The reason these gears break is the Nissan flat drive engagement which puts pressure on two very small points. Billet gears alone does not resolve the issue. We have carried out our own R&D and have on offer a range of replacement spline drive kits for various RB oil pumps including OEM,N1,Nismo and aftermarket i.e. Jun, Nitto Greddy and Tomei. Our kits are used on various high power RB engines and cars globally. Good luck with the build the billet gears are an improvement over stock.
Wow...was wondering what happened to you but seeing the better quality and editing I can see you've been working hard. awesome to see you post. Great job.
Supertec spline drive kits eliminate the risk of pump drive failure for high horsepower application. Rather than having two "flats" to drive the pump, a spline collar is tight fitted to the crank to drive a converted pump gear.
There are actually several issues that can also combine to cause the oil pump gear to shatter. As Supertec Racing said is correct, and to add to that, the early rb26 crank had a small drive area from the crank, which resulted in uneven wear and thus causing fractures, resulting in then a shattered pump, the other, which is ALWAYS overlooked, is the failure of the harmonic balancer to absorb unnecessary vibration from the rotating assembly. I always recommend running a new oem/Ross/Ati balancer when fitting the new oil pump, and since, have not had a single failure in 10 years.
its also a really good idea to use locktight on the 7 screws. nissan oil pumps screws tend to come loose. i noticed mine was half unscrewed when i replaced mine. engine had not been opened before. i was very lucky.
Good video. One quick correction on your statement. Fluid does not compress. If you get water in your cylinder, the piston cannot compress it and that's how you bend connecting rods. So the way it actually works. At 6:49 you can see the channel in front of the gear. The oil is forced to that channel when the chamber is closing and that is what creates the oil pressure.
love ur work but i hate to tell u the biggest problem with the pumps is the play between the driving gear and the crank.at hi rpm the gear starts to vibrate witch in turn shatters the gears.I have seen even after markets pumps and gears shattered because the real issue of the play bettween the crank and gears where not fixed. There is a clearance of .006 iether side of the gear/crank a total of .012 witch is to much. When im building RB26/28 engines i use crank collars that have a total of .006 clearance ie .003 iether side of crank and collar with standard 34 pumps and have had no issue with any of my engiens/pumps failing
How do you find one with tighter tolerances? Is it more of a purchase and pray types of situations? Why dont oil pump producers make small inner driving gears?
I believe the bolt pattern for the housing to bolt onto the block is the same across 20/25/26s. The difference comes with the internal design. If you look at a Tomei oil pump the housing which the actual gears sit in is much larger then mine. I believe the 25 internals of the oil pump are different again to the 26. So as to which one is better I would say the N1 pump is best and also the Tomei. But it comes down to money. I think just replacing the gears to something like the ones I have will be great for street/track and you'll never think twice about them breaking. If you were going hardcore track ect. I would suggest looking into it more and coughing up extra cash.
stevenminix Nope you should get an oil head drain kit. And also get the oil gallery restrictors that go into the block. One will be a complete blank and the other is either 1.2mm or 1.5 from memory. The oil restrictors are very important. The head drain not as much but if the motor is out I'd do it all
stevenminix I think you'll be A ok so long as you service and change oil frequently. Is it a street car? The oiling problems occur with constant high rpms so as long as it's not a dedicated race car I think you'll be fine with those mods
Nice vid, wish you would have done a side-by-side comparison of the factory gear on the crank vs the aftermarket gear. It looks like there's a lot of play with that aftermarket gear! Also, wouldn't you want to use some threadlocker on the oil pump back plate housing bolts? EDIT> Also, some people replace the Phillips head screws with allen key'd screws for that back plate to prevent rounding the heads!
I did check it myself but this was after I recorded the video. The amount of play is near the same as the gears I removed. You have brought up a good point and I will deem to look into it. And as for the thread lock you can use that by all means. I just got em real tight with the impact driver.
I've read that the nose of the crank on the 1989 to 1991 RB26DETT is too small. The clearance between the nose of the crank and the part that drives the oil pump inner gear was too loose. This causes the crank to hammer against the pump drive gear which shatters it. Apparently the only proper fix is to change the damn crank :( EDIT: Michael's response speaks of a different solution :)
not true. you can shrink fit a spline drive crank collar to the short nosed r32 crank. allso the 33 and 34. the spline drive then drives new spline drive gears in the oil pump. this is the ultimate solution to this issue. i went with std r33 crank and reimax oil pump gears. much like the one's he is useing. i allso used thread lock on the bolts inside the pump.
JohnnyNismo look at supertech's reply in here. they have a very good solution for this. what I described. unfortunately the crank has to come out. I would have gone that route if I knew before I bought the reimax billet gears.
You are actually wrong about that. The RB26 came from factory with 2 oil galleries to the head. One of those had already been blocked off. This one is between cylinders 4 and 5. The other oil feed has a 2mm hole. I have put a 1.5mm plug over the top of that. All the other RB's have both oil feed holes open. This video doesn't solve the oiling problem to the RB engines. It's ONLY for the oil pump gears. Besides I am not racing this motor. If I was going to rev it hard I would also add an oil head drain kit to it. The oil restriction mod I have done will be enough for my engine! You are right but, more oil to the rb head means less to the bearings which is very bad, but not in my engine :)
Do you realise that the bottom end gets oil starved because of restrictive flow from the head? Upgrading the oil pump makes this worse. How am I wrong about that?
Besides the oil pump is upgraded not to increase flow, it's to stop the gears from breaking. Just because of the wave profile doesn't mean it's gonna flow 10x more.
The smaller restrictor placed to prevent oil accumulating in the head was a misconception perpetuated by Tomei when they released their upgraded oil pump. Nissan never utilized a "head drain" nor employed a restrictor in the oil galleries for any of their competition vehicles. Many people have documented on forums where they have closely inspected Nissan race cars, particularly those used for the Bathurst, and not found head drains as well as being told that restrictors had not been used in the oil galleries.
