Crazy Horse

Thanks for the discussion on this, it is a project of interest to me that may fill a void in my current sailing options. I would suggest that there is a more constant load on the centre case from a fixed bulb than the occasional weight to right the boat from a capsize. As the boat goes over swell the bulb will accelerate forward and back, twisting from the bulb is real in addition to the righting moment. The board would also need to be locked down once lowered to prevent it moving in a knockdown, broach etc. Please don’t see my comments as knocking the idea, I just want to explore the possible issues to find the risks before maybe doing something similar. There must be older donor boats out there that need a new life? revintage - where did you get the foil extrusion from?

This is an interesting project. How do you propose to strengthen the hull at the centrecase to take the weight and lever force of the fin and bulb ?

This is Vivace, sailed regularly out of Mackay, Queensland. Committed owners who have made several mods and really work hard to remain competitive. Great boat to watch when the breeze is up.

If you search for how CAV filters work on the YBW Forum there is a snip from an old CAV manual that says I am totally wrong. I stand corrected but will leave my filter as is as it works.

Dylan, take my advice as you see fit. It was my attempt to assist in this situation from many years of experience, just because it is not on the internet doesn’t mean it doesn’t have some truth to it. Humour me by tracing the fuel flow through the filter the next time you have it apart, why would the design have all the crud dropped into the top when there is a collection method before the filter? Not as sophisticated as the Racor but similar in that the fuel is directed in a way to drop crud and water prior to the element to increase the life of the element. The genuine 7111-296 CAV elements are very good, down to 5 micron, through the spiral wrap design have a large surface area. Happy sailing

Yes totally absurd, carry on as you were!

The water passes through the filter, interesting? Next time you have one of these filters apart have a good look at how they work then you may want to make comment. The fuel should turn to drop the water (heavier than diesel) and some of the debris in the fuel in the glass bowl, to do this is must go down the inside of the filter and then up through the element, remember this is not a pleated element like most filters. You believe what you want to, that is your right but you may learn from the experience of others?

You will find that the arrows cast into the housing are incorrect, this was discovered years ago but they still make the generic/aftermarket ones incorrectly. How does water get into the glass bowl if it is plumbed as per the arrows?

These CAV filters are different to a standard pleated filter that flow mostly from the outside in. They are spiral wound and should flow from the bottom up, you can see the construction in some of the shots that Dylan put up when he dismantled it. A simple fix to plumb correctly that will give longer filter life. Put a restriction gauge in the system and only change on that not visual will get the best life from these filters.

You are seeing this crud on the top of the filter as it is plumbed incorrectly, all should collect in the glass bowl or on the bottom of this spiral wound filter media. Top should be clean.

Racor turbine series will certainly provide great filtration but how much fuel flow returns to the tank to continue the clean up process? If its mostly leakoff from injectors then it will take a long time to do anything. The 500FG & 500MA did come with 2 micron elements from new in the past which is way to fine for your purpose, 30 would be better . Would respectfully suggest running all this contaminated fuel through your diesel heater onboard which will be less fussy and run a portable tank for the engine. When the boat tank is empty dose, clean and syphon out dose again then when confident all is clear hook back up to the engine. The bug has acids as a byproduct that can be hard on injection components. Happy sailing

The aftermarket CAV agglomerator filter heads have the arrows going the wrong way. Fuel should flow down the middle, turn to flow up the element dumping water and other foreign crud on the way. Plumbing this way will also give you new threads to deal with. Originally olives with running nuts were used on most of these and tails are available.

We used Mylar cut to shape to overlap on Tornado’s, it took a while to get the area glued right without the Mylar bending out of shape permanently. We installed a piece from a rubber wash up glove at the front to help it closed and fair it when the board was up. The right preparation and glue was important as many contact glues are not water proof. With the board down there was little gap and minimal disturbance or water in the case, you would actually get a Venturi affect. You knew when it came off. Can’t see that rubber would have the rigidity to work at speed?

Oil has many functions and cleaning is one of them especially in a diesel. If it is not getting dirty then it is the wrong oil. These engines don't want to "good" an oil, lived through the 80's with many Japanese engines needing to be rerung under warranty due to bore glazing and Castrol GTX a contributor. Just to slippery gor the technology. Plain oil, run engine hard and hot ( within limits) and change oil regularly are my recommendations. Your engine though do what you see as best.

Have a look at magnet treatments for the diesel bug such as Purafiner made in NZ. Snake oil, smoke and mirrors or whatever but they appear to work?