Cheap 496 mag upgrades (375hp)
01-25-2011, 11:23 AM
#131
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01-26-2011, 12:15 AM
#132
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That is my undersdanding as well. If the engine is set up such that it will inherantly want to detonate the Merc knock control system will not protect it. Sounds like this system would: http://www.jandssafeguard.com/safeguard.html
In all honesty, I think you are SERIOUSLY splitting hairs that in the end won't net much.
You can study a text book on law and know all or most of the answers but most people still need the attorney to show in court. Often times, the experience prevents the attorney from having to go back and read the book again. You can put every single warning alarm on your engine and still screw it up. That goes for all of us.
If the engine is setup and run properly, there is no need to do this. For that matter, nothing lasts forever obviously and if it matters that much one could always park the boat and never use it.
Question is: how far to take the worry? It's all just junk waiting to break no matter what product you buy or who you buy it from. Detonation happens when things aren't done properly.
To try and tie this into a 555 is overkill.
You fix it and move on. It's just one mans opinion.
01-26-2011, 08:12 AM
#133
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Rage, I don't doubt for a second whether or not you're a sharp guy. I'm sure you're probably much sharper than I am. I doubt that.
In all honesty, I think you are SERIOUSLY splitting hairs that in the end won't net much.No doubt.
You can study a text book on law and know all or most of the answers but most people still need the attorney to show in court. Often times, the experience prevents the attorney from having to go back and read the book again. You can put every single warning alarm on your engine and still screw it up. That goes for all of us.Agreed.
If the engine is setup and run properly, there is no need to do this. Not necessarily true. I know my engine is set up properly because it is fundamentally a HP3 Gen II config which is extremely reliable. The only exception is the custom A/F fuel table which I would like to sweep from idle to WOT with a suitable detonation screening method to confirm that there is no hidden glitch. I do not expect to find anything because there are lots of hours on this engine and no evidence of anything but a sweet running engine when I pulled the heads. However as you know S**T happens. The detonation detector thing is mostly to provide some kind of warning should the fuel pressure regulator creep and I miss that or an injector goes lean or a fuel pump developes a problem or the fuel is contaminated or.... For that matter, nothing lasts forever obviously and if it matters that much one could always park the boat and never use it. Never happen.
Question is: how far to take the worry? It's all just junk waiting to break no matter what product you buy or who you buy it from. Agreed but sometimes there is less breakage if you can catch it early. Detonation happens when things aren't done properly. Yes that is the primary cause but not always as mentioned above.
To try and tie this into a 555 is overkill.
You fix it and move on. It's just one mans opinion.
In all honesty, I think you are SERIOUSLY splitting hairs that in the end won't net much.No doubt.
You can study a text book on law and know all or most of the answers but most people still need the attorney to show in court. Often times, the experience prevents the attorney from having to go back and read the book again. You can put every single warning alarm on your engine and still screw it up. That goes for all of us.Agreed.
If the engine is setup and run properly, there is no need to do this. Not necessarily true. I know my engine is set up properly because it is fundamentally a HP3 Gen II config which is extremely reliable. The only exception is the custom A/F fuel table which I would like to sweep from idle to WOT with a suitable detonation screening method to confirm that there is no hidden glitch. I do not expect to find anything because there are lots of hours on this engine and no evidence of anything but a sweet running engine when I pulled the heads. However as you know S**T happens. The detonation detector thing is mostly to provide some kind of warning should the fuel pressure regulator creep and I miss that or an injector goes lean or a fuel pump developes a problem or the fuel is contaminated or.... For that matter, nothing lasts forever obviously and if it matters that much one could always park the boat and never use it. Never happen.
Question is: how far to take the worry? It's all just junk waiting to break no matter what product you buy or who you buy it from. Agreed but sometimes there is less breakage if you can catch it early. Detonation happens when things aren't done properly. Yes that is the primary cause but not always as mentioned above.
To try and tie this into a 555 is overkill.
You fix it and move on. It's just one mans opinion.
We do have different philosophys but we both love to run them hard and fast.
Last edited by Rage; 01-26-2011 at 08:18 AM.
