streetzlegend

iTrader: (8)

We all know that most of bearing and other wear is caused at start up, specially for cars that sit untouched for a while. So I have done some searching around and found two good solutions (which have been used since way back in the day).

Accusump method
- One of them is very simple, you have a tank that holds anything from 1qt to 3qt or more, when engine is on this tank is filled with oil at w/e your oil pressure is, if you go WOT and get 95psi then the tank will hold that 95psi worth of oil in it using a solenoid to prevent it from being released.

- Then when ever you turn your car on, right before you crank you hit a button or turn key to ON and the solenoid opens, allowing for the tanks oil to be released and therefore prelubing the whole motor. This is also used on race cars that come across some extreme gforce, so when they make a hard turn that the oil in the pan is not present the solenoid releases instantly.
Here is a promising product: http://www.autoenginelube.com/ordernow.html

Pump method
- The other solution is using a pump, basically you tap the lower oil pan or use the drain plug as your source, then run a line from there into a pump, and from pump into either a sandwhich plate or T on the oil pressure sending unit.

- So before you start the car, you hit a button, the pump forces oil into motor building up a little pressure and prelubing without engine even being on. then you turn on the car.

- Some say this is dangerous because you will be pumping unfiltered oil into the oil gallery, but in my opinion this is false specially if you use a sandwhich plate. The ports on sandwhich plates let out unfiltered oil, meaning if you pump oil into one of those ports it will then go into the filter and then into the motor. The only issue with using this method is leaks, one would need a one way checkvalve so that the pressurized oil once the engine is on wont back into the pump and into the oil pan. (A shurflo pump would work pretty good)

Discuss.....

ajm8127

iTrader: (8)

What about having a switch that controls the power to the injectors? Turn it off and crank the engine to build oil pressure. Removing the plugs would be best because lower combustion chamber pressures equal less force on the bearings, but that's not feasible to do every time you start your car.

SurraTT

iTrader: (59)

I really like that Accusump!!

Ive been thinking of getting something like this but didnt know what was out there.

SurraTT

iTrader: (59)

http://www.autoenginelube.com/satisf...sanmaxima.html


installed on 04 maxima

streetzlegend

iTrader: (8)

Thats exactly what you dont want, the whole point is to not turn the crank when there is no oil pressure present. So with or without fuel your still turning a crank on bearings that are 'dry' initially. These methods will build up pressure without cranking.

streetzlegend

iTrader: (8)

Yeah and the price as awesome based on my search. Including lifetime warranty. The only thing I have seen is that someone with that system had their solenoid break into pieces releasing oil all over the place, but the manager of the company got on the forum and cleared that, the solenoids are made to withstand like 1000psi or something lol. so it was probably installer error.

98SEBlackMax

iTrader: (9)

Accusumps can be setup with an electronic solenoid so that they will add oil when the pressure is low and collect oil at higher pressure. With some electronics work you could have it oil at start up and under hard cornering. I don't get that valvetrain noise under cold start ups and I've only had the oil light flicker once under hard cornering but never consistantly enough to justify an accu$ump $etup.

If for some reason I was able to get my car to consistanly handle well enough to slosh the oil around the idea I had was to move the windshield washer tank to the trunk (for better weight distrubution). Then put a 1 quart accusump with its solenoid electronics in the place of the tank. It is close to the engine and the oil cooler also it only requires the minimum length of oil hoses.

streetzlegend

iTrader: (8)

Correct, it can be used for both preoiling and for sudden starvation during races. In my opinion this is something every car should have, even if there is no noise.

In my case, it really bothers me to see that as soon as I start the car the oil pressure gauge takes about 2 seconds to build up oil, thats a no no for me, I am most likely going to be ordering from the link I posted on the accusump style. I have a large oil cooler, plus turbo feed, which might be part reason why it takes a little bit for oil to build up, so the tank will feed the cooler and turbo's line then create a little pressure, even 5psi is good enough im sure it will make more.

98SEBlackMax

iTrader: (9)

Every car I've ever driven has low oil pressure on start up for 1~2 seconds. More so in the winter times. So this maybe the norm for most production cars.

I've also heard the arguement against Accusumps, in that if your car corners that fast it really needs a dry sump setup and that an Accusump is just an easier but less effective fix. A dry sump is not something any Maxima I can think of will ever need.

However for cold starts I do not think there is much difference between a dry sump setup and a Accusump, which is your main concern. IIRC the storage tank on a dry sump is not pressured when the engine is off. They have heaters on some race cars to warm the oil tanks before firing up the engine.

This is probally why they are putting more dry sumps on high performance cars these days. Safer engine starts and to maintain oil pressure during fast cornering.

It is good to know that I am not the only one looking into these things. On this motor I do not think its Accusump worthy but if I ever build a motor up I would intergrate one especially if using high performance crank/rod bearings.

streetzlegend

iTrader: (8)

Yeah a dry sump would be ideals, I just dont want to go on that mission in building or putting together such setup. an Accusump in my case would be so much simpler, im not worried about the cornering or anything since I doubt i'll ever be doing any road racing or autox, I only race in a straight line. I wanna protect my built engine as much as possible, so I want to see that oil pressure gauge go up before the engine is even on.

