Which way do new KE70 pistons go?

[HomesteadOC]

I just got my new pistons today and there is no arrow to show direction of the piston in the block, but there are reliefs cut for either the exhaust or intake. Im not sure how they are supposed to attach to the rods in relation to the lettering and the 渡ub on the crank side of the rod. The manual doesnt mention anything about it, maybe it doesnt matter? I think it should matter, any help is appreciated.
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New piston top, which way do the reliefs go?
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Side view to show orientation of the rod.
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Underside of new piston.
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Old piston top and side with artow towards front of engine.
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Underside of old piston.
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Connecting rod side with lettering and nub on the crank side
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Back side of rod, no lettering or nubs

 

[HomesteadOC]

Ok, figured it out i hope. Rod lettering faces forward in the engine, and the reliefs match the valves so the piston reliefs are closest to the injector side of the engine. If this is wrong please let me know, they have not been installed yet so theres still time.

 

[HomesteadOC]

Also, I just noticed that the valve reliefs do not line up with the valves. They do not run parallel with the piston pin, is this normal? Both pistons look the same, but they have the same markings in the reliefs (from same casting).

 

[Ilikeurtractor]

Those are intended to line up with the discharge of the swirl chamber in the head so they should be on the injector side of the engine. Although they appear to be valve reliefs they do not provide any relief in this application. They are not machined correctly to line up as intended with either the valves or the swirl chamber discharge. Although they will work I would avoid this type of piston if I had to do it again. I mentioned this in another post. These pistons lower the compression by about 3 points by adding 4cc of volume to the combustion chamber leaving the ratio at around 17:1 (assuming an original ratio of 20:1) which will make it more difficult to start. I do believe the lowered compression will reduce cylinder wear so there are some good trade-offs. Correct on the lettering towards the front of the engine.

Paxman History Pages - Paxman Diesel Engines Since 1934

The Ricardo Comet section applies.

 

[HomesteadOC]

Im in southern california so Im hoping for not too many cold starts. Ill see how they run once I get them in and Ill keep an eye on the temperatures and how great it starts up. Generally its never below 50F here when the sun is up even in the middle of “winter” which we call our “rainy” season. Night time it will get down to mid 30s, but Ive never seen a frost or a freeze in 15 years of living here. I did see some ice, but that was middle of the rainy season on a dock that was hosed down with water in the middle of the night on a record cold day. Most times this tractor will be used at 70+ degree days for 90% of the time and the other 10% during 50+ degree days. I say 10% because if its raining I wont be operating, and by mid day were in the 70s so this only applies to mornings in the winter. Hopefully my new pistons can cope with our rainy winters.

 

[Ilikeurtractor]

They'll be fine. Unless the engine is up to operating temps, starting will be harder with lower compression over all ambient temperature ranges. It will just take a little more cranking and glow plugging.