BlackMaxGTR

iTrader: (3)

Im in the process of building my motor and was wondering what both stock valve sizes are for the 3.5 motor. Has anyone had a valve job done with theirs?? And by this i mean bigger valves. im trying to figure out how big i can go with my setup without it being too big and sluggish on motor, thanks for any help!

SR20DEN

iTrader: (7)

Start by reading the stickies. They are there for you too.

http://forums.maxima.org/showthread.php?t=345720

Nealoc187

iTrader: (23)

Then continue by using the search function.

BlackMaxGTR

iTrader: (3)

Thank you guys for the oh so predictable responses, i mean i never thought about trying those.......... but i was not asking what sizes everyone already had (stickies) and could not find what i was looking for with that search "function". but yeah thanks anyways

SR20DEN

iTrader: (7)

orly ? Then what was the purpose of th following question?

You didn't find the answer to that question in the stickies? And if you didn't care to know then why did you ask it? Stock is what everyone has.



That means you didn't look enough or the imformation simply isn't here.

There have probably been a few people but if so, they haven't posted it here.

No one on this site has used the larger valves.

Jeff92se

iTrader: (82)

I'm curious as how far along you are in the process. Are you an experienced builder?

Valve size IMHO is more restricted by the phyical dimensions of the head.

And more than anything, cam specs will determine how the engine responds. You probably couldn't get a valve big enough to get an engine "sluggish". How much a valve flows is not just a function of the size.

VQ20

Does anyone no of anyone who did modifications to a VQ20 and what they did??? Keepin it N/A. I read up on a related post with regards to a strokerkit, does anyone no if the 2500CC bottom end would bolt up on the 2000CC???

Any info or pointing in the right direction would be helpful.

Nismo3112

iTrader: (12)

Wow 2.0 V6..

Nealoc187

iTrader: (23)

I say get a VQ35 from the states and throw that in...

ajcool2

iTrader: (43)

I never knew there was a vq20 until now.

Alex_V

theres also a VQ25 as well.

~Alex

Zack342

iTrader: (89)

trinidad ehhhh

Pics of the car please.

SR20DEN

iTrader: (7)

And a VQ23DE

japmaxSE

iTrader: (7)

I just took my 3.5 heads apart recently and I'm doing my research as we speak on the various options for heads to flow.. -+
I'll have some info maybe later this summer.

vipervadim

iTrader: (10)

cams do determine the valve height, and they determine how much air is coming in, a good reason to upgrade valves is if you are raising the rev limit to the point where the valves will start to float (i.e. over 8K consistently)

larger valve size will not help with stock cams and stock rev limit, however if you do replace the stock valves with much lighter (+stronger) titanium valves and springs (don't necessarily need to get stiffer springs) you can gain hp by minimizing weight.. add 3.5L cams and a PF TB on top of a 00vi (looks like you have headers) and maybe the EU, tune with a WBO2 and i forsee a crazy n/a 3.0L motor with emphasis on the mid-range and top-end

GodFather

iTrader: (10)

those 2.0L vq's are common in my home country in taiwan. There was a company called Lieban which reinforced the combustion components and increased bore sizes. vq20de's are the stupidest V6 engines in my country. Everyone complained that it burned so much gas and produced so little power. It was a sluggish engine for a V6.




i totally agree and i have experienced it myself. these are my mods, though now i took the jwt cams out again because it snapped again for the 3rd time. but i can tell you, my top end power was insane! Enjoy...

CATTMAN HEADERS
CATTMAN CAT-CONVERTER
CATTMAN CAT-BACK EXHAUST
PLACERACING COLD AIR INTAKE
NISSAN'02 PATHFINDER THROTTLE BODY
MID-EAST VARIABLE INTAKE MANIFOLD (MEVI)

(ELECTRONICS/IGNITION/TIMING)
"JimWolfTechnology" 7200 ECU
"JimWolfTechnology" CAMSHAFTS (Now, I'm runnign stock cams because JWT Camshafts snapped 3 times already)
"JimWolfTechnology" VALVESPRINGS
NGK PLATINUM G-POWER SPARK PLUGS
SPLITFIRE DIRECT IGNITION COILPACKS
BLEHMCO'S CUSTOM GROUND WIRE KIT
DURALAST 125-AMP ALTERNATOR
OPTIMA YELLOW TOP BATTERY
SUMMIT RACING RPM SWITCH

