N1 Oil Pump - Epic Fail

[ali-turko]

i have been speaking to ben over the last couple of weeks, and he has told me not one circuit gtr has blown one, only dick heads who smash the limiter,

i was guna but the gears offered in the group buy, but i dont really wanna be a guinea pig,

he told me any pump will break the gears if the the moron behind the wheel smashes the limiter,

ben has advised me to get a tomei pump if i want piece of mind

even he hasnt heard of a tomei pump breaking

[GT-RZ]

Still awaiting a reply in the group buy topic. Without any form of answer to the questions being asked i'm not very confident on buying considering these will be the first lot for testing.

Id feel much more confident if they were made of 4340 not that 4140 is rubbish but why not go for the best? impact and tensile tests IMO are a must on a test piece of steel that has been tempered to the specifications used in this gearset/collar.

On a side note who was it that got the standard gears tested for hardness??? Did it get done?

[bigmikespec]

I would rather go an external pump and be a dick head every now and then instead of play Russian Roulette...

[works 510]

So, ive been following this thread with interest and have a couple of thoughts and idea's.

So far limiter bashing has been the main reason for smashed gears in the pump, what if you could back the timming right off before the limiter? One would assume that it will help the cause?

Asking this as Im building a rb30 for drift use, I dont plan on holding it on the limiter, but hitting it is something that I cant really control.

Cheers,

[nemini90]

how can you call a person a dick head for hitting limiter when most drifters will tell you its a must

you cant just up shift when you want to extend a slide sometimes

if you want an easy fix go external pump

[ezy_09s]

As good as these splined gears sound..until they are proven i wont be jumping in as a guinea pig.

Get some testing done first (like other guys have already asked for) before subjecting everyone to a product that could be an epic fail as dIrtgarage said.

I would rather the reinik gears..atleast they are proven

[Swiper the Fox]

As good as these splined gears sound..until they are proven i wont be jumping in as a guinea pig.

Get some testing done first (like other guys have already asked for) before subjecting everyone to a product that could be an epic fail as dIrtgarage said.

I would rather the reinik gears..atleast they are proven

Nitto pumps can eat engine parts...and still live.

Ive seen one eat...it was amazing.

Their gear material is the best of any pumps/gearset's on the market...period. Parent material from Sweden...machined in Germany...no contest. The only OEM style pump i would use or recommend.

Edited September 9, 2009 by DiRTgarage

[bigmikespec]

Nitto pumps can eat engine parts...and still live.

Ive seen one eat...it was amazing.

Their gear material is the best of any pumps/gearset's on the market...period. Parent material from Sweden...machined in Germany...no contest. The only OEM style pump i would use or recommend.

That is bloody insane!

We use a small VW oil pump on one of our drill heads at work, as soon as a tiny bit of metal (from a shat bearing) went through the pump, the shaft snapped instantly.

[DRIFTER]

lots of drifters smash limiters without breaking pumps, i don't think you can assume that limiter bashing breaks pumps.

[R31Nismoid]

There are some tricks to tuning to make it easier as well on the pump.

[Marko R1]

Nitto pumps can eat engine parts...and still live.

Ive seen one eat...it was amazing.

Their gear material is the best of any pumps/gearset's on the market...period. Parent material from Sweden...machined in Germany...no contest. The only OEM style pump i would use or recommend.

i can attest to the above comment, ive also witnessed this metal eating pump.

[Swiper the Fox]

lots of drifters smash limiters without breaking pumps, i don't think you can assume that limiter bashing breaks pumps.

i am the biggest moron limiter basher you will find. so far only killed 1 x N1 and i suspect it ate turbo bearing anyway. Or it could have been just me being a moron smashing it at 9500rpm.

[Swiper the Fox]

DP

Edited September 9, 2009 by DiRTgarage

[T04GTR]

someone needs to make a crank collar with a corse 6 or 8 spline drive and a oil pump to suit. aka all toyota inlne 6.. i havent really heard much of 1 and 2j engines with oil pump problems.

it will work.

a good example is the v8 ute series engines i work on, the modular ford v8 5.4 quad cam. smashes oil pumps very easily and has the same square drive as our rb engine. we had to get custom steel gears made, but still have the oil pump problem, insted of them cracking they bend and gall up..

where as the ls1 and newer 6.0L has the multi spline drive oil pump. never seen one break in a ute with over 4 years of racing. and they are a powder metal drive with sinterd oil pump gears.

[GT-RZ]

The flat drive is a bad design especially when you look at the gears and see how little the wall of material is left on the gears.

The more splines the better because as the number of splines increases the surface area increases and the size of the tooth decreases which means the overall minimum thickness of the gear has increased (stronger). Even the smallest amounts can make all the difference.

here is a quick example i did for work:

'x' shear pin with a 15mm diameter produced a UTS shear loading capacity of 4.3 metric tons

the revised sheer pin is 19mm in diameter and made of the same material which holds a max of 6.9 metric tons

Now if you look at these gears (posted earlier) you can see how thick the gear teeth are but how small the minium thickness of the gear is. And where did it shear? in between each tooth. If that had lots of small teeth the minimum thickness could be doubled or tripled easily.

The next problem is of course heat. You will all have seen the tiny splines (like on a three piece crank of a cycle) they are very small, maybe 1mm at the base of the tooth max but teeth like these would be no good in an engine as the smaller the teeth the smaller the components tolerances must be. That's why the toyota design is a win because they have done all the work for us and we just need to copy it! perfect. Not sure how many teeth they have but the 2jz has allot more than 8.

