GM 90 cogen project

[squarebob]

Veggie, here is a pic of mine as it came with the water pump and gov spring in the original position. Mine is on the closest stud. I guess that is why they say "specifications subject to change". The second pic is the current setup. The water pump is taking up space on a shelf right now. Might find a use for it later on.

Bob

[squarebob]

Ran the engine again today and I have discovered a coolant leak at the base gasket. Water puddling on the crank base on the ledge of the crankcase base and the cyl head base on the fuel rack side and near the valve guides. Checked all coolant fitting for tightness and all were OK. Shut down the engine, wiped up all the "mess" and cleaned the area with Q tips. Started the engine back up and in short order coolant began to reappear. I would assume if coolant is leaking out, it is also leaking in and contaminating the oil. Haven't opened up the crankcase yet so can't verify at this time. Is this a common occurrence? Looks like I may have to do a major tear down and replace the base gasket. Or would a small amount of "block seal" in the coolant fix the problem. It sure worked well in a car engine with a bad head gasket I had a few years ago.

Bob

[squarebob]

Jens, you are right. It is running down the stud. I will remove the head and replace the gasket. Is there a tightening sequence on the head bolts? Is there a torque spec? Can't find one in the manual.

Bob

[lowspeedlife]

The GM-90's should not have this problem but, while you have the head off you need to check the cylinder liner protrusion, iirc .000 to .002 is the correct spec (if i'm wrong some one will speak up). if using the copper gasket an old trick is to carefully peal back the copper sheet & liberaly apply some floor wax (johnson floor wax is what they used to use) to both sides of the fiber interior of the gasket. the wax will soak into the material & prevent the coolant from migrating thru the fiber. a better fix is to use a "gaskets-to-go" replacement gasket, they are a fiber gasket with a fire ring & silicone beading applied to the gasket surface. they are being stocked in the US now & should be able to send one to you in a few days. here's a link http://www.listergaskets.com/#Listerheadgasket


 Scott.

[sailawayrb]

Lowspeed is correct that the "gaskets-to-go" will solve the coolant weeping into the head bolt cavities.  I once had an opportunity to confirm that these gaskets will stop this weeping over a wide cylinder protrusion range.  Frankly, I am surprised that anyone would use the copper gaskets these days.

[squarebob]

I ran the engine out of fuel today. I filled it back up then cracked open the high side fitting at the pump, turned it over until I got fuel, then tightened it back up. Cranked her over and she started. But now it is not making full power. At full load the rack is fully open and I am only getting 55 Hz. Could there be air in the line between the pump and the injector causing this problem?

Bob

[Crofter]

Yes, a bit of air can get trapped and act as a cushion keeping you from getting the solid displacement volume. Usually it will clear but you may have to bleed it further.

[Henry W]

It will take a while to bleed the air out of the standard GM-90 fuel filter. It took about 5 hours to have all the air to work itself out by letting it sit and constantly bleeding air out of the top of the filter housing. I went through the same you are going through. Try bleeding the fuel filter again. Also bleed all the lines to the injector pump.

Henry

[squarebob]

Time really flies when you are having fun. Here are my latest project updates. I have installed a Delco 10si on the GM90 to charge the starting battery. Works good. Now the problems with the 24V system.  I have a 150amp, 24V alternator with an external regulator. The unit puts out 28.5 V and works OK. But I wanted to have a better way to charge the battery bank so I saved up and got a Balmar MC-624. The Mac Daddy of regulators! Removed the factory reg and hooked up the Balmar. Nothing, nada, no juice. The unit ramps up the field voltage to 25 volts but the darn thing will not energize. I hooked up the factory reg and everything works fine. What could be wrong? So I also have a Leece Nevelle 110-412 24V 75amp unit. I put that unit on the GM90, hooked up the Balmar and presto........... Everything works just fine. Nice ramp up to bulk charge and everything is happy. So I know the Balmar works and I know the 150amp alt works but they won't work together.  Any ideas as to what I need to do to get the 150amp unit to make some juice? Here are some pics of the 150 amp unit.