Micro CoGen.

Hi, Al.  The parts are finally coming together.  I tried to post to your blog but it didn't seem to go through - I have a basic question:  I am using similar bushings and pulleys that you did.  Do the bushings need to be pressed into to pulleys and then the assembly pressed onto the shaft (ie with a hydraulic press)?  Did you need a retainer on the end of the PTO?  Seems like a tight fit and I don't want to permanently bang it all together for the test fit.

Thanks,
Ryan

Al, one more question - does the Kubota shaft have a key?

Thanks, I'll try E C Power.  Since I'm buying some parts in the US (like a lot of brass fittings I got while home at Christmas) and some here, I will have mismatched metric/english sizes - will surely confuse anyone who tries to work on it in the future.  I'm trying to keep the alternator for the genset and for my main engine similar so that they can be exchanged as spares - both alternators (a Balmar 110A and an Electromaax 160A) have K6 serpentine belts so I will have to try to find a big (7") serpentine belt pulley that will fit on the Kubota shaft.

I hadn't seen the surpluscenter.com catalog before, impressive.

Yes, the label on the small plastic bag is just for the washer... I don't have the part number for the return assembly, but I ordered it from NextGen.  They use it on their gensets so I'm sure they could tell you.  (I just pulled out my NextGen receipt - the other Kubota parts have Kubota parts numbers but the return fitting part number is SCSRETURN-FIT so it may be their own part.)

As for the alternator bracket, I would have the top bolt hold a flat adjusting bracket and have the alternator pivot on the lower mount.  The photos I included are from a classified ad I came across.

Ryan

The alternator bracket:

Thanks for checking - 2.5:1 will make a good 1120 rpm for my impeller pump.

I was going to modify the flywheel takeoff I have by adding a splined shaft and have k6 and 1/2" pulleys made up but the first machinist's quote was outrageous (I am in Hong Kong so I'm limited by language where I can go) - $550 for the shaft/pulley assembly and $55 for a simple mild steel bracket, so I think I will try to find the Kubota takeoff that you used and find standard pulleys.  Did you order direct from Kubota in Japan?

There's a pic below of the new fuel return fitting - the nipple is bigger than standard so hopefully that will make hose sizing easier.  Not sure what I will do with the other nipple since I am using an external tank/filter  but maybe it can be a bleed valve.

I think this guy (pic attached) has the right idea for the alternator bracket.  I will make a template unless someone knows if it is commercially available.

Ryan

I took a closer look at the layshaft yesterday - it's actually even more than 2:1, maybe 2.5:1.  I will mark it and measure better, I didn't see a reference in the manual.

I started to say in my last post that the pump is rated for about 10-20 lpm at 1150rpm which seems reasonable for this engine.

I'll let you know how it goes.  As for the hand crank, I didn't know it was half speed, that would help a lot.  I would rather have all belts on the other side of the engine but it may not be possible - I am thinking about putting a pulley on that shaft, removable with one bolt to use for hand cranking if the starter fails in an emergency (could rig up an electric pump for raw water circulation temporarily).  I would have a pulley welded to a tube about the same ID as the OD of the shaft, with slots for the hand crank pins, then drill and tap a hole in the end of the shaft for a retaining bolt.  Still not sure that's a great idea.  Cutting the housing is an option, too.  The pump

About the air return, I obviously don't know anything about it either... I've taken off off the jetstart so it may not be necessary.

Hi Al, just saw your response, thanks.  I got some good info a while back from our blog - I am almost exactly in the stage of your #1 of 20 pictures.  Bending my brain on the best platform/mounting  for the space I have right now.

I am installing this in a medium sized lazarette (I may box it in with some insulation and a blower depending how loud it is) - I did get the nextgen exchanger.  Do you find it does the job?  There are also two nuts on the side in the freshwater part which I guess could be used for external circulation.  Your set up and some of the commercial versions out there seem to run the raw water pumps at 1:1 or so with the crankshaft... at 2800 rpm (although I think you run at 1800) that could be 30+ lpm which seems like a lot for a 6hp engine and I would guess not great for the impeller.  I think I have the same waterlift you have, a 1.5" Vernalift - no problem with that amount of water for yours?

I also ordered a return fitting from Nextgen thinking it would have a larger nipple (it may) - but it has two fittings, one of which the rep said goes to the air bypass line on the injector pump.  Not sure this is necessary except maybe to bleed the system?  Stock set up has only the one return.

I'm using a Facet fuel pump and got a second one to use as a transfer pump from my main diesel tank.  We'll see if it's strong enough to push 15 feet or so after a filter.

Ryan

I'm building a genset/watermaker for my boat based on an ebay EB300 and I've got plenty of questions that I'd like to put to the collective wisdom of the group.  I've been working on petrol engines for years but don't have much experience with small diesel engines.  I've taken a look at MV Viking Star's blog site - I think the owner is on this board as well.

The unit will be used in temperate to hot weather in a saltwater environment.  It will be installed in a small space so I will use a heat exchanger and probably an exhaust blower for ambient heat.  The fuel tank will probably be mounted below the engine so I will use an external fuel pump.

I've only seen a few heat exchangers for these engines and have seen various complaints about build quality.  The nextgen unit is available for about $400 and seems to be the best bet - any experience or better yet does anyone have a secondhand one they'd like to unload?

Are most accessories interchangeable between the EA300 and EB300 (I'm thinking mainly of radiator/heat exchanger)?  While I'm at it, I have the manual for the EA300, what are the main differences between the two?

Fuel:

I'd like to simplify the fuel system - there are 5 lines to and from the tank.  Can I removed the jet-start system and reduce to a single feed (inline pump and filter) to the injection pump and single return from the injector?

For the fuel pump - what's the acceptable range of supplied fuel pressure/flow rate since I won't be using gravity feed?

Exhaust:

The exhaust port on the Kubota is about 30mm ID.  Can I use 30mm ID exhaust pipe and tubing throughout (and for the waterlock), or should I upsize after the mixer since my raw water pump will be putting through 4-6 GPM of cooling water?

Vetus has waterlocks, mufflers, goosenecks, and anti-siphon devices which together seem like overkill for a small system (at a high cost).  Can I get away with just a waterlock if 1) the heat exchanger is a foot or so above water level, and 2) I put a high loop in the exhaust hose between the waterlock and the overboard outlet?

Thanks in advance for any insight.