DIY_EFI Digest Friday, October 15 1999 Volume 04 : Number 582 In this issue: Re: marine engine FI Re: marine engine FI See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Fri, 15 Oct 1999 15:32:22 +0200 From: nhoj@xxx.se Subject: Re: marine engine FI Stuart Hastings wrote: > > The Ficht has a whole lot of other parts to break. (And it seems to be > > doing so with gusto...:)) > > Hmmm. Oddball injectors, computer to drive them, special alternator, > and an oil injector in the crankcase... I guess you have better > sources than I do, but I had understood that most (catastrophic) Ficht > failures were related to internal engine parts, like pistons, rings, > and cylinders. Stuff that was supposed to be well-debugged by now :-) . I don't think anything really breaks when the injectors stop working. After all, oil is passed another way. That's why you don't hear much about it, I guess. > > I doubt the marine engine manufacturers would fit a compressor unless > required by smog regulations. It adds weight, complexity, and cost. > But I personally would consider owning such an engine. Well, in theory they could move to slip bearings and a conventional crank. That would save a good pile of dough... > > This may be true. I read somewhere that it is doubtful that a significant > > amount unburnt gasoline passes into the environment because of the high > > temperature of the exhaust gases. > > It has been definitively shown here in California that most of the > MTBE found in surface water (lakes, reservoirs) came from non-DFI > two-cycle engines. OK. > Here in the Silicon Valley, the local water authority permits > powerboats on three of our ten drinking water reservoirs. One of these > is open to Personal Water Craft (e.g. Jetskis(tm)) at the beginning of > every season, and promptly closed to them after the MTBE concentration > rises above a certain threshold. PWC dealers in Northern California > have mostly been driven out of business. My four-cycle boat is still > permitted on all three reservoirs. Well, having any boats on water reservoirs is asking for trouble, IMHO. > When DFI manufacturers claim 25-30% improvements in fuel economy, > they're talking about raw fuel that was formerly blown out the > exhaust. This is a settled issue. Yes. My point was that the high temperature of the exhaust gases would cause oxidation of the hydrocarbons in the exhaust stream once they leave the low oxygen athomosphere of the engine. > > That can easily be fixed with a holesaw, if you're worried. :) > > I'm not worried, because I insisted on four-cycle power when I bought > my boat. I'm not a "greenie," but spitting oil (and/or gasoline) into > the water dismays me, in spite of all genuine advantages of two-stroke > engines on a boat. If there is a significant environmental problem with spitting fuel into the water, it should be avoided, of course. The problem with DFIs and two strokes is that there are none in the really high output segment. (Unless OMCs 250 has been released.) > Most marine engines (in the U.S.) exhaust underwater because it's > essentially required by the U.S. Coast Guard for basic > safety. Boat-engine exhaust is typically mixed with water shortly > after it leaves the engine. I know. Dry stacking changes the tuning characteristics of the pipe, since the exhaust gases have different acoustics, and more engergy, at the higher temperature. > Most sterndrives (marinized car engines) > have many rubber parts in the exhaust just downstream of the water > port; if the water supply fails, the rubber parts promptly melt. I have no experience with sterndrives; Swedish gas prices are about four times higher than American prices, so we try to keep boat sizes reasonable... > If nothing in the boat is hot enough to start a fire, there should be > fewer boat fires. Nobody was thinking about ecology when these rules > were established. Of course. The situation is a bit different with an outboard, though, since it hangs a fair bit behind the boat. (I have about 40cm offset, for example.) Regards, John Hornkvist ------------------------------ Date: Fri, 15 Oct 1999 16:03:17 +0200 From: nhoj@xxx.se Subject: Re: marine engine FI Espen Hilde wrote: > > > I have 2 2.5efi high performance engines that I am reparing, line > boring > > > > Are they any fun? > Just problems so far, I've heard that they require far too much rebuilding for a "standard" engine. > but nice to look at with mahle forged pistons, > lots of ports .aluminium Nicasil treated sleeves. Big reed blocks. > and the v8 inspired trottle body. The loverunits are beauties, I have a > slightly modified Yamaha 225hp with nose cone that I have to fill with > padding all the time, I want to weld it but maybe it will change because of > the heat. What kind of filler do you use on the nose cone? (Mine is welded, and the paint is coming off, but the putty stays...) What kind of boat do you run those beasts on? I have a Hydrolift CR22. > Maybe the new lowerunits from Yamaha with biger skeg and > low water pickups has the same gear and internals as the one I have . I know someone who replaced the gears of a 150TRP gearhouse with the innards from a 225, or possibly 220. > I have very modified Yamaha 200 > What modifications have you done? Wayne Taylor heads and exhaust plate, HydroTec pipe (but that one is going to be replaced with a cut 225 pipe), ported front half, big intake and exhaust ports, shortened sleeves, cut pistons (forged from Wiseco), finger ports, dry stacked. I've also built a turboscope, but I've not had time to test and see if it makes a difference. > that will get an EFI > > system if it is still running when I can aford one (eg MADEFI) or find > time > I have looked at the mad efi myself, no I am hoping that 332 efi would > do the trick. If EFI 332 gets down to reasonable size; an 8x8 inch four layer board + driver boards is rather ridiculous, IMHO. Something like the ECU6 or ECU7 system would probably be good enough for an outboard, anyway. > I would like to play with the ignition also... > Do you have any info on recalibrating the ignition system on the Yamaha > engine? I don't, sadly. I know a Danish guy who may have the info, but I don't have his email address. He has a lot of tuning info from Yamaha. You may consider contacting them to find out... > > to build something... Performance below 4000 RPM is not exactly stunning > when > > using carbs. > What hp does it make? I don't really know. I had it tuned by a Swedish shop in Vasteras that have a DynaFlow, but they made a horrible mess of things. The porting they did was OK, but they made the heads totally wrong; the squish was going the wrong way, and the pistons kissed the heads. Then it gave 240hp from 6000 to 7000 RPM. In the boat I never got it to rev over 6200. Due to the mess they made of it, the crank broke after about 20 hours. Needless to say, I stay away from them these days. Now I have good heads, much larger ports and finger ports, and a modified exhaust system. 275-300 at 8000RPM is an educated guess. I don't wont to go much higher than 8000RPM, because that's how high Yamaha's own high output engine went. It used (or uses?) the same crank and bearings as the standard engines, but had longer rods and different pistons. (I don't think it used forged pistons, by the way.) The long rods make a huge difference I'm told. I think Hydrotec sells them, but I'm not sure. A bit too expensive for my taste, anyway. > I read somewhere that the ox66 engine used GM corvette ecu. Really? One would expect them to use Japanese components... That would be cool, though, because I bet there are lots of info on Corvett ECUs floating around. Regards, John Hornkvist ------------------------------ End of DIY_EFI Digest V4 #582 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".