Re-power comments [Warning this is long but its fr

[Al]

Some Re-Power Notes These are free so value accordingly With the EPA requirements eliminating the K, KT, Magnum series Kohler, 243000 and 32600 Briggs family and rumor having it that one more year and the 400000 Briggs twins will be gone, alternatives are needed. As I have done a lot of research in this area, I thought I would touch on some issues that one needs to be aware of. Fallacy #1. An engine is an engine. Not true. Engines are built in many configurations, for different applications. That is why when you look up parts for an engine you may find up to a hundred or more “Spec” or “Type” numbers. This is what determines what is in the engine or what it is designed for. For example the K341 Kohler, there are 3 different blocks, one with straight sides that the sump bolts from the bottom, [ala Cub Cadet etc] One with ears that the sump bolts on from the top [ala Simplicity, John Deere etc], One with ears and cut outs inside the ears. Two of the three are NOT able to replace the other. Specs also determine carb, air cleaner, whether the air comes from the flywheel housing to the air cleaner, or from the engine compartment. Starter and charging systems and capacities are identified by spec etc. An example of how the wrong engine could be a problem. In some Haulmaster trucks there were some spark plug fouling problems in the 16 Vangard. The problem was due to people using them to easy and too much idling. A kit was installed that closed up some of the baffles and warmed the engine up. If you got one of these kitted engines and put it in a tractor to mow, you could have serious cooling problems. So if you are buying engines on the surplus market be sure you know what you are buying. If one buys a new 18 hp engine with a 3 amp dual circuit charging system and puts it in a tractor with an electric clutch, doomsday ahead. One must match all of the specs needed for the application to the engine being purchased. Fuel pumps are another special issue. The light duty vacuum pumps don’t work in hot weather if they have to lift the fuel more than 6 inches from the tank. The heavier vacuum pumps are good to 12 inches. Beyond that one needs a mechanical pump or no pump and an electric. If one goes electric the pressure MUST NOT exceed the Mfrs. Spec for pressure [often 1 to 2 lbs. Sq. in.] Next is a ducted or non-ducted engine needed. In the newer enclosed engine tractors heat re-circulation is a problem. If you look at an old John Deere like a 112 or a 129 Cub you will notice that the cooling shrouds extend over and around the muffler. This is done for a reason. It is to control the air flow and eliminate the heat re-circulation problem. Heat re-circulation is when heat from the cylinder, muffler etc is pulled by the fan back to cool the engine. The path over the engine and under the hood is common. If you were to look at a 5216, you would see a foam strip ahead of the flywheel on the fan housing that contacts the hood. This is to STOP heat re-circulation, and it is important it is there and in good condition. The flat steel plate over the muffler on the 7116 is there for the same reason. A typical issue is like the Sim 9020 the cylinders and heads spill their hot air outside the hood, the hood has a lot of special baffling for the intake air and the air from the muffler is pushed into the battery [bad deal]. Put in a V twin and all of the cylinder heat that was spilled outside the hood is now under the hood, many new cooling problems. Plan how to address this. Heat re-circulation results in catastrophic engine failure operating in a hot environment. This is why all of the attention has been given to the ducting. Engines that fail this way are often rejected for warranty by engine mfrs. Another common failure is Valve seats coming out. This is almost always an overheating issue, caused by not running the engine wide open when it is working, [ex mowing at ½ throttle]. Or having the fins partially plugged. Engines with these failures, the Warranty claims are almost always rejected. Dealers don’t make these decisions, the engine companies come in and do a failure analysis and determine if it is their fault or the customers fault and whether they will pay for it. Another issue is the air intake. If the air cleaner is pulling hot air, the fuel line is in too hot of an environment, or inadequate fuel pressure, vapor lock becomes a problem. Depending on the application it may be better to pull the air from the fan housing and blow it into the air cleaner. One of the drawbacks of this is that in dirty environments the fan sucks up a lot of dirt and creates another problem. Other applications it is better to pull the air from the outside world. Typically an OEM designs a unit and then it is run at full throttle, loaded on a dyno to about 3000 to 3200 in a 110 degree room for one hour. The cylinder head temperatures are monitored at the base of the spark plugs, the oil temperature is monitored in the center of the oil pan. The cooling air intake is monitored at 12, 3, 6, and 9 o-clock positions at the flywheel. The fuel temp is monitored at the carb. and often the temperature in the venturi. The back pressure of the muffler is monitored to be sure the muffler doesn’t throw the emissions out of spec. If they pass these tests they can be fairly certain they will not have a problem with engine failures that are not warranty and are their fault. Next we need to look at the real estate we have, what will fit, crankshaft height is the length the same, if not, do we line up the front or the back and how do we compensate. What do we use for exhaust, will it be a cooling problem. How about liability if we put the muffler outside and the neighbor kid gets burned on it???? This is no longer state of the art. Things like electric clutches that for example worked on the Magnum series no longer fit the CH series. Changes like standard bolt circles to metric. Things like metric drive adapters to replace standard adapters, which connect to standard driveshafts. Things like is there room for the oil filter, does it need a remote kit, where will is mount and stay cool? Electrical, do you need to change from battery to electronic ignition? Will you use a solenoid actuated Starter? If so the old wiring and ignition switch will not handle the pull in currents to reliably kick the starter in. We have developed some kits that adapt the old wiring to the new electronic ignition systems without changing the ignition switch and safety switch circuits. Just connect 4 wires, kit can also fix the starter problem. I am offering this to help people to understand what is involved in powering a tractor and some of the things that need to be looked at when re-powering. Look carefully at the unit you are starting on and try to understand why things are the way they are and then try to envision things that can contribute to problems when repowering. This is provided as food for thought, and not as a rigid guideline. I just hope this might save someone some headaches by allowing them to look at the whole job before tearing into it. It is something that will need to be dealt with soon. Respectfully Al Eden

