They are very nearly equal for typical four-stroke non-turbo diesels under load. A turbo diesel under load should have slightly more radiator loss than exhaust loss.
At the bottom is a link to the technical spec sheet for a Cat 3412 powered genset. It's a probably a bit bigger than what you had in mind. It is a turbo with aftercooler (A/C in the doc below). Since it is setup for stationary power, the turbo is big, heavy, slow and efficient, and the aftercooler has a substantial heat rejection.
All industrial engines will have sheets like this. They can be customized by the mfg for unusual operating conditions such as high altitude or arctic conditions. This lets the dealer's installers get everything sized and arranged right on the second try (and they just love to fly to northern Alaska to fix stuff in the winter).
For over-the-road diesels, the heat rejection for internal jacket water and exhaust would be closer together. Radiators are draggy and heavy and you design vehicle engines to minimize them. You can reject more heat from surfaces in a vehicle.
Cat has a nice engineering primer on engine cooling - http://s7d2.scene7.com/is/content/Caterpillar/CM20160713-53120-13199
Vehicles often use air-to-air aftercooling and oil cooling, so the aftercooler and oil cooler heat doesn't end up in the radiator. Most larger engines use jacket water for aftercooling and oil cooling, so you need to add those values to the internal jacket water heat to size the radiator.
Cat 3412 genset technical data sheet (see section titled heat rejection on page 2)
I'll try to dig up a similar sheet for mobile equipment engines later. Or someone else can ;)