SR20 Differences

The purpose of this article is to outline the main differences between the motors and to clear up any misconceptions about the variants.

It is not to list every single difference between the motors, however if i have missed something you think is important feel free to post, but dont post rubbish or things you do not know for fact.

Anyway back to the topic at hand:

Differences between red top and black top SR20 engines

For the purposes of this discussion we will define 3 main types of SR20 engine:

S13 Red top SR20: 1991-1993 model year
S13 Black top SR20: 1994-1998 model year
S14 S15 Black top SR20: 1994-2001 model years


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S13 RED TOP SR20:

This engine was only available in S13's manufactured between 1991 and 1994 - its identifying charateristic is that the rocker cover is painted red.

All these engines came out with the following specifications:

* T25G turbo
* 370cc injectors
* no VCT (variable cam timing) or VVT or VV anything else.

When comparing this engine to later model S14 S15 SR20's the following charateristics can be noted:

* NO VCT bump on intake side of the rocker cover
* NO slope on the back of the rocker cover
* LOW mount intake plenum - the intake plenum sits under the intake runners.






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S13 BLACK TOP SR20:

This engine also came out in S13's only. However it was produced in 1994 model S13's. Its mostly seen in 180sx's but may have also appeared in very late model silvia's.

This engine is almost exactly the same as the S13 Red top SR20

Yes thats right, the S13 Black top SR20 is almost exactly the same as the Red top version. Apart from the colour of the rocker cover there are very litttle changes to the engine itself - the things that were changed possibly include a slightly different head casting (fins on the outside of the head), also in the update model 180sx's (type X 1996-98) there was a different ECU and some different sensors (water temp sensor).

There are probably other differences i have not mentioned however they are not really important. People sometimes mention different cam profiles in the blacktop motors but until someone conclusively proves this i wont be stating it.

I am running a 1994 model blacktop engine in my silvia using a Red top loom and ECU - it runs perfectly with no problems.
*****not me personally lifted from onother site****

This motor DOES have the following things:

* T25G turbo
* 370cc injectors
* no VCT (variable cam timing) or VVT or VV anything else.

* NO VCT bump on intake side of the rocker cover
* NO slope on the back of the rocker cover
* LOW mount intake plenum - the intake plenum sits under the intake runners.



AS YOU CAN SEE THE S13 BLACKTOP HAS THE SAME FEATURES AS THE S13 REDTOP



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S14/ S15 BLACK TOP SR20:

The S14 and S15 SR20DET has a number of significant differences that need to be pointed out.

This motor was available in all S14 and S15 200sx's & silvia's from 1994 to end of production in 2001. Confusingly Nissan produced the S13 black top motor at the same time.

The main differences between this motor and the S13 SR20's are:

* Larger T28 turbocharger
* VCT on the inlet cam
* Revised intake design (high mount plenum chamber).
* Different loom and ECU design (not interchangeable with earlier models)
* Different oil filter thread (ryco filter Z445 vs S13 filter which is a Z442).


As mentioned this motor has a T28 turbocharger, some models have a ball bearing version of this which is subject to a lot of debate - the best way to determine if it is a ball bearing turbocharger is by the small garrett id-plate on the turbo itself:

(courtesy of _omg on this forum)
466541 = ball bearing
466543 = bush bearing
and for the second section of the number:
-001 = S14 turbo (no splitter between wastegate and turbine exit)
-002 = S15 turbo (splitter between wastegate and turbine exit)

Later models also have larger 480cc injectors which are brown in colour - early S14's had smaller injectors which from memory are 370cc.

The sloped cam cover, high mount inlet plenum and the bump on the cam cover for the VCT are dead giveaways.