines comes a renewed aftermarket interest in the manufacture of dedicated performance parts.
I can almost guarantee that if you inquired about the most common replacement parts for your Y-block engine in your average chain auto parts store, you would be met with a blank stare from the eighteen-yearold behind the computer. I look for an old-time, established parts store, where I am more likely to encounter employees with years of experience, a willingness to help, and access to actual parts catalogs, not just a computerized inventory.
Connecting rod reconditioning consists of resizing the big ends (crankshaft end) to make them concentric, replacing the bushings in the small ends (piston end) to remove any play created by years of wear, and the replacement of hardware (rod bolts and nuts).
Connecting Rod Installation
Here’s a tip: I have chosen to replace the OEM five-decades-old connecting rod bolts with stronger, more modern hardware from ARP in both of the engines. Taking into account that these engines are more than 50 years old and have experienced the stresses of normal use and countless cycles of heating and cooling, replacing the connecting rod bolts in a Y-block rebuild falls into the category of inexpensive insurance.
Step 1: Remove Burrs on Rods
The original bolts have been removed in preparation for resizing. Use a flat file to go over the connecting rods and remove any burrs from the cap and rod. If the connecting rod has any burrs on its machined areas, there could be a mismatch between the rod cap and rod.
Step 2: Grind Faces
Have a machine shop perform this procedure. A Sunnen cap-grinding machine corrects the faces of the mating surfaces of the connecting rods and caps. This process removes a couple of thousandths of material so that a flat surface between the rod and cap is attained.
Step 3: Remove Burrs on Caps
Use a flat file to remove any burrs or sharp edges after the caps and rods have been refaced. Be careful not to mar or damage any of the freshly machined surfaces. Install the bearing when the engine is reassembled.
The small-block Chevy V-8 connecting rod (top) is compared to the Ford Y-block’s connecting rod (bottom). The Chevy rod is broach-cut to accommodate its bolts while the Y-block rod is spot-faced, leaving more material for greater strength.
Step 4: Use Parts Washer
Step 5: Face Rods
Face the sides of the connecting rods on a head-resurfacing machine. Once again, it is just to remove burrs and sharp edges. Very little material is removed during this process since the purpose is simply to smooth the surface of the rod.
Step 6: Verify Rod Bolt Length
The 292 (EBU forging) and 312 (ECG forging) connecting rods are different lengths. The 292s measure 6.324 inches while the 312s are 6.252 inches and use different-length bolts. According to ARP, the correct bolt for the 239- to 292-ci engine is ARP PN 154-6005, while the correct bolt for the 312 is PN 154-6004. Some folks believe that the 292 truck connecting rod (C1TE forging) is stronger than the passenger car forging. If, for any reason, you are thinking of using the truck connecting rod, please note that they are the same length as the 312 rod at 6.252 inches.
Step 7: Install Rod Bolts (Important!)
Secure the connecting rods in this fixture in a press to install the rod bolts. Use a brass drift to install the ARP rod bolts. It is important to ensure that each bolt goes into the connecting rod straight and that it seats fully against the spot face. If, for any reason, the bolt does not fit tight in the connecting rod, the rod should be replaced.
Step 8: Torque Bolts
You absolutely must read the ARP instructions that come with rod bolts. If you have prior experience with this brand of bolt you know that three torque sequences are no longer required to pre stretch the bolts. Torque the bolts one time for proper stretch. Also note that when using the included ARP lubricant, torque values other than OEM specification are listed.
Step 9: Torque Bolts (continued)
Tighten the ARP connecting rod bolts to the recommended torque value to prestretch them. A stretch gauge is not required, and these particular ARP bolts require just one torque application on their bolts.
Step 10: Inspect Connecting Rod
Big End Preparation
Step 1: Set Tolerance
Step 2: Resize Ends
Small End Preparation
Step 1 : Inspect Small Ends
As part of the reconditioning of the connecting rods, the bushings in the small ends will be replaced. Note that the bushing and rod both have an oil hole drilled in them. These holes must line up. If they are not properly aligned, the wrist pin does not receive adequate lubrication, and catastrophic failure could result.
