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  1. curtis74

    Propylene Glycol vs. Ethylene Glycol/water

    Most people who have tried PG have reported about a 10 degree increase in their overall coolant temps, but what we don't know is how its measured or how accurate they are... nor can we know the weakest point of each individual cooling system to see where these numbers are coming from. I used...
  2. curtis74

    Propylene Glycol vs. Ethylene Glycol/water

    I politely disagree. Higher engine temps can have big benefits - reduced friction, better MPG, greater thermal efficiency. The traditional thinking is that engines overheat and get damaged at 240F, but we know that its the boiling that allows superheating of areas of an engine causing damage...
  3. curtis74

    Propylene Glycol vs. Ethylene Glycol/water

    So, is there a benefit, a drawback, or is it a wash? Here is what I'm looking at: Benefits: reduced corrosion from lack of water, reduced nucleate boiling, reduced (or eliminated) diesel-induced cavitation. Drawbacks: potential for increasing internal engine temps (oil, iron, etc) to the...
  4. curtis74

    Propylene Glycol vs. Ethylene Glycol/water

    I'm trying to do some math, but would settle for some real-world simplicity since engines don't run on math. :) I'm trying to verify some empirical claims from a well-known coolant manufacturer that sells non-aqueous propylene glycol coolant. I'm thinking about using it in my own personal tow...
  5. curtis74

    DIY structural foam (or honeycomb) panels

    Berkshire... that sounds like a nice plan. Do you happen to know how it does with hydrocarbons (e.g. fuel/oil)?
  6. curtis74

    DIY structural foam (or honeycomb) panels

    Hansmeister... yes I've thought about using plywood or balsa that is skinned with something to prevent the impact and flex damage, but the likelyhood of water ingress to the wood substrate is still pretty high. So far there have been enough promising FRP and other synthetic materials that...
  7. curtis74

    DIY structural foam (or honeycomb) panels

    Looks like FRP bar grate might not be any weight savings, but it sure seems like a pretty permanent fix. I found some distributors that have a pre-bonded 1/8" laminate on top. I'm just waiting to hear back from them re: spans and weight capacity.
  8. curtis74

    DIY structural foam (or honeycomb) panels

    My problem with plywood is that (in his application) it only lasts a few years. Dropping an anchor on the floor or the flexing of a pedestal seat causes fissures and cracks to develop, and then its just a matter of time until its a rotten mess. I refuse to put foam back in. I've never pulled...
  9. curtis74

    DIY structural foam (or honeycomb) panels

    Good call on the airline salvage... The aft end of the stringers are doweled and epoxied to the transom. The front is currently tied together with a 3/4" plywood bulkhead as a temporary support until I finish designing the floor. The original design was this way but it didn't suit me. I will...
  10. curtis74

    DIY structural foam (or honeycomb) panels

    Apologies... link troubles.
  11. curtis74

    DIY structural foam (or honeycomb) panels

    It isn't quite a commercial fishing boat but its used as such from time to time. Its a 19' Baja that the customer is completely in love with. He fishes recreationally about 8 hours a day and the rest of the time its used as a utility/rescue/repair boat for a fishing lodge. In a pinch it also...
  12. curtis74

    DIY structural foam (or honeycomb) panels

    I like that idea a lot. My concern with the stainless is denting. It would only take a few times setting down the anchor to make the deck distort/conform to the bar grate. ... but maybe some FRP bar grate with FRP sheet bonded to it This is grate... I mean great. My knowledge of materials...
  13. curtis74

    DIY structural foam (or honeycomb) panels

    I'm engineering a new boat floor for a customer's boat. He uses the boat very heavily and he's tired of replacing the flooring every few years and wants something a bit more permanent. I've discussed some FRP panels and some monocoque honeycomb skinned panels that would do well, but the cost...
  14. curtis74

    Whats going on?

    Changing the spark location changes where the flame front begins. In effect you have shortened the distance from where the flame starts to the piston crown. Mean Effective Pressure theoretically shouldn't change, but you may need to play with initial lead. My guess is that you will need more...
  15. curtis74

    (ask) Dry Ice for cooling air intake temperature

    Let's also not forget.... how will you get fuel to evaporate at such cold temps? Might be overkill. Carb - no way. EFI - maybe, but still too cold for practical max power.
  16. curtis74

    Intake Valve Design(Diesel)

    Brian.. I had read that and agree. My thought was that increasing any existing swirl could help, but I also said, "I'm not entirely sure you'll notice a measurable difference." We're on the same page, just different words. :)
  17. curtis74

    max compreesion water injection

    Quote: "Pat I agree with you about the variables described. However if you look at the published cr ratio from the major automobile manufacturers designed for 87 octane fuel they all fall within half a point of 9:1." Don't use manufacturer's published recommendations for anything but toilet...
  18. curtis74

    Intake Valve Design(Diesel)

    Depending on the type of chamber in the piston, swirling air might help. If you can get the incoming air to swirl enough that it continues all the way through compression until injection it might help slightly. I know what you're proposing; instead of injecting fuel into stagnant air, inject...
  19. curtis74

    (ask) Dry Ice for cooling air intake temperature

    without doing the calculations, I would assume that any temperature drop from dry ice would be directly counteracted by the increase in CO2 being ingested. Using dry ice to cool the intake is something that has been used for years, but putting it in the intake ducting would probably be...
  20. curtis74

    Older Ford OEM camshaft specifications needed

    The best resource I've found is Melling's website (I think its www.melling.com) They have the most extensive listing of factory replacement cam grinds I've found. Its not perfect since their factory grinds are not direct copies, but they at least duplicate factory duration, lift, LSA, and ICL...
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