THE SHOCKING TRUTH BEHIND MOPAR INDESTRUCTIBLE 225 SLANT SIX ENGINE

THE SHOCKING TRUTH BEHIND MOPAR INDESTRUCTIBLE 225 SLANT SIX ENGINE

DISCOVER the story of a tough engine that withstood wars, harsh desert conditions and decades spent buried in junkyards, and still runs! Despite not being a Hemi, this engine has earned a solid reputation among mechanics for its surprising durability. See why this small block is a legend.

Learn about the history and controversy surrounding this legendary power plant.

Back in the 1970's I made my living as a mechanic. We had one customer who owned a large plumbing outfit and he didn't believe in oil changes for some strange reason, just keep adding oil. His vans were all Dodges with 225 slant 6's in them and he had about 50 of them. These engines would routinely give up the ghost at around 150,000 miles and he would bring them in for rebuilds. The insides of these things were loaded with, not oil, but thick black gunk. One of the things we noticed when tearing these engines down was how the pan was filled with crud about 4" deep but there was always a hole in it where the oil pickup was. My boss asked the customer if we could try something and the customer agreed to it. At 100,000 miles he would bring the van in and we would pull the pan and clean it out and then reinstall it. This one small change in the servicing got about 25,000 more miles out of those same engines because the oil pump was no longer starving for oil.
When the customer finally decided to retire one of these units at about 200,000 to 225,000 miles, my boss would buy them for about $50.00. We would pull the engines, tear them down, and rebuild them. The cranks were ground, the cylinders bored out and fitted with oversize pistons, and the heads received guides and a seat grind with all new valves. Once done, we would sell these rebuilds off to customers who needed a rebuilt motor installed for around $600.00 each in a car, $650.00 in a van. Funny thing was our biggest customer was the same plumbing guy. He didn't realize they were his motors to begin with........

AMERICAN Car History, Season 1

Performance—and Its Limits:
The 225 Slant Six was not designed for racing, but with mild performance parts (factory two-barrel "Super Six" intake, hot cams, or aftermarket headers), output could be increased significantly—making it popular in grassroots drag racing and even factory performance cars in Argentina and Australia

Global Impact
Used not just in U.S. compacts, but exported and built worldwide—some variants surviving in regular service into the 21st century

Performance Surprises
Modified Slant Sixes, especially those with forced induction or period-correct "Hyper-Pak" style upgrades, can deliver performance on par with—or even exceeding—many stock V8s. Stories abound of turbocharged or supercharged 225s putting lightweight cars into the 12-second quarter-mile range, embarrassing unsuspecting V8 owners

Affordability & Accessibility
Compared to more exotic powerplants, the 225 is usually cost-effective to source and rebuild. Aftermarket support (especially from specialists like Aussiespeed) means you can find forced induction kits, manifolds, and go-fast parts reasonably easily