Step 2: Insert in Vise
Step 3: Remove Old Bushing
With the connecting rod secured in a vise, use a hammer and driver to carefully remove the old bushing. The technique is to place the pick as close to the joint in the bushing as possible and then drive against it with the hammer to force the bushing from the rod. Before proceeding, the connecting rod receives yet another close visual and tactile inspection for burrs.
Step 4: Choose New Bushing
Step 5: Install New Bushing
Lubricate the bushings with 30-weight oil and align the bushing on the edge of the bores. Use the soft-jawed vise to press the new bushing into the rod. The chamfered side of the bushing then goes up against the chamfered side of the connecting rod. Pay careful attention to the alignment of the oil hole in the bushing relative to the oil hole in the connecting rod.
Step 6: Verify Oil Hole Alignment
With the new bushing installed, visually check the small end of the rod to ensure proper oil hole alignment. Ensuring that the oil holes in the bushing and connecting rod are properly aligned is critical for proper lubrication of the wrist pin.
Step 7: Burnish Bushing
Step 8: Resize Rod
This fixture on the Sunnen connecting rod resizing machine is used to hone the inside diameter of the newly installed bushing to proper tolerance. The honing stones remove small amounts of material until the desired dimension has been achieved. When finished, there is a small clearance between the bushing and the wrist pin (which connects the piston to the rod) to allow for lubrication.
Step 9: Verify Inside Diameter
It is time for balancing when the crankshaft is clean and has been checked for cracks, the rod and main bearing journals have been either machined undersize or polished, and all of them thoroughly cleaned again. As it relates to automotive applications, balancing refers to equalizing the weights of reciprocating and rotating components.
Reciprocating weight is the force each piston and connecting rod exerts on the crankshaft as they move up and down. To determine reciprocating weight the individual weight in grams of the pistons, wrist pins, wrist pin locks, piston rings, and small ends of the connecting rods are determined and added together. The big end of the connecting rods is not part of the sum of reciprocating weight. The big- and small-end weights of the connecting rods are determined separately.
This is achieved through the use of a special fixture. Placing each connecting rod in this fixture eliminates the small end of the rod from the indicated weight. Once the big ends of the connecting rods have been weighed each is machined by removing material from the pad on the bottom of the rod cap so that all match the weight of the lightest rod.
Next, small-end weight is determined and, again, each is matched to the lightest rod by machining material off the pad at the top of the small end of the rod. This weight is then added to the total reciprocating weight total.
Rotating weight refers to the centrifugal forces exerted on the crankshaft from the mass of the big ends of the connecting rods and rod bearings as it spins. To calculate the rotating weight (in grams) add the weight of the big ends of the connecting rods to the weight of the connecting rod. The reciprocating weight and rotating weight are used to create the bobweight.
To determine bobweight, 50 percent of the reciprocating mass is added to 100 percent of the rotating mass. The crankshaft, with its balancer attached, is then mounted in a balancing machine fitted with a magnetic probe attached to the balancer at the centerline of the crankshaft. Bobweights are then assembled and clamped to all four connecting rod journals of the crankshaft. The crankshaft is test spun by hand. Then the flywheel is fitted to the crankshaft, and the balancing machine is activated. A digital readout indicates where weight should be added or removed from the crankshaft to achieve balance.
Rotating Assembly Balancing
Step 1: Weigh Rotating Assembly (Documentation Required)
Use a gram scale to accurately weigh the components of the rotating assembly as part of the balancing process and then record the weights. The recorded component weights will be used to determine where material should be removed to achieve the closest possible balance between components.
Step 2: Weigh Wrist Pin
Step 3: Weigh Ring Set
Sep 4: Weigh Pistons
Weigh the pistons (without wrist pins). The custom-made forged-aluminum pistons from Race-Tec for my high-performance engine build weighed exactly the same across the board. This is a testament to the quality of the product and attention to detail by the manufacturer.
