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Table Of Contents/Index: Page 1: General Info on Everything I Could Think Of | Props from SR20 Forum Page 2: Compression Theory | Physical Differences B/N Regular DE | Efficiency | Power Page 3: Comp. Theory Cont. | OEM vs. Tubular Header | Which ECU? | Water Pump? | USDM IM w/ RR VC | Engine Break Down Page 4: Dyno Testimony | Reg. DE & RR DE VC Compat. | Water Pump Compat. | Power Curve Diff. | Pulleys | Boost Capability Page 5: ECU Tuning & Ign. Timing | 4CW Crank VS. 8CW Crank | Swap Complete | PCV Schematic - USDM IM | 96-99 Almera GTI
What Does That Mean?: IM = Intake Manifold VC = Valve Cover RR = Roller Rocker CW = Counterweight B/N = Between
simple way to check: carefully insert something narrow, long, and sensitive but rigid(lol) into the plug hole. (like a bent up coathanger) sweep it from wall to wall across the top of the piston carefully. if you feel it dip in and out it's a 9.5:1. str8 across is a 10:1. hope this helps-as thjerse a lot of haze on this topic and this way instead of taking soemones advice on your motor you can see for yourself.
Keep in mind the following:
1) That I don't think pistons really signify compression, I believe the size of the combustion chamber on the the RR engines are different from ordinary DE's. I may be wrong.
2) Even if... The difference b/n having 10:1 Compression, 9.8:1 Compression, and 9.5:1 compression for our RR motors REALLY doesn't make much of a difference. At the maxumum 5% difference in compression rate.
3) Some of the above identification schemes were done on JDM highports as well
All in all, the compression thing is only a minor thing... It can be found out if you really want to go through the trouble of doing it... i.e. taking it to a Nissan Proffesional, or Opening your motor and investigating, or Testing. I'm pretty sure that of all the JDM motors bough from Soko, more of them were 9.5:1, but most of those were highport. That's all I know from searching though.
thanks for the additional info bro btw, how do i know if my RR sr20 is a 130hp De or a 140hp DE? is there any way to tell the difference visually or something rather than have it dyno tested? thanks
thanks for the additional info bro btw, how do i know if my RR sr20 is a 130hp De or a 140hp DE? is there any way to tell the difference visually or something rather than have it dyno tested? thanks
You'll have to search for that one... Use the "search" function and let us know what you find...
I really don't know the distinctions...
Last edited by XxToKeSxX : 03-11-2006 at 10:41 AM.
thanks for the additional info bro btw, how do i know if my RR sr20 is a 130hp De or a 140hp DE? is there any way to tell the difference visually or something rather than have it dyno tested? thanks
Well the difference between those is the intake cam and the header, so put on an aftermarket header and some S3r's you will have overtaken the 140hp model anyway.
Well the difference between those is the intake cam and the header, so put on an aftermarket header and some S3r's you will have overtaken the 140hp model anyway.
Mike
ic! when my car was being done i was able to get a look at the header for a while as the heat shield has been removed to be cleaned. the header looked like a tubular 4-2-1 unit but has an oxygen sensor on the 2nd cylinder in the 1342 firing order meaning the rightmost pipe when facing the engine. when i tried to search about the jdm tubular header, i saw that it didn't have any provisions for the oxygen sensor on the rightmost pipe.
Are you sure its tubular? You may have a cast header...
Tubular exhaust manifolds don't have sensors in them... I think the sensor is in the downpipe (secondary pipe). Are you searching correctly? If you have pics please post them... because I've never seen what your stating on a tubular. Although I may be wrong... We need as much information as possible to help you, otherwise we will be going back and forth with questions...
This is tubular...
This is Cast...
My JDM engine looks like the following, and it has a cast manifold similar to USDM
Last edited by XxToKeSxX : 03-11-2006 at 12:11 PM.
Are you sure its tubular? You may have a cast header...
Tubular exhaust manifolds don't have sensors in them... I think the sensor is in the downpipe (secondary pipe). Are you searching correctly? If you have pics please post them... because I've never seen what your stating on a tubular. Although I may be wrong... We need as much information as possible to help you, otherwise we will be going back and forth with questions...
This is tubular...
This is Cast...
My JDM engine looks like the following, and it has a cast manifold similar to USDM
i stand corrected, bro. i think i have the cast manifold instead of the tubular header. very sorry for the mix-up any idea how much horsepower these motors make ( cast manifold )?
Another great distinction, I always asked myself why do the USDM Roller motors have that pre-cat exhaust manifold that is restrictive, the JDM ones dont, they have that cast manifold and no EGR, so im wondering if the JDM ones make more power, or does it equal it out? Hmmm.... Something to think about.
Would switching to a JDM manifold yield much more power? It still similarly incorporates a 4-2-1 design but seems that the tubular has longer lengths before that 4-2 part takes place. I understand that it IS a better design though. If it does yield more power, I imagine that it is negligable (sp?)... This is all in my opinion though. Even if, the advantages would be minimal compared to the drawbacks IMO... For instance... this is what I feel:
1) There are ton's of aftermarket options that would probably supercede the JDM design. (Hotshot, SSAC, what have you...)
