VINTON, Iowa (Nov. 21, 2024) – IMCA Modified drivers will have a third engine option next season.
New in rules for 2025 announced today is a spec engine alternative to existing claim and crate options and legal for use in sanctioned competition beginning on Jan. 1.
“The spec engine can be built from a 604 crate short block or can be built from scratch,” explained IMCA President Brett Root. “It uses parts drivers and builders are already familiar with in a third engine option. Both drivers and builders will be able to use known components to build these engines.”
EngineQuest or DART cylinder heads, an Edelbrock intake manifolds are required.
“These parts are well known to Modified drivers and to drivers in other IMCA divisions,” said Root, “and the valve spring rule is compatible with the 604 crate.”
Maximum two-inch rear spoilers will be allowed on Modifieds with spec or crate engines. Both may use the same carb adapter, must be used with the maximum 6,800 rpm rev limiter and neither can be claimed.
“We have built and dynoed one of these engines since the end of the (2024) point season. Its performance is very, very compatible to a 604 while having some of the characteristics of a claim motor,” Root said. “You can start with a 604, SportMod claim engine or a Stock Car 500 cfm engine option and build one of these engines.”
“All told, we are trying to get an option that is competitive with the crate that can utilize the 2” spoiler,” Root emphasized. “The spec engine is both economical and competitive.”
The engine option being used must be indicated on the driver’s side roof post.
2025 rules and a second story on rules for seven other IMCA divisions have been posted on the IMCA website. RaceSaver Sprint Car rules will be posted when those become available from RaceSaver.
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