Originally Posted by exbury2
Does anyone have experience in changing a 4108 to a Yanmar or Beta engine or other?
Very tight compartment.Restriction of prop size to 18' Would like as few changes to the engine beds as possible.
For the moment:4108 with a hurth
150 2.6 to 1 reduction 18 X 14 " blades prop Maximum revs possible 3000rpm full bore.
Thanks in advance.
Yes - Perkins
4-108 replaced with Yanmar 4Jh5E, retaining the existing Hurth 150V transmission
and prop shaft, and changed the propeller
from a Martec 2 blade
folding to an 18" diameter MaxProp 3 blade
feathering. I repowered starting in November of last year, and over the weekend was finally able to haulout (with clear weather
here in San Francisco) to repaint the bottom and put on the new MaxProp.
The Yanmar 4JH5E is slightly smaller in all dimensions than the Perkins 4-108, produces slightly more horsepower (53 vs 50) at much lower revolutions (3000 vs 4000). The increase in piston displacement
is huge: from 108 cubic inches to 134 cubic inches.
I can provide all the details of exactly what I did, if you're interested.
Work involved: replacing entire exhaust
system, adding second water lift muffler
, replacing (and raising) engine beds, replacing engine gauges and then replacing the tachometer mechanism, moving fuel
filters, replacing alternator
, moving the raw water
intake thru-hull, and a host of other small issues. Total cost was $22,350 (that's all for parts
, less $90 for 1 hour consultation on the exhaust
system - everything else I did myself). Upshot is the only original part of the Perkins remaining on board is the transmission and prop shaft.
works a treat, is quieter, lighter, more powerful, and the three blade MaxProp is quieter than the two blade Martec plus developing more power at the cost of some additional drag under sail.