SteveB123

iTrader: (2)

Dry sump pumps are engine driven, so no pre-pressurization.

aic96max

iTrader: (12)

wow. man, doesnt sound like a bad idea for a car that is parked for days, but for a daily..... weve got plenty of vqs w well over 250k on the clock as is.

In the turbo buick world, for those on a budget, they unplug the ecu wire so that there is no combustion during initial crank which takes away from having cylinder pressures and the load on the bearings during cold starts.

besides the additional potential point of failure and leaks, that kit seems like a great value for 200 bucks

streetz let me know how it works out, if you use without failures i may want to get this kit for the GN

streetzlegend

iTrader: (8)

Alvaro if a car is sitting for a long time, it dosnt matter if you disconnect ignition and fuel, turning the motor alone will cause them to wear. Specially for your GN that probably sits for a long time with no start.

Weimar Ben

iTrader: (5)

This sounds great in theory, but is it really necessary???? They also resort to dishonesty.

"And every time the engine is started, several hundred revolutions of the Crankshaft occur before pressurized oil is present to lubricate the bearings."

Uhh, no. My engine oil light goes off within 1-2 seconds. @1200rpm idle speed, that's 20 revolutions or so. There's also zero load at idle.

The oil doesn't get completely squeezed out either after the engine is shutoff. If it did, we'd get spun journal bearings all the time. This is why when rebuilding an engine, you MUST use assembly grease on the bearing surfaces.

How many failures are there on VQ engines from journal or rod bearing wear anyways? On the VQ35, the bearings will outlast the rings, so what's the point???

Weimar Ben

iTrader: (5)

There's no need for a switch. IIRC, 2000+ maximas will cut fuel if you give it 100% throttle while cranking.

streetzlegend

iTrader: (8)

The theory sounds great, I guess its true, VQ's arent really known for having bearing issues.

BriinumsBo

1) since its cold here in winter, 20mins ago i came up with this idea. But i thought about cutting power to fuel pump as cutting ignition to sparks would damage ignitor (i have 94 mr2 turbo). google search brought up this forum.
Basically need some arguments. Does cranking the engine with starter really does much damage to bearings n stuff? I think the most damage occurs when the engine actually fires - the combustion pressure is about 4x higher than simple cranking. Thus the combustion pressure with dry system should do much heavier damage. Especially I`d start the car without pressing the clutch so the cranking is slower and easier on internals..

2) If this is a good and safe idea (except for starter, but id trade starter for worn engine) why not make automatic switch connected to oil pressure light via relay - then it would cut fuel on cold start and not provide fuel until oil pressure reaches the sensor. Of course it should be smarter circuit than this to prevent fuel cut-off when cornering hard.

3) Of course it would also be s a good idea to cut fuel if we have loss of oil during cornering but fuel pump cutoff would lead to slow fuel pressure degradation which would still provide fuel at low pressure and make the mixture lean (engine blowup under hard accel)

Weimar Ben

iTrader: (5)

Ignition coils turn on and off several times a second, so cutting power to the coil will not damage it.
No, not unless you do it for a prolonged period of time without lubrication.
No, combustion pressure is much higher than cranking. Try 110 bar (1500psi). But there's still zero load on the engine.
Huh? Unless you've tampered with the clutch interlock switch, you must press in the clutch to start the car. How would starting the car while in gear be "slower and easier?"
You could, but it'd be unnecessary.
I've never heard of a low oil pressure condition on hard cornering on a VQ.
There's better ways to cut fuel besides disabling the fuel pump. A temporary, less than a second lean mixture does not blow NA engines. Probably wouldn't in a FI or nitrous either.

But this is a really dumb conversation. VQ engines, like most modern engines, simply don't have bearing problems unless they're starved of lubrication. By starved, I mean zero oil pressure. This is such a freaking waste of time and money.

BriinumsBo

ok, I should have mentioned that I talk about this topic totally disregarding VQ engines (so i`m not taking into account your comment "VQ engines, like most modern engines"). I own 1990 Celica ST185 and 1994 MR2 SW20, both 2.0 liter turbo 4 cylinder. in AutoX racing they do suffer of oil starving under heavy cornering. And in cold mornings I can feel the engine struggle when it fires up but has no oil for ~1sec ( i have hard poly engine mounts), after pressure is up, its smooth.

About combustion vs cranking pressure - I meant that engine running with fire & combustion during dry startum does much more wear than cranking with no fire? So in theory (or my assumption) cranking for 2-3 secs with no fuel until oil pressure is up would be much safer than runing the engine for 1-2 secs without oil in the engine.

I totally messed up with the ignitor stuff, cause it doesnt have anything to do with this topic (unles i cut power to sparks, but the engine would be flooded with fuel). So basically there is a choice between cutting power to injectors or fuel pump. propably injector cutoff would be better as the pump would build fuel pressure and fire instantly when the injectors are switched on.