Tom, who rides for the Louth-based Honda Racing team, is currently riding high in sixth place in the rider standings and will be anxious to add to his points tally this weekend.
Tim races for Morello Racing and will also be seeking a good set of results on the big Kawasaki.
There are two races for the twins this time, one on Saturday and a second on Sunday.
Most Popular
Timetable: Friday – free practice 11.55am and 4.40pm; Saturday – qualifying noon, race one (23 laps) 2.45pm; Sunday – warm-up 9.10am, race two (24 laps) 11.10am.
* Jason O’Halloran also heads north of the border for round five of the 2019 British Superbike Championship at Knockhill on Sunday.
The Australian rider, based at Market Rasen, was testing at the Scottish track a couple of weeks ago so should have found the ideal settings for the McAMS Yamaha to challenge for race wins this weekend.
After two top-10 finishes at Brands Hatch, O’Halloran has edged his way up the rider standings into 10th place.
Two good results from Knockhill’s two races will move him closer to the top six who go through to the end-of-season showdown to challenge for the title.
Timetable: Friday – free practice 10.20am and 3.45pm; Saturday – free practice 10.25am, qualifying 4pm; Sunday – warm-up 9.40am, race one (30 laps) 1.30pm, race two (30 laps) 4.30pm.