SR20 Head Upgrade Questions
 

I'm in the process of breaking down my motor to rebuild it for roughly 320rwhp, and had a few questions about upgrading the head. I've read the 9k rpm head article and tons of other stuff but this being my first build, I wanted to seek the wisdom and experience of guys that are currently running the similar setups.

My current plans are:

Mostly stock bottom end with new OEM piston rings, ARP studs
New Timing Chain and Tensioners
Cosworth or Greddy Headgasket
264 Cams and aftermarket sprockets
Rocker Arm Stoppers
Greddy Intake Manifold
Z32 MAF
GT2871 Turbo
550cc or more injectors

I want this to be a solid motor, in terms of reliability, and it will be mostly used as a DD.

The head is intact and in good shape right now with roughly 100k on it. I haven't broken it down yet, except for cams, because I didn't know if I should be upgrading the valve springs and retainers, etc, or if I'll be fine with just cams, sprockets, rocker arm stoppers and upgrading headgasket and arp studs. Any other guys running stock springs and retainers, valves etc reliably with 350hp? Thanks for any input you might have.

With your power goals, tomei 256deg poncams and oem springs are fine. 264 cams are not going to be much of an advantage, and would require springs in most cases.

This is all I would do with the .64 2871r with your power goals.

Poncams
Cosworth valve springs w/ oem retainers
740cc injectors

Noted. What is your current setup if I may ask?

My head's setup is very similar to the one in the 9000rpm head thread.

Supertech +1mm oversized nitrate intake valves, and +1mm oversized inconel exhaust valves.
6mm bronze intake and exhaust valve guides (stock exhaust valve stem size is 7mm, converting to 6mm reduces valve train weight).
Dual keeper rocker arm conversion with Tomei solids (the trick here is setting the tip height with the two keepers then setting the valve lash by shimming the the tomei solid by placing the shim under the pivot instead of raising the rocker arm via shimmed guides)
Supertech dual valve 106lb springs & ti retainers
HKS Step3 272 cams

With that said, I have built a SR with nothing but springs, 256 cams, 740cc nismo's, z32 MAF, rom tune and a 2560R turbo. It was an absolute blast. In fact a friend of mine will be doing the same thing with the only difference being the Tomei turbo.

Yeah sounds awesome, you did all the head work yourself? Did you have any prior experience doing head stuff yourself and what resources did you use to assist in the build?

get an apexi head gasket
best of the best

With the exception of the valve guides, I assembled the head, but all of the machine work was done by Mazworx. They are also the ones who developed the 6mm conversion and Mark (owner) is the guy who came up with the solid lash adjustment method I'm currently using in order to run dual keepers for the rocker arms.

Yeah I guess because since it's my first time putting everything back together (swapping motors is one thing-rebuilding them is another) it seems a little daunting, but I see it as a challenge and good learning experience, and will take plenty of time to research and carry it out, as well as get supervision from a few friends who have built race motors before.

I've heard good things of Mazworks.

Anyone running 264 intake and 272 exhaust set up? I've heard its a good setup...

SR's don't respond well, to my knowledge, with mixed intake/exhaust cams.

With that said, for your power goals and for best street driving, 256 Tomei Poncams are what you want.

For the price, BC Single Wound valve springs are a good bet too.

RAS are a good, cheap insurance. I know a lot of people say you don't need them, but you know what, for 70 bux, why not?

Good choice on headgasket.

550's should work for injectors, but I would go with 740's so that you don't max your injectors, and if you decide to turn up the boost to get a little more power, you won't be limited by your injectors.

Good turbo choice for street driving and your power goals. I would recommend the .64 A/R.

What fuel pump will you be using?

Are you going to upgrade your cooling system at all with your build?

I would recommend an aftermarket oil pan that has a baffle to help ensure proper oiling of your motor.

Sounds like it will be a good set-up with the right tune. Enjoy!

Oh, I forgot to ask, do you have a S13 or S14 SR?

Yeah thanks for the advice, much appreciated. I'm running an S13 SR. Right now I'm running a Walboro 255 which should be fine for 350hp goals, last time I checked. Good advice on injectors, hadn't though too much about them, but I want to play it safe and have a semi-reliable build that I can keep for more than a couple years.

Cooling wise, I was going to run an ISIS or Greddy oil pan. I've been toying with the idea of also running an oil cooler if I can find one here (Japan) for cheap, but I'm not sure if that's a little overkill since I don't and won't really track this car.

BTW are you in Japan right now? I'm living with my family in Chiba. What's your current setup?

