kurtis500

@luckydave sounds like your doing it fine. Looks like this one split around the mold line

Id take a look at how your storing the ski and it what temperature and humidity it stays at year round. That can speed up the process

Bones are just like tempered glass. They are super strong but in certain angles and impact pressures they will break easily. If your not being paid to ski, dont do anything that will cost you

@Such_a_brett This is in Logan? I live in Park City most of the year and during the summer there is a non-stop stream of boats coming through here from Salt Lake to Jordanelle/Rockport/Echo. Moving from Phoenix and boating year round in AZ and the Colorado river I was shocked how many people have boats here. The boat per capita in Utah has to be high. Hopefully you do well.

so whats the relation between the precise fin adjustment and the diameter if the hole(s) in the fin??

I’m pretty confident that if someone added $100,000 to the prize money at every event you’d see more records go down than with micron level adjustments.

@horton some simple ASTM tests are cheap and easy... But its up to the builders if they want that information

Rudder/Elevators on an airplane are design dependant on the airfoil/fuselage. The properties of an airframe are known. Do we know what the properties are for the ski before the fin is added? Do skis undergo any standardized ANSI tests? If not, why not?

Theres way too much data missing. To know what the fin is doing we first should know what the structure is doing, in this case the structure is the ski. Just for starters there should be flex, torsion, CTE and other numbers from the ski makers. These numbers really should be taken from NIST equipment so consistency is known. ANSI tests that all the skis are subjected to would show which is stiffer, softer or etc. Without these numbers theres no way to tell exactly what the ski is doing under a load. Just getting back in the boat and downing a sandwich and a couple bottles of water then jumping back on the ski changes the load on the ski and the amount of flex. And theres a lot of ways to test flex.. NIST equipment and ANSI tests..... Anyone know if the skis have undergone this testing and is the data out there? Without it the case made that .002 can drastically alter a ski seems too incomplete.

@dbski yeah, theyre all aftermarket builds. The GM blocks have always been great crate motors. Mercruiser makes some darn nice motors and that twin turbo motor is actually a good price. Except you cant put those turbos under an engine housing without cooling jackets and etc.....bummer... Would be nice tho.

@the_bogan Your number of .01 is 2-3+ times the size of what was brought up. Just mentioning so nobody is confused

If a ski adjustment is made at one (air) temperature then thrown into the cooler water at a change of say 25F, what does that do to the fin? Plug in the fin length and area into a CTE calculator. Find both linear and volumetric expansion rates....it’s a set of calculations....scientific calculations.....then see how much of a .002-.004 tolerance is left after just the temperature change. Making an adjustment in the morning versus one made in afternoon heat and thrown in the same water temp will yield another number. If a tight tolerance like that is required then why are theses made of aluminum. Aluminum will warp more than most other metals. These factors must have been calculated in somewhere if aluminum is the choice @horton maybe rethink the carbon fin just on CTE versus aluminum alone. Hmmm

@lpskier what .005 adjustment can you feel? And what other factors do you calculate when making this adjustment.

@Horton what measurement or alteration can be moved .004 that goes from well behaving to misbehaving? Is the ultimate tool of measurement ‘feel’?

Distributor is on the correct end, just needs to be at an angle

@horton "Most short line skiers accept that a fin move of .003” or .005” is enough to make a real performance difference. " A human hair is .004 and people are saying they can feel that?

What purdueskier said. Your center post could be apart of the beam support. Looks like the trusses rest on the beam and not the garage walls so there is bearing weight there. If so the concrete/rebar may be designed for a center post. Whatever it is the engineer is your best bet and a contractor may require it for these reasons. Your code may require these plans before permitting.

@horton yes. The vertical surfaces can be opened up some. Holding the ski sideways it would be possible to look through it and also see the inside of the tunnel.

@RichardDoane I think so. I havent used them yet but the center mount design and construction seem top notch.

@bracemaker yes. foam was shot in the ends just in case but it floated without it. The boots float also so that helped a bit, and at 1540 grams before the nutplates it didnt need a lot of buoyancy. The fin is tig welded grade 5 Titanium (Ti 6Al-4V) so minimal weight added in the rear. The 2 peice structure will need to be opened up to allow water to drain out. Mouseholes or etc...

Quick facts: -Not a slalom course ski although similar. Closer to a Maha 360 or Andy Clark cut-n-jump -solid carbon with no foam core. -Purpose is to demonstrate heated tooling under autoclave pressure (multiple atmospheres) - 2x2 twill used for exterior layer only (decorative) - concave bottom I mentioned a few months ago on this site I would be doing a ski for demonstrating heated tooling in pressurized environements. Composites made with the highest strength and lowest void content are made under pressure. High pressure compaction of laminates eliminate the ability to use core materials during cure (high tonnage compression molding, autoclave cure with multiple atmospheres) More to explain later but I wanted to follow through with my coments a few months ago. This demo is made off the tools under vacuum, but not in the pressurized environement. I'll post those later

Not suggesting this to you but food for though on raising temperatures...... In our v-drive flatbottoms we would put a 3/8 nut inside the 5/8 water hoses... The restriction brought the temp up jus right and I still have my flatbottom setup this way after 25 years.

@markn what does the manual say is the proper operating temperature? One more question, did you install the thermostat upside down? Some are able to be installed both ways and the direction of water flow will hold open the thermostat. Again, depends on what thermostat you use

From the information provided it’s hard to really know where the problem is. First, what does the manual say is the ideal operating temperature? Second, after many years of racing and building my own race motors I can say 130f is well below normal OPERATING temperature. Extended operation at that low temp will effect the heads, valves and cylinder bores over time. Dyno results have shown this numerous times and the motor is down on hp when it’s too cold. Engines will run at low temp as they warm up but hundreds of hours at 130 has side effects. Based on your description of the temp going up after shut off I’d say you have too much cool water flowing somehow.

@horton you ever thought of trying it again? Was this something you built or had a company do?