Updated: Mar 24, 2020
By Joey Lee
Toward the end of June 2019’s MAPerformance’s MAP Proving Grounds part 1, we were gathering our things, ready to hit the road back home after a wonderful weekend at Brainerd International Raceway. A very simple, yet clean Mazda RX-7 (Mazda FD) cruised pass us and caught our eyes. Particularly the rear plates that state “RWD DSM.” We reached out to the owner, and he said it was a 6-bolt 4G63 conversion. We had to learn more.
I was able to get a hold of the owner, Camden Marquette of St. Cloud, and speak to him more about his 1993 Red Mazda RX-7. Camden has owned this RX-7 for about 4 ½ years now and actually purchased the car in New York. The idea itself of running a 4G63 in a Mazda RX-7 was a dream of Camden’s since he was in high school and when the opportunity presented itself, he took the leap.
The conversion had already been completed by the owner at the time who had decided to put the car up for sale. A friend of Camden had showed it to him, so they went out to New York, ended up purchasing the car and bringing it home. Although as nice as it seems, it came with its own modifications that didn’t fit Camden’s liking. For example, he had to redo the entire sub-frame as it wasn’t completely set to work with the 4G63 conversion and the color changed to Porsche’s Panamera “Volcano Grey” and smaller personal touches as the stereo and such.
The car itself pushes about 540 horsepower with the Precision 6266 turbine on the 6-bolt 4G63 DSM block. The 6-bolt 4G63 block terminology can be found on the early DSM’s (Diamond Star Motors). The motors were based after the number of bolts on the flywheel and the 6-bolts were typically thicker, and stronger from everything between the crankshaft to the rods than its 7-bolt successor. Easy manufacturer basis of the motors were deferred on what motor came in what cares. Like the limited 1991 Mitsubishi Galant VR-4 (Vicious-Realtime-4WD), 1st generation Mitsubishi Eclipse and Eagle Talons turbo models (pre-1995) used the 6-bolt 4G63 and the turbo 2nd generation Eclipse and Talon models (1995+) were 7-bolt 4G63’s.
Camden has his knowledge of Mitsubishi’s Sirius Engine (aka 4G63) as he also currently has 3 first generation Eagle Talon’s and pits them on the ¼ mile drag strips. As of now, he doesn’t truly drive the Mazda as much as he could and has become a nice cruiser for him. He still does still makes plans for it as he wants to put in a 2.1 stroker (Long Rod) 4G63 motor for higher rod ratio and lower rod angle which in turn has more reliability at high RPM's. He didn’t have a timeline on when or if he could accomplish this, but if he does and is able to get that running while being fine-tuned in that RX-7, the automotive word known as “Sleeper” is only the beginning. Can’t wait to see it next year.