(FUEL/OIL)
350Z OIL PUMP
300Zx Fuel Filter
REDLINE MT-90 TRANSMISSION FLUID
BENALI NANO-PHOTON FUEL BOOSTERS
EXON MOBILE 93-OCTANE GASOLINE
MOBILE 1 SYNTHETIC OIL
MOBILE 1 OIL FILTER

(DRIVE TRAIN)
STAINLESS STEEL CLUTCH LINE
MOTORSTORM UNDERDRIVE PULLEY
XTD STAGE 3 CS 6-PUCK CLUTCH
FIDANZA LIGHTWEIGHT ALUMINUM FLYWHEEL
(Stillen flywheel snapped in 2 pieces even without Forced Induction)
CUSTOM ENTERPRISE SHORT THROW SHIFTER
CUSTOM ENTERPRISE LEATHER SHIFTER BOOT
TOP ELEMENT POLYURETHANE-FILLED SHIFTER BUSHING

TRANSMISSION:

MAXIMA-ALTIMA HYBRID TRANSMISSION GEARS:
(TRANSMISSION IS REBUILT FROM MIXING GEARS)
FACTORY-------->NEW GEAR RATIO
1ST= 3.285-------->3.400
2ND= 1.850-------->1.955
3RD= 1.272-------->1.272
4TH= 0.954-------->0.954
5TH= 0.795-------->0.740
Final Drive= 3.823----->3.823

SUSPENSION:
2 INCH DROP MAXSPEED SPRINGS
TOKICO'S BLUE STRUTS/SHOCKS
EIBACH CAMBER ADJUSTMENT KIT
J-CLAW DRAG RACE TRACTION BARS
PARADOX FRONT STRUT TOWER BARS
PARADOX REAR STRUT TOWER BARS
(CATTMAN) ENERGY SUSPENSIONS FRONT SWAYBAR FRAME BUSHINGS
(CATTMAN) ENERGY SUSPENSIONS LOWER FRONT SUBFRAME BUSHINGS
(CATTMAN) ENERGY SUSPENSIONS FRONT SWAYBAR END LINK BUSHINGS
(CATTMAN) ENERGY SUSPENSIONS POLYURETHANE CONTROL ARM BUSHINGS
(CATTMAN) ENERGY SUSPENSIONS POLYURETHANE MOTOR MOUNTS

BRAKE:
HAWK'S BRAKE PADS
CUSTOM BLUE BRAKE CALIPERS
POWER SLOT CROSS DRIILED ROTORS

nismology

iTrader: (8)

Snapping cams? Are you properly torquing down the cam bearing caps? And in the proper order?

GodFather

iTrader: (10)

Yes, properly torqued them down to specs, proper order, and sequence. my mechanics did it three times after i snapped all three of them. funny thing is, everytime we run stocks cams, nothing would happen, but with jwt cams, those f-er's just keep snapping. they snap at the dowel pin section.

i am suspecting that my main timing chain tensioner is weak, so everytime i shut off the car, it came loose. so everytime i crank it back up, it would strain the cam's sprocket section and snap the cams. anyways, after it snapped 3 times, i'm scared to put the cams in. the thing is, i used to have timing tensioner problems. they were loose, so timing chain kept slapping the chain cover once in a while. during the course of having jwt cams, i only have replaced the cam timing chain tensioners, not the main chain tensioner. so i am really suspecting this to be it. anyways, now that i've replaced all the tensioners, i don't think there's going to be problems. i'm going to put the cams back in the future.

in addition, jwt isn't friendly about selling me the replacements for the snapped ones. just to give you an idea, i bought 2 sets of their cams and an extra one that kept snapping. it wasn't nice, all that money i threw at jwt.

right now, i still have 1 complete set left after snapping different ones from the last time. i'll try to put them back in again. when i had the cams in my engine, that top end was crazy. i missed it dearly. low end loss is kinda bad, but it picks up from about 3500 rpms and runs strong up from there, so it isn't so bad after all. under 3500 rpms is where i drive slow on normal days. after 3500 rpms is my wild drive anyways, so i think these cams are great for my taste. besides, in a race, i am only under 3500 rpms in 1st gear for a short while since i have hybrid altima's shorter 1st and 2nd gear durations. after each rev limit shift, my rpms drops back to about 5100 rpms with the help of my jwt 7200 ecu; right where it hits my power band from cams, mevi, and splitfire coils. this is a wonderful setup for me. that's why i'm willing to risk the last hassle and money to put the cams back for the last time.

japmaxSE

iTrader: (7)

GodFather have you made any passes with that setup?

