To install the Comp Cams checking...
To install the Comp Cams checking valvesprings, White Racing uses a portable valvespring compressor. These light-pressure springs allow the checking of the valvetrain geometry, pushrod clearance, and valve-to-piston clearance. These checking valvesprings will be removed before the cylinder head is final-installed on the engine.
|CHASSIS DYNO RESULTS |
| ||StockHeads: || ||EdelbrockHeads: || |
|RPM ||TQ ||HP ||TQ ||HP |
|5,400 ||253 ||261 ||280 ||287 |
|5,500 ||259 ||271 ||297 ||311 |
|5,600 ||298 ||318 ||321 ||345 |
|5,700 ||318 ||345 ||355 ||385 |
|5,800 ||336 ||371 ||388 ||428 |
|5,900 ||350 ||390 ||390 ||436 |
|6,000 ||332 ||386 ||385 ||438 |
|6,100 || || ||372 ||431 |
How To Swap Buick Heads
The father-son team of Dan and Chris White at White Racing go throughan exhaustive checklist when installing a set of Buick cylinder heads.Here are the majority of the steps they perform:
* Check for debris, and machine away burrs or casting flash
* Inspect for and fix any rough casting transitions in ports (the Edelbrock heads are CNC-machine port matched, so this was already done on the Performer RPM heads)
* Clean parts thoroughly with lacquer thinner and clean rag
* Check installation clearances
* Install checking valvesprings on one intake and exhaust valve
* Measure valvespring rate for valve-closed and max-open height
* Measure chamber volume to determine static combustion ratio
* Mock assembled cylinder head on block with head gasket and two head fasteners
* Measure valve-to-piston clearance
* Rotate crankshaft until piston is at 5 degrees after TDC
* Push down on valve until it touches piston head. Measure retainer height from the base of the valvespring seat (ex: 1.020 inch)
* Let the valve sit in its closed position and measure the height of the retainer (ex: 1.900 inch)
* Determine maximum intake valve lift by multiplying the intake lobe lift height (on your cam card) by the rocker ratio (0.312 inch x 1.6 = 0.499 inches of lift)
* Make sure there is at least 0.030 inches of retainer-to-valve seal clearance at this height
* Subtract the max valve-lift number (ex: .499 inch) from the closed valve height (ex: 1.900 - 0.499 = 1.401 inch) to get the max lift height
* Now subtract the valve-to-piston touch height from the max valve lift height to determine if you have enough clearance
* The difference in the max lift and piston-to-valve contact height should be at least 0.090 inch. If it isn't, pistons with valve reliefs will need to be installed in the engine, or the valve lift needs to be reduced.
* For the exhaust valve, rotate the crankshaft to position the piston 10 degrees before TDC and repeat the test on the exhaust valve using the process described above for the intake valve
* Install pushrods/rockers/adjuster nuts to check that the pushrod has clearance in the head's pushrod hole
* Check valvetrain geometry (that the rocker tip stays on the center of the valve tip)
* Determine the ideal pushrod length, and recheck pushrod clearance to the head
* Check that the rocker has clearance around the valvespring retainer
* Mock up the exhaust and intake manifolds with the gaskets to make sure they fit
* Install the valvecover with a gasket to check the clearance between the valvecover and the rockers
* Remove the head from engine, and inspect the block to determine the vintage
White Racing then mocked up...
White Racing then mocked up the Performer RPM cylinder head on the engine and tightened two head stud nuts (with the head gasket in place) to begin the checking procedure.
* '69 and earlier Buick blocks had an oil passage near the front that will need to be plugged with a 0.350-inch-diameter aluminum plug when using the Edelbrock heads
* Remove the rockers and checking valvesprings, and install the Edelbrock valvesprings, retainers, and locks
* Inspect the existing valvetrain (camshaft lobes, distributor drive, lifters)
* Install the head gasket with it covering the coolant holes (it can be installed two ways)
* Make sure studs or fasteners screw into the block hand tight, then apply thread sealer on the threads and final install
* Install the head on the block, and install fasteners
* Torque down the head fasteners in radial sequence from the center outward, making three or four passes until the top row of bolts are torqued to 110 lb-ft, and the bottom row to 110 lb-ft
* Install the pushrods with a dab of engine assembly lube on the tips
* Install the rockers with some engine assembly lube on the cup of the rocker
* Disassemble the rocker lock nuts/Allen screws, wipe some Moly on the threads, and reassemble
* Hand thread the rocker lock nuts on the rocker studs
* Starting at the number one cylinder, set the valvetrain preload on each valve
* Drain the old oil out of the engine
* Add some new engine oil, pour it over the lifters, cam, rockers, pushrods, and valves when adding (add an engine oil supplement for starting a brand-new engine)
* Install the exhaust gaskets and headers
* Using an engine oil pump pre-oiler, spin the oil pump until the engine has oil pressure
* Rotate the crank in 90 degree increments for 720 degrees until you see oil at all 16 rockers
* Install the intake manifold with gaskets and sealer
* Install the remaining engine components until the engine is assembled
* Install the distributor set at 30 degrees static advance (set engine at 30 BTDC and set the distributor in place with the rotor pointing at the number one cylinder post)
* Fill the coolant system with a 50/50 coolant/water mix
* Leave the radiator cap off for startup to top off the coolant system before it gets hot
* Start the engine, bring it to 3,000 rpm, top off the cooling system, and install the radiator cap
* Set the timing using a timing light to 30 degrees BTDC with the engine running
* Shut off when the engine is up to temperature
The passage where the Comp...
