Hemi Crate Engines

Every single crate Hemi™...        read full caption Every single crate Hemi™ is dyno’d. Every single one. In fact, Arrow Racing’s Bill Hancock notes, “The last five 528 Hemi engines we’ve run across the dyno have been within 5hp and when you are talking about 610hp you are talking about a differentiation of less than one percent! If Mopar Performance had said they wanted these engines that close, we wouldn’t have signed up for this program.”

While the one-time engine...        read full caption While the one-time engine builder would use Plastigage or maybe Vernier calipers to establish tolerances, the crate Hemis assembled at Arrow Racing are measured using tools such as this Federal DimensionAir air gauge.

Each Hemi block, whether standard...        read full caption Each Hemi block, whether standard or siamesed bore, are qualified by measuring the cylinder bores, the main journals, the rod ends, and, as shown here, the lifter bores. How precise is this gauge? It measures to the fifth decimal place in .00005-inch increments.

Trued bores are an important...        read full caption Trued bores are an important key to the repeatability of every Hemi crate engine. To gain that level of equity, every block is honed with a torque plate on the Sunnen CK-10.

The block inspection and cleaning...        read full caption The block inspection and cleaning process is standard procedure as part of the pre-qualifying process at Arrow. Notes Hancock, “We can’t afford to have a failure.“ However, if a failure occurs, the customer will never know. Nothing leaves Arrow unless it meets or exceeds the standards they have established and Mopar Performance guarantees with every Hemi crate engine.

Each internally-balanced assembly...        read full caption Each internally-balanced assembly is fitted with the appropriate amount of Mallory metal in order to gain a balanced reciprocating assembly—another exercise in making the crate Hemis the best they can be.

Many of the procedures require...        read full caption Many of the procedures require state-of-the-art tools to simply qualify the part. Here, the rod journal is checked to determine surface roughness that will promote even journal oiling and bearing compatibility. If it doesn’t meet the standard, it won’t be installed.

Larry Shepard of Mopar Performance...        read full caption Larry Shepard of Mopar Performance notes, “We’ve tried to build these engines to be street motors, not race motors. We put in a hydraulic camshaft, we aim for a 9:1 compression ratio—these are docile pieces. The dyno curve is big and flat.”

Every step along the way is...        read full caption Every step along the way is handled as if the engine were a custom build. Note the pipe plug and sealing that takes place. This ain’t no remanufactured unit.

Every step of the way is calculated....        read full caption Every step of the way is calculated. Note the correct crosshatch pattern in each cylinder bore and the painted block—painted prior to assembly!

Our own research shows that...        read full caption Our own research shows that if you were to buy the components, and install them yourself, you certainly would not be ahead financially. The crankshaft, piston, connecting rod and wrist pin, ring set and bearings are available from the Mopar Performance catalog. Shepard notes, “Most of the Hemi pieces we introduced as individual products. We would put the parts on our test mule engines. “By putting the entire crate Hemi engine together, we found that there were parts we needed, like the crankshaft key that locates the balancer. I never thought that I needed it. Bill didn’t need it ’cause he had 10,000 of them. But I went through the bill of materials and said I need to make one. So we took a part number out on it. Defining the part is easy. Then, in many cases, I call the original manufacturer and say, ‘You remember that part we canceled two years ago; I wanna make some more.’ And the crank key was such a part.”

Each connecting rod is pre-qualified...        read full caption Each connecting rod is pre-qualified by checking Rockwell hardness, its center-to-center length, and weight in grams. Then sets of eight are made up aiming for the most compatible pieces.

The volume of engines that...        read full caption The volume of engines that Arrow Racing assembles offers them the advantage of having both time saving and precision instruments to gain the very best results. Note the ABS ring grinder...

...the cylinder bore ring...        read full caption ...the cylinder bore ring locating tool for correctly placing the ring to an installed height...

...and checking of the ring...        read full caption ...and checking of the ring gap with a common gapping tool .

Arrow’s Tom Skrentner...        read full caption Arrow’s Tom Skrentner dials in the cam, using the specifications that they know will generate the most reliable power from the camshaft.

Components vary slightly depending...        read full caption Components vary slightly depending upon which crate Hemi you purchase. The most obvious difference is the 528 engine’s aluminum cylinder head. The 472 and 426 Hemi’s are fitted with the cast-iron Hemi head.

This pallet of P4876857 aluminum...        read full caption This pallet of P4876857 aluminum Hemi heads gives an indication of the volume anticipated by Mopar Performance and Arrow on the 528ci Hemi crate engine.

Hancock notes, “We’re...        read full caption Hancock notes, “We’re the development center. It is our mission—our charter—to both build these Hemi crate engines and to find fault. We are as much a quality unit as we are a development center.” Bill tried to pass off this fixture engine as a goof up: “Yep, the guys were building Wedge engines and Hemi’s side-by-side, and this is what happened!” Actually, this test fixture engine offers Hancock and the crew at Arrow Racing the use of the SpintronTM as a rotational device while a laser peers through a window on the block to measure valve operation, especially valve bounce or float. The result of this testing provides the end consumer with a reliable valve/valvespring combination that has been tested by only one of 18 such fixtures in the United States today!

