THE GREAT CRATE EXCHANGE
All the little details for dropping in a new engine
All the little details for dropping in a new engine
An engine swap is likely the most time-honored process within the art of car building. Our grandfathers likely struggled through it using a ratcheting come-along hung from a tree branch or a hastily welded A-frame that could have doubled as a kid’s swing set. Today, we have better and more sophisticated tools to do the job, but it still requires some prior planning if the swap is to go smoothly. As with any other mechanical effort, a little preplanning can make the job much less frustrating. We’ll show you what we’ve learned and offer a few details.
In our case, we were yanking a tired 383 out of our 1964 El Camino that was suffering from a chronic case of GCS—Gigantic Cam Syndrome—a muddled combination of an overly long duration cam hampered with low static compression. It idled poorly, was generally unresponsive to tuning, and demanded a fat air/fuel ratio to run properly. Basically, as a parts-chaser and cruiser, the engine was underwhelming and no fun to drive. This left us with a choice. We could pull the engine, change the cam, and do something about the compression or just slide in a brand-new Chevrolet Goodwrench crate engine that had a warranty. The new engine offered greater promise and less hassle.
The Goodwrench engine we chose is the standard, two-piece rear main seal version that is both the least expensive yet most popular crate engine that Chevy offers. With 8.5:1 compression, this 350ci will run on 87-octane all day long with cam specs at 194/202-degrees of duration and 0.390/0.410-inch valve lift. Our sister book Hot Rod tested one of these with long-tube headers and a Q-jet and made 249 hp, which is impressive since Chevy rates this engine at 195 hp. With castiron exhaust manifolds, likely we’ll be making around 225 hp. For this application, it’s more than enough
when all we want to do is pick up bolts at the hardware store.
We’ve probably muscled through this ’60’s muscle car engine swap a couple of dozen times yet each one is always a little different. At first we didn’t anticipate many hiccups but from the beginning, little things promised to offer resistance. We’ve outlined most of them here that you can use as guideposts for your next engine swap effort.
One little thing that promised to trip us up right out of the box is these Goodwrench engines come with provisions for dipsticks on both sides of the block. A plastic bag containing two balancer timing tabs and two small steel plugs accompanies the engine. Choose the dipstick style you want to run and use the appropriate steel plug to seal the block on the opposite side. The block comes with little plastic plugs that are not intended to last long-term and will eventually leak badly, especially the one down by the starter motor on the right side. So make sure to plug the dipstick hole you did not use. If you forget, don’t blame us when it starts puking oil.
Once we had unboxed and painted the engine Chevy Orange, we realized that while some parts like the V-belt pulleys and accessory drive would swap over from our
previous engine, we needed a pile of new parts to complete this project. For example, the Goodwrench engine doesn’t come with an intake manifold and the old small-block ran Vortec heads. This meant we had to find a new intake. Plus, the 383 is an externally balanced engine so we would not be able to use either the harmonic balancer or the flexplate.
We quickly decided to assemble a list of parts that should make this swap go a little smoother. It’s really frustrating to have to stop in the midst of a project because you lack the right parts. It’s better to plan the event through as many details as possible. Our list quickly grew nearly book length, which reinforces how many small parts are required to complete even a simple engine R&R.
For example, we originally planned to retain the radiator, but closer inspection revealed a minor leak had begun near the top of the core, which demanded a replacement. Summit offers a bolt-in aluminum, three-row radiator for our early A-body so we put in an order and it literally showed up in two days. We also needed other small, yet important items like new heater hose, nipples, and clamps as the old
ones were too abused to include on a new engine.
With the old engine out, this is a great time to replace the motor mounts if they are weak. The TH350 we planned to use needed adapter fittings for the cooler lines to allow us to use -6 AN hose between the transmission and the radiator. We’ve included those part numbers as well. If you really want to get down to the little details, you might also need a length of 1/8-inch vacuum hose to connect between straight manifold vacuum and the vacuum modulator.
Since the intake manifold would not transfer, the best deal was one of Summit’s intake manifold packages with an aluminum dual-plane intake, one of Summit’s annular discharge 600-cfm carburetors, gaskets, bolts, and RTV. We’ve included the kit as well as the separate part numbers for the intake and carburetor. The carb is not a traditional 4150 style Holley, but in previous testing it ran great on the dyno because of its
annular discharge boosters. It uses many traditional Holley parts like jets and the accelerator pump diaphragm so tuning it shouldn’t be a problem.
The distributor had to remain with the previous engine as it was destined for another project so we opted for a new HEI from Summit to fill that void. We also added new spark plugs and wires and set the initial timing at 12 degrees BTDC.
