Diagnosis: (minimum) 1 blown head gasket PER engine.
Took boat out for a second water test this morning (Friday) with the local marine mechanic as a second set of eyes / ears. Even with the TPS sensor fixed, we were still under powered. I opened the boat up twice to red line (or at least I tired to), each time for maybe 10 seconds. This was the ONLY time the engines were in boost. All other times, the engines were below 3400 rpm’s and pulling manifold vacuum.
86.1 mph at 4800 rpm.
While this might sound good to most, last year I hit 90.9 mph with 150 less hp per engine (550 vs. 700). Also, I was running the exact same props. More HP usually = more speed.
Knowing something was still wrong, I cruised back to the marina at a gingerly 3000 rpm (she felt fine there). As I get to the launch ramps, I open the hatch to find oil EVERYWHERE. I mean… E-V-E-R-Y-W-H-E-R-E!!! It wasn’t just normal oil either. No sir, this was that “special” oil that looks like a frosted coffee latte from 7-11.
I took pictures of the mess, but I’m too disgusted right now to post them (I’m also on a dial up).
So, I sent the boat back to the marina and they are pulling the engines out this weekend. After that, I’m taking them back to the engine builder in Detroit for further analysis. Both the builder and I believe the ECU calibrations caused partial load detonation, which blew out both the head gaskets. If it only happened on one engine, it could easily be called a fluke, but both engines blowing out within 15 minutes of initial operation in the boat?
That part the REALLY chaps my ***, is that I have no idea what has been done to the ECU’s. I’ve tried many times, in vain, to get the parameters that have been changed documented somehow. Heck, ANY type of documentation would have been nice. I am also suspicious that my original Merc ECU’s (from a 454 mag) were never updated to 502 specs. Even though I mentioned this numerous times, the calibrator never mentioned to me that any of this was ever performed… I would simply get a “they’re done” response. Again, SOME sort of documentation would have been very helpful here.
So, am I done for the season?
I statistically could still have a pleasant, worry free day on the water this year. Of course, I stand a better change of winning the state lottery while Elvis simultaneously crashes a fully loaded 747 in my backyard.
Cliff Notes: EFI sucks, stick with a carb(s).
Took boat out for a second water test this morning (Friday) with the local marine mechanic as a second set of eyes / ears. Even with the TPS sensor fixed, we were still under powered. I opened the boat up twice to red line (or at least I tired to), each time for maybe 10 seconds. This was the ONLY time the engines were in boost. All other times, the engines were below 3400 rpm’s and pulling manifold vacuum.
86.1 mph at 4800 rpm.
While this might sound good to most, last year I hit 90.9 mph with 150 less hp per engine (550 vs. 700). Also, I was running the exact same props. More HP usually = more speed.
Knowing something was still wrong, I cruised back to the marina at a gingerly 3000 rpm (she felt fine there). As I get to the launch ramps, I open the hatch to find oil EVERYWHERE. I mean… E-V-E-R-Y-W-H-E-R-E!!! It wasn’t just normal oil either. No sir, this was that “special” oil that looks like a frosted coffee latte from 7-11.
I took pictures of the mess, but I’m too disgusted right now to post them (I’m also on a dial up).
So, I sent the boat back to the marina and they are pulling the engines out this weekend. After that, I’m taking them back to the engine builder in Detroit for further analysis. Both the builder and I believe the ECU calibrations caused partial load detonation, which blew out both the head gaskets. If it only happened on one engine, it could easily be called a fluke, but both engines blowing out within 15 minutes of initial operation in the boat?
That part the REALLY chaps my ***, is that I have no idea what has been done to the ECU’s. I’ve tried many times, in vain, to get the parameters that have been changed documented somehow. Heck, ANY type of documentation would have been nice. I am also suspicious that my original Merc ECU’s (from a 454 mag) were never updated to 502 specs. Even though I mentioned this numerous times, the calibrator never mentioned to me that any of this was ever performed… I would simply get a “they’re done” response. Again, SOME sort of documentation would have been very helpful here.
So, am I done for the season?
I statistically could still have a pleasant, worry free day on the water this year. Of course, I stand a better change of winning the state lottery while Elvis simultaneously crashes a fully loaded 747 in my backyard.
Cliff Notes: EFI sucks, stick with a carb(s).
) and sonic cleaned. Engine builder has gave me a date of Saturday the 17th as his target to get the long blocks back together with new head gaskets. Once I get the blocks back I need to redress them before making another dyno run. If the one engine appears to run the way it was supposed to from day one (i.e. NOT lean) then I will forgoe dyno testing the second engine.