More qualifying of components...        read full caption More qualifying of components includes checking of the Brinnell hardness of the cylinder heads. Two machined parellel surfaces, other than those that are gasketed, are checked to verify this hardness spec.

How serious is Arrow Racing...        read full caption How serious is Arrow Racing and Mopar Performance about zero defects on the Hemi crate engine? Consider this photograph where Arrow’s Dale Matthews displays bubbles where porosity from the water jacket to the port is visible. Obviously, this head did not qualify. Quotes Bill, “Arrow simply can’t afford a leak; we pre-qualify every part!”

Every component in the Hemi...        read full caption Every component in the Hemi crate engines can be found in the Mopar Performance catalog. Every one.

Notes Shepard, “What...        read full caption Notes Shepard, “What feeds the program is all the tooling that we spend to get all of the parts. That’s nearly a million dollars in tooling! Without that million dollars, we couldn’t do the crate engine program.

Bill Hancock is very proud...        read full caption Bill Hancock is very proud of what Arrow has accomplished with this program. “The last five Hemi engines we’ve run across the dyno have been within 5hp, and when you are talking about 610hp , that is merely one-percent!”

The evaluation doesn’t...        read full caption The evaluation doesn’t end with a successful dyno pass. Each and every engine is leakdown tested and verified. Notes Hancock, “I’ll answer the question before you even ask it. No, your dyno sheets are not available for each individual engine. But we do ship the engine with the distributor in at max power spark. “I could tell you the day it was built, who built it—we have internal records here. No, they are not available, either. We know what the cylinder leakage was in every cylinder, what its compression was, its power, the torque, its oil temperature, its water temperature, its vacuum. We have to in order to maintain our records in order to verify changes with the guys at Mopar Performance.”

Following the dyno test, the...        read full caption Following the dyno test, the oil filter is removed...

...cut open...

...and inspected as shown...        read full caption ...and inspected as shown here by Todd Claucherty of Arrow Racing. The inspection looks for any metal shavings that may have been caught in the filter. If they are found, the engine does not qualify and is not shipped.

Shepard says, “The wires...        read full caption Shepard says, “The wires do stay on it. Since Arrow is dynoing it, these pre-made Mopar Performance wire sets are left in place with the distributor.” Larry continues, “Yes, they have their own part number in the catalog, but they are not in the latest edition. They are 7.5mm as opposed to the original 7mm. This is what the end user gets.

Once Arrow is satisfied with...        read full caption Once Arrow is satisfied with the dyno evaluation and leak-down testing, the finished engine is die stamped with its consecutive number. This assembly is the 24th 528 Hemi produced at Arrow Racing as of the first week of April 1999. Bill told us, “We sequentially number the engines, but it only gets the number after the dyno test. The stamped number goes on when it is put in the crate. But why do we wait until then? Because only then is it an official piece. If it fails anywhere in the food chain, we kick it out and don’t use up a number on it.”

The package. It is what makes good individual parts great. But it is more than the sum of the parts and we offer as an example the three Mopar Performance crate engines—the 426, 472, and 528.

The Market
The reputation of the Hemi™ could easily have been Mopar Performance’s sole marketing tool for the crate Hemis. But rather than rest on reputation and then rely on 35-plus year old components and tooling, the individual Hemi components found in the 1999 Mopar Performance Catalog and in the crate Hemis are new. Even more impressive to us are the processes behind building the crate Hemis—from the development of the program to the individual components, to the uncompromising qualifying of every single component. We felt strongly that the Hemi crate story needed to be shared with the readers of Mopar Muscle. Can Crates Sell?

Veteran Mopar Performance engineer Larry Shepard says, “The 360 Commando and the following 360 Magnum small-block crate engines proved to us that there was a market for turnkey assemblies. However, that has not always been the case.” Larry looked back in time and commented, “We tried to sell Hemis right off the assembly line in the late ’60s and early ’70s. We put 25 in stock and took one for a race car. Five years later, there were 24 still sitting there. There wasn’t interest in it then.” So what changed?

Says Shepard, “People have changed in what they want. When you take the variety of MP Hemi parts available and select a company like Arrow Racing to assemble it, the options on how you put it together are far more versatile than they were in 1964 or 1965. Now we can make a 528! In those days it would have been more difficult—we didn’t have the siamesed bore block or the long stroke crank, or all that stuff.”

Today, we know the Mopar faithful are intrigued by the crate motor program—and all eyes are on the Hemi. However, Shepard notes, “There are things other than the Hemi that could influence the sales of crate engines. The small-block, the 505 and 545 Wedge, even the V10.”

Remember, simply because the Hemi is the icon of Chrysler performance engines doesn’t mean that it is more important for MP to sell Hemis than small-blocks. In fact, the aggressive nature of the crate and short-block engine programs leads us to believe that while the individual parts remain of primary importance for those of us who choose to build our own engines, it will be the crate assemblies and short-blocks that sway the racers and drivers of other manufacturers’ powerplants into joining the Mopar ranks. To convert people to Mopar is an objective of Mopar Performance.