Because this is a flat tappet camshaft engine, we were concerned with proper break-in procedures. The key to proper cam survival is using high-quality break-in oil so we added five quarts of Lucas 30w Break-In oil to ensure that process would go well. Then we pressure-lubed the engine beforehand to ensure that oil pumped to all 16 rockers before installing the engine.
With all the peripherals installed, including coolant, we pre-filled the carburetor by pouring gasoline through the vent tube so the engine would start on the first crank. After the engine started, we quickly brought the rpm up to 1,500 and then varied that by 300 to 400 rpm for the first 10 minutes to make sure the lifters were constantly splashed with oil. Then we shut the engine down and allowed it to cool for a half-hour and buttoned up any remaining details and to make sure we had no leaks.
After confirming all our connections were tight and making sure the throttle linkage offered free movement, we promptly fired the new engine and immediately put it on the road to load the rings and break them in. We had a scare when the temp gauge hit 220 degrees but within a block after we turned around, the gauge dropped back to 180. It’s possible the new thermostat stuck for a moment before opening.
There are dozens of opinions on how to break-in a new engine, but piston ring engineers and professional engine builders all agree that extended idling over very light throttle running is the wrong way. Instead, they recommend applying load as soon as the engine reaches a normal operating temperature. Varied light acceleration for the first 10 minutes followed by successively higher loads is the best way. After 15 minutes of that, try a couple 75-percent throttle runs followed by a few wide-open-throttle events in a safe, legal location away from traffic.
Once we completed our break-in and drove the car for about 100 miles, we drained the break-in oil and replaced it with Lucas Hot
Rod 10w30 that has a higher zinc level and a new filter. This may not be necessary and Chevrolet doesn’t require it, we did it as a precaution to make sure the cam is fully acclimated to its lifters. After perhaps another 2,000 miles you could switch to a quality off-theshelf API oil, or continue to use high-performance oil with higher zinc levels.
Overall, our simple engine swap was a complete success. The new crate engine runs smooth and makes exactly the power that we thought it would but is docile and more fun to drive now than our old, balky smallblock. The new engine will deliver tens of thousands of reliable miles, which is exactly what we need for our parts chaser. What made the swap much easier was creating a checklist of what we needed. And now you have the list too. CHP
01 | Bolting in a new crate engine isn’t difficult, but it helps to have all the parts and tools. The more prepared you are ahead of time, the less aggravation will occur.
02 | Here’s our Goodwrench 350 after we removed it from the crate. It showed up at our shop door with no drama, shipped through Summit at no charge. With headers and a four-barrel induction, this engine will make almost 250 hp, which is plenty of power for the daily driver it’s going in.
03 | We yanked the old engine (left) but realized that many of the parts would not transfer to the new engine. The old engine was an externally balanced 383 with Vortec heads.
04 | We installed a new Dorman balancer using a simple press-on tool from Summit Racing. We always coat the inside of the balancer and the installer threads with antiseize to prevent damage.
05 | Note how the stock valve cover(right) interferes with the intake manifold. The covers can be trimmed to produce the clearance. Instead, we chose a set of cast-aluminum covers that are relieved on the inboard side (left) to clear the intake.
06 | The starter motor stayed with the previous engine so we picked up a replacement from Summit. We chose a 168-tooth flexplate so that requires the starter motor with the offset bolt holes. The smaller, 153-tooth flexplates use the starter with the inline bolt holes. 07 | This photo shows the little plastic plug that blocks the stock dipstick hole on the passenger side of the engine.The engine comes with a steel plug that must be driven into place with a hammer. We used the original dipstick position on the left side of the engine.
08 | We’re using an inexpensive pressure lube tool from Summit but you can make one using an old Chevy distributor. Just remove the gear and shaft, cut off the top of the shaft so it will fit into a 1/2-inch drill motor. Then fill the pan with oil, spin the drive clockwise until oil squirts out of all 16 pushrods onto the rockers. This might take 5 minutes or more.
09 | We pre-filled the Fram oil filter with Lucas 30w Break-In oil and put the remaining 5 quarts in the engine.
10 | The old radiator had been thoroughly abused, was leaking, and had significant fin damage so we replaced it with a direct-fit, threecore aluminum Summit radiator. We filled it with a fresh 50/50 mix of antifreeze and filtered water to ensure proper anticorrosion protection.
11 | The Goodwrench engine comes with two different bolt-on timing tabs intended for either a 7- or 8-inch balancer. We used the tab for the larger balancer and set the initial timing at 12 degrees BTDC.