Story By: Trenton Berry / RacinDirt.com
Joplin, Missouri based Hatfield Racing Engines has been a major player in Dirt Late Model and Modified engine business for the last decade and a half. Owners Tony Hatfield and Park Jones oversee a shop of five employees and strive to stay on the cutting edge of race engine technology.
The USMTS spec head is the primary cylinder head for USMTS and USRA competitors. Hatfield Racing Engines have built their Modified engine program with the spec Chevy head over the past six years. Recently they had the opportunity to branch off and assemble their first Ford based USMTS, USRA spec headed engine. While there are a few similarities between the packages, the Ford engine actually outperformed the Chevrolet on the dyno, according to Hatfield.
“The spec head we are working with on the Ford is just a better product,” commented Hatfield. “Flow numbers are not always indicative of power, but when the cc runner volume is smaller and it still moves the same amount of air you know it's a quicker head. Anytime you are dealing with a restricted engine combination, a little difference amounts to a lot.”
While on the dyno, numbers were consistently 20 horsepower better, with better torque readings. The overall cubic inch of the engine is 434, compared to 428 on the GM side. The engine is also assembled to withstand the same amount of laps between freshens as the counterpart.
“The Ford head is built a little better too,” Hatfield added. “It features no offset rocker arms which allow it to operate a little easier. The bore and stroke combination was proven in the GM, so we knew what we were working with there. To date these are the best and smoothest power and torque curves we've built in a spec headed engine.”
On the financial side the engine is just a bit higher, but the gains are likely to make the difference in parts cost a non-factor for most. The guys in the shop also took time to develop this package. They started with a clean slate and only used their ideas and input on the project.
The total power of the spec headed combination was considerably lower when originally introduced. Through time, power gains were inevitable as development progressed and Hatfield Racing Engines now claims to produce almost equal power to the open steel block engines they previously produced for the Modified division.
Find out more about Hatfield Racing Engines and what they have to offer on their website, Hatfield RacingEngines.com. Be sure to like their Facebook page to keep up with all the current projects and engines for sale.