rkazz98

Hey I was wondering if it would be ok to use nitrous with a 3.5L that burns oil? I was planning on getting a wet kit soon but I don't want to break anything further on the motor. thanks

rockfordmaxII

iTrader: (3)

personally i dont know if i would put an already oil burning motor through anymore stress, unless you want to be buying a new engine soon

2002AltimateV6

iTrader: (7)

How extensive is the oil burning? My 3.5 burns about 1/2 a quart every 3k miles, which is typical and I've run nitrous through it w/o any problems. If your car is burning more then that I'd be more worried about the engine then getting a nitrous kit.

rkazz98

im burning about a quart every 2-3k miles. I should probably focus more on the engine. But i dont think it worth it to buy another motor that might have the same issue. unless i just buy a cheap engine and build it up

streetzlegend

iTrader: (8)

i think all or most 3.5's burn up oil. Do you have a catch can? if not get one asap. While spraying the oil going into the combustion is going to decrease fuel octane and increase chances of detonation. how many miles on the motor?

VQrebuild96

iTrader: (1)

20w-50 With thick lucas and some high octain gas should do the trick.

nismology

iTrader: (8)

VQrebuild96

iTrader: (1)

SOME 3.5's are beat on from previous owners. The 3.5 is just as reliable as the 3.0.

nismology

iTrader: (8)

Well that's not entirely true either. Oil burning incidences seem to be independent of driving habits.

VQrebuild96

iTrader: (1)

Please explain...i kinda dint get what you said.

nismology

iTrader: (8)

Some grandma'd 3.5's will burn oil and some thrashed 3.5's won't, and vice versa.

95BLKMAX

iTrader: (10)

some 3.5s do burn oil, but how did it get there to begin with? From my own experience it was blow-by. Dont you dare spray that motor with all that blow by oil going back into the IM. Get a catch can and it should significantly help the situation

rkazz98

the car has almost 90k on the clock. so i should be fine if i get a catch can? again im not going to use the nitrous alot

95BLKMAX

iTrader: (10)

if its loosing oil due to blow by yes a catch can will def help. Look inside your IM and if you see a puddle of oil (clean that off please), add a catch can. Most of that oil you'd loose to combustion otherwise will now collect in the can.

nismology

iTrader: (8)

Only in the mild cases is oil lost solely through the PCV system. In severe cases, it is due to insufficient scraping of oil off of the cylinder wall by the compression rings; primarily the 2nd compression ring. This is proven by the fact that severe oil burning is not always accompanied by poor cylinder compression.

grey99max

iTrader: (12)

I've been through three 3.0s which I sprayed - hard -and they all spewed oil into the intake. I regularly took the top off the MEVI and wiped out the oil. No "catch-can" on these engines.

Now I have a cammed 3.5 sitting in my car, and when I got it w/62K, the intake manifold had streaks of oil inside, and the piston tops had caked deposits on some of them. I'm gonna spray this bad boy, too - hard. I'll put in an oil-air separator on anything that pulls air into the intake, but I'll spray it.

My opinion is that the VQ motors just aren't very tight - blowby seems to be a fact of life here. Nitrous doesn't care about the oil, but the increased combustion pressures will make more blowby through the engine. I figure that Mobil1 oil is cheap.

nismology

iTrader: (8)

Well both the 3.0 and 3.5 share a .010-.030 mm piston to cylinder clearance, so I wouldn't say they're not "tight".

Every engine in existence experiences blow-by which power adders will exacerbate.


PS. To clarify, I mean to say that every normal, non-burning engine experiences blow-by. An engine that burns oil will not necessarily experience more blow-by than one that does.

00SEMAX19

iTrader: (4)

I have been spraying for over a year with an engine that burns a qrt every 1000 miles and havn't noticed a difference. Oil problem started way before I started spraying

grey99max

iTrader: (12)

Published clearances are - nice - but when you drive normally for 500 highway miles and find the MEVI coated with oil inside, that's blowby. When you experience the same thing on three engines, that's consistent blowby. When you buy three engines and open them up a bit and find the USIM dripping with oil inside, that's enemy action.

Back in the day, I preferred a motor that blew some oil over one that was squeaky-tight. Better too much lubrication than too little, I always say....