The passage where the Comp Cams 3/8-inch pushrods pass through the cylinder head was checked to make sure the pushrods steer clear of the cylinder head. White Racing checks this by shining a light up from the intake valley through each hole and looking for light around the pushrod throughout the full range of the motion of the rockers--it is not acceptable for the pushrod to touch the head material during the rocker motion.
When making a cylinder head...
When making a cylinder head change on an engine, it's always a good idea to check that the valvetrain geometry is properly set. This is checked by mock assembling the valvetrain with the pushrods (engine builders often use an adjustable length checking pushrod), and inspecting that the rocker tip stays on the center of the valve tip. Where the rocker tip touches the valve tip is adjusted with the pushrod length. White Racing ordered Comp Cams 3/8-inch-diameter, 9.650-inch long pushrods and they produced excellent valvetrain geometry.
White Racing has a lot of...
White Racing has a lot of experience with boosted engine packages (turbos, blowers, nitrous), so they are big on gluing the gaskets on the intake and exhaust mating surfaces. On the intake side, they apply a very light bead of Permatex Black Super Weatherstrip Adhesive to the head side of the intake gasket and position it on the head. This holds the gasket in place during the cylinder head install.
Note that the head gasket...
Note that the head gasket material covers all the cooling passages on the deck of the Buick's block--make sure you install it in this fashion to cover those holes.
Carefully lower the Edelbrock...
Carefully lower the Edelbrock heads down over the studs. In this case, the long studs on the driver side of the engine need to be put in after the cylinder head is installed to get around the master cylinder booster. Before the install, the block threads of all the studs should be wiped with thread sealer, threaded in hand-tight, then turned another quarter turn. Moly lube needs to be wiped on the nut threads of the studs before they're installed.
The heads were then torqued...
The heads were then torqued down using factory recommended sequence and torque figures: 110 lb-ft on the top fasteners, and 100 lb-ft on lower fasteners. Make two or three passes on the fasteners to sneak up on the torque setting. From here, the valvetrain was assembled on the Edelbrock heads.
In preparation for pressurizing...
In preparation for pressurizing the oiling system, the White team drained the old oil and added new oil to the engine with the intake still off the engine. White Racing does this because they like to pour oil onto the cam lobes/lifters/pushrods as they fill the engine. Once the engine is fully assembled, they spin the oil pump until oil squirts out the pushrods at the rockers, slowly rotating the crank.
The valvetrain preload was...
The valvetrain preload was then set. The big Buick V-8s have a firing order of 18436572 (same as a small-block Chevy V-8) with the number one cylinder at the front of the driver side of the engine, so the engine was set at Top Dead Center (TDC) on the number one cylinder. From here, the process of setting the valvetrain preload was begun.
To prep for installing the...
To prep for installing the intake manifold, the White Racing team likes to apply Permatex Ultra Black Silicone on the china walls (front and back) and coat the gasket with Permatex Aviation Form-a-Gasket. The intake is then set on the engine (the Buick has dowels on the back driver side and front passenger side that the intake sits in) and the china wall silicone is wiped and pushed back into the gap before the fasteners are hand started, then torqued to 25 lb-ft.
Once assembled, the engine...
Once assembled, the engine was started and brought to 3,000 rpm (varying approximately +/- 200 rpm) for 20 minutes with a bunch of fans blowing through the engine bay. You should be busy checking for leaks, making sure the engine has enough oil pressure (approximate 10 psi per 1,000 rpm, minimum of 30 psi) and setting the ignition timing advance. The total timing advance was set to 30 degrees before TDC with the engine running at 3,000 rpm.
After the startup procedure...
After the startup procedure was completed, the vehicle was backed onto White Racing's chassis dyno for some blasts through the rpm band, where it showed that the engine picked up 50 hp at the top end. Truly impressive power from a set of impressive cylinder heads.