[jackcobb]

Wow, how timely this is for me. I have been thinking of going tractor pulling. My plans were to pick up a 321 or 341 and have it redone. Then slip it in my 712. I didn't realize the blocks were different? Knew the cranks were, but I figured I could buy the right one of those during the rebuild. So I guess this leaves Cadet, Wheel Horse out. Sounds like a Deere (what a shivering thought!)would work. Thanks

[SmilinSam]

Some of the best advice of the year, I'd say. Thanks for posting it. Sam

[JDSnyder]

Al, thanks for the information. It really should be added to the Do It Yourself section.

[johnmonkey]

Thanks for the input. If I ever decide to swap an engine that info is very valuable. In an earlier post I saw a 16hp briggs that looked exactly like my 7hp 700 wonderboy and my 725 monkey wards gardenmark. Does anyone know if the 16hp briggs will replace the 19d engine? Thanks and Happy Holidays, John.

[PGL]

Another "keeper" Al. Thanks.

[BradW]

Al, I'm happy to see you participating in the club again. I don't think casual visitors realize the amount of time it takes to respond intelligently to questions. I always read your well written and informative posts thoroughly. Thanks for taking the time. Wishing you a Merry Christmas & Happy New Year

[SmilinSam]

Johnmonkey, The 9hp - 16hp are different sized blocks. Someone put one in a 725 tHat came through my hands once. They had to cut the frame and drill new holes to make it fit.Then it still wasn't right. Sam

[dlcentral]

Northern, has many engs. to fit all needs.The 321 is a no prob fit in a 712.I have a complete 321 here for sale and a shortblock for rebuilding,,, Happy Holidays to all!,,

[MikeES]

Jack, good luck on finding a K341, they are rare, the tractor pullers have scarfed them all up. The narrow block for the Cub Cadets are harder to find than the wide blocks. Dave C. if you lived over here in WI. I would consider your 14hp. for my puller. (shipping cost) :( Good Luck! Mike S.

[SmilinSam]

Rebuildable K341 blocks are good property. I usually get and sell 2-4 a summer for about $300 ea complete. All out right now.