About 10 times a year I get the same question..."I want to repower from my Atomic 4 to a diesel, what do I get?"
At one time this was a very expensive task and there was no real "drop in" replacement. That has changed now with the Universal B series of engines. While still not a simple "drop in" in all cases, nor an inexpensive task, it has been made easier with this line of engines.
Before going on, I have to give the standard disclaimer stuff. Featherman Enterprises can not be held responsible for any problems, liabilities etc that may arise from the following information. It is being presented as a service based on the information provided by Universal ... aka Westerbeke, in order to give you some basic information to begin the repower process. As with any project of this kind it is your responsibility to check all the dimensions, prices and the background of any person(s)and/or companies you choose to buy an engine from and/or have them install.
Universal has developed B series engines for most of their later model diesel engines. The B's offer cleaner emissions, reduced noise and increased horsepower at low RPM's. For Atomic 4 replacements, the M-25XPB, M3-20B, M-30B-31, M-35B and M-40B offer foot prints that are close to the Atomic 4 and therefore reduce the amount of changes required to the engine compartment.
For more information on these engines, contact your nearest Westerbeke/Universal dealer. if you don't know of one in your area, go to the Westebeke web site - www.westerbeke.com - find the distributor for your area and contact them for the nearest dealer.
The following table presents some basic specifications for these engines:
 |
Atomic 4 | M-25XPB | M3-20B | M-30B-31 | M-35B | M-40B |
| HP | 30@3600rpm | 26@3000rpm | 20@3600rpm | 27@3600rpm | 35@3000rpm | 37.5@3000rpm |
| Cylinders | 4 | 3 | 3 | 3 | 4 | 4 |
| Weight | 350 lbs | 295 lbs | 241 lbs | 272 lbs | 352 lbs | 356 lbs |
| Typical Fuel Consump. | – | 1 gph @ 2500rpm | 0.75 gph @ 3000rpm | 1 gph @ 2500rpm | 1.3 gph @ 2500rpm | 1.4 gph @ 2500rpm |
| DIMENSIONS | ||||||
| Length | 26.6in | 28.4 in. | 26.4 in. | 28.8 in. | 32.7 in. | 33.2 in. |
| Width | 18.2 in. | 18.9 in. | 18.8 in. | 16.96 in. | 18.9 in. | 18.9 in. |
| Height | 19.1 in. | 22.1 in. | 20.1 in. | 19.75 in. | 22.0 in. | 22.1 in. |
| Mounting Centers | 11.5 in. | 11.5 in. or 16.0 in. | 11.5 in. or 16.0 in. | 14.56 in. or 11.5 in. | 11.5 in. or 16.0 in. | 11.5 in. or 16.0 in. |