These Sealed Power .040 oversize replacement pistons are for my stock engine rebuild. All pistons weighed within 2 grams of one another. Matching the heaviest pistons with the lightest of the 292 connecting rods easily compensates for the difference in weight. The decision to bore the 292 block .040 oversize was based on the machinist’s evaluation of the cylinder walls. The advice of a professional machinist is invaluable and should be sought when making such decisions. Failure to do so may result in you buying unnecessary parts.
Step 5: Weigh Big Ends
Step 6: Grind Rod Cap
Once the rod with the lightest big-end weight has been determined, the other connecting rods must match that weight. To do that grind small amounts of material from the pad of each connecting rod cap until the weights are equal.
Step 7: Record Total Weight
Step 8: Make Weight Adjustments
Any discrepancies in the weight of the connecting rods after the big-end weights have been equaled is compensated for by removing small amounts of material from the end of each rod until all match in weight.
Dynamic balancing refers to a process in which the crankshaft is fitted into a specialized machine and spun to determine if the counterweights are in harmony with one another and within factory specification for balance. A crankshaft that is out of balance causes premature main bearing wear; in a worst-case scenario, it will cause a detectable vibration in a running engine.
Step 1: Insert New Pilot Bushing
Before the dynamic balancing process begins for a manual-transmission car or truck, the crankshaft must have a new pilot bushing. In a pinch, I have used a large 1/2-inch-drive socket and a hammer as a pilot-bushing driver. The important thing here is to drive the bushing in straight and make sure it is fully seated in the crankshaft.
The driver must match the diameter of the pilot bushing. Use a substantial hammer to seat the pilot bushing into the back of the crankshaft. Make sure that the bushing is properly aligned with the opening in the crankshaft before driving it in.
Step 2: Install Bobweight
Based on previous calculations, affix the bobweights to the crankshaft, which is mounted in a balancing machine so it can be spun. Properly balancing the rotating assembly eliminates annoying and potentially damaging vibrations when the engine is running.
Step 3: Install Flywheel
Step 4: Install Balancer
Step 5: Install Rotating Assembly
Step 6: Add or Remove Weight
This digital readout on the crank balancing machine tells the operator where weight needs to be added or removed from the rotating assembly to bring it within balance. You add or remove weight from the large counterweights of the crankshaft until the ideal balance is achieved.
Step 7: Add or Remove Weight (continued)
Step 8: Inspect Balancer
You must measure the block’s critical dimensions to determine if it is within the tolerances recommended by the manufacturer. Usually an old or worn Y-block needs machining to bring it back to prime operating condition. You should take detailed measurements of all of the block’s critical areas before you start the machining process.
Deck Surface Squaring
You are performing a professional-caliber engine rebuild and, therefore, all deck surfaces need to be flat and square. If the deck surfaces are not square, the heads aren’t effective against the block, cylinder pressure drops, and performance degrades. Most likely you will notice oil seeping between the heads and the deck surface, and it appears as if the engine has a blown gasket. At this stage, several important machining processes are required so that deck surfaces are square.
Step 1: Inspect Block Surface (Critical Inspection)
If you used the simple but effective straightedge method to determine that the deck surfaces of the block are not completely flat, set it up in a machine for resurfacing. This process ensures that the decks are level and also removes the slight rust and pitting to allow the head gaskets to seal more effectively.
Step 2: Measure Deck Surface
The resurfacing machine has a dial indicator that accurately tracks the amount of material to be removed. You may need to remove only a few thousandths of an inch to true the deck surfaces. If more than a few thousandths of material is taken off, the head is closer to the centerline of the crank, the TDC of the piston is higher, the bore and the compression ratio increases, and valvetrain geometry (the angle between the pushrods, rocker arms, and valvestems) changes. All of these dimensions are interrelated, and when one changes, it changes another.
Step 3: Check for High Spots
Step 4: Remove Material
You can easily see the high spots once the resurfacing machine has made its first pass over the deck surface of the block. An additional cut makes it level and provides the desired smooth surface for gasket sealing.
