It's your local SR20 fan Ameen here. As some of you know, recently I have had some problems with my current engine. To cut to the chase: I recently purchased a newer JDM lowport Roller Rocker SR20DE that a member (ever so kindly) picked up for me. . I actually didn't know much about the differences between a normal SR20 and the Roller Rocker version. I figured that I should do some information hunting and post for all to see. Hopefully this will help other people in the future that may decide to go this option. (As well as encourage people that the Searching Before You Ask is your best friend on this forum.)
Had to Live up to my word
I really hope that this all helps... As it helped me... Maybe later this can be a sticky? Please feel free to ADD.
I will be making a fully organized thread on all the research of this particular engine and for roller rockers in general... As I didn't find lot of support for this engine... I also will be making a similar detailed thread on the swap process. I know I wouldn't be the first person to have a JDM RR, but I would like to get rid of all the misconceptions and boost support for this option.
All in all, I really just got lucky (others wouldn't think so)... And I plan to take advantage of the fact that I have been blessed to have the chance to do something that not everyone does, and stick with it (regardless of the rumors).
With the possible help of some of the people here: I hope to share the information that I get in the future so that more people will hop on the train (per se).
The JDM/USDM Roller Rocker SR20DE
Info Thread Starts HERE!!!!
Even More Information on Following Pages...
Press Ctrl+F to search for Specific Words on a Page
Disclaimer: There may be contradictions here but most of the stuff here is quoted... I am just learning and this information is here for people to learn from and discuss. This isn't posted here because I think its all right. I did not post names under the quotes because that isn't what this is about. If you see something here that you would like credit for.. Please let me know.. I will make a Bibliography/Props Section! Feel free to add or PM me to add information that is also crucial.
Check out my RR Swap Process Here:
First off, The Roller Rocker SR20DE Roll Call List... Add Your RR & Name!!!
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
Compat. = Compatibility
Diff. = Difference
Ign. = Ignition
Comp. = Compression
The SR20DE(t) Compression/HeadCode List
Lot of good information in this thread.. Please see the codes...
Some more Head/Block Code Information
My JDM Roller Rocker Engine Information:
53J: '91-'93.5 P10 (USDM high port intake manifold)
94Y: '93.5-'96 P10 (USDM low port intake manifold)
2J2: '01?-'02 p11 (Roller rocker arms, Low port intake manifold)
52F: Highport DET RWD (blacktop)
54C: Pulsar GTiR
53J: FWD '91-'02? G20 (unsure what block was used in P11 but I think 53J)
78E: AWD Primera T4 (DE), Bluebird SSS(DET)
52F: RWD DET (blacktop)
54C: ??AWD DET (Pulsar)
- I really feel like its from 97 or 98... not sure though...
the engine code is lower than my usdm code... The bold is what I have...
I purchased this engine for $550 from Soko/Soken Engines in Chicago, Illinois. They have different locations. They were very helpful and there is a 6-month warranty on all parts. Here is the information:
Ribs on the head
All Silver RR Valve Cover
53J On the head
Distrib facing the fire wall (No Distributor/swapping 98 over)
Big TPS (Not sure)
Auto Tranny (I have an auto flywheel, need to switch)
Lowport (JDM Manifold/Needs to be switched]
5R on the head (distrib side)
tubular exhaust manifold (I think mine is just like the USDM)
-> Soken Southgate Cali. - 323-563-2018
-> Soko Engines Chicago - 847-451-1400
-> Soken Engines (Forget Location) Cali. - 310-324-7788
I Popped my VC when I recieved the engine... I had never seen what roller rockers look like... its a pretty simple concept.
Here is what they look like after the engine was mounted
Similar Engine as Mine...
Information on JDM engines (easily swappable for a Lowport)
Where Should I buy my Used Engine??? Different Engine Importers in the U.S.
let me clarify. sr20 motor that bolts in the easiest to the lowport 200sx with the least amount of modification of sensors etc., such as a certain year primera, bluebird, or whatever.
P10 PRIMERA SR20DE 53J 40-60k mi $375.00 6 Month 0/15 Champagne
P10E PRIMERA SR20DE 53J$600.00 6 Month Yes 0/-1 09/90~04/93 Red/Black
P10E PRIMERA GT SR20DE 89J EGR & Tubular Exhaust Manifold $1,000.00
P11 PRIMEAR SR20DE Silver 2J2 $750.00 6mo/6k Yes 0/0
P11 PRIMERA SR20DE Black 2J2 $750.00 6mo/6k 0/0
P11 PRIMERA SR20VE Black 1N5 $2,200.00 Startup Picture 0/0
P11E PRIMERA SR20DE $1,300.00 0/0
Why JDM engines have low milage & are cheap...