Walboro will be fine. If you haven't bought it yet, since your in Japan, just buy a GTR fuel pump. I think one of my friends has one for sale right now actually. Also, since your in Japan, get a Kts oil pan...it's the exact same thing as Greddy and you can get them SUPER cheap on auctions. I live right next to Tachikawa, near Hachioji.

My current set-up:
S14 SR, Kouki (kouki turbo) Boosting 1.0 bar
Trust 1.2mm Headgasket
BC single wound valve springs
Tomei 256 PONcams
Tomei RAS
KTS oil pan
Stainless Manifold (don't know the manufacturer)
GTR fuel pump
KOYO 3 core radiator
FMIC

With my "special" final gear, I am able to keep up with 400hp cars no problem...this set-up is SUPER responsive and SUPER reliable...it's a mild build but has the right parts in the right areas and is geared more towards keeping everything reliable.

Whats the lift? If your talking about HKS Step 1 cams...then thats fine. If you're trying to run big boy cams of atleast 11 lift (tomei pro cams, HKS step 2s, etc) then you'd be hurting the response of the engine. Dont go over kill on the cams, get some Tomei poncams, 256 or 260s and you should be golden.

For the head, I'd upgrade the valve springs, valves and retainers.

BC Springs are by far the cheapest when I've been looking at spring options, I guess I'm wondering though if they will work well with the Tomei or HKS Stage1 cams? I don't know enough about the springs in terms of rate, and performance over the stock OEM ones.

Thanks for the input. I guess the SR20 head really flows well, even with a basic cam upgrade. A lot of people just say "cams" when talking generally about good upgrades for the SR but obviously there are a lot of different options so that helps me understand that even a basic cam upgrade works well. I have a few friends here that are into drifting, but don't know as much about SR20 tuning, and how to get good power out, while not blowing the motor a year later. I'd really like to meet some Japanese or even guys stateside that are into tuning.

Oh, little off the head topic, but I'm wondering if you guys are running with the stock fuel rail. Should I be ok to use it or do I have to upgrade? I'm planning on upgrading the FPR, but didn't know if the stock fuel rail would suffice.

Stock fuel rail is good for much more power than you're after.

BC valve springs will work with any camshaft. BC valve springs are A LOT stiffer than stock, so they will handle high rpm abuse and help ensure the safety of your head/engine.

What are your concerns regarding tuning that you wanna meet someone for?
Since your in Japan, not too many people know about the 2871 turbo, they all use gtrs, which is the closest one to it...

Stock fuel rail is fine.

Do you drift and if so, where at?

Jim Wolf Technology S3 cams (260* 11.2ish lift)
Stock Springs
Stock Retainers
8,000 rpm all day, without any issue.


Typically not found in the automtovie world, but as the whole, it's the best setup out there, while being the cheapest overal. Bolt in like stock, no need for cam gears either. These cams prove themselves constantly both NA and Turbo....and IMo are the best cam out there to mate with a 400 hp 28RS or 2871 .64 car. Dump truck torquey midrange and some nice lift to boot.

By the time you go out and buy all of the fancy springs/retainers/nonsense from BC, and then the crappy cams, you'll have over 1000 dollars into your head, and make less than the JWT Setup.

The bigger thing to worry about are properly designed parts, that actually work with the engine. Unlike BC, JWT actually does true cam reserach and development (beyond just throwing a duration/lift out there and hoping it works) they have extensive development in their lobe profiles and ramps (go figure as they make a big lift cam that is safe on stock stuff).

To me the BC stuff are really just improperly designed for the engines...but this is what you get with a copy cat company. Sure it may work, but work well is another. Not my valvetrain as they say, and I can point out countless first hand examples of both turbo and N/A variety to me that have been running S3's forever, without an issue, all making great power.

Cody, you on JWT's payroll yet? :P I swear you're their best internet sales rep.

In all seriousness though, I'd be saying the same thing as Cody except you live in Japan, which makes getting the JWT's a lot more expensive than the Tomei PonCams. While not exactly as great as the JWT's, they are more than capable of doing the job, also while retaining the stock valve train.

Also like Cody, I'm not a fan of BC components, and would rather see you get either new oem valve springs, or tomei/hks ones should you be set on replacing them.

Yeah, actually I was planning on running a GT-RS at one point till I found out a 2871 is cheaper, and puts down similar power. A few of my friends here have the gtrs on their drift cars and love them.

I guess since I live in the country that has so many famous tuners that know the SR in and out, I'd be interested in talking to guys that build them all day long. My Japanese isn't that great yet, but I'm hoping to live here for a while and learn what I can from guys. Same goes for when I'm in the states, but there aren't a lot of 240 guys in virginia that aren't ricers.

Don't have a drift car yet here, but when can afford one and a place to keep it I will. For now I've been going to Mobara twin circuit when I get free time.

