propellors
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Geoff Johnson
Fellow Ericson Owner
I've seen adds in the sailing magazines for a prop made specially for the Atomic 4.
I have a '71 E-29. When I purchased it, the prop was completely wrong. The engine would labor and could not reach optimal RPMS. I saw adds from Indigo for a prop designed for an A-4. I went to http://www.atomic4.com/propeller.html and bought their prop. It made a huge difference! I can easily get over 6 knots, and the engine no longer strains.
Unfortunatley, the boat pulls to port as a function of engine speed. I don't know if this is due to the prop, or if the prop shaft is not correctly aligned. Otherwise, I am extremely satisfied with the prop.
Unfortunatley, the boat pulls to port as a function of engine speed. I don't know if this is due to the prop, or if the prop shaft is not correctly aligned. Otherwise, I am extremely satisfied with the prop.
Regarding the comment about the engine pulling to port --
Every boat we have owned has shown some torque steer at cruising speed.
I could adjust it out on the prior outboard aux. boat by turning the Yamaha Hi Thrust a couple degrees to correct it.
The Olson, with its 3 cylinder diesel, has some pull, but nothing the AP cannot easily compensate for. And the human helmsperson gets used to putting in a couple of degrees of turn on the wheel to make the boat go straight.
Of course, all these problems go away when you are under sail....
Be glad you do not have a boat with the prop really close to the leading edge of the rudder .... like the otherwise-legendary Ranger 33. The tiller can vibrate a lot under power and tire you out.
Counterpoint: having that prop in front of the rudder is what gives you quick turning power, at low speeds in the marina......
"Everything's a compromise!"
Best,
Loren in PDX
Every boat we have owned has shown some torque steer at cruising speed.
I could adjust it out on the prior outboard aux. boat by turning the Yamaha Hi Thrust a couple degrees to correct it.
The Olson, with its 3 cylinder diesel, has some pull, but nothing the AP cannot easily compensate for. And the human helmsperson gets used to putting in a couple of degrees of turn on the wheel to make the boat go straight.
Of course, all these problems go away when you are under sail....
Be glad you do not have a boat with the prop really close to the leading edge of the rudder .... like the otherwise-legendary Ranger 33. The tiller can vibrate a lot under power and tire you out.
Counterpoint: having that prop in front of the rudder is what gives you quick turning power, at low speeds in the marina......
"Everything's a compromise!"
Best,
Loren in PDX
clohman
Member II
I installed a Campbell Sailor, 3-bladed prop and am pleased. It produces a slighjtly higher hull speed with the same RPM and is advertised to offer less drag than ther larger 2-bladed prop. More to the point of your question, they were very helpful in calculating the correct dimensions for my boat. The price is much less than a folding or fethering prop and it has the advantage of better (more reliable) backing power.
Prop
Just installed a 3 blade prop on my E29, improved dramatically, used to have the 2 blade 12/7 I bought the prop from Tom Stevens advertised in Good Old Boat magazine for the atomic 4, 275 dollars and fits perfectly, under full load and calm seas, I get 6.4 knots, that is if my speed is correct, don't know the rpm but at 5.4 knots, the boat feels alot quieter than with the other prop, the backing has performed much better now. If you want I can get you the E Mail address Bob
Just installed a 3 blade prop on my E29, improved dramatically, used to have the 2 blade 12/7 I bought the prop from Tom Stevens advertised in Good Old Boat magazine for the atomic 4, 275 dollars and fits perfectly, under full load and calm seas, I get 6.4 knots, that is if my speed is correct, don't know the rpm but at 5.4 knots, the boat feels alot quieter than with the other prop, the backing has performed much better now. If you want I can get you the E Mail address Bob
sailingdeacon
Member III
Campbell prop
I am also a big fan of the Campbell 3-blade prop. It it quite innovative in design. Unless I were racing I'd have one. In my previous boat it was a pleasure. And the company does quite well in sizing it properly.
I am also a big fan of the Campbell 3-blade prop. It it quite innovative in design. Unless I were racing I'd have one. In my previous boat it was a pleasure. And the company does quite well in sizing it properly.