Step 5: Inspect Level Surface
If the cylinder bores remain concentric and show no excessive taper, you may be able to get away with just honing them. Keep in mind that during the honing process, material is being removed from the cylinder walls, and this may take the bore beyond tolerance. In other words, if in doubt, opt to bore the cylinders. Any high-mileage engine greatly benefits from boring, as this restores the cylinders to a concentric shape and improves their alignment relative to one another.
Once you have decided to bore the block, you must decide how much oversize you need to go. As a general rule you want to bore the cylinders as little oversize as possible. A big consideration when boring a Y-block Ford engine is the availability of oversize pistons and rings. Staying within the dimensions of available replacement parts saves a considerable amount of money in piston costs and hours of work required to hand-fit piston rings. It is also critical that the deck surfaces of the cylinder block are flat and without excessive rust or pitting. Machining the deck surfaces ensures that they are square relative to the crankshaft, and head gaskets seal better when the engine is reassembled.
Step 1: Use Boring Machine
Step 2: Inspect Overbore
The boring bar overbores this 292 block to .040 oversize. When boring the cylinders, a few thousandths of material is left. You remove this during the honing process, which provides the desired finish for sealing the piston rings to the cylinder walls.
Block Line Honing
Line boring trues the main bearing saddles and main bearing caps and larger bearings must be installed. It must be carefully checked for any misalignment. You need to pay attention to the distance between the main saddles of the cylinder block and the main bearing journals of the crankshaft. If the line bore is out of specification excessive wear to the main bearings results. Should there be any discrepancy in the line bore of the cylinder block, it is easily corrected through the use of a specialized honing tool.
When using improved main hardware (studs or ARP main cap bolts, for example), it is imperative that the cylinder block be line honed even if the line bore had previously proved to be within specification. The reason for the line hone is based on the fact that the improved main cap hardware provides superior clamping forces when torque is applied, and this alters the bore diameters.
Before the honing process begins, chamfer the tops of each bore using the honing tool attached to a drill.
Use three different honing stones, ranging from 70 to 280 grit. You achieve the final finish by using a high-plateau hone that has abrasive, impregnated bristles that remove microscopic peaks and scuffs in the cylinder walls. This final finish allows piston rings to seat immediately, resulting in better compression, oil control, and lower emissions.
During the honing process, check each cylinder periodically, both visually and with a dial bore gauge, which ensures that it remains within specification.
Cam Bearing Installation
It is imperative that the cam bearings are properly installed in the cylinder block, and that the clearance between the bearings and the camshaft journals is sufficient to allow for smooth operation. A specialized tool is used to remove the old camshaft bearings and install new ones.
Because of the critical nature of the installation, I recommend leaving this process to a qualified machinist.
Step 1: Choose Tool (Special Tool)
Dura-Bond cam bearings are widely regarded as the best choice for the Y-block Ford V-8. Machinist Gil Jordan uses this specialized tool to install the cam bearings in the cylinder block. Great care must be taken to align the oil holes in the cam bearings with the oil passages in the block. Although cam bearing installation tools are commercially available, and it is possible to install cam bearings in your home shop, you should leave this critical procedure to a professional.
Step 2: Align Oil Holes
Feed a thin metal rod through an oil passage in the block to ensure that the holes in the cam bearings have been properly aligned with the oil passages. Using a handheld light, check the proper alignment between the cam bearing holes and the oil passages in the block. You must be sure they are properly aligned, because any misalignment leads to oil starvation to the upper end of the engine. This would ultimately cause parts to wear and fail prematurely.
Step 3: Test Fit Camshaft
This die grinder and cut-off wheel constitute a specialized tool that may be required when fitting the camshaft to the cam bearings in the block. The cam bearing bores on Y-blocks typically have a slight misalignment. After the cam bearings have been installed, it is imperative to test fit the camshaft into the block. If the camshaft does not turn easily upon installation, this homemade tool offers the solution and provides more camshaft-bearing clearance.
