Engine Saga Continues 001

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Comment by bob mitchell on May 10, 2010 at 3:27am

COMPRESSION CHECK FOR FORD OSCO: here is a pressure gauge set up specifically set up for a Ford Osco engine (the osco part does not really matter because the Ford 172 and 192 are just standard tractor and industrial engines). Basically it is a fuel injector shape, with the same ubiquitous copper washer on the end (that regular injector has) that makes the high pressure seal in fuel injetion lines. Note the small o-ring fitting to retain the copper washer. There is a very SMALL hole and tube where the injector is to limit the amount of air to be compressed beyond what is in the cylinder so that you get an accurate compression reading.
The hold down dog (slotted bar perpendicular to tube body) is aju sted for height - the trick being to not let it interfere with compressing the washer, but still have enough BOLTthreads to tighten - so it is a little wobbly after you insert the nozzle down the fuel injector hole (see other photo) until you take your two injector bolts and anchor it down.
SHUT OFF FUEL AND DISCONNECT FUEL LINES FROM INJECTORS, DO NOT BEND LINES, PLUG ENDS. I really don't know what I am doing, and I am only telling you what I have figured out on my own (and with good old boy help) so this is NOT PROFESSIONAL ADVICE!
To test the compression you must first loosen the tappet adjustment screws enough so that you can remove the push rods for the cylinder you are testing, remove the injector, and insert the tester in the injector hole. (see last post for injector removal)
Now put the pushrods back in, but don't tighten tappet adjustment screws until you have seated and tightened the tester nozzle bolts. Then tighten the tappet adjustment screws to adjust the valve clearance. The reason you need the valves to open is that if the intake valve does not open the proper volume of air to compress for a correct reading will not be in the cylinder. Now bump the engine for a few revolutions with the remote starter that is connected to the ignition and any positive terminal (see photo)- my ignition had to be on and the remote starter was connected to the center terminal - that does not mean thats the way yours works - remember - I am an amateur and definitely did not know what I was doing a few days ago - it took significant work to get even to this knowledge base. The remote starter allows you to bump the engine over without being at the ignition.
REMEMBER, IF THE PUSH RODS ARE NOT SEATED PROPERLY IN THE CAM FOLLOWER
(TAPPETS), OR IF YOUR VALVES ARE ADJUSTED WRONG, YOU CAN BEND A PUSH ROD IN A SECOND, OR BEND A VALVE. (Idid it) The whole rocker arm, pushrod assembly dance seems initially complex, but becomes a practiced routine once you start putting your engine time in. Note, you can also slide and rotate the rocker- continuied on next photo