365 cid Dodge R5P7 NASCAR Engine - Engine Builder Magazine

365 cid Dodge R5P7 NASCAR Engine

Never heard of the La Carrera Panamericana? Neither had Scott Eatmon of Eatmon Racing Engines. But that didn't stop him from building this 365 cid Dodge R5P7 NASCAR engine for a new customer looking to enter the Mexican endurance race this October. Find out the full details of this engine with a NASCAR history.

In 1950, the Mexican government sponsored a race to inform the world that Mexico had a new system of roads known as the Pan-American Highway, which stretched across the country from north to south for commerce and tourism. That race was the original Pan-Am.

Today, known as the La Carrera Panamericana, the race features up to 100 vintage racecars starting down in southern Mexico in October to race nearly 2,000 miles back up north. It’s seven days of racing, around 350 miles of speed stages, over closed, public roads through some of the most beautiful country north of the equator. The race has been explained as of the Mile Miglia, the Targa Florio of Italy and the Grand Prix of Tripoli.

When the original race was canceled in 1955, its purpose had been accomplished. In 1988, a group of Mexican and North American auto enthusiasts revived the Pan-Am as a “pro-rally” or “stage rally” race.

If you’re like myself and Scott Eatmon, the owner of Eatmon Racing Engines in Wilson, NC, then you haven’t heard of this race either, until now. However, one of Eatmon’s newest customers was involved with this race and came to Eatmon because he had heard of the shop’s Dodge NASCAR engines, and wanted one specifically for the La Carrera Panamericana.

Eatmon Racing Engines was founded by Scott’s dad, Harold Eatmon, in 1980, and features an engine shop, machine shop, a dyno service, a parts supply store on ebay, and focuses on Ford, Chevy and Dodge NASCAR-type engines, dirt late-model engines and racing engines for boats.

“It’s a wide variety of stuff we deal with,” says Eatmon, who started in the shop in 1991. “We’ve been doing this a long time. We have four full-time employees and we’ve always been here in Wilson, NC.”

One of those employees is Scott’s 19-year-old, youngest son who is enrolled at the local community college CNC machining program.

“We’ve had three generations come through the shop now,” he says.

In addition to all of the things Eatmon Racing Engines offers, the shop does 30 percent of its business internationally, shipping engines to places like Australia, New Zealand, Norway, Sweden, France, and England.

“People are racing with our engines all over the world,” Eatmon says. “A lot of our customers are road racers, some of them are dirt track racers. We have drag racing and boat racing customers too, so a wide variety of customers.”

The shop’s claim to fame was building NASCAR engines through the ‘90s through Robert Yates Racing.

“Back then it was the Busch series and we used to build engines for Dale Jarrett, Ernie Irvan, Kenny Irwin Jr., and then as more and more money got pumped into NASCAR and the teams, all the NASCAR teams started having in-house engine builders,” Eatmon says. “The Cup teams started taking over all the truck work and the Busch series work, which kind of cut outside shops like us out. But I kept my connections up there with all those guys and I go up there regularly and we buy a lot of their NASCAR parts and we bring them back here to our shop and then we build the Ford, Chevy and Dodge NASCAR-type engines to sell to people all over the world. That’s probably our biggest business is selling the NASCAR-type engines outside of NASCAR and people use those types of engines in all sorts of racing.”

Eatmon’s new customer looking for an engine to use in the La Carrera Panamericana race got set up with a Dodge R5P7 NASCAR engine.

According to the race rules of the La Carrera Panamericana, all engines are limited to 365 cid and must be set up with a wet sump oiling system. The cars are also not allowed to exceed 144 mph during the race.

“To start, it was actually not a complete engine,” Eatmon says. “We assembled it from parts that we had here that all came from the NASCAR teams – Evernham Motorsports and Penske Engines – is mainly where all the components came from for this engine. Some of these components are used and some are new.”

The engine has a Bryant crankshaft and Carrillo rods. The NASCAR teams don’t run these cranks and rods for more than one or two races before they shelf them.

“We have a good relationship with them, so we go up there and buy a majority of all their used parts and Magnaflux them and inspect them,” he says. “Then we put them in engines to sell to guys like this customer.”

Eatmon did have to use a new set of custom JE pistons made for the low compression ratio, because one of the rules in this endurance race is you have to run pump gas also.

“They have to stop at the actual gas stations and fill up along this route that they’re racing,” he says. “So we had to make the engine low compression for pump gas.”

The engine block got some internal machine work done to convert it from a dry sump system to a wet sump. Eatmon milled out the cam tunnel so all the oil would drain to the oil pan.

“There’s no provision for an internal oil pump in these NASCAR blocks, so we have a one-stage external oil pump on the front of the engine,” he says. “We also have a custom-made, fabricated oil pan that we made ourselves. We cut the sump off of a wet sump oil pan, and then we take the NASCAR dry sump oil pan and cut a hole in the bottom and we weld those together. Then we make a custom pickup to get the oil out of the pan to the one-stage pump. The customer will have to mount a remote oil filter somewhere under the hood, and that feeds to the front of the engine.”

