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Old 10-02-2017, 08:38 PM   #13
Nomad Willy
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City: Concrete Washington State
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 18,743
These Perkins engines are not 50hp.

In a British taxi cab they were 50hp but they were rated at 4000rpm.
Never heard of one in a boat going over 3000rpm. Most of these old 4-107 and 4-108 engines came from the 70's. The 107 had wet replaceable liners whereas the 108 did not. Never heard of anybody replacing the liners but the seals gave trouble when they got old so consider it a blessing if you have a 108. My seals were leaking ... (a 107) one of the reasons I repowered.

These Perkins engines gave 36hp at 3000rpm. But in the 70's it was vogue to over-prop and most of those engines only made 36hp (approx) in their over-propped state. At 2700 to 2800rpm.

Any Prarie getting an honest cruise speed over 6 knots w this engine should be happy. No significant improvement is possible.

Cappy,
Somebody put an 80hp Cummins in a Willard and claimed to get 8 knots. I would think the Prarie would do a bit better w it's SD hull.
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North Western Washington State USA
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