02-29-2012, 01:40 PM
#134
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Ok, I figured I would post in this thread rather than start a new one since there are many on this subject. I have been contemplating doing the MAG to HO conversion and have pretty much changed my mind a hundred times. My 32 Advantage, with twin 496 runs fine around mid 70s. I realize that the approximate 100 hp will not affect speed much at all but it surely won't hurt and they just sound better. I already know the price, and know who I would have do it. About a month ago, I was convinced and was planning on the trip to take the boat. Now, with talk of gas at $5 a gallon, I am faultering on my commitment. The roughly $5K it is gonna cost will buy quite a bit of gas. I think I already had the GF sold on the idea by telling her that it would "raise the resale value of the boat if we wanted to sell since they are will still be technically stock". I bought the boat summer before last at a repo seller, and it showed 44 hours. (not sure I believe it though) The boat sat for a while, and the engines look brand new, but the outdrives look a little more worn (not bad though). Anyway, I figured since my builder would already have the engines out, he could scan each motor for a realistic run time(they show 71 now), and also check them out to make sure they are in good shape even though they ran like tops last summer. I went and re-read this whole thread and opinions run from "Don't waste the time or money" to "Best upgrade for the buck available on the 496". Just trying to re-convince myself.
02-29-2012, 01:53 PM
#135
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Ok, I figured I would post in this thread rather than start a new one since there are many on this subject. I have been contemplating doing the MAG to HO conversion and have pretty much changed my mind a hundred times. My 32 Advantage, with twin 496 runs fine around mid 70s. I realize that the approximate 100 hp will not affect speed much at all but it surely won't hurt and they just sound better. I already know the price, and know who I would have do it. About a month ago, I was convinced and was planning on the trip to take the boat. Now, with talk of gas at $5 a gallon, I am faultering on my commitment. The roughly $5K it is gonna cost will buy quite a bit of gas. I think I already had the GF sold on the idea by telling her that it would "raise the resale value of the boat if we wanted to sell since they are will still be technically stock". I bought the boat summer before last at a repo seller, and it showed 44 hours. (not sure I believe it though) The boat sat for a while, and the engines look brand new, but the outdrives look a little more worn (not bad though). Anyway, I figured since my builder would already have the engines out, he could scan each motor for a realistic run time(they show 71 now), and also check them out to make sure they are in good shape even though they ran like tops last summer. I went and re-read this whole thread and opinions run from "Don't waste the time or money" to "Best upgrade for the buck available on the 496". Just trying to re-convince myself.
02-29-2012, 03:14 PM
#137
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Scan the motors while they are in the boat and if the numbers match your meters leave it alone and put that money in the tank and enjoy the summer boating!
02-29-2012, 05:53 PM
#139
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Ok, I figured I would post in this thread rather than start a new one since there are many on this subject. I have been contemplating doing the MAG to HO conversion and have pretty much changed my mind a hundred times. My 32 Advantage, with twin 496 runs fine around mid 70s. I realize that the approximate 100 hp will not affect speed much at all but it surely won't hurt and they just sound better. I already know the price, and know who I would have do it. About a month ago, I was convinced and was planning on the trip to take the boat. Now, with talk of gas at $5 a gallon, I am faultering on my commitment. The roughly $5K it is gonna cost will buy quite a bit of gas. I think I already had the GF sold on the idea by telling her that it would "raise the resale value of the boat if we wanted to sell since they are will still be technically stock". I bought the boat summer before last at a repo seller, and it showed 44 hours. (not sure I believe it though) The boat sat for a while, and the engines look brand new, but the outdrives look a little more worn (not bad though). Anyway, I figured since my builder would already have the engines out, he could scan each motor for a realistic run time(they show 71 now), and also check them out to make sure they are in good shape even though they ran like tops last summer. I went and re-read this whole thread and opinions run from "Don't waste the time or money" to "Best upgrade for the buck available on the 496". Just trying to re-convince myself.
02-29-2012, 06:23 PM
#140
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My last statement got me to thinking, so I went back and pulled up some prop shaft dyno tests I've done. Interesting comparison. At 3000 RPM the 496 Mag made 445 Ft. Lbs of torque, the HO made 448 and the stage 1 HO made 479. That is a 30 ft. lb. increase over the stock HO program at the critical planing rpm and the gains carried all the way to 5100 RPM, where the stage 1 made 410 pshp and the stock HO made 395, the Mag made 351 hp @ 4700. Anyway, just more stuff to think about. Carry on...
Bob Lloyd
Full Throttle Marine
Bob Lloyd
Full Throttle Marine