That experience exacerbated my opinion of the VQs. And now I have a 60K 3.5 that delivered with puddles and streaks of oil in the lower intake runner and oily goo in the three intake ports fed from the bottom of the intake manifold's plenum, and burned deposits on those three pistons. Sigh....

Oh well, nitrous will clean that right out of there.

Just my opinion.... heck, I'm not really complaining, just stating what I've seen. Maybe a new Nissan slogan? You need GOO to GO fast! ????

nismology

iTrader: (8)

Well I was just making the point that every engine in existence today experiences some form of blow-by. It's a mechanical constant. If the compression spec's out, then the rings are in perfectly good condition and have seated properly. If this is the case, all that oil in the intake tract means is that the valve cover baffles aren't really doing a good job of trapping the oil vapor or there is oil windage for whatever reason, not necessarily because of excessive blowby. I would seriously doubt the latter is the case unless the crankcase had been overfilled since the upper pan has a baffle that acts as a windage tray, of sorts.

grey99max

iTrader: (12)

relax - just giving you a hard time....... I choked a bit on "exacerbate".

nismology

iTrader: (8)

95BLKMAX

iTrader: (10)

Good point my FSM guru friend. The valve covers..... replacing them is how a local tech at a dealer near by would fix quite a few of the 3.5s that would come in complaining about loosing oil. Just food for thoughts

grey99max

iTrader: (12)

Interesting - would you know why this worked? Is the new valve cover a different design? Did the tech replace anything else to fix the oil spew?

I still don't understand why the VQs would push oil out unless there was air pressure from blowby to make that happen. Maybe the valve covers trap the oil vapors better.....

PS
Since my car with new engine mostly installed is sitting in the driveway, maybe I should finish the wiring and see if it will start....

streetzlegend

iTrader: (8)

Can it be the quality of the check valve? Maybe VQ guys should use another design or type of check valve. I say if someone is really concerned about oil in their manifold/cylinders, they should have a vented crankcase setup. It may roughen up idle slightly but at least ur not running oil through yo thing.

xmaxima95x

iTrader: (2)

Do it

Jime

iTrader: (10)

I just have a little filter on each valve cover and it doesn't burn any oil, but it also didn't burn any when the pcv was in place. This is my 3rd 3.5 I am using now and none of them burned any oil and I have no idea why some do.

z00york145

I say any shot you have to put nitrous in, go for it. It would look cool too . As for the burning oil thing, I don't think you have to worry so much about it.

rkazz98

sorry to bring this back but now i have some extra money. I do not plan on using nitrous all that much but i was wondering what all i should get prior to nitrous. From what ive read on this thread a catch can is a plus but is there anything else? I do plan on changing spark plugs asap. I was going to go the the ngk copper but should i go with a colder plug? I plan to buy the nitrous kit in pieces so i wont have if for about a month or so. I dont know if colder plugs will affect performance without nitrous. Also while changing the plugs i will also change the intake gasket and look at the rear valve cover to see if any oil is in the spark plug holes.

Aaron92SE

iTrader: (128)

It depends what shot of nitrous and what system you plan on running.

But with a normal 50-75 wet shot of nitrous, yes, get 2 step colder plugs. You will not be able to notice a performance difference either.

Also, get a bottle pressure gauge, bottle heater, fuel pressure gauge, wideband o2 sensor (A MUST), an inline nitrous filter, and new fuel filter. You might as well replace the fuel filter while the pressure is relieved. Also, you might want to look into installing Thermal Intake Spacers while you have the intake manifold off. No gaskets are required with these spacers and they work nicely with nitrous.

Also, make sure the plugs are gapped to .036-.038" to prevent misfire. And there is nothing wrong with NGK copper, in fact, I prefer them since they are cheap and so easy to replace on my VE30DE engine. But, they are harder to replace on the VQ35DE engine. So you can look into Iridium plugs, which will last much longer than Coppers. But remember that Platinums should never be used with nitrous.

2002AltimateV6

iTrader: (7)

You wont need two-step colder for a 55-75 shot on the VQ. Just go with NGK Coppers at the stock heat-range and you'll be fine. As for the fuel filter, it's in the fuel pump. So replacing that is unnecessary. But if you plan to run a 100 shot or over, 2 step colder plugs are a MUST! As for gapping, I've been running my plugs at the stock .44 and haven't had any blow-by problems with upwards of a 75 shot. But better to be on the safe side and gap them lower.