(On used engines) Sensors being broken off can happen to any used engine you buy. This can happen in shipping and handling. These things are the least of the problem becasue they can be changed over from the old motor being pulled out of your car. The motor itself needs to be in A1 condition the sesors are secondary.
Please note when you are buying a used motor is is used it is not some new motor you are buying from the dealer or a parts catalogue.
Highport, Lowport... What is THAT???
In Japan, when a car reaches about 30,000 miles on the clock (maybe it's 50k Kilometers?), the vehicle has to go through a complete inspection to be re-licensed for use on public roads. During this inspection, every bearing, every bushing, every seal, and every weld is examined with an ultra-fine-toothed comb. By the time the inspection is done and all "insufficient" parts are noted on a list, it's just as economical for a Japanese car owner to buy a new car as it would be to "fix" their cars. The result is thousands upon thousands of perfectly good engines and transmissions (not to mention bodywork, bodyglass, signal lenses, and so on) that just sit in a junkyard, discarded.
A few years ago, somebody got the brilliant idea to start importing either powertrains or even whole front clips to the US, where cars aren't "old" until they've clocked 150-200k miles. This is how we can get complete 30,000-mile engines and transmissions for $600 to your doorstep. Even special engines like SR20VEs or SR20DETs can be had for a fraction of the cost of a normal engine from a US junkyard.
High-port - throttle body sits below the injectors (you can see the injectors but not the throttle body).
Low-port - throttle body sits above the injectors (you can see the throttle body but not the injectors).
91-93 SE-Rs, 91-93 NX2000s and 90-93 G20s had high-ports, while '94 and above SE-Rs and G20s had low-ports.
I believe that there were some 94's that actually had highports early in production. Check me on that...
Some differences in Pre RR SR20's and Post RR SR20's
If you're not boosting it, a RR motor is a good choice because it's a newer motor. 2000+. Probably means low mileage.
1. Smaller ring lands. Keep the detonation away, you'll be fine, but they can't take huge amounts of ping like the older ones.
2. 4 counterweight crank vs 8 on the older ones. Probably won't be a problem unless you're revving really high or making mega power.
3. Weaker valve train. They went and put roller rockers in it, but then gave it weenie valve springs that prohibit much above 7500 rpm.
The weak point of the SR20DE RR is the higher land ring on the stock piston. Some say that 250 whp is the max power with out any problem....but i thinks that you can go higher on stock piston...but not much more (if conservative)
A VE water pump is the same as a roller rocker water pump. IE 00-01 SR20.
the roller rocker motor can be found from 2001 and up sr20 powered cars. there are also jdm versions of them available. the roller rocker valve tran can work in older heads but requires a little work to be done properly. everything pretty much fits but the valves and corresponding parts would have to be swapped from the rr head to older de head, becuase they are a couple mm shorter. yes the rr valve train is nice
There are contradictions (on the net) ^^^ here I believe... about the RPM limits. I believe for the JDM it was a little higher than USDM, and this can be solved by incorporating better valve train constituents like springs, cams, ect... Correct me if I'm wrong.
...you have the regular P11 SR20DE. Nissan lowered the idle speed from 800rpm (AT/MT) to 700/680rpm (AT/MT) for P11 engine. One of the very first generation (oldest) SR20DE came with 850rpm idle speed. Biggest difference between P10 engine is you have the roller rocker arm engine. For North American market, they didn't use Roller-Rocker engine until the year 2000. Another difference is the red line. earlier SR20DE had redline at 7500rpm, but your P11 motor is redlined at 7000rpm. There are a few difference in electrical system and fuel system also.
No they are not, some non GT roller motors also rev up there (either 7200RPM or 7500RPM). They dont all come off the Primera, this motor can also be found in the Bluebird.
Some differences in USDM RR SR20's and JDM RR SR20's
This has been done at G20.net. All you have to do is swap your existing intake manifold and valvecover and you are good to go. Look up a post by Mike.com he did it on his P10 and LOVES the roller motor in N/A form, a lot peppier and he does rev still to 7400RPM without a problem. That motor you have is the J-spec roller motor which revs to 7200RPM so you shouldnt have a problem.
Well this is what I know about US and JDM roller rocker motors. I know the US motor uses top feed injs while the JDM motor uses sifr feed injs. I might be incorrect but the 3 JDM roller rocker motors I have got had side feed injs.
The Determinent!!!! COMPRESSION! Testimony, Facts, FSM, 10:1 or 9.5:1???
