When I bought a 40ft container with 2 cars and lots of parts from Louisiana, there were heaps of strange spares that came with that lot.
I am just rebuilding the TC engine which was probably fitted to 4688R, and I have found the following:-
Siezed cam chain tensioner, the silver bullet at the end of the spring had seized solid in the water pump housing.
Main bearing caps not torqued up, one was finger tight.
Small ends rusted solid so the engine won't rotate at all.
This engine had been completely rebuilt, with new gaskets everywhere, but never run, and must have been sitting around for many years. It had zero oil in the sump, just lots of rust particles, larger than sand grains.
I managed to get the tensioner bullet out by heating the casing with a gas torch, but I need to carefully drill the hole 13.5mm to get the bullet to slide freely in the water pump casing.
I managed to get all 4 pistons and con rods out, but here is where the problems started. It took 6 tonnes of pressure to get the gudgeon pin pressed through the con rod and out of the piston. All 4 gudgeon pins were badly rusted. 2 piston skirts got damaged during the pressings, but luckily, there was a box containing 4 new standard sized pistons that came with the spares. The new gudgeon pins pressed into place through the con rods using a bench vice.
But................ the new pistons have raised crowns, so are high compression pistons.
Does anyone know how much raised crown pistons reduce the volume of the combustion chamber by, so I can work out the compression ratio. I think the combustion chamber is 41.6cc so with 1588/4 + 41.6 = 438.6 : 41.6 = about 10.4 : 1 CR without the raised crowns.
The raised part of the piston comes to 55 thou above the height of the block.
Just think I have worked it out. Diameter of raised part = 67mm. Raise = 1.4mm. Volume = 3.142 x 67 x 1.4 = 294 cubic mm = 3 cc.
So 1588/4 = 397 + 41.6 - 3 = 435.6 gets squashed into 38.6cc = 11.3:1. The only error is the volume of the head gasket when torqued up. I reckon the volume of the head gasket is 2cc, 82.5 mm bore x 0.085mm thick gasket, so 397 + 41.6 - 3 + 2 = 437.6 gets squashed into 41.6 - 3 + 2 = 40.6 which gives a CR of 10.78 : 1 which does not seem too high. Can anyone fault my calcs?