Step 4: Remove Sharp Edges
Use an old camshaft as a tool to remove a small amount of material from the face of the cam bearings, so the new camshaft spins smoothly in its bores. Use a die grinder and cutting wheel to make diagonal cuts into the bearing journals of the old cam. The sharp edges of these cuts serve to hone material from the cam bearings when the improvised tool is placed in the block and rotated a number of times. Repeat the process until the new camshaft spins smoothly in its bores.
Step 5: Install Cam Core Plug
Note the close proximity between the cam bearing and the opening for the cam core plug at the back of the block. Do not drive the cam plug in too far when installing it in the block. Cam installation tools are not available for the Y-block, so please follow this installation procedure. With the cam bearings in the block, install a new core plug in the back of the camshaft bore. Apply Permatex sealer around the opening that retains the plug and then use a driver and hammer to install the cam plug in the block. It must align with the shoulder of the block; be careful not to drive the cam plug down in the block any farther than the surface of the shoulder. If the plug goes in too far it binds the camshaft and does not allow adequate endplay.
The cam plug is now installed. Again, it should be no deeper than flush with the shoulder of the opening. While at the back of the block, also install new threaded plugs into the oil galleries. Use thread sealer on all galley plugs.
Step 6: Apply Sealer (Professional Mechanic Tip)
Apply a thin coat of Permatex sealer around the freeze plug openings in the block. Although the interference fit between the plugs and the block is typically adequate to prevent leaks, the sealer provides extra insurance.
Step 7: Install Freeze Plug
Step 8: Add Thread Sealer to Galley Plug
Use a thin coat of thread sealer on each of the galley plugs to be installed in the block. Use a hex-head socket, as opposed to a hex key, to install them. This ensures that the plugs are tight and don’t leak.
In this book I work with two engines as well as two distinctly different sets of cylinder head castings. The first set is OEM 1957- vintage cast-iron heads that adorn the engine I chose for my stock rebuild. The second set is current state-ofthe-art high-performance aluminum castings from John Mummert. These were selected to provide maximum performance and efficiency to my 322-ci-performance Y-block engine.
The stock castings are thoroughly reconditioned; they received new valveguides, seals, valvesprings, keepers, and a three-angle valve job to ensure effective sealing. Although the aluminum cylinder heads are brand-new and ready to bolt on out of the box, they must also be checked to ensure that there are no unseen issues.
Cylinder Head and Block Preparation for Assembly
Step 1: Inspect Cylinder Head Passages
Sludge buildup often clogs the oil-feed holes in the cylinder heads, and this has contributed to the Y-block engine series’ bad reputation for reliability in some circles. Chamfering the oil holes helps to correct the problem.
Step 2: Chamfer Oil Passages
Use a die grinder to chamfer the oil passages in each cylinder head. Chamfering removes the sharp edges and sharp turns from the opening; doing so eliminates areas where debris could collect and improves oil flow. It only took five minutes to perform this important upgrade to these cylinder heads, and it was well worth it.
Step 3: Chamfer Oil Passages (continued)
The oil feed hole has been chamfered. The finished product reveals that very little material had to be removed to make an improvement in the lubrication of the top end of the engine. This procedure will pay dividends in reliability and longevity.
Step 4: Remove Bowl Area Rough Edges
It’s a good time to make a few other improvements to the cylinder heads while the die grinder is out. Begin by gently blending the bowl area under the valves and removing rough edges and any casting flash. The purpose is to improve flow, which in turn aids power and efficiency. It also removes hot spots caused by flashing and sharp edges.
Step 5: Remove Bowl Area Rough Edges (continued)
Blend the bowl areas under each intake and exhaust valve. In doing so, you are not attempting to change the cylinder heads’ original configuration, but merely seeking to improve efficiency for a better-running, longer-lasting engine.
Step 6: Remove Intake and Exhaust Port Rough Edges
This lump of casting slag is in one of the intake ports of the cylinder heads. It’s a perfect example of the type of imperfection you should take the time to remove. Slag, left over from the casting process, can cause hot spots and impede flow. In the worse-case scenario, slag can break off and damage vital engine parts.
