Thread: JWT S3R's

So searching through the forums I see a few dyno graphs with these cams and they seem to nose over power wise around 6k~6.2k. There was also an article in some magazine but I forgot the name, similar results as well.

JWT used to sell springs that theoretically allowed these to run to 7.5k instead of the 6.8k with stock USDM springs. Why sell these if it couldn't make power up there? Would the Brian Crower springs BC1200 be up to the task as well?

Why is the power limited to this low rpm if it has the 'same performance' as the S3. From JWT's site: "S3R CAMS SR20 2000+ ROLLER .450" LIFT/262 DEG. DUR. SAME GREAT ALL AROUND PERFORMANCE OF THE S3 CAMS, BUT DESIGNED FOR THE 2000+ ROLLER ROCKER ENGINE."

Anybody run these cams with upgraded springs and made worthwhile power above 6200? Were cam timing adjustments necessary to do this?

Any insight from experience would be nice as I have a set I would like to install into a JDM engine so I'm just looking at what would be the best supporting mods to do at the same time.

I dont think they sell springs for the RR but some company is working on it. Check with Greg from Gspec.com he has them posted on his website.

Yea he has a listing and it says 'not available yet' or some such. What is the special requirement of the RR spring? The JDM engine has a redline of 7k, figure with the higher duration I might be able to run it a couple hundred above that maybe.

The best person to talk to about implementing roller rocker mods is JP on the forum, he has some very good baseline information on what each modification does with these roller motors. I'm sure you've come across this link before but it has some pretty good information in it as well.

RR SR20 N/A Buildup Thread - Sport Compact Car
SR20 Engine Buildup - Tech - Sport Compact Car Magazine

^^^ is a great writeup on the buildup of a b13 w/ a swapped roller motor in it. In conclusion; even though there were springs made at one time for the roller valve train there is little power to be gained since they were originally designed for a powerband with tq a little earlier than the variant DE.

Almera Owners Club Discussion Thread on the S3r's I started a little ago
Almera Owners Club Forum

There's a little info here as well ^^^ as to what the UK Almera boys have tried... (even though their rev limits are a little lower than the jdm roller motors everything still applies). From what I've experienced, even though the cams are designed for the early tq specific powerband, you can still see your peak HP at 7k or so, respectfully - but even with the JDM motor you will get a little valve float above that on the stock springs.

Some of the information may be old, but take advantage of it... but if anything newer has come out disregard...

I don't care what anybody says, but keeping the timing around 15 degrees yielded me best results w/ the cams in and a stock computer. And from what I understand, the best results with these cams are yielded from real tuning, and grabbing yourself a set of cam gears and advancing the intake cam ONLY... leave the exhaust cam alone.

If you don't want to mess with all that, you can always switch to the non roller valve train and go from there but the roller valve train is slept on. Clark Stepplar w/ JWT had some information to share about some developments that got stopped in there tracks with the RR variant as well.

Hope that helps a little. If you have any questions I'll try and share what I've gathered.

The VE and RR motor share the same valve spring installed height. Get inner valve spring seat shims and you can run the BC or Supertech valve springs in your RR motor.

A lot of the power differences has to do with the tuning and the cam timing as well. The USDM intake manifold could use some work as well to make more power up top. Also, get a good header.

To remove the Roller Rocker valvetrain from the head you will need to remove the valves from the head because they are shorter than normal DE valves. These are the same installed height as the VE.

Part of the reason the "race" motor made marginally more power than the stock one is because the 300ZX pistons are heavy.

With the S3R's you won't need to be revving the knackers off the engine to get power, stock redline will suffice. Like Tokes said, the springs will prevent float even if your not revving to 8k.

If you wan't a big cam convert to non RR, I did so I could use C2's...but you do need to change the valves, springs, rockers, oil squirters and the cam cover. But it does give you so much more cam choise.

I was going to make some custom RR profiles just as options for people that want larger cam choices but I know its a very limited market so that is why I have not done that.

Thanks ameen, that is the article I was referring to. I was trying to link to that almera forum but I gota join to read the article. Was going through your RR thread and got linked to it. I will have the capability to adjust cam timing and I can also do ECU tuning so no problem there.

Thanks for that tidbit there snickers I didn't know the VE and RR DE had same installed valve spring height. I had suspected it and had thought of running an inner spring but again the right combo was the problem. I had also suspected the not so impressive performance in that article was due to the heavy 300ZX pistons, I seem to recall Mike K alluding to that in another engine build and although it was the 11:1 holy grail at one time, with 16VE pistons available it doesn't look so atractive. Its a JDM engine I'm working on so its got the JDM intake. As for header I've got a JDM tubular header and a couple VE headers (complete), was liking the construction of the VE header and thinking a bit of slotting and it might just outperform the SSAC if I use it with a custom secondary.

The issue now is springs. So what are the specs of the Crower VE/GTiR springs, he only specifies for the single spring set (BC1200) the seat pressures. And in the supertech range there are 3 possible springs, the VE specific and 2 sets for the H22. So which set of the H22 ones would be preferable. SPR-H1000D Seat pressure 80 @ 35.5 or SPR-H1005D Seat pressure 93 @ 35.5. I don't know the price of the VE specific but I know the H22 ones can be had for about $140.00 + shipping. Which one was used in the VE before the Crower springs were available?

GTi Kurt, what is the advantage of keeping the RR DE head converted to non RR as opposed to just changing the head to a highport?

I wasn't plannning on revving too high actually just didn't want to loose anything to valve float if I did want to rev to say 7200. Actually if I can make peak HP/torque round about 6800 that would be perfect for me.

It was availability more than anything to me, non rr highports are quite rare over here as they were only in the early eGT Primera's and N14's....both of which never sold that well and are rare cars these days...so finding an engine lying around was more hassle than just working with what I already had.

for the springs, get which ever are cheaper. a good header will do wonders for power on the motor more than just trying to raise the peak hp.