Great info! Your motor has side feed injectors, USDM roller motors have top feed.
- Uddated 03/13/06
There has been testing done on a stock RR engine from a P11 Primera by a member named "jp"... his testimony is on page 3 of this thread. There is also very useful dyno information as well
There has been a long dispute on the compression for the roller rocker engine...
hopefully and eventually this rounds it up... Here it goes
There is a contradiction ^^^here about compression though...
I haver personaly tested que gen 1 (hp) ,my motor is a jdm sr20 2j2 head and 53j short block (this motor came stock in owrs primeras) its 9.5 cr 143hp(factory specs)
9.8:1 for sr20 in 2000 and 2001 b15 fsm manuals 9.5 for 1.8l...
BTW here is an image of the FSM... try seeing what it claims..
There is also another image on the FSM for the 2002 g20motor in that thread
It reads 9.5:1... It is shown below and has been resized
Keep in mind the compression & timing difference for the G20/B15Sentra in the FSM
The b15 reads 9.8:1, and the G20 reads 9.5:1
Interesting... but something isn't the same.
Difference between 10:1 & 9.5:1 Pistons, its in this section...
How to indentify a 10:1 or 9.5:1 SR20DE.
Check out the valve timing... also different.
Checked other year models... G20 and sentra are consistently different from each other in valve timing and compression. Very very weird.
Keep in mind the following:
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.
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 from most of 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.
Highport to Lowport Information
The engine fits, but here is what i found. I got rid of all the smog system on the new motor and made a block off plate to cover where the EGR tube enters the intake manifold. I had to re-route the water lines that go into the egr valve when i removed it (yes water line on egr). the old power steering pump does not clear the oil filter so you have to grind off the little nipple that holds the line on the bottom of the pump, loosen the nut and rotate it a inch, A word to the wise dont try to put the oil filter assembly from your old motor on the new motor it doesnt fit because of the new intake manifold. This all leads to the fun part. It seems in 2000 when nissan revised the sr20de to a roller rocker motor they changed the head (of course) so your old intake manifold will not bolt up and the new intake manifold has high impedence injectors (17ohms). Guess what the old one used low impedence(11.5 ohms). The ecu wouldnt trigger the injectors so i had to figure out a way to make it work. Here where my options.
a) Jim wolf reprogram computer
b) Find top feed injectors low impedence
C) Figure out how to make the the ones i have work
I decided to go with option C. What i ended up doing is measuring both the high and low impedence injector and figuring out the voltage drop needed to get the ecu to think that it was firing a low impedence injector. To do this i wired a 39 ohm resitor in parallel with the two wires that fire each injector. the car fired the first time. Beside from a few vacuum leaks making the car idle kind of high everything works great. the new sr20de does rev alot quicker and seemd peppier than the old one but there are some downfalls. The rev limit is lower 6800rpm and the bottom end is not as strong as the older versions. the older version have this massive girdle that bolts onto the block via the main bearing caps the new one does not. In the future i will be taking the bottom end from a used sr20det rebuilding it and bolting the newer head to it. As soon as i get a chance i will set up a site for everyone to view pictures if wanted. oh and the old distributer bolts right up.
Lowport to JDM Lowport Swap Information:
http://<b>Why JDM engines have low m...highlight=soko
But this new SR20 doesn't just drop in and replace an earlier one. Nissan saw fit to completely change the engine management, so making the new engine run with the old wiring harness and ECU requires a fair amount of rewiring, like the sensors and injector leads. This isn't a swap for the cautious or, frankly, the intelligent.
Answer Below VVVVV
Originally Posted by XxToKeSxX
Since I live in SW Ohio, and we just got rid of E-Check <^><^> I am thinking of keeping the JDM intake manifold and also keeping my OEM one if I find a job out of state. I hope to swap it in maybe mid-late march (spring break or beginning of next school quarter)... (oooops... I let it slip!!!)
good info on wiring a g20 ECU
Take it out the top or bottom???
Im glad you decided to go with that platform. The USDM roller rocker is 9:5:1, fu*k what everyone says that its 9:8:1, that was 1 person and that was not proven and Nissan always claimed 9:5:1 145hp. The only roller rocker that is 150hp is the P11 Primera GT motor which has the same USDM intake manifold but it has a different ECU for some reason and it is 10:1 compression and JWT can crack the code (1998-up). The 10:1 motors have a black valve cover.