The last problem is getting the material correct, and that's it. which is why i insist we go through the testing process! If they have readily access to 4140 and 4340 then go the 4340 it makes all the sense as 4340 is better at withstanding shock (like that of limiter bashing)

didn't get time to proof read this i gotta run. hope it makes sense.

Edited September 10, 2009 by GT-RZ

[Jez13]

My N1 blew and I never hit the limiter. I pratically never even take it to 6k rpm.

[bubba]

someone needs to make a crank collar with a corse 6 or 8 spline drive and a oil pump to suit. aka all toyota inlne 6.. i havent really heard much of 1 and 2j engines with oil pump problems.

it will work.

It's already happening, I guess I'm going to be one of the guinea cops!

[proengines]

Still awaiting a reply in the group buy topic. Without any form of answer to the questions being asked i'm not very confident on buying considering these will be the first lot for testing.

Id feel much more confident if they were made of 4340 not that 4140 is rubbish but why not go for the best? impact and tensile tests IMO are a must on a test piece of steel that has been tempered to the specifications used in this gearset/collar.

On a side note who was it that got the standard gears tested for hardness??? Did it get done?

4140 is a good material for the gears. I spoke to the heat treaters who recommended it over 4340 because although the 4140 doesn't end up as hard, it will not be as brittle. Hardness isn't as critical as toughness for the gears as they are very well lubricated and wear isn't a big issue. Cost wise there's very little difference. If you weren't going to harden the gears you'd use en26 or similar.

[GT-RZ]

Both can be treated to the same tensile strength. then it's the impact resistance that sets them apart. good info below:

There is a huge difference between these two alloys chemically, namely the nickel content: 4140 nominally has no Ni and 4340 contains between 1.65 and 2.00 % Ni. This contributes to substantial differences in hardenability and fracture toughness, and also has a positive effect on distortion during quenching and corrosion resistance. As a surrogate for K1c values, I'll use Izod impact energy as a comparison of the relative toughness of these two alloys:

-------------------------------------------------4140 / 4340

tensile strength in MPa ----------------------impact energy in Joules

~1965 MPa (tempered @205C) ---------------------15 / 20

~1720 MPa (tempered @315C)---------------------- 9 / 14

~1020 MPa (tempered @595/650)------------------ 93 / 100

This data is for room temperature. 4340 will be MUCH tougher at lower temperatures. 2% Ni shifts the ductile to brittle transition temperature appreciably-- for low carbon steels it would be a delta of ~ 100 degrees F, for medium carbon steels it is less.

Having said all of this, these alloys can be used for many of the same applications. If the application does not require the higher level of fracture toughness (especially at low temperatures) that 4340 offers, then 4140 can be used as a direct replacement, with the caveat that distortion during heat treatment will be higher and thicker sections will not quench to the same hardness. I would caution you against ever saying that an alloy is suitable or unsuitable for a generic application without fully understanding the operating environment (forces, temperature, corrosion, etc.). You may want to provide some additional details about the types of components you manufacture, their operating environments, etc. so that we can better answer your question.

But then i guess if they are doing the tempering it's what they say goes. i'm not a metallurgist. tougher the better imo for a high toleranced gear, maybe not so important if it was a push fit or alike (driveshaft etc)

keep us informed with more details, i'm keen but would like more info!

Edited September 11, 2009 by GT-RZ

[shanef]

Sorry for not replying earlier guys, had shoulder surgery on wednesday.

Generally things must be surface ground after nitriding due to the surface expanding unevenly. That is the gas can be absorbed at different rates in the material. However given that these are gears and not a bearing surface (like a crank) it should not matter as much.

Cryogenic treatment is excellent in making material stronger. So you have a good mix. Nitriding does nothing for strength but makes the surface very tough and cryogenics does nothing for toughness but adds strength (re-aligns the grains correctly i believe)

potentially Allows obviously a more plyable material to be used which IMO is a good thing when it comes to gears.

GTR standard pumps would be the go imo! Looking forward to these, hopefully a cheaper cure to this problem.

PS: How many splines are there going to be (sorry if this was mentioned earlier also) As obviously the more splines (think 10 splines per 25mm) the larger the surface area but with that comes smaller splines which requires smaller tolerances which may not be suited for the heat expansion that these gears will come under during the operation of an engine. Looking at the Supra design posted earlier in this thread would be a good way to go, not very many splines but it's clearly a tried and proven logic.

PS: If possible 4340 is the superior material compared to 4140 but obviously it does come down to the manufacturing processes s available.

Expansion from nitriding will be based on how long the material is left in the 'oven'. Seeing as we are only after a 4-6thou penetration depth, expansion will be minimal and this tolerance will be built into the original machining. Also the isotropic finish we are going to use will give us back some of that extra clearance, as this finish microscopically removes the 'peaks and valleys' on the material.

We are going to use 24 splines. The more splines used the greater the machining cost as cost is based on per mm of cutting. 24 will be ample for the size of these gears.

As greg posted below, 4140 is the material of choice as we feel its properties are optimimal for the application.

4140 is a good material for the gears. I spoke to the heat treaters who recommended it over 4340 because although the 4140 doesn't end up as hard, it will not be as brittle. Hardness isn't as critical as toughness for the gears as they are very well lubricated and wear isn't a big issue. Cost wise there's very little difference. If you weren't going to harden the gears you'd use en26 or similar.