440icd N, S, pistons and injectors

[pop pop]

i will start out with some questions that i am pondering while messing with these 440ICD's
how can a guy figure out what type of pistons and injectors he might have in a DD 2-53 ?
i know the N piston is a 21;1 compression ratio, and the S piston is 17;1 compression ratio(maybe S is 18.7;1 i dont know )'
and are the injectors suppose to match the S or N type piston, and if it matters and why?

moving on to the injectors,,,
how can you tell which is which? N or S.
do they have different "pop" pressures?
or different spray tips?

[jimmydiesel]

Pop Pop
I am not an expert but have worked with 53 Series Detroit Diesel engines since the late 70’s.
The 2-53 that Detroit built for John Deere is a 2 valve 17 to 1 engine with 35 injectors. 2-53 engine production ended in 1972.
The best way to know what injectors your engine has is to remove the valve cover and look at the injector body. It should have a
aluminum tag pressed into it. The picture below shows a 35,35,S40 and N45 injector.



Later production 53 series engines were “N Series” The N series engines were 21 to 1 compression ratio 4 valves per cylinder and had N injectors.
The N injector has different internals, tips and a higher “pop” pressure.

The higher compression ratio was achieved by reducing the size of the combustion chamber in the piston. The picture below shows a 17 to 1 piston from 2-53 and the 21 to 1 piston replacing it.




When rebuilding an “S” engine it is best to upgrade to the N liner kits and injectors. This will improve cold weather starting and reduce smoke.
The 18.7 to1 compression piston were used in the “T” turbo charged engines.
N series injectors can be installed in an engine with S series pistons but it is best to upgrade both.
The 2-53 engine installed in the 440 and 435 has small 35 injectors installed to match the HP to the John Deere drive train. The engine was built without an oil cooler or the piston cooling oil spray nozzles in the connecting rods that other higher HP 53 series engines had. The number on the injector indicates its output 35,40,45 etc. the bigger the number the more fuel output.

[pop pop]

thanks jimmydiesel, thats a quite interesting reply.
i do have another lingering question thou,
on the injectors, how can you tell between an N and an S version does anybody know?
i have some N injectors in one of my crawly's but I cant SEE a difference
i am currently working on S injectors,(i think)
the tip has a number 165 on it and also a number 8-005 and it has 8 spray holes so maybe that number means 8 holes at .005 diameter

[jimmydiesel]

Pop Pop
The picture below shows exterior differences between a 35 and N45 injector.
The tag number
The tube nut on the 35 has 1 groove. On the N45 the tube nut has 2 grooves. My experience is all N series injectors have 2 grooves.
The nozzle tip on the 35 is pointed the nozzle tip on the N45 is rounded.



You are correct on the 8-005 numbers The 165 is the spray angle.
The chart below shows info on the different injectors.

[pop pop]

so messing with these injectors, there is a tiny button(called a valve in the IT booklet) with a crossways grove on one side of the "valve".
i am trying to determine which way the groove should face without tearing another injector apart to see.
i sort of determined that the groove should be against the "valve cage" and not the "spring".
if any jector wizzerds know of this, please enlighten me, thanks.

[jimmydiesel]

Yes the groove goes towards the cage.