The Kaulig Racing driver was 25th in practice and two seconds off pace-setter Connor Zilisch before a gearbox issue in qualifying cost the #11 Chevrolet Camaro driver valuable time.

Brown and compatriot Jack Perkins were part of the first group of qualifying. Perkins was third in while Brown was 13th in the 19-car field before the second group improved the benchmark.

All told, Perkins was 11th and Brown 27th.

Zilisch took pole position for the 75-lap race, nearly half a second clear of his nearest rival Justin Allgaier.

“I probably wasn’t feeling as comfortable as I hoped, to be honest,” said Brown.

“I just had a little drama. I don’t know if I burred second gear or something happened.

“I had one miss-shift probably on lap two or three and then was just really struggling to get it into second gear.

“That was just hurting all my braking zones and everything like that. I felt like I couldn’t get in a rhythm out there.

“We’ll start off the back. It’s a long race. We’ll slowly see if we can pick a few off. We’ll get it sorted and see what happens.”

How to watch Will Brown, Jack Perkins in NASCAR at Portland

Brown said he struggled to get up to speed in practice, making the transition from the stiff touring car to the soft stock car.

“They’re a lot different to what I’m used to… obviously I drove the Cup car, but compared to the Supercar they move around a lot more.

“They pick up the front, they roll a lot, so that was something to get used to.

“You can’t feel the lock-ups as easy, but I’ve just got to do a better job and hopefully we get this sorted and we’ll be right.”

Zilisch said he needs to stay out of trouble to convert pole position into another win.

The #88 JR Motorsports driver is searching for his eighth Xfinity Series race win of his rookie season.

“Keep it on track, first of all. This track gets really dirty. It’s pretty tough to manage, especially in that last section over there when guys are cutting that chicane and picking dirt up on the track, so that’ll be first,” said Zilisch.

“Then try not to go through the cut-through at Turn 1. I had to do that once in practice, so hopefully I don’t have to do that again in the race.

“I don’t want to get used to it but it sure is fun getting to go to the track every weekend knowing that you’re going to have a shot.”

Coverage of the NASCAR Xfinity Series at Portland International Raceway is live on Fox Sports and Kayo Sports from 9:00am AEST.

Results: NASCAR Xfinity Series Pacific Office Automation 147 Qualifying, Portland International Raceway

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