The motor you have is clearly from Japan (intake manifold) and they are commonly found in the Primera and Bluebird. My first JDM motor that went into my first P11 after blowing it up with boost was from a Bluebird, the current one I have in my car is from a P11. Both have the same intake & exhaust manifold's but the throttle body is a lot smaller than the USDM one. I have talked to many overseas dudes and it seems these motors were rated at 140hp as well, im guessing the different intake manifold and bigger throttle body makes up for the 5hp extra in the US but it makes me wonder why they rev to 7200RPM and in the US they are only at 6750-6800RPM.
You will be amazed with what some S3R cams can do. I wouldnt even bother with that JDM Intake manifold. Make life easy for yourself, swap the valve cover and your existing intake manifold and keep your current computer and read up on the rest of the stuff from Mike.com.
The main troubles with the JDM mani is the WIRING, do you really want to try to figure out which wire is what and have to cut your stock harness and be throwing check engine lights left and right. You already know there is no EGR on the intake side or on the exhaust manifold, so that alone will trip a code as there is literally nothing to plug it too, also im sure the 02 sensors are different. Its just too much of a hassle, if you want a nice clean swap without the headaches, then just keep your USDM stuff, take all the JDM stuff off (make it a nice longblock) stick your stuff on it and you are good to go.
We followed Mikes instructions when a girlfriend of my friends who owns a shop blew her 95' G20t motor, he mistakenly bought a RR from a 2001 Sentra, and couldnt return it (thinking all SR20s are the same) so I gave him the instructions and 2 days later the car was running great. She was happy that it was peppier too.
There have been lots of opinions on this...
The Actual Swap Process:
Thank you for this...
My Swap Process!!!!!
Check it out!!!!
Exterior Pics of My New JDM RR Head/Block
Modding The JDM Roller Rocker!
Aftermarket Pulley Information
Please, Do NOT Purchase aftermarket pulleys for your USDM RR engine.
There is an argument... but its not super valid... There have people that have installed them and had no problems. I do not think that its the actual pulley that is the problem, I think it's people incoherently revving "faster" and hitting higher revs then they would in the normal amount of time.
Originally Posted by Andreas Miko
For all you SR20DE 2000-01, SR16VE and SR20VE owners, do not, I repeat, do not put any type of aftermarket pullies on your crank. These motors have a 4 counter weight crank shaft that is prone to vibrations in the higher RPMs. If you put a aftermarket pully that does not have a dampener in it like the UR pullies you will have premature bearing wear in your motors and also you can have problems with your clutch bolts or flywheel bolts coming loose.
USDM 91-99 SR20DE 8 counter weights - underdrive crank pulley seemingly ok
USDM 00-02 SR20DE 4 counter weights - underdrive crank pulley (maybe) not ok.
The roller rocker USDM SR20DE engines USDM 00-02 should have problems using an underdrive pulley, however, in the last 6 years I have not heard of one having problems. Experts say they should not be used but... Most of the VEs are 4 countet weight, except the 20v.
Since I am using my USDM Manifold, my Injen Intake from my 98 will bolt right up.. I will need some information on what other people do... I imagine that there is an intake that you can purchase for the 01-02 b15 if you have the USDM Roller Rocker. I will have to check into that.
Headers that are incorporated for Lowports will bolt right up but you will have to check about the Bung for the EGR tube. Since I have my USDM 98 Intake manifold, I was able to use a Hotshot Gen 3 and it bolted right up...
Please let me know if you would like your name mentioned here if your words have been used in this above information. I would love to give you props/credit/thanks for helping me. Names weren't disclosed to cut down on argument over contradictions.
I would like to thank:
-TUNED200, for doing me the favor of picking up a great engine for me, and actually going out of his way to grab it... and giving me some great insight on what I should do for a swap.
-Domiken, for taking the time to give me more insight and correcting me on this type of engine & swap.
-wnwright, for taking the time to look into compression differences for me.
-jer_760, for being patient and replying to a lot of my posts...
-jp, for giving us all the useful dyno information, and testing to determine correct compression ratios!
Some of the sites information was taken from:
and many more... to come?
Feel Free to add Good Relevant Information...
I Shared What was Found for a Reason!!!
(I also apologize... I know its a little overwhelming in size)
Peace, and remember... SEARCH!
Edits & Changes...
03/05/06 - Addition of JDM information
03/06/06 - Addition of Highport/Lowport Differences Thread
03/06/06 - Correction on Idle Speed Information
03/10/06 - Compression Information Update
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
03/25/06 - Addition of References to Dyno Info & Compression Testing/Testimony
03/29/06 - Addition of Mods Section, My Swap Link & Updating Information
04/02/06 - Added a couple of Pictures of Roller Rockers
04/28/06 - Addition of Table of Contents and Shortcuts