The Dodge R5P7 NASCAR engine also features a Jesel belt drive instead of a timing chain. It also has Jesel roller rocker arms and roller keyway lifters, a COMP Cams solid roller camshaft, which is a custom grind that Eatmon Racing Engines had done just for this build. The engine has Del West titanium valves and retainers. The valves are coated for the unleaded pump gas, otherwise they’ll wear out quickly.

“The heads are CNC ported Dodge P7 cylinder heads and the engine has an Edelbrock ported intake manifold to match,” Eatmon says. “The engine also uses Cometic gaskets and seals throughout, Clevite bearings and Total Seal rings.”

Now that Eatmon and his team have put the finishing touches on the Dodge R5P7 NASCAR engine, it puts out 750 horsepower at 7,800 rpm and peak torque of 540 lb.-ft. at 6,500 rpm with a 10:1 compression ratio.

This Dodge engine is now headed south of the border to Mexico for the historic La Carrera Panamericana 2,000-mile endurance race from October 13-19. Buena suerte (Good luck).

The Engine of the Week eNewsletter is sponsored by Cometic Gasket.

If you have an engine you would like to highlight in this series, please email Engine Builder magazine’s managing editor, Greg Jones at [email protected].

You May Also Like

2,662cc Air-Cooled and Turbocharged VW Engine

This 1969 Volkswagen Beetle was just $600 when Steve Dalton bought it in high school. Having tweaked the performance of the car every year, he’s gone way past that mark and several iterations of the VW engine. Today, it’s a 2,662cc air-cooled and turbo’d VW with a bunch of aftermarket goodies.

There’s just something inherently awesome about seeing a Volkswagen Beetle wheelie off the line at a dragstrip. It’s even cooler when you know the engine making it happen is also a VW and not some sort of swap. We caught up with Steve Dalton, the owner of such a Beetle, during Sick Week 2024. His air-cooled and turbocharged Volkswagen engine competes against a sea of V8 horsepower, and it holds its own, so we wanted to know how the 1969 Beetle and the VW engine got to this point.

Volkswagen Beetle’s Air-Cooled and Turbocharged Engine

This Volkswagen Beetle cost owner Steve Dalton $600 when he bought it back in high school for use as a daily driver. Every year since he’s owned the car, the Beetle and its engine have gotten some sort of performance upgrade to the point that it is at now. Steve is a regular on the

ProCharged 572 cid Big Block Chevy Engine

Inspired to build a hot rod with all its systems exposed, Leroy Edwards used his 50 years of mechanic experience to build this cool-looking car himself. Powering this hot rod is a ProCharged 572 cid big block Chevy engine with nitrous adding an extra kick. Check it out!

big block Chevy engine
Twin-Turbo 6.4L Gen III Hemi Engine

After rebuilding his ‘Lil Red Express truck for the past two years following a collision during the Midwest Drags, Rick Russell got back to drag-and-drive competition at Sick Week 2024. This time, ‘Lil Red Express featured a twin-turbo 6.4L Gen III Hemi engine!

Lil Red Express
All-Billet K24 2.2L Honda Engine

We’ve known JBR Engines owner Jose Bello for a few years, and well before that, we knew his shop was one of the premier shops in the Honda and import engine scene. During a recent visit, we got to see an all-billet Honda K24 2.2L engine coming together for a customer looking to improve upon his 5.86-second quarter mile time!

Other Posts
Turbocharged Nissan SR20 DET Engine

For a number of years now, Derek and Rita Cho-Sam of DRZA Auto in Tavares, FL have been among our top Nissan engine shops. When we realized that Sick Week would be rolling through their part of Florida, we made arrangements to stop by and see DRZA in person. Derek and Rita gave us a

Nissan SR20 DET engine
Kevin Smith’s Turbocharged 388 cid LS Engine

Kevin Smith, owner of KSR Performance & Fabrication, has been a big part of the drag and drive community for a while now. His shop, in addition to all the performance and fab work it regularly does, stays open during events like Sick Week, so competitors can utilize the lifts and tools to get back

KSR LS engine
Richard Guido’s Turbocharged 521 cid Pontiac Engine

Known by many as the Canadian Chuck Norris, Richard Guido has been a staple of the drag-and-drive scene for a long time. Not only does his Pontiac GTO, boasting a turbocharged 521 cid Pontiac engine, drive literally everywhere, the car gets it done on the track as well having won back-to-back Sick Week Stick Shift

Pontiac engine
Turbocharged 414 cid L8T Engine in a Honda S2000

As we’ve mentioned in other Sick Week interviews, there aren’t tons of import cars at the annual drag-and-drive event in Florida, so when we see something like RC Flint’s Honda S2000, we take notice. Upon further investigation, RC opted to forgo the 4-cylinder for a 414 cid L8T engine, and we got the full scoop

L8T engine