Step 7: Smooth Ports
Just a few minutes of work with the die grinder removes the slag, and, by doing so, you eliminate potential problems that might have been created by leaving it in place. The addition of Viton positive valve seals is another modern improvement you can make to your engine. These seals replace the old Ford umbrella-type seals; they provide a better seal and are less prone to cracking because of heat.
Step 8: Turn Down Valveguide Shoulders
Step 9: Cut Casting
The installation tool for the Viton positive seals cuts the casting around the valveguide shoulders to the proper diameter to allow the installation of the seals. A machinist performs this procedure because improper use of this tool could ruin an otherwise good set of cylinder heads.
Step 10: Cut Casting (continued)
Mount the tool used for cutting the valveguide shoulders to size in a 1/2-inch drill. The teeth of the tool cut away just enough cast iron from the valveguide shoulders to allow fitting of the new seals.
Step 11: Inspect Valveguide Shoulders
Step 12: Install Valve Seals
Step 13: Confirm Clearance
Take a measurement with the Viton positive seal now installed. With a valvespring retainer installed, take a measurement from the top edge of the seal to the lower edge of the retainer. This indicates whether there is enough clearance to allow for valvespring travel because of camshaft lift. Too little clearance here, combined with a highlift camshaft, could cause valvespring bind.
Cylinder Head Resurfacing
Step 1: Inspect Cylinder Head Surface (Critical Inspection)
I discovered this slight imperfection in the surface of one of the cylinder heads, likely caused by moisture and the engine being unused for many years. I machined the faces of both cylinder heads several thousandths of an inch to remove these imperfections and any others. This process also trues up the faces of the cylinder heads, which provides for better sealing of the head gaskets.
Step 2: Level Head in Machine
Before machining the surface of a cylinder head, ensure it is level and lock it down in the machine so you achieve an accurate cut. Once the head is leveled in the machine, adjust the cutting head for the first cut.
Step 3: Measure Head Surface
Step 4: Finish Milling
Slight irregularities were still evident after .003 inch of material was removed from the surface of the cylinder head on the first cut. A second cut of .002 inch resulted in a clean, flat surface that provides good sealing for the head gaskets when the engine is assembled. A total of .005 inch was removed from the face of each cylinder head during this process. This amount of milling does not have a significant impact on compression ratio or the angle of the mating surface between the intake manifold and cylinder heads.
Step 1: Inspect Valveguides and Valveseats for Wear
Replace valveguides and valveseats in cases of excessive wear or damage. If your Y-block has more than 50,000 miles, or has been sitting for an extended period of time where moisture exists, in most cases the guides and seats need to be replaced.
Step 2: Remove Old Valveguide
Step 3: Remove Old Valveseat
Here is the cutter in action removing the old valveseat from the cylinder head. Once the old seat has been cut away, press the new seat into place and then face it.
Step 4: Install New Valveseat
Use a driver and hammer to press the new valveseat into place in the cylinder head. The next step in the process is to face the seat with cutting stones.
Step 5: Modify Valveseat Face Angles
Use these cutting tools and stones to achieve the face angles in the valveseats that provide the tight seal required to contain cylinder pressures. Give the cylinder heads a classic three-angle valve job. Cut the face of the valve at 45 degrees and cut the seats at 30 degrees above the seat. Cut a 46-degree cut where the valve contacts the seat and is 60 degrees below the seat near the bowl area. The discrepancy of 1 degree on the valve provides for positive interference where it contacts the seat. The valve and the seat have more contact at the upper/outer machined surfaces of the two, and this contact gets better as the engine runs and breaks in.
Step 6: Make Valve Seat Cuts
This shiny area shows the first angle cut into the valveseat. There are two more angles to go before the seat is finished.
Step 7: Inspect Valveseat
After being faced with the stones, the finished product is a valveseat that provides a positive seal between itself and the face of the valve. Gil Jordan does not believe in the old-school process of lapping-in the valves, which is smearing an abrasive valve-grinding compound between the valve and seat, and then using a tool to spin the valve. This process is messy, time-consuming, and forces the abrasive compound into the metal surfaces. He believes that two precision-machined surfaces do not need any further work.