GodFather

iTrader: (10)

first time installed the cams: snapped on cranking up.

second time installed the cams: snapped the same long intake cam on crank.

third time installed the cams: drove for little more than 2 weeks. car died. this time, short intake cam broke. (this is my 3rd time snapping the cams)

my mechanics quit on my car saying that i must put the stock cams back in, or else, they'll charge the f outta me for putting my last available set of jwt's back in. well, at that time, i don't have money to put the cams in again. so i quit. unfortunately, i never got to run the track with these cams on my car. sorry to disappoint. but as long as i still have these cams at hand, they will go on my car one day, and i'll run that pass on the track. as of now, i need to get the fawk outta college first.

GodFather

iTrader: (10)

best i've done with these short lived cammed races is when i raced my friend's 2001 auto camaro z28 again. i always race him when i get new mods.

1) with basic bolt-on's, (intake, ypipe, and megan catback exhaust) z28 owns my max

2) with moderate bolt on's, (jwt ecu, mevi, splitfire coils, cattman's full header to exhaust, udp, stillen fw, spec stage 2 clutch, ground wire, intake, took seats off for lightweight), he and i stayed close on take off to the end of second gear, then he walked me on 3rd gear. and then it's a run he did on me at the end of 3rd.

3) rebuilt with jwt cams, valvesprings, 3.5 oil pump, mevi, jwt ecu, splitfire coils, intake, exhaust, and all the rest of my mods and with hybrid tranny, I shot out a car ahead on take off, walked a little more on second gear, and on third, he was 3 cars behind me, and neither of us can gain or gap off each other. this is based on several runs with similar results.


that Z28 is bone stock except with new Exhaust and test pipes. He's also running that O2 simulator to by pass his testpipe's engine code. His run on qt is around flat 14's on a good day, and low 14's on a average. I am not too credible to compare my timing this way, but this gives me a good idea of where i'm at. I know that feeling, and I can only vouch that it was mad fast once i hit my power band from around 4k and up...

UK-nissan

They both have the same stroke as far as I am aware, 73.3mm, so the only way up is to overbore, if I am wrong then it is 69.7mm for the 2, and an overstoke would take you to 2.1litres.

Mike

vipervadim

iTrader: (10)

wow i never heard of snapping cams on vq motors!!!

stock 3.5L cams are a good cheaper alternative to the jwt, but not that aggressive, but compared to stock 3.0L cams much better for mid and top-end.

i think it should be mandatory to change the tensioners when installing more aggressive cams, especially if the engine has more than 90K miles on it.

GodFather

iTrader: (10)

Well, here is my deal:

This summer, I'm getting a 00vi for sure, plus I'll get the Vortech blower, charge pipe and a few more things for my supercharger kit. But I'll not complete the setup yet. There are deals that I called dibs for already on these items.

Or, I can skip the above proposed deals, and go straight to install my last set of JWT cams. But I'll lose good deals on the dibs I called. and That's not good.

I am serious about making a vq30 screamer, but for this summer, I can only do one of the 2 options. What do ya'll think?

GodFather

iTrader: (10)

Hey, get splitfire ignition coilpacks for that 2.0L VQ. That's what they do in Taiwan. You'll squeeze about 12 whp with that mod. That extra whp won't cost you to lose any low or mid range. You'll simply start to pick up horses after exactly 5000 rpms. It's like MEVI, but with no torque loss.

This has been proven by many VQ20 Cefiro's in Taiwan. Base cost is about 300 US dollars (Converted from Taiwanese Currency). Good luck, I paid about 600 bucks to buy them and air ship them to the states.