Aaron has already mentioned a few good things to buy for the kit but unless you're planning to run a 120+ shot a fuel-pressure gauge and wide-band gauge aren't really needed. If you're worried that your fuel pump might go then you can always buy a fuel pressure safety switch. It basically cuts power to the nitrous when it senses that the fuel pressure has dropped. As for the A/F, just make a quick run on a dyno and you'll know exactly where your A/F is.

Another VERY good thing to get is a WOT/TPS switch. So far I've had VERY good luck with the Nitrous Express WOT switch. It basically reads of our TPS wire so that when you go wide-open throttle the nitrous will activate. Once you let off the throttle.. even just enough to get the reading down to 99%, it'll shut it off.

Another good thing to have that'll make your nitrous installation a lot easier is a PTP Fuel Rail Tap. Here's a link: http://www.tuningmotorsports.com/pro...age=1&featured
It's very popular with the 350Z guys. Makes installing it a lot easier since you wont have to worry about issues with fuel leaking/etc. when you chop the fuel line to install the "T".

Aaron92SE

iTrader: (128)

I would not recommend anybody to spray even a 35 shot without always knowing their AFR. That's just me. I like to go above and beyond.

And on my VE30DE, I was detonating with a 50 shot with stock timing and one step colder plugs. Having 2 step colder plugs shouldn't cause any fouling problems. So you might as well go safe.

Also on my VE, I misfired a few times with a 35 shot when I sprayed with the stock gap in 3rd gear. The engine load was just too high and on top of that, my coil packs may be weak. Since I reduced the gap, I never had a problem since.

And as you said, a fuel pressure guage isn't needed, but it's cheap and easy to install when the fuel pressure is relieved. I use it every time I am trying to diagnose problems. I think my fuel pressure guage and Tfitting cost $25. I got mine from Summit.

And the fuel pressure safety switch is a good thing to have, especially if there is ever the chance you would go over 75 shot one day. And it's cheap too. Instead of having a FPSS, I am going to have an AFR Safety Switch that will cut nitrous if your wideband reads above a certain value. This will also work with a stock narrowband o2 sensor and it will cut nitrous when it's lean. Dynotune has one for only $99. Also, Nitrous Express has this feature in some of their progressive controllers.

2002AltimateV6, remember that I am only stating my experience with the VE30DE. I don't have any experience with the VQ35DE and nitrous. Plus, I like to play things safe. I can't live without my wideband. I use it every single day, even if I'm not spraying. The one thing I don't like with a one-time dyno tune is that your AFR can easily change. If you change your air filter, or if you remove your headlight, that can change your AFR drastically! Plus, with every nitrous user, you will have the urge to put in a higher shot. I know I do! And this will change any AFR you've already tuned for. I think you can get widebands for under $300 now. The price has really come down in the last couple years. I paid $340 for my PLX Devices M300 unit several years ago. It's still working even with the occasional leaded fuel usage.

t6378tp

iTrader: (69)

I ran stock plugs with a 55shot no problems but when I changed to a 65shot I notice the plugs were getting too hot and went 1 step colder. then I went with a 75shot and started to get blow out and had to lower the gap to .037 and now that I and tuning for a 100shot I am going with a 2step colder side gapped plugs set to .035

this is a good item cause it will let you know if your pump is able to keep up during a nitrous pass, example if your n/a or nitrous and your at wot and notice your fuel psi tappering off but not enough to trigger your fuel psi safety switch this could be a early sign that your pump is not big enough or is going to die soon

I would suggest a a/f safety switch over a fuel psi safety switch. a fpss will only shut down the nitrous system if the fuel psi goes below and preset # but will not do anything if your fuel soleniod sticks

A a/f safety switch is better cause it monitors your engines a/f ratio and will shut down if goes out of the preset values, so if either the fuel or nitrous soleniods stick, fuel pump, injectors or etc die's system will shut down


^ what he said this is what I have learned over time, I do not have a wideband but wish I had one and will be getting one soon, nothing will replace dyno time but a wideband will sure reduce your visits