2) If you switched to the JDM header you would definitely have to have the secondary pipe in conjunction. Simply because the JDM's location from primary to secondary is closer to the ground.
3) I imaging the JDM tubular header is rare here in the US. If you did damage a single part of the pipe, you would have more trouble finding a replacement. whereas USDM parts are readily available everywhere.
I know here in this part of Ohio we just got rid of Emissions E-Check, but I don't think that it would be worth it to switch from OEM... Again, this is just what I think.
As usual... I'll check into that... Because I may not be correct and am still learning all about this myself...
Another thing thats on my mind is if you swapped from a 98 lowport to a JDM RR lowport... would the ECU's match? I will check into this also and post. If anyone knows that would be a great thing to post about (including where you find the information from) as well...
Last edited by XxToKeSxX : 03-13-2006 at 12:55 PM.
Would switching to a JDM manifold yield much more power? It still similarly incorporates a 4-2-1 design but seems that the tubular has longer lengths before that 4-2 part takes place. I understand that it IS a better design though. If it does yield more power, I imagine that it is negligable (sp?)... This is all in my opinion though. Even if, the advantages would be minimal compared to the drawbacks IMO... For instance... this is what I feel:
1) There are ton's of aftermarket options that would probably supercede the JDM design. (Hotshot, SSAC, what have you...)
2) If you switched to the JDM header you would definitely have to have the secondary pipe in conjunction. Simply because the JDM's location from primary to secondary is closer to the ground.
3) I imaging the JDM tubular header is rare here in the US. If you did damage a single part of the pipe, you would have more trouble finding a replacement. whereas USDM parts are readily available everywhere.
I know here in this part of Ohio we just got rid of Emissions E-Check, but I don't think that it would be worth it to switch from OEM... Again, this is just what I think.
As usual... I'll check into that... Because I may not be correct and am still learning all about this myself...
Another thing thats on my mind is if you swapped from a 98 lowport to a JDM RR lowport... would the ECU's match? I will check into this also and post. If anyone knows that would be a great thing to post about (including where you find the information from) as well...
I have a harness for my motor JDM motor so I can check the ports if anything. I also have 2 of these JDM exhaust manifolds and heatshields I need to get rid of. I know one of our G20.net members WITH a roller rocker motor in the UK (10:1 Primera GT) got his JWT turbo program and they were able to crack the code (as it was a 1998 Primera).
03/13/06 - Addition of RR Roll Call Thread
03/13/06 - Addition to Compression Section
03/13/06 - Cleaning Up, Organization & General OCD Relief
Okay, so I think that you can use a RR with a b14 ECU... as long as the intake manifold (I'm glad you advised this, you know who you are)... I really don't want to spend hundreds on a new engine harness. http://www.g20.net/forum/showthread....ler+rocker+b14
Quote:
"you can't put a b14 ECU in a 00-01 G20 any way, not without switching half the damn car."
Actually you can, all you need is the intake manifold, harness (which is literaly attached to it), and ECU. Im going E-manage but if it doesnt work, I already have a whole thing waiting for me after someone else that I know down here goes VVL.
Quote:
Some good news. I've been PM'g Craig aka CoalitionsSE-L on SR20Forum.com about making an adapter plug that will enable Roller Rocker SR's to use a B14/B13 ECU (i.e JWT ECU). With this plug, there will be no need to splice the wires as per the JGY instructions. And if you decide to go back to stock, just remove the adapter and plug in your stock ECU. He is in the process of doing one for a B15 and in a week or two will get pricing info. Just thought you guys would like to know.
Anybody have any info on this?
Last edited by XxToKeSxX : 03-13-2006 at 04:33 PM.
Today I measured the difference between the JDM and my old motors Throttle Bodies... But they were the same?!... Hmmmmm, I thought someone told me otherwise...
All the lowport p10 stuff bolts right on the roller rocker. Now the only way to tell it's a roller rocker engine is the head code.
I used the water pump from my old engine since it was recently changed. I noticed both the water pump pulley and crankshaft pulley are lighter on the roller rocker motor. Guess Nissan did make some improvements.
At this point all that's left is going over the parts then installing the tranny and installing the engine. I still need to get that incompatible bracket for the p/s CV axle.
If all continues to go well then this will arguably be the best replacement for a bad lowport P10 not looking for a turbo setup and trying to keep smoggable. The P11 motors have less miles and the roller rocker engines have a bit more horsepower. Most important, you get to keep all of your emissions stuff for smog purposes.
Centered NISSAN on the valve cover is a JDM 10:1 roller rocker engine, which
is like the 00-01 Sentra SE engine. Its the newest style SR20DE. They make
pretty decent power, should be in better shape since its newer too.
Mike Jez
Uh Oh...
Last edited by XxToKeSxX : 03-24-2006 at 10:25 AM.
I have the pistons out of this one, it is not a 10:1 motor.
The throttle body on my USDM roller motor is bigger than the JDM roller motor, I never said all SR20's, which is probably why older sr20s rev higher than 7k and the USDM roller motors dont pass 6800
btw, how do i know if my RR sr20 is a 130hp De or a 140hp DE? is there any way to tell the difference visually or something rather than have it dyno tested? thanks
