Interior Magazine

INDIANAPOLIS -- Will Power experienced the seventh engine issue for Chevrolet in two days of Indianapolis 500 qualifying when his Team Penske entry sputtered Sunday during practice ahead of the afternoon pole shootout.

The manufacturer had six engine problems Saturday, when Power joined teammates Scott McLaughlin and reigning Indy 500 winner Josef Newgarden in sweeping the top three spots based on four-lap average speeds.

Honda hasn't had it much easier at Indianapolis Motor Speedway, with seven engine changes since last weekend's race on the road course. Two of the engine changes were made for Graham Rahal, who openly has asked if Rahal Letterman Lanigan teammate Takuma Sato has received a favorable top-performing engine from Honda.

Rahal, who was bumped from the field last year, is among four cars trying for the last three spots in the 33-car field Sunday. Sato is the highest-qualified RLL driver after going ninth Saturday, putting him among the 12 going for the pole.

Power, who leads IndyCar with a record 70 career poles, has never won it for the Indy 500, and he has said for more than a month that a Team Penske car will be leading the field to green on May 26 for "The Greatest Spectacle in Racing."

"Pretty tired of hearing Will say it's going to be a Penske front row, but yeah, we're pretty motivated," said Arrow McLaren driver Alexander Rossi, who also has Chevrolet power.

It didn't hurt McLaren's hopes when Power suffered what Chevrolet calls a "plenum event" during Sunday's practice.

"The engine just stops, it dies. It kills your speed massively," Power said.

Chevrolet officials addressed the issue after six cars had the problem Saturday, and Kyle Larson and Pato O'Ward of McLaren both had engine changes. Also affected were Conor Daly, Ed Carpenter, rookie Christian Rasmussen and Agustin Canapino, who was on a flier of a qualifying attempt and about to make the Fast 12 until his engine hiccuped on the third of four laps.

The Argentine was screaming in Spanish in frustration on his radio and Chevrolet took full blame for the issue.

"We feel terrible," said Jim Campbell, the U.S. president of performance vehicles for Chevrolet. "When we have an issue that is on us, we feel bad. It's racing. When you have an issue, you're either going to ignore it or dig in and work to fix it and mitigate it, and that's what we're doing."

Campbell promised that General Motors would be working globally to address the plenum events, which IndyCar program manager Rob Buckner said involved components inside the engine that misfire on downshifts. The issue cost O'Ward a victory in the 2022 season-opening race when his McLaren seemed to briefly shut off.

"On top of the cylinder heads in the air inlet system of the engine is a plenum, and there's some port fuel injectors up there," Buckner explained, "so while these engines are sustained high speed, that plenum is very full of fuel, and if we have any event over a downshift that can ignore that fuel, it ends up evaporating the plenum of its fuel air charge, temperatures rise rapidly, and to the driver it's a perceived engine kill.

"They vary in duration. They vary in severity. Unfortunately here, the ones we had were very noticeable to the drivers," Buckner added. "Anything around Indianapolis is very noticeable to the drivers. It pretty much scrapped those runs, which we really hate for all those drivers that we impacted their day."

Honda, meanwhile, staunchly defended its distribution of engines and implied that Rahal was speaking out of frustration when he was talking about the powerful engine that put Sato in the pole shootout.

Honda changed Rahal and Marcus Armstrong's engines last weekend, and Rahal has had a second engine change during Indy 500 qualifying prep. Álex Palou, last year's pole winner, and teammate Scott Dixon both had engine changes, as did Chip Ganassi Racing teammate Kyffin Simpson. Pietro Fittipaldi of RLL also had an engine change, and Honda said all were for various reasons, though it has yet to have a plenum event like Chevrolet has experienced.