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Discussion Starter · #1 ·
SD33T 87 engine, standard
Having a weak compression, I decided to do a major engine repair.
I ordered segments, bearing bushes, connecting rod bearings and bearing seal and disassembled the engine.
The first unpleasant surprise, a big crack in piston number 6. The second surprise, all the other 5 pistons have a crack under the valves.
I found only one 12010C8711 piston in the Netherlands, but the company has several 12010C8612 pistons from the SD33 nonturbo engine.
In pictures and measurements the two pistons seem identical, but I ask you, is it ok to buy 6 pistons of a non-turbo engine to equip the turbo engine with them? Better looking for secondhand pistons?
Thank you!
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Discussion Starter · #3 ·
The turbo version has 3 piston rings while the non-turbo has 5 rings. As for as I know,that's the only difference between the pistons but I'm not a great expert.
above I put the pictures with turbo and non turbo pistons. The turbo ones have a different code and have those wrinkles on the piston collar.
Otherwise, as for dimensions, bolt depth, bolt diameter, everything is identical ... or so it seems.
We hope for some experience of other owners.
Anyway, in desperation, I will put non-turbo pistons and I hope everything is perfect. Thank you!
 

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nissan
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The turbo version has 3 piston rings while the non-turbo has 5 rings.
I expect the 5 ring set of piston rings you speak of will have a 3 piece oil ring but it fits in the same groove as a single piece oil ring so there is no difference to the piston whether you run one type or the other.
 

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2016 CRD wagon
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on the right is the turbo piston and on the left the non-turbo piston. Other codes but look the same. Didn't anyone change the pistons on the SD33T?
I think I read somewhere once that when the sd33t was produced, Nissan built all sd motors using the same upgraded internals.........so I believe the piston should be identical in both turbo and n/a motors from that time on( that's if what I read was correct)
It probably means Nissan only keeps the upgraded piston as spare parts for the NA too.
I hope someone else can conform this for you

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Discussion Starter · #7 ·
I think I read somewhere once that when the sd33t was produced, Nissan built all sd motors using the same upgraded internals.........so I believe the piston should be identical in both turbo and n/a motors from that time on( that's if what I read was correct)
It probably means Nissan only keeps the upgraded piston as spare parts for the NA too.
I hope someone else can conform this for you

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thank you!
Anyway, I'm in a extreme situation.
As 5 pistons are slightly cracked and one is seriously cracked, and I haven't found any new turbocharged pistons anywhere ... all I have to do is enjoy the new non-turbo pistons found in stock and pack the engine, hoping it will last a long time from now on.
thank you!
 

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1985 SD33T MK LWB Wagon
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thank you!
Anyway, I'm in a extreme situation.
As 5 pistons are slightly cracked and one is seriously cracked, and I haven't found any new turbocharged pistons anywhere ... all I have to do is enjoy the new non-turbo pistons found in stock and pack the engine, hoping it will last a long time from now on.
thank you!
As @trev zd30 has said, after the SD33'T' was produced (upgraded internals compared the old SD33 N/A), the N/A versions from that year on got the same internals as the turbo motor. So any aftermarket replacement pistons from then on (late 1983-early 1984 I think?) are made to turbo specifications and can be bolted into either version of the engine.
So you should be fine to use any pistons branded as being made for an SD33 of any kind. Company's will produce 1 piston (the turbo-style piston) and create 2 different part numbers so that when searching for parts for either motor something will pop up.
Unsure as to why the piston branded as a turbo piston has the extra grooves at the top though.
 

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Rust is just natural weight reduction.
1986 SD33T SWB
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The only difference between the pistons that I can tell are the grooves at the top of the turbo piston. I suppose combustion/detonation control for the top ring.

The N/A piston also appears to have the steel insert for the top piston ring, same as the turbo engine. The only other difference I can think of, but cannot see, is that maybe the crown is thicker on the turbo piston than the N/A.
 
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