tecumseh flathead vertical to horizontal conversion

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rwd4evr

rwd4evr

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i'm converting a tecumseh 6.75 horsepower vertical flathead from a craftsman mower to horizontal. it has an oil pump so it is ideal i think. i started to talk about this in my build thread for my kart but figured i'd start a motor thread since its always talked about.

I opened it up to see whats going on inside and found an oil pump(on the bottom or sump side) it pumps off the camshaft with its own lobe. it pumps oil through the cam into the flywheel(up side when its vertical) side of the block then into a squirter for the cam lobe and gear, then the main bearing.the original oil pickup was in the lower sump. i filled the gap around the cam bearing so it sealed and ran a 1/8 npt hole from the out side into the cam bearing hole for a new pickup point. a hose now goes down to the bottom of the new sump(old drainplug hole). i assembled it and spun it with a drill and it pumped oil. priming it from the top tube helped. the motor will sit with the cylinder slightly up from horizontal.
 

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rwd4evr

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i may run a small line to the valve area from the screw in galley plug, not sure its necessary yet. i will make an area above the main bearing on the pto side to collect more oil, there will be plenty of splashing going on to fill it. i made a intake adapter/riser out of some two inch aluminum i have. i drilled the quarter inch holes to mount it then used a gaket to mark where it needed to be cut out. the port in the intake and head aren't round but a 7/8 hole saw worked almost perfect. a little port matching and its all good. black sharpie helps this.the carb has to be rotated 90 degrees but that is easy. that is a carb rotater from another motor but i'l make another. it is one inch thick polyethylene. just drill holes 90 degrees opposite each other. if they interfere with stuff use cap head bolts and countersink them. i'll get more pics when its done.

time to go to DMV. yay.
 

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rwd4evr

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got the motor done and it runs good. idles ok with the clutch on it. one inch thick aluminum carb spacer and a half inch thick exhaust adapter. running the stock duraforce muffler for now. i cleaned up the ports and opened them up a bit on the short side turn. made some mounts from 1 1/8 square tubing with a 90 degree bent. they come out to have the exact same bolt hole spacing front to back as a briggs so that worked out well. mocked up on the cart. doing some frame repair tonight then welding in the new mount rails. should be rideable in a day or two. i'll post some more when its done. sorry the pics are a little dark.
 

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rwd4evr

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a couple minutes. the external oil line is see through so i can see if its pumping oil or not. hope fully it lasts a while on the kart,. if not i'm making the mounting rails so i can change engines easy. my buddy is a scrapper so mower engine come pretty easy. have a couple 5 horse horizontal briggs too. i really just did it to see if it would work, got some machining practice too so i'm not too scared to start turning my duraforce crank down. and all the stuff was free except for a few bolts and a head gasket.
 
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this is the mount system apart.
 

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i'm curious to see how much power it makes. the valves are smaller than the wasted tecumseh horizontal that was on it but they are angled away from the piston to improve flow. did lots of port work too. the head has plenty of flow room too. its rated at 6.75 hp but who knows what kind of test thats from. i havent found out if the horizontal out side magnet flywheel will work. my briggs flywheel has a different taper, the other tecumseh horizontal also has a different taper and inside magnets. so i'm puttin a blast shield around it!

the kart is coming along good in my other thread. check it out.
 
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rode the kart with it sunday. it rips pretty good. i had problems with my home made tach so haven't wound it out to much yet. didn't want to blow it up quite yet. check out my kart thread for any more updates.
 
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