Parts are Parts
Ask just about any gearhead, and they’ll tell you parts are parts. What they forget is that their own engine building experience is an important key. Perhaps more important than the parts. ' When you put great parts in less-than-great hands, you’d likely have an assembly that would fall short of the Hemi legend. Mopar Performance knows this and, rather than bolt a bunch of parts together and call it a crate engine, the longtime partnership of Arrow Racing and MP has resulted in what we believe is the highest quality engine assembly program—including custom builds—available to those seeking Hemi power.

Arrow Racing’s Bill Hancock notes, “That is not to say there are many who, with a reasonable set of hand tools and some mechanical talent, can take a stack of parts and turn it into a running engine. However, what Mopar Performance and the customer get by working with Arrow Racing is something that is unseen.”

Bill illustrates: “The camshaft has been picked for you based on our testing. The tolerances have been picked for you; the compression ratio has been picked for you. Go get the parts only, and you don’t necessarily get that engineering. If you did elect to buy the parts from a variety of sources and perhaps use what you have, they may or may not work. The crate Hemi has been dyno’d, but what you don’t see is why the parts were chosen. For example, we have proven which valve springs will live versus those that won’t.”

That unseen is what we intend to show in this article. Hancock says, “Yes, at this point, the Hemi assemblies are custom engines. All the bearing clearances are measured, which is not typically done on a production engine.” Beyond that, however, not only is each and every crate Hemi hand-built at Arrow Racing, but the program is continually evaluated for improvement. For the guy wanting to buy now, he can rest assured that not a single Hemi crate engine leaves Arrow Racing or carries a sequential die-stamped number until every part inside has been qualified. That includes a final dyno evaluation—and post-dyno inspections.

Arrow Racing also assembles engines being developed for future DaimlerChrysler production vehicles. In referring to the DaimlerChrysler Tech Center, Bill says, “At the ‘Big House,’ they want everything very close for control.” While the two entities of MP and CTC are light-years different, the engineering aspects are very similar.

Shepard offers this opinion: “One of the things that is interesting about taking a crate motor assembly process and translating it into a crate motor program is that you build a race engine first—perhaps not a race engine, but certainly a custom, hand-built, exacting-tolerance engine.

“However, we want to build many of them! That is much more difficult. You don’t want to lose any of the advantages of the single custom engine build-up. We want repeatable performance, built nearly as exact as possible, using components that are as identical as possible.”

Bill makes the final point, “And it is cheaper to buy it as a unit assembled than to buy just the parts. And imagine the cost to complete the evaluation by inspecting and qualifying every individual component and testing it on your own!”

What About Quantity
So just how many have been sold, shipped, and plan to be sold? Perhaps that’s not a question that needs to be answered as quantities don’t necessarily indicate success of the program.

Shepard offers this illustration: “When we put the Hemi crate motor program together, we thought it would appeal to the drag racers in Super Gas and Super Comp—especially Super Comp because they need 500 to 600hp for their dragster. Because the Hemi has the big valve covers, its impressive. One’s ego is much better off with a Hemi behind you in a Comp dragster. In Super Gas, the guy had to have a Mopar-bodied racecar prior.”

Did MP overlook the street market? Shepard answers “No, our street machine/street rod customer is looking for an assembly that won’t require them to spend their life building. Much of their creativity goes into what surrounds the engine. That is their expertise.

“In fact, when we did the Hemi block six to eight years ago, we said half would go to the racers and half to the restoration market. When we brought the block out for the first three years, not a single one went to restoration. But I know we have sold more Hemi blocks than there are Hemi race cars! Where are they going? I surmise that over 1,000 are someplace other than in racing.”

That knowledge piqued the interest of engineers like Shepard and those marketing and expanding the product line at Mopar Performance, but it didn’t blind them from reality. Shepard says, “We know we can sell 100 blocks for each crate engine sold. Obviously, more people were buying the blocks and building their own combinations. Now, however, they have the option of buying an assembly. We never forget the fact that what feeds the program is all the tooling that we spend to get all of the parts. For the Hemi alone, that’s a million dollars in tooling. Without that million dollars, we couldn’t do this crate engine program.”

Bill concurs, “Remember, the other benefit is that there are other people who have a car and want to race, but they are not set up to build engines. They can’t afford to build engines; they don’t have a good machine shop locally; they don’t have an engine builder; they don’t have a dyno.”

Shepard points out, “And they are only going to do one engine.”

Bill concludes, “A primary reason to buy a crate Hemi is that it takes a year to three years to become proficient at building one. The guys here at Arrow Racing come in day after day, 250 days a year, and screw brand new Hemi engines together. They get really good at it.”

Good is an understatement.

Here, our unique perspective is to not show each bolt-by-bolt install, but rather, display the rigors behind each Hemi assembled at Arrow Racing. Upon completing this brief, yet detailed, review of the Hemi crate engine build, we think you’ll agree that at any price, the Mopar Performance crate engines are a bargain. They are “The Right Stuff.”