L89 427 Big Block Engine Build - Build It Right The First Time

Now each piston is brought up to TDC and the distance from deck to the piston is measured with a dial indicator. We found our pistons were 0.0010 down in the hole, which some builders would run. Speed-O-Motive likes to put the race engines at a zero deck. We asked Jeffrey Strech shop foreman/lead cylinder head/engine designer to explain the benefits of the zero deck and here is what he said. "We set this motor to a zero deck height because it will provide us with the optimum quench distance of 0.040. So when the piston comes up to TDC the quench area, or flat area of the piston and head, compresses the air fuel mixture and sends it at high velocity throughout the combustion chamber. This movement tends to cool hot spots, suppress detonation and increase power."

All the components were removed from the block and it was chucked into one of Speed-O-Motive's machines to shave off 0.0010 from the block. After the machining process was done, the block was put into a heated parts washer to remove any metal shavings or dirt. Then Chuck put the crank and the rest of the rotating assembly together for good.

Now its time for the valvetrain. Chuck coated our Big Mutha' Thumpr cam we got from Comp with assembly lube...

...and carefully slipped it into the block. Then he spun the cam to see if it turns nice and easy, which it did. If there is a hard spot in the rotation then there is an issue with either the cam being bent, the cam journals not in line or the cam bearings.

Now Chuck installs Comp's full billet timing chain straight up for now. The crank sprocket has 9 different keyways for 2-degree incremental adjustability, 8-degree maximum advance/retard of the cam.

Now with a degree wheel on the crank, a dial indicator on the piston, and one on the lifter he degrees the camshaft. The purpose of degreeing a camshaft is to ensure that it is phased correctly with the crank. Cam degreeing is a full story on its own and not something we can explain in one caption. Comp offers a full degreeing kit that has a DVD dedicated to this process if you really want to know the full story.

Another good reason to have a professional shop blueprint your engine is it will have all the little things that are usually forgotten, like these locating pins for the heads. Try finding a set of those on a late night in your garage.

Now we moved onto the heads that were preassembled by Dart. We provided our cam specs when ordering so we already have the right springs keepers and retainers. Still to be safe things need to be checked like seat pressure and coil bind. Jeff removed one spring and replaced it with this gauge. This will tell us the installed height.

With that information and the lift of the cam Jeff compressed the spring to the install height measurement. Then the scale below his tool tells him the seat pressure, which is 150 pounds. Then he compresses the spring to full lift to check to make sure the spring is not coil binding. We still had some clearance between the coils so we are good to go. As with all blueprinting jobs Jeff checked each valve.

When bolting on a head you want to use a good moly lube like the one ARP supplies with its bolts. Put it on the threads and on the flange of the bolt and the washer to minimize friction at these points and provide a more consistent torque setting.

Now Chuck checks the camshaft endplay, which is the distance the cam can move fore and aft. One danger with significant cam endplay is the possibility of a roller lifter contacting an adjoining lobe. With the front timing cover installed Chuck moved the cam back until it stopped and forward until it stopped and wrote down this measurement.

The spec is to keep camshaft movement to around 0.005-0.010 inch. Knowing the distance he had Chuck grabbed this roller-bearing cam button. This style button uses an internal roller bearing that does not wear into the timing-chain cover and has small shims that will allow us to set the endplay within spec. Chuck stated that our flimsy stock timing chain cover would deflect a bit. We'll need to buy a water pump that has an adjustable stop on the back to counter act this issue without having to reset the endplay if we changed to a different cover.

Now its time to figure out pushrod length by first installing the lifters, studs and guide plates.

Because there are so many variations in deck heights and head designs there is no standard pushrod length when you are working with aftermarket stuff.

Now Chuck grabbed a handful of assorted length 3/8-inch pushrods and installed the very cool Ultra Pro Magnum rocker arms from Comp. The pushrod length determines where the tip of the rocker arm hits the tip of the valve. Ideally you want it to fall just above center because when the arm starts to push down on the valve it move forward just slightly. After swapping in a few different sets Chuck had the right sizes, 7.900-inch for the intake and 8.800 for the exhaust.

Some blue marking compound on the tip of the valve will show you exactly where the contact patch is. As you can see Chuck got us perfect. Some companies offer an adjustable pushrod so you don't need and assortment. Just put it in, adjust it to the right length, and then measure so you know what lengths to order.

It's time to seal up the bottom end. After an oil pump rod was dropped in the hole, Chuck mounted up our billet spur gear oil pump from Moroso. This monster is a standard volume pump made form a 061-T6 billet housing with three times larger mounting boss area to prevent breaking and it weights 1 pound less than stock oil pump with pick-up.

Chuck put a blob of clay into a small bag and set it right on top of the oil pump. Then he installed the Moroso pan with gasket to make sure the pick up was the proper distance from the floor of the pan.

The pan will crush the clay and show you exactly the distance you have. Basically, you don't want the oil pump to be touching the floor of the pan nor do you want it to be more than a 1/2-inch away. We were a little under the 1/2-inch spec so we reinstalled the pan for good. With that, the long block was complete and ready for phase two. We'll go into more detail about our recipe, how to install things like an intake and ignition system, properly break in the motor and how to make adjustments for max power next month.