GA16DE and variable valve timing

RiceBox · Jun 1st, 2002, 07:58 PM

Does the GA16DE in a '98 Sentra have some kind of variable valve timing. My dad's b14 Sentra really surges at high revs in first gear. It feels like VTEC

but I'm wondering if Nissan had a similar system.

sentra94xe · Jun 1st, 2002, 08:09 PM

From what I know, Nissan has a "vtec-like" system called NEOVVL--- a Variable Valve Lift system. I am pretty sure this is not present on any USDM spec motors to date... but can be found overseas on the V-code motors (SR20VE, VET) and others (RB26DETT, RB25DET, etc). The new Z could have VVL.

barnoun · Jun 1st, 2002, 09:07 PM

The GA16DE has VTC(variable cam timing). It adjusts the intake cam timing continuously so you can't really feel it, but at 6600rpm you can feel when the VTC retards the intake cam, reducing power.

RiceBox · Jun 2nd, 2002, 02:32 PM

Well if it's not variable valve timing what would make the engine surge like that???

barnoun · Jun 2nd, 2002, 07:40 PM

It is variable. As for the surge, I'm not sure, but I think I know what you mean. In my auto, when I drag launch from 1, it starts slow then at about 4000rpm or a little higher it pulls hard to redline. Maybe the VTC is "feelable" then...

AznVirus · Jun 3rd, 2002, 01:29 AM

Quote:

Originally posted by barnoun
The GA16DE has VTC(variable cam timing). It adjusts the intake cam timing continuously so you can't really feel it, but at 6600rpm you can feel when the VTC retards the intake cam, reducing power.

ive never heard of this before, id like to know where you found this out. thanks.

barnoun · Jun 3rd, 2002, 01:50 AM

I don't remember where I found it out, but do a search on your favorite search engine for ga16de and vtc and you'll get links that say it's true.

James · Jun 3rd, 2002, 09:36 AM

it has variable timing on the intake camshaft. that's why there is that lump on your valve cover on the left hand side.

200'side · Jun 3rd, 2002, 12:01 PM

There is something definitely feelable passing 6 grand. I dont know too much about internals (and I might get ridiculed for this) but I always thought it was the second cam kicking in or something. But its the Variable valve timing adjusting the intake cam? Ok.

James · Jun 3rd, 2002, 12:10 PM

Quote:

Originally posted by 200'side
There is something definitely feelable passing 6 grand. I dont know too much about internals (and I might get ridiculed for this) but I always thought it was the second cam kicking in or something. But its the Variable valve timing adjusting the intake cam? Ok.

W/ VTC you don't have the variable lift as w/ VTEC. (VVL has it tho). It adjusts the phase of the timing. Isn't the newer systems called CVTC? Well BMW and Ford also use this type of system... I think Toyota does too w/ their VVT-i and Hondas new VTEC systems also incorporate this technology...

200'side · Jun 3rd, 2002, 12:13 PM

Right on. Everyone has their own version. Didn't BMW incorporate it into their new M series. Im sure I read up on it somewhere and it seemed pretty nice.

James · Jun 3rd, 2002, 12:15 PM

BMW has it on both intake and exhaust cam shafts and they've been able to do away w/ the throttle body. ford only has it on their exhaust shaft for better emissions.

sentra94xe · Jun 4th, 2002, 02:24 AM

Quote:

Originally posted by James
BMW has it on both intake and exhaust cam shafts and they've been able to do away w/ the throttle body.

Would this be their "VANOS" system?

James · Jun 4th, 2002, 09:18 AM

yep Double VANOS is what BMW calls it.

barnoun · Jun 4th, 2002, 02:50 PM

Double VANOS is their variable valve timing system, but their new system that doesn't use a throttle body is called valvetronic.