Fuel Tank size and consumption

I have just purchased a 1978 Erickson 29 with an Atomic 4 gas and I am trying to find out what its fuel tank capacity is and what its general fuel consumption is. Appreciate your feedback.

A4 good stuff.....

Sorry about the delay in replying, I've been swamped at work.

I have an A4 in my 1970 E32. Most of the original fuel tanks have been replaced in the Ericsons of our vintage by now. Most have been replaced with the Tempo Plastic tanks, like mine was. I have 18 Gallons, if you think that is the type you have, you can measure / sight the size and then go to West Marine to compare what's on the shelf.

My A4 burns 1 gallon an hour at 1700 RPM, and that gives me 5.7 knots. At 2000 RPM the burn goes to 1.2 gallons an hour and speed hovers right around 6.4 smooth seas. Can be .2 higher for glassy, or lots slower for choppy. I have had the boat surfing with main only and seen 14 knots for almost a minute. The engine unloaded, but never got over 2250 RPM.

I have a 12x5 two bladed sailor prop, RH of course. The prop tips at 2000 RPM are almost supersonic, and that translates into a light tube at night in the phosphorescense.

I have added the oil cooler/oil heater, crankcase vent and oil filter to mine, Buck will try to talk you out of it, but it has really tamed mine down. I change oil and filter religiously at 50 hour intervals, and grease the water pump shaft thru the cap every fourth time I run it. I carry a complete set of ignition parts, and have a couple of good references for you if you need them.

Good luck, hope this helps.

Michael Krebs
"Voice of Reason"
1970 E32-134
King Harbor - Redondo Beach, Calif.

Thanks for all the great info. If this sentence was a test I failed...The prop tips at 2000 RPM are almost supersonic, and that translates into a light tube at night in the phosphorescense. I have no idea what that means. Can you translate?

The Pilot-Engineer in me.....

Sorry, I fly for a living, and I spout stuff like that not thinking about it sometimes.

The transmission in the A4's (most of them) is a direct-drive type; no reduction gear. So 2000 engine RPM equals 2000 propeller RPM. If you did the math, that 12 inch diameter propeller at the tip would be travelling VERY fast thru the water. Most propeller engineers would talk about the incredible loss of effciency as the prop (or parts of it) approached that speed (noise, shock wave, etc.) Not to mention the power that all of that would require. So why not slow it down? The A4 comes into it's power band right at 1900, and peaks at 2300. Most people (including me) don't run them much over 1950 or so. So the only way to get every one of the 'potentail' 30 horses to the water is at that kind of RPM.

Light tube..... Run the engine to speed at night sometime. Look over the rail if you need to (you won't). There will be a 'tube of light' about 12 inches in diameter extending for quite some distance behind the boat starting at the propeller. On a good dark night here in SoCal, it will go back 2 boat lengths at 6 knots. All those little critters don't like that shock wave either. They glow when disturbed. Again, attibuted to the (relatively) high propeller speed.

My Hunter 43 has a 3 blade 18x16 turning at 750 RPM at speed. Only one quarter of the light down there in spite of higher boat speed, and much more horsepower being delivered to the water.

Where is your boat going to be?

Michael Krebs....