Step 8: Face Contact Seats
Step 9: True Valve Ends
Step 10: Check Seat Pattern
Use a dye, such as Prussian Blue, to coat the face of the valve and then insert it into its seat in the cylinder head to determine if a proper contact pattern exists between the valve and seat. The margin shown toward the top of the valve (upper edge) reveals that the desired pattern has been achieved.
Step 11: Check Vacuum
Step 12: Clean Heads and Parts
Cylinder Head Assembly
Step 1: Check Valvespring Pressure
I installed valvesprings from a 1969 Ford 351 Windsor V-8 on the Y-block 292 heads. These 351 Windsor springs are the same size as the 292 spring, but are easier to buy and are offered in various spring pressures. These springs provide the engine builder with greater flexibility when aftermarket camshafts are used. Even if your valvesprings are new, check each one for pressure. These particular springs have 85 pounds of pressure on the seat at installed height, which is sufficient for this stock rebuild.
Step 2:Verify Valvespring Height (Critical Inspection)
Use a barrel micrometer or a dial caliper to determine valvespring height. Push the valve against its seat, then install the valvespring retainer and split locks. Measure the gap from the bottom of the retainer to the point on the cylinder head where the valvespring seats. In order to avoid spring bind on these heads I am shooting for a spring height of 1.82 inches.
Step 3: Install Valvespring Retainer
Along with the selected 351W valvesprings, I chose onepiece valvespring retainers from Liberty Performance (PN LR-2500) to replace the antiquated two-piece OEM retainers. Place the retainer on top of the valvespring and use a valvespring compressor to compress the valvespring and retainer. Compress these components until the tip of the valvestem protrudes above the retainer and then align the split locks in the grooved area of the valvestem. Once the split locks are correctly installed, release the pressure on the compressor. You can use graduated shims under each valvespring to achieve the desired assembled height.
Step 4: Coat Freeze Plug
Install the three 29/32-inch freeze plugs into the Y-block cylinder heads. The passenger-side head has a bung for the water temperature sender that takes the place of one freeze plug. Before installing the freeze plugs, apply a coat of Permatex sealer to the opening in the head.
Step 5: Install Freeze Plug
Select a driver of the correct diameter to install the freeze plug in the cylinder head. If you don’t have a set of drivers, a socket of the correct size may be substituted. The finished product is an evenly and fully seated freeze plug that does not leak under pressure.
Step 6: Inspect Cylinder Head
Here is the completely refurbished cylinder heads for the stock engine build shown from the bottom. They have been cleaned of five decades of dirt and corrosion, had new valveseats and guides installed, received a three-angle valve job, and have freshly machined head-gasket mating surfaces.
Piston and Connecting Rod Installation
Step 1: Install First Snap Ring
To hang the pistons onto the connecting rods begin by installing a snap ring in one side of the wrist pin opening in the piston. Note: If the snap ring has a beveled or rounded side, that side goes toward the wrist pin. Thoroughly lubricate the wrist pins with 30-weight motor oil at this time.
Step 2: Organize Connecting Rods
Lay out the connecting rods so that they are in proper orientation to the pistons. The stamped identifying numbers on the connecting rods face toward the outside, or oil pan rail, of the cylinder block.
Step 3: Determine Orientation
Once the proper connecting rod–to-piston orientation has been determined and the rods are laid out, mark with a Sharpie on each rod to specify the direction in which it mounts. Laying out your work in the correct order, on a clean, well-lit work surface, is the correct way to approach it.
A notch (as shown) or an arrow on the top of the piston often indicates piston orientation relative to the cylinder bore. The orientation mark faces forward in the block.
Step 4: Install Second Snap Ring
Once the pistons have been mounted on the connecting rods in the proper orientation, install the second snap ring using snap-ring pliers. Note the open end of the snap ring goes toward the bottom of the piston. This particular piston manufacturer’s explanation for orienting the snap rings this way is: “To take advantage of the largest bearing area to withstand the greater upward inertia forces.” Read the manufacturer’s instructions for their recommendations.
Written by Charles Morris and Posted with Permission of CarTechBooks