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Step 15Building the new engine.
Building the Engine
With the parts all ordered and received I spent about a week building the engine. One thing I did was ordered a set of over-20 rings. This means that the gap between where the ring when it is fully compressed in the cylinder is .020 over the stock gap. This is done for a few reasons. Mainly its if you had an engine with a worn cylinder and needed more available ring to fill that void. The ends of the ring are then filed down until a desired ring gap is met. In my case I did this to intentionally make the ring gap far tighter than stock. Usually a stock engine will come with a 0.10-0.20 ring gap. In my case I wanted to have a 0.004-0.006 gap. This would give me more compression overall. Doing this is tricky if you're like me and don't have a ring grinder tool handy. But it can be done. Simply mount a mill file in a vise straight up and down and very slowly pull up on the ring with the end of the ring filed as level as possible. Only file one side of the ring too because doing so means a greater chance of having an uneven gap. Every few strokes put the ring in the cylinder and tamp it level with the top of the piston. Measure the gap with a feeler gauge. Eventually you'll arrive at the correct gap. I accidentally filed too much and wound up having it down to a .008 gap. Ooops. Not that big of a deal so that's what I installed it as.
The crankcase was thoroughly cleaned and the hole which the governor lever came out of was blocked using a bolt and nut. The next step was to install the new valves. In addition to ordering new valves and keepers, I also ordered a stronger set of valve springs. These are double layer springs with a smaller inner spring that is removable. What I wasn't aware of was that you don't want to use the center spring. I spent hours sweating bullets trying to install the new valve and keepers because the dual springs were so stiff. The first time I did this I was pressing the spring down with a socket when it slipped. The tiny keepers flew off into the wild blue yonder, never to be seen again. What a pain! I never found them as they were hopelessly lost somewhere in the shop. Thus I ordered 3 extra sets. With the center springs removed it was much easier to push them down and drop in the keepers. Slowly let the pressure off the springs and the keepers will usually fall into place around the groove of the valve stems.
With that done it was time to install the piston and rod. The rod needs to be installed using exacting torque settings. The final is @ 28 foot pounds. First, apply a bit of oil to the bolts. This will enable you to do what's called " Wet torquing". Using a torque wrench, set it for 16 foot pounds. go back and forth from one bolt to another until you arrive at 16 foot pounds. Then go in 4 pound increments until both are snugged to 28 foot pounds. This is vitally important. Incorrect torquing can mean a snapped rod.
With the parts all ordered and received I spent about a week building the engine. One thing I did was ordered a set of over-20 rings. This means that the gap between where the ring when it is fully compressed in the cylinder is .020 over the stock gap. This is done for a few reasons. Mainly its if you had an engine with a worn cylinder and needed more available ring to fill that void. The ends of the ring are then filed down until a desired ring gap is met. In my case I did this to intentionally make the ring gap far tighter than stock. Usually a stock engine will come with a 0.10-0.20 ring gap. In my case I wanted to have a 0.004-0.006 gap. This would give me more compression overall. Doing this is tricky if you're like me and don't have a ring grinder tool handy. But it can be done. Simply mount a mill file in a vise straight up and down and very slowly pull up on the ring with the end of the ring filed as level as possible. Only file one side of the ring too because doing so means a greater chance of having an uneven gap. Every few strokes put the ring in the cylinder and tamp it level with the top of the piston. Measure the gap with a feeler gauge. Eventually you'll arrive at the correct gap. I accidentally filed too much and wound up having it down to a .008 gap. Ooops. Not that big of a deal so that's what I installed it as.
The crankcase was thoroughly cleaned and the hole which the governor lever came out of was blocked using a bolt and nut. The next step was to install the new valves. In addition to ordering new valves and keepers, I also ordered a stronger set of valve springs. These are double layer springs with a smaller inner spring that is removable. What I wasn't aware of was that you don't want to use the center spring. I spent hours sweating bullets trying to install the new valve and keepers because the dual springs were so stiff. The first time I did this I was pressing the spring down with a socket when it slipped. The tiny keepers flew off into the wild blue yonder, never to be seen again. What a pain! I never found them as they were hopelessly lost somewhere in the shop. Thus I ordered 3 extra sets. With the center springs removed it was much easier to push them down and drop in the keepers. Slowly let the pressure off the springs and the keepers will usually fall into place around the groove of the valve stems.
With that done it was time to install the piston and rod. The rod needs to be installed using exacting torque settings. The final is @ 28 foot pounds. First, apply a bit of oil to the bolts. This will enable you to do what's called " Wet torquing". Using a torque wrench, set it for 16 foot pounds. go back and forth from one bolt to another until you arrive at 16 foot pounds. Then go in 4 pound increments until both are snugged to 28 foot pounds. This is vitally important. Incorrect torquing can mean a snapped rod.
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