[jeffp]

well here I am once again with this car and the oil pressure issue. The car had been running good at 60psi with high RPM. I decided it was just a little shy of what I feel to be good oil pressure to float the crank at high RPM levels. I was wanting to see 70psi at 4K and up to 7K red line.
I bought a bob sharp spring kit off of Ebay (and I think I paid to much for it) and I installed the kit today. I checked it out and it was still a little shy of the pressure I wanted so I shimmed it up another .100 thousands and it was good. I decided to go get sopme beer (dont tell my wife LOL) to let the car warm up to make sure of the pressure when it was hot and ran into some problems. The pressure was dropping off under hard acceleration, BAD< so I was not to happy about that. Now there are just a few things this can be. Since the pump inlet is right out of the pan, and my oil pressure gauge is right out of the gally in the block I had two possibilities. First, I am running -8 lines to the oil cooler and that could have been a problem (I should have run -10 lines to be really safe)
Second, the pump was running out of oil in the pan for what ever reason.

I checked the oil and it was a quart low (and on a new engine I am not impressed with the oil consumption, I spoke to Dave Robello about it and decided to put some more miles on the car and see what happened. It is getting better, so I am thinking the rings are not seated all the way yet, I hope, if not it's going back to Robello to get fixed.) so I filled the oil up and went for another run. The pressure stayed up, so that indicates to me I need a larger capacity oil pan.
I am going to give malvern a call and see about spending the 375.00 on the aluminum pan and gasket. I do believe it is a 7 quart capacity pan, and that should take care of my problems. That pan is baffled, which is good for hard acceleration, and it has a windage tray so that is good also, might as well scrape all the oil off the crank and rods while I am at it.
So the conclusion, my car needs a bigger oil pnn for hard acceleration, and I need to make darn sure it is topped off all the way until I get it done. The lower oil pressure was alright because there was less flow rate through the engine. Again my car is costing me money.
One more thing, I was driving back and met up with a Toyota supra but could not do anything because of a small truck in front of me. Good thing to because I was out of fuel (empty tank) and that to has some peroblems under heavy acceleration also, the pump runs out of fuel and the car goes very lean because of it. I was planning on doing the FINAL fix for that this weekend. I got my duckies in a row now about it. If anyone ever suggests to you install a twin turbo pump in your tank slap them for me would yua, that has been a major pain in the butt getting that thing right but I have the design perfected now.
Have a good one all

 

[John Coffey]

Jeff,

Another thing to consider is that the oil that gets pumped up into the head is having a hard time getting back into the pan. The Ford Duratec V6 had that problem under long duration high rpm use. Eventually the oil pickup would starve and the engine would spin a bearing. Reducing the oil pressure, increasing drainback hole flow, opening up the main bearing girdle, and modifying the windage tray fixed the problem.

L6 engines can also experience this problem particularly if you're running an oil spray bar and a cam with oiling holes. A good windage tray/scraper combination is important in these engines used for competition.

And I would go with -10 oil lines at a minimum. -12 is better (but heavier).

- John

 

[240Z TwinTurbo]

Had the same problem.

My pump was suspect, but what I found was that I had used 10-30 oil and forgot. As the oil warms the already low viscosity becomes even lower. Try swapping to Valvoline 20-50 Race and see if your problem does not clear instantly. I also swapped the pump for a new one as mine was several years old. BTW, what oil are you using? If synthetic then that is most likely the problem. The low viscosity could hinder the pump or cause the oil to move to the back of the pan during hard acceleration. I would try the oil thing as it is the cheapest test.

 

[jeffp]

Re: Had the same problem.

Thanks for your input John and James. First off, I am running the oil bar and the drilled cam for the oiling. I have almost taken off that iol bar a number oftimes, but I like the extra oil on the cam. I think it would also help the idle oil pressure when the engine is hot if I took it off, but for now I think I will keep it and try to work this thing out and do that as a last resort. I am running for the most part 20-50 castrol oil right now. I have run 50wt oil in the past and that seemed to be about the best, but when it is very cold out (at my moms house in winter) I did experience some chain slapping a couple of times on the old engine first start in the morning.

The problem did go away when the oil was full, I was about a quart low. I would like to see a little more head room in that part of the system, so I will end up changing out the pan for a higher capacity pan. I have tried to get the pan Nismo sells, but they have none right now. I think I will call again and see what the status is on getting more of them made and how long that will take. You guys are aware that Ron quit, or was cut back from Nissan racing right? He was very knowledgeable on the zcar stuff, to bad he is not a part of nissan performance now. And if that doesn't work I will get the aluminum pan and that should shore up the problem also, but I dont really like the aluminum pan to much as it sits a few inches lower in the car then the other pan from Nismo. I think with that pan I will build a skid plate to stop the road hazzards.
Funny you should mention the way the head drains John, I have had the valve cover off a number of times and noted the poor draining of the oil from the head.
So here is the question, if I do go with the bigger capacity pan and everything is happy, what about the excessive oil around the valve stems, will this create a leak problem in the valve guide area? I cant remember the valve stem geometry of the topside of the head. I do believe the valve guides do stick up out of the head about a 1/2" and the guide seal goes on that part of the guide. So I could be facing a problem of excessive oil in the top of the head and that would be very susceptable to leaks(I hate valve cover leaks with a passion) anyway, what do you guys think? Will the larger capacity pan correctly solve the problem? or am I going to end up with a head full of oil and still run dry in the sump?
I am thinking that with the extre 2 quarts available to pump, the head will get to a higher level of oil, but it will drain sufficiently and keep the sump with enough oil so the pump doesn't run out of oil.

 

[John Coffey]

Re: Nismo

Regarding Nissan Motorsports, here's a message from Keith Thomas regarding some positive changes occurring at Nismo:

-----
Regarding parts from Nissan Motorsports-

A good many years ago, maybe 10?, Nissan cleaned house at
Motorsports. They called everybody into a meeting and fired
them on the spot. When the employees got back to their desks
they had been locked out of their computers, etc. etc.
No warning, no compensation, very ugly. About the only people
left in the aftermath were Frank Honsowitcz, Ron Johnson, and
a secretary or two. Frank and Ron have now moved on or retired.

Fortunately for all, word on the street last week was that
Ron is being replaced by one of the former employees,
Steve Christiansen (who went on to form SMC Products after being
"let go" from NISMO). Steve had always been our fountain of knowledge
at NISMO, and we are happier than pigs in slop about this new development.

Hopefully things will get better after his offical installment (I think
early November).

Regards,
Keith Thomas
Chet Wittel Racing
-----

- John

 

[John Coffey]

Re: Oiling issue

> So here is the question, if I do go with the bigger capacity pan and everything
> is happy, what about the excessive oil around the valve stems, will this
> create a leak problem in the valve guide area?

I doubt it. If you have a valve guide/seal problem you would see it already. Same with the valve cover leaks. You're only going to have an excessive amount of oil in the valve train area under high rpm use. At the next stop light the oil will fdrain back just fine.

> Will the larger capacity pan correctly solve the problem? or am I going to end
> up with a head full of oil and still run dry in the sump?

I think you'll have enough of a reserve in the pan to make sure there's oil covering the pickup. You might still have a windage/drainback issue. When you get your pan make sure it has a good set of scrapers and maybe a windage screen to get the oil off the crank. That way, oil draining back doesn't get whipped around the crankcase delaying its return to the sump.

- John