Engine and Clutch Disassembly

Updated: Jul 19




The disassembly of the 563.7 cubic inch engine was a long and complex process. First we removed the ignition wire copper conduits. Next the cast aluminum cylinder cover / water manifold was removed before lifting the engine.


As we mentioned earlier, the engine oil pan was removed before lifting the engine. This picture shows the design and shape of the pan. It probably weighs about 50lbs.

After lifting the engine, we proceeded to remove the clutch pressure plate and disc from the flywheel. The clutch pressure plate and disk are held onto the flywheel by 12 specially designed hardened cap screws. Note the numbers on the cap screw heads, 11 and 12 are visible here. All 12 cap screws were held in place with castellated nuts and cotter pins.


The size of the clutch pressure plate and single steel disk can be scaled against the 12" X 12" solid rubber floor tiles.

With the clutch cover and disc removed, we were able to access the eight bolts that fasten the flywheel to the crank shaft. After removing the flywheel we cut the safety wire in order to remove the seven fillister head screws that hold the crank shaft oil slinger in place.

This is a view of the back end of the crank shaft. Note the extremely thin, finely ground, edge of the inner part of the oil slinger which is of course adjacent to to rear main bearing. As pictured above the bronze oil slinger housing is finely machined to slide over this portion of the crank shaft and thus prevent engine oil from leaking.


Crank case with pan removed


Crank shaft journal with connecting rod in place

Exposed connecting rod bearing journal. The main bearing journals and rod journals are 2.75" in diameter. The Simplex engine has a full pressure oil system which supplies oil to the main bearings, rod bearings, the camshaft bearings and the timing chain and sprockets. After a preliminary inspection of the crank shaft we needed to remove the cylinders from the crank case.

This picture shows the engine oil pan shortly after removal. Fortunately we found very little sludge. It took many hours to clean the pan using solvent, wire brushes and other instruments. We have a commercial bead blaster. We decided that it would be a great risk to assume that we could ever remove all residual media. Therefore we did not use the bead blaster on most of the interior engine components, including the crank case.


Before the engine was removed from the car each of the twelve port plugs were removed from the two cylinder castings. A special factory made socket wrench was used for this job.


The above port plug pictures are of one of the six made to accept spark plugs. Each of the twelve port plugs were numbered from the factory. The other six ports are machined for priming cups. At this point we contacted Olsen's gaskets and ordered all new gaskets.


This picture shows John modifying a conventional valve spring compressor for our purpose. After the modifying the tool to fit the spring cup. We also fabricated a spacer to rest upon the top of each valve so that the tool could fully compress the spring.

This picture is of one of the two valve chambers. The valve lifter spider/retainers have been removed. Two of the precision made roller valve lifters have been removed.

This picture clearly illustrates the excessive wear that was found with many of the valve guides. Note that the valve stem is off center as it contacts the lifter adjusting anvil.


This picture shows the extreme length of the valve stems. The valve heads are two inches in diameter, the stems are 3/8" and the overall length is 9 1/4". The lower portion of the valve stems are machined to accept both halves of the split collet keepers.

Valve lifter retainer


Before removing the cylinders from the crank case, we removed all of the attached oil lines. The upper portion of this picture shows the spun brass oil filler cover. The cylinder in the middle of the picture is the oil filter screen housing.


This picture shows the outlet fixture from the oil pump. On the far right of this picture you will see a steel rod with a square head. This rod is connected to the check engine oil level petcock.



When adding oil to the crank case, the level is sufficient when oil begins to run out of the open petcock.


After removing the valves, springs, and lifters we were able to unbolt and lift both cylinder assemblies away from the crank case.


Before the crankshaft and camshaft could be removed, we first had to remove two of the three timing chains. The timing chains and three of the six sprockets were severely worn.


This sprocket was removed from the nose of the crankshaft and is severely worn. It drives the accessory sprocket shaft which turns the water pump, generator, magneto, air compressor and cooling fan.


This picture is the front sprocket on the accessory shaft. This hardened sprocket is an integral part of the accessory shaft. It would prove to be a real challenge.


This assembly shows the air compressor gear. The cooling fan pulley bolts on to the threaded, keyed, shaft on the left of this picture. The drive sprocket shown in this picture is also severely worn.


The oil pump after removal


After the timing chains, sprockets, and drive shafts were removed, we were able to remove the connecting rods, pistons, camshaft and crankshaft.



Center main bearing cap after crank and camshaft removal


Two of the main bearing cap screws. Almost every part on a Simplex automobile and engine are numbered from the factory to assure proper assembly.


Check out the size of the connecting rod and piston assembly. The original bore is 4 3/8" with a 6 1/4" stroke. The rods are fully machined and high quality forged steel.


In this case a picture is worth a thousand words!


Heavy it is!



Crank case interior, shows oil pump drive


Crank case interior


Crank case after disassembly

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