GodFather

iTrader: (10)

I have also been reluctant to post a thread about JWT's cams being snapped 3 times. Well, I am tired of protecting their reputation while their stuff keep f-ing up. So, after my final exams, I'll snap some pictures of the Broken cams. Let everyone have a say on this.

chris'smax

iTrader: (3)

**** pete, i wonder if i f'd up by not replacing the tensioners! My nismo cams are more agressive than those JWT cams We checked everything and it all looked to be in great shape, but i wish we had just went ahead and did it. O'well too late now

chris'smax

iTrader: (3)

yea ya'll have to see this ****. One of them broke about 1/4 of the way from the end

GodFather

iTrader: (10)

hey chris, your tensioner should be fine because the problem with 4th gen tensioners has been redesigned and that part number has been superceded to the 5th gen tensioners. besides before i did my cams, i had bad tensioners already, but i only replaced the tensioners for the cams. didn't do the main tensioner, and that's where i f-ed up. but i think you'll be fine. no worries.

before i start on jwt cams, my timing chain cover area has been making clanging noises. had the mechanics open it up and they found the cam chain tensioners to be weak and the plastic router on them was beat up. they told me to replace the cam chain tensioners. it is at that time when i saw those stock cams, and thought about going with jwt cams and the whole good old deal. gone thru 3 set's of jwt cams and none of which worked. i'm regretful to say that it must by my main timing tensioner that i never replaced till i snapped the 3rd jwt cams set. when i put the stock cams back, i bought those new main tensioners and put it in. Those new tensioners had a slightly different angled spring and oil hole than the original 4th gen tensioner. So I'm going to try to do the jwt cams again when I have enough money.

Also, all of the mechanics who worked on my cams are b!tches who's negating performance parts on my car. I find Nick to be the only guy who loves to put those performance parts in the car for me. So, he'll be my main man for the cam job next time.

japmaxSE

iTrader: (7)

All 4thgen VQ's have this problem especially at around 100k -120k is when it starts to make noise.

GodFather

iTrader: (10)

Yes, Japmax, you are very right. My car was at 128k miles when I start to hear the clicking noise in the timing chain cover. And it later became pretty bad, the chain basically slaps the chain cover.

I also want to suggest to all 4th gen guys that if you are doing a cam job, replace all of your tensioners in the timing chain assembly. It'll be good for the long run and rule out the possibility that your cams may snap like mine. if there's a write up for the cams, this should be added on there.

japmaxSE

iTrader: (7)

I vote second on this to be added in the stickies somewhere. I hear allot of maxima's with slapping chains. The owners don't even realize it. Until it snaps then there like WTF I only have 120k on my motor.lol

VQ20

Thanks man and i agree with your post before bout the vq's. the VQ20 is sluggish and does burn planty gas and i have gotten beat up on by NA SR20's don't even talk bout the VE's. the car jus does not perform at all. Most i have gotten is 190Km/h(damm speed cut) even sum qg's have kept up with me from time to time.

I was seriously considering buyin a 3.0 or 3.5 from the states and slapping it in. the only thing i studyin is the cost for shipping. i did sum research on de splitfire ignition systems and think it is a must. Also not sure if its relevant but i have a 5th gen model 2001 A33 from singapore. This is exactly what the car looks like same color everything. only thing different is the rims. it came with 15's stock.

http://www.cars-directory.net/galler...b936259_p.html

Thanks for all the assistacne. realise i don't hav a good platform to work with so a new engine is in order.

SR20DEN

iTrader: (7)

Are you kidding?

VQ20

No why??? Pls share. i new to the VQ so any info i get will be appreciated......

J187SD

use search man, no one knows the answer to your ?

GodFather

iTrader: (10)

In Taiwan, my dad told me that many VQ20DE Cefiro's are buying the splitfire's for that little extra umph! Not trying to dispute your comment, but those who bought it said it's such a good mod for their sluggish 2.0L cars. My dad's a VQ fanatic in Taiwan. He's the one who got me into buying the Splitfire's Coils. I'm using it right now and I am just too poor and have no time to go to that dyno. But I am very positive about its noticeable gains after 5k rpms, just like what they said in Taiwan about their little 2.0L's.

SR20DEN

iTrader: (7)

It sounds like you guys need a SMT6 or a EU so you can advance the ignition timing on the VQ20s.

VQ20

Did it using a consult2 and acording to the consult it could only go up to 12degrees. We adjusted it to 12degrees and i didn't notice any difference.

Read up on the smt6, seems like a good product, but would it be better to buy that an tune yourself or let technosquare re-program de ECU???

nismology

iTrader: (8)

Doing it through the Consult only changes your base timing and doesn't advance the timing throughout the rev-range. It's a pseudo-modification. For real gains, you'll need the SMT-6 or EU.