Hi Colin,
I understand that the 225 John Deere is a very good engine, although it is very hard to beat the Lehman, especially if you just need to rebuild it.* 10-12,000 hours prior to rebuild is not uncommon.* Parts are still obtainable, according to other cruisers I know with Lehmans.
The 210 Cummins in WESTERLY was installed by the previous owner to replace a 150HP Bedford, so I don't have direct experience with the repowering.
However, I know that the*engine and gear exchange was made through the pilot house top, a fiberglass patch*is completely hidden under non-skid deck coating.
The same 1-3/4" shaft was used, but the engine was located further forward so a small jack shaft was installed, but I ended up removing it when replacing the shaft a few years ago.
I'm sure that there was not any gain in speed, as the sweet spot for this hull is very close to 7.4 knots.* I run at 1750 rpm to make that speed with a 2.66:1 reduction and*24 x 23 4-blade prop.* The engine consumes around 2.5gph which means an engine output of around 45HP.* Max cruise speed is 9.5kts.
For some of the newer Pacific Trawlers installed with 330+HP and fixed trim tabs at the stern, planing*is possible*at around 12 knots with a fuel burn of around 15 gph.
How fast do you want to go?* Or do you just want to have a more modern engine producing the horsepower to go 7.4 kts?
According to my FloScan meter and speed log:* 1600 7.0 kts 2.0 ghp, 1700 7.3 kts 2.3 gph, 1800 rpm 7.5 kts, 2.7 gph, 2000 rpm*7.8 kts, 4.0gph, 2200 rpm 8.4 kts 6gph and 2600 rpm 9.4 kts 10gph.
This*is a good size engine for this boat, as*it*is not overloaded for its service level.
Good luck.****Jay N***
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