Author	[Modern View]
LarryM 06-19-2012 18:49:35 76.208.68.23 Report to Moderator	This is a long one but brevity would not allow me to fully explain my dilemma. A few years back I bought a 450 LP with intentions of parting it out but when I got it home the original tach was reading 2700 hours. Everything was super tight on it so I decided to convert it to a gas tractor. I had a parts 450 with most of the mechanical parts I needed to put it together but no sheet metal. So it has sat in the shed and on my list of things I should do. A few weeks ago I made an order at Goodson and they sent me the email with my invoice number but the parts never came. I called them and they have no history of the order being made. Darn internet orders. So I ordered the parts over the phone. I had a day set aside to finally get my MH44 engine together but that now that was a waste… or so I thought. I took a moment to check an online free classified site and someone had listed a 450 on there with good tires and bad engine for $1000. So I hooked up the trailer and loaded up my Dad and we went to look at it. It has the best set of hoods I have ever seen on a farm tractor. It had all the parts I needed to complete my 450LP to gas conversion. It only took me about 2 minutes to figure out I was going to buy it. At what price though? It has a spun main bearing. Not stuck but no compression. Any way the seller had another mostly parted out 450 sitting next to it that had stuck engine that supposedly had not been stuck long. After talking for awhile I offered his asking price of $1000 on the tractor as long as I could buy the engine at a good price. Package deal $1200. So I got the engine home and it has Rock-It governor on it and it was barely stuck. The rod bearing are dated 1998 and it looks like they put all new valves, guides, and seats in the head. I ground the valves and honed number 2 & 3 with pistons in it and put it together with the used head gasket it came with. Lots of coppercoat. The pistons look to be the same design tractor supply sold way back when were still being sold ten years ago. So now I am starting to get to my point. I said starting; not quite there yet. When I bought that 450 LP I took the head and cleaned it up and threw it on an Super M engine that I was going to sell but needed a head gasket anyway. I put it on the dyno with a 450 LP manifold and it had 70 hp at 540 but would not hold it. At that time I thought that the issue was one of three things. Either the head was rough and the valves were not sealing properly, the LP manifold was too cold for farm fuel, or the octane was too low for the compression. I sold the head and manifold and put the Super M engine back together and sold it as well and for the most part forgot about it. So now flash ahead 3-4 years and I get this engine. I forgot to mention it has very nice 450 LP manifold. So this last weekend I got it in the tractor and it had about 50hp. I let it run on the dyno at 45 hp for about 1-2 hours and then it had 62 hp at 540. And now I get to my question. It would not hold the 62 hp. It would drop down to 57 hp. If I let it idle for a couple minutes then it has 62 hp again for about 30-40 seconds. I found that my fuel cap was plugged and thought I had solved my problem. That was not the case. I pulled the plug on the carb and gas just keeps running out rapidly for much longer than I should have let it considering the price of gas. So I have been thinking about it and maybe I am missing something here. Maybe my float level is to low in the carb. Maybe I need to get the number drills back out and go after the jet. I have other carbs to try. I just have non-ethanol off road fuel in the tractor. Does the LP manifold run to cold for farm fuel? Would a larger diameter venturi decrease the delta P across the carb and therefore increase the temperature in the manifold? The main reason I am typing this up is because I figure there are some very experienced people on here that can shed some light on the situation. I would rather say I don’t know and have someone point me in the right direction than figure it out on my own. I am thinking the carb is the first thing to address but I am uncertain. This winter I intend to put in a reground cam and LP head on it but for now I would enjoy runnging her down the track few times with my $200 engine. [Reply]   [No Email]
LarryM 06-24-2012 20:59:17 76.208.68.23 Report to Moderator	Re: Farmall C-281 Engine issues in reply to LarryM, 06-19-2012 18:49:35   I reworked my fuel delivery system and carb and now when I crank it down on the dyno she is at 63hp at 540 but the same problem exists where lose 4-5 hp if I leave it there for a couple minutes. What I figured out is the the LP intake manifold drop in temperature is directly proportional to my loss of horsepower. I am goping to post a new message about this. [Reply]  [No Email]
hills 06-22-2012 09:25:31 50.41.97.243 Report to Moderator	Re: Farmall C-281 Engine issues in reply to LarryM, 06-19-2012 18:49:35   have you checked your valve lash, if their too close when its heating up it may be holding your valves open [Reply]  [No Email]
bp4455 06-21-2012 09:05:50 166.249.116.74 Report to Moderator	Re: Farmall C-281 Engine issues in reply to LarryM, 06-19-2012 18:49:35   dont fool with a reground cam. Its almost always a waste of time on a small-cube motor. you will usually lose torque. [Reply]  [No Email]
North Puller 06-21-2012 17:09:54 68.171.231.84 Report to Moderator	Re: Farmall C-281 Engine issues in reply to bp4455, 06-21-2012 09:05:50   You're sending your cams to the wrong people, or else you're installing them wrong. If you want more torque, and tell the grinder that, then you should get it. [Reply]  [No Email]
North Puller 06-20-2012 10:50:08 68.171.231.80 Report to Moderator	Re: Farmall C-281 Engine issues in reply to LarryM, 06-19-2012 18:49:35   Few simple things to try Larry Check your ignition system out. Coils (especially older ones) can start to fail as they heat up. For the time and money involved, give 93 octane a try. Maybe colder spark plugs. Are you sure it can get enough fuel? Richen it up till you see a little black smoke. Can it maintain the black exhaust for a while on the dyno? If it can, then fuel flow is good. Good luck and keep us posted. [Reply]  [No Email]