Okay, so after a lengthy conversation with an expert, I have some perhaps little known information on the various oil pumps for the VQ motors, why they were designed differently, and which you should choose for different applications. Some of this is known, but not all of the "why" is known, which is important to understand when building an engine intended to operate at a higher range of RPM. Just wanted to share with the community. I will go into as much detail as I can remember, and if you have these parts in hand available for comparison feel free to post pics/specs or something. Also, keep in mind this knowledge is coming from a real-world racing perspective, you may get away with using these parts in a street car for a while, but it's likely that problems will eventually creep up that were seen in racing... just not nearly as soon.

Also, let this thread not get into an argument of dry sump vs wet sump, or off-topic. Obviously everyone knows dry-sump is better, but it's not financially an option for every build. This is intended for street car builds or dual purpose street/track cars. You can choose to accept this information, or ignore it and make your own adult decisions. Also, I'm not a mechanic or engineer... so if I explain something in an "off" fashion, excuse me please, but feel free to correct me.
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DE Oil Pump - Softer metal on internal gears. Rated to 6600rpm from the factory due to the inherent vibrations in the crankshaft causing increased wear on these gears at higher RPMs through extended/endurance testing. Not recommended for high RPM use.

Rev-up Oil pump - Harder metal used on internal gears to accommodate increased vibrations and wear placed on these gears from higher rpm. As the engine spins faster, these vibrations increase in amplitude. Otherwise, basically the same. Recommended for higher revs in VQ35DE non-revup (eg 7500rpm-ish).

HR Oil Pump - Changes in crankshaft design minimized previous problems with vibrations at higher RPMs allowing for a softer metal to be used in the gears. This pump flows more volume, but if modified for use on a rev-up, or DE may result in increased wear/failure from extended high RPM usage due to the softer metal. Apparently the metal hardness of HR oil pump gears is similar to DE's since the vibrations caused by the crankshaft were no longer as much of an issue to overcome. Not recommended solution for high-reving DE motors because the crankshaft vibrations in the DE may cause excessive wear and/or failure of the soft oil pump gears.

Alternative solutions:

Nismo Oil Pumps - Have seen great success in real world race applications prior to dry sump oil systems being allowed per the rules. In some applications, the crankshaft would break prior to any limitations of the oil pump being met. Higher RPM, as well as high torque applications would break crankshafts in race applications due to the increased stress and torsional load on the crankshaft where-as the Nismo oil pumps did not fail. I have it on good authority that these oil pumps were very reliable in professional race applications.

Poor Man's Modified HR Oil Pump (For engines intending to rev higher) - Since the Nismo oil pumps are ~$1,200, a solution to help with oil pump gear wear caused by crankshaft vibrations is to replace the gears altogether with a stronger metal (billet steel). You will have to source a company that has experience in this area. I didn't ask what companies offered this service, so don't know. This was used in professional race applications as well when Nismo oil pumps were unavailable due to Nissan factory production outages caused by the 2011 Tsunami.

Problem's inherent in all VQ wet-sump oil pumps - is the aeration at extremely high RPM use (sorry can't remember much more about this - drinking beer... chime in if you can expound on why again). If you plan on going much beyond 7500RPM, it would be a good idea to install a dry sump oil system.
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Water pumps - Later production FWD VQ engine cars water pumps sprockets and overall design remain nearly identical to the early VQ35DE water pump, except with a change in the impeller design. Should be a direct replacement/upgrade.

DE vs Rev-up vs HR water pumps - I originally planned on installing a rev-up water pump, as I had read (but not confirmed) it was under driven, and should provide more coolant flow at higher RPM's. The problem with this is it may affect the timing of the engine (eg cam timing).

 

another option would be some type of cryo treatment or nitriding on the hr pump gears. its not really that expensive and i know getting custom pump gears machined can be pricey.

 

Check with Boundary Engineering, they do billet chromoly gears in fully assembled units for Mazda BP engines. If there is a market they have plenty of experience.

 

An important difference between the DE and Rev-up oil pump is that the Rev-up pump has a stronger pressure relief valve spring which allows slightly higher pressure and thus slightly higher volume than the DE pump.

Also, the HR pump has a significantly thicker/larger gear than the DE and Rev-up pumps.

 

I forgot who it was but there was a thread a while ago where a guy had all 3 of them apart, showing the differences in gear thickness and the pressure relief spring, esp in the HR oil pump.

 

This is true, I forgot to mention that, and from what I was told Nissan uses this same oil pump design for a variety of engines. They just have various thicknesses of the assembly for thicker/thinner gears as needed.

I think the HR oil pump can be modified to work on a DE if it was fitted with chromoly gears like 1cockyz suggested. This would be on par with a Nismo oil pump then. Don't quote me on that though until someone actually installs one.

 

did anyone look at the cosworth oil pump for vq35de?

motoIQ took it apart.

http://www.motoiq.com/MagazineArticl...Up-Part-1.aspx

 

I have been out of the VQ build seen for a while. Is the oil pump a problem now?

 

No, just a comparison between pumps.

 

It has always been a weak link for high rev applications.

 

Has anyone made any billet gears for the revup pump? If not, is there any interest? Trying to figure a way around drysump, too hot here in Louisiana/Texas for no a/c.

 

I think you would be better off just getting the Nismo or Cosworth pump instead of attempting that. How high do you intend to rev with those twin 6766 turbos once you get the new block? Dry sump would still be prudent if you intend to beat SP's numbers and pick up where they left off.

 

I think around the 8600-9k range. However, I need to see what the graph looks like to see if it's really needed to go that far to the right. If it stops making power at say 8500, then there is no need to go any higher.

Three things keeping me from dry sump. 1. It is hot in Louisiana/Texas and dry sump pump gets rid of the AC. 2. Funds for that system. Yes I have a good bit of money tied into this and it would be a good security investment for the motor. 3.Not ready to make it racecar only status yet lol.

 

you want to rev past the power drop so when you shift, you are back in the main powerband.

at 40psi, you could make power well past 8500 rpms, essentially the GTR alpha omega powerband at higher numbers because of manual transmission

 

This is a situation where you may not be able to have your cake and eat it too. Aeration is a big problem at elevated RPM with the OEM pump design. Dry sump really is the way to go for 8000+RPM. I thought I read somewhere (don't recall where) that the AC can be retained with some modifications. Have you contacted Fontana Nissan and asked them about their dry sump system?

 

That makes sense. That's some pretty insane power from the GTR. I just hope to God, my car stays straight if I ever push 40+psi, witch I probably will at some point.

I know, but I want to

Well if we can figure out what those modifications are, then we MIGHT be in business. I have actually talked to Dailey, Performance Motorsports, and few other shop that deal with dry sumps. Might just have to bite the bullet on this, IF we can in fact keep AC. Could by me one of those portable fans that plugs into the charger plug in lol.

If anything, just wont push it until I can do dry sump.

 

40 psi at 7500 rpms will still boogey. no reason to wait for dry sump for that.

 

I just talked to another Z owner that pushes the revup pump up to 8500RPMS regularly making over 800rwhp. So, I might go this route and see how it handles for the time being, and just watch the pump and gears, between refreshes.

 

thank you for the information! great job!

 

Hi.
I have a 2006 3.5 SE V6 nissan altima ( VQ35DE ) and I changed its oil pump and I used the one used in the 350z ( part # 15010-ac70a )is this ok?
Some say the new pump is so powerfull and can damage some parts of the engine. What do u think?
Thanks