It's funny you say that, because I've had a few guys I know back home that sold their BC cams and got Tomei, JWT, or Greddy. It could've been that they were just going a different route with the motor, but I'm not sure. It's good to know the JWT S3s will work fine with stock springs and retainers, I may just go that route.

The only thing I've taken out on the head has been the cams, should I just leave the springs and retainers, etc as they are or replace them with new? (engine has about 100k miles on it and compression was good (i.e. 150 range across all cyl) when I bought it)

Haha, I thought the same thing, but I'm glad he's being honest about what he's seen and that gives me more of an idea of which route to go.

Tomei's cams are a lot easier to get a hold of here, used and new. Not sure if I would even put used cams in unless they were from a friend though. Is there anything else other than marks on the lobes that I would look for? I getting a bad used cam could screw up everything, so I'm really hesitant about getting anything used.

I personally don't like the idea of used cams, but some of my friends have tried to relate it to buying a used exhaust.

Tomei PONCAMS are super cheap on auctions...I paid 20,000-30,000Y for mine, new. (Can't remember exactly, but I bought them on auctions).

I don't personally know anybody with BC cams for the SR. My friend bought them for his 1j (jzx90) and he made awesome power with them. The Japanese tuners were really amazed at how much torque they made too. They had never seen a power curve like that and were quite impressed. I am by no means trying to defend them for use in the SR because I don't know about them first hand.

You are safe to run drop in cams without doing anything else to your valvetrain. Plenty of people do it (in Japan) all day long. People in the states just like to "build" everything.

I'm sure JWT cams are great, but since you live in Japan, Tomei cams are cheap, their a great product, and tuners here are very comfortable with them.

I've really noticed that when talking to friends here about their SRs, and they're always questioning why I want to replace certain components when they never have. Part of it is used parts are easier to come by here when something breaks, but also people just don't put the miles on their cars we do in the states, although they put just enough if not more track abuse into them. Most of the S13s I see here are all tracked, and occasionally see a few on the street.

Haha I'd love to in exchange for parts, but at the same time then I'd also feel like I'd cheapen my opinion, as many would see me as 'selling my brand' if I was associated. I'd rather just be a positive 3rd party supporter (if that makes any sense)

Most certainly. Tomei is about the only other cam company (and HKS on the low end) I'd really suggest in regard to cams. The fact he lives in Japan certainly puts Tomei to the front of the pack as it's certainly much cheaper there, and their support is close. The only thing that I have an issue with Tomei is where they measure their total lift at...their listed durations often aren't the same at traditional lift points...not to say it's bad, just different...260's really perform like tradition 256* duration, and 264 more like 260* and so on.

Most certainly! Bottom line BC stuff is entry level garbage. Sure it's cool to use if you want to increase your signature list, but the reality is they are no better than OEM. I'd suggest matching springs with cam companies...that is, Tomei cams = Tomei springs, JWT cams = JWT springs (for C series), etc etc.

I've got personal friends who like Supertech stuff, and all exclaim their products to be good, but I personally have no experience with them...so I'll refrain from any review.

Me too. :P

Just wanted to thank you guys for the information in the thread, it was semi-useful to me, usually you don't learn something new on Zilvia. Other than how to flame people. :P

Nothing wrong with used cams as long as you make sure they are good cams, which really just takes a notepad and a digital (doesn't have to be but god does it make it easier) micrometer. Measure everything, lobes, journals etc and make sure there are not any dramatic variances.

HKS and Tomei cams are made of much harder material than the rocker arms, so usually in a oil starvation situation the rocker arm takes the biggest beating. I actually have worn arms that show what I mean, I'll find and take pictures of them. I also have a used oil starved HKS Step 3 272 cam and can show you what it looks like too.

Yeah I second that, I'm very grateful for all the info posted, and hope others will gain something from it.

^^^ Pics would be great if you don't mind taking the time to post them. I might go used, but I think I'm going to try and get a deal on new 256 Poncams, too bad the exchange rate sucks right now 83円 to $1 USD FTL...

Its not a problem, just gotta track down the rocker arms.

I like the current exchange rate, I'm looking at working in Japan on the economy so the terrible exchange rate is nice, for now :D too bad the bank of Japan is trying to intentionally de-value its money so Japan can export more goods to the US. Hurray for our dollar's terribad performance on the international market.

Assuming one is already following Codyaces recipe for a 400+ HP SR, I have a couple head questions.

What advantages are there to upgrading to aftermarket valves, and valve guides besides extra strength? Can better flow can be expected from +1mm valves? Or are valve upgrades unnecessary at the 400-450 hp range?