REIMAX (Collar clearances, pics)

[Black BNR32]

the other possibility is that usually when one metal is softer than another, the hard one, even though only marginally harder, (even different grades of hardened steel) will still deform the softer metal, so if the oil pump gear is harder than the crank itself, it makes sense that these old cranks you measure here are soo much larger clearance wise, because they've been deformed from the original perfect shape!

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i believe the forces are not high enough. even if deformation occurs in this application, it is likely in the .0001 magnitude.

[Black BNR32]

yep^^

I've been saying whats been said since 2007. Just look at the posts ive made over the years in other sticky threads in this forum. Its only been since recently that people take note of it. Too bad jun/nissan cant figure this out :S Dont need to be smart to know its just a sloppy design.

to vaderj: Its cheaper to replace a collar that machine a new pump gear. Also, with a collar built, it would suite most pumps (jun, OEM//N1 + more Im sure) So if you wanted to upgrade to a better pump, you could do so. or you can machine a new gear each time like you said.

If you guys have time, take another read at my f/s thread. Ive updated a bit ago with lots of easier to understand info. Its over 2000 words to read :

http://forums.gtrcanada.com/parts-sale/42468-f-s-rb-crank-collars-1-2mm-orifice-10an-drain-fitting-rb30s-more.html

I still think a 2J style drive would be best is you were to even consider making a new custom gear set. Screw this 2 flat drive style. Then, you can use the oem pump, slap in the new 4140 alloy gears with a 2J drive collar. 3 pieces, hopefully cheap enough most us guys can afford it. Its something ive been wanting to do for over 4 years. Id jump right on it but it takes capitol to get it done and I just dont have any. I dont want to jump into it and have to wait a year to get my investment back. if anyone wants to sponsor this, i can get a quote within a week. Have everything drafted a couple weeks after and do a small production to start. Then need people to try em out. If everything works well, do a larger production and then cheap gears and collars for everyone! I already have the plan, just need to pick a pump style and send the info to get a program built for the CNC then go from there.

Allen, I'd happilly do the engineering and drafting for free.

[jdms13rhd]

i believe the forces are not high enough. even if deformation occurs in this application, it is likely in the .0001 magnitude.

That doesn't make any sense. Ive been talking to archaeic_bloke. I was telling him that there is an engineering equation to prove two theories. One for the difference in stress put on the pump with loose clearance and then with tight clearance. Believe me, there is more stress put on the pump with loose clearances. Plus, how would the drive round off when its tight. Another, is the percentage of area used and that used with the amount of load the pump sees using both loose and tight clearances. .002 is damn tight! if your oil pump has been used, its actually an almost press fit with the collars I made. With that said, its as little stress that design will see.

I'll get the engineering equation this weekend and if I can figure out the math, Ill prove to everyone with professional reference. End one more debate.

[jdms13rhd]

Allen, I'd happilly do the engineering and drafting for free.

I will let you know for sure. I got a friend that is a drafter at the same shop as the CNC. It may be easier to get him to do it so there are no complications with out of house consultations. But in the end, the cheaper, the better for everyone. I'll get in touch for sure when the time comes and we can go from there. thanks!

[Brando13]

what would happen if you took the time to spline it on instead of the flat surfaces? sorry if i took a swing and missed but that seems like the obvious answer to me....

[Black BNR32]

That doesn't make any sense. Ive been talking to archaeic_bloke. I was telling him that there is an engineering equation to prove two theories. One for the difference in stress put on the pump with loose clearance and then with tight clearance. Believe me, there is more stress put on the pump with loose clearances. Plus, how would the drive round off when its tight. Another, is the percentage of area used and that used with the amount of load the pump sees using both loose and tight clearances. .002 is damn tight! if your oil pump has been used, its actually an almost press fit with the collars I made. With that said, its as little stress that design will see.

.

I believe that deformation (http://en.wikipedia.org/wiki/Deformation_(engineering)) is not occuring, as Josh claims.

You are correct in that a loose fit creates more stress as a shock load is introduced.

[Black BNR32]

what would happen if you took the time to spline it on instead of the flat surfaces? sorry if i took a swing and missed but that seems like the obvious answer to me....

Yes, a splined connection would be best. But, your manufacturing costs increase.

[jdms13rhd]

I believe that deformation (http://en.wikipedia.org/wiki/Deformation_(engineering)) is not occuring, as Josh claims.

You are correct in that a loose fit creates more stress as a shock load is introduced.

maybe I just miss understood what was said...

I just figured since there is less stress with tight clearances that would practically eliminate any chance of the drive and gear deforming from slamming the pump gear. Because, from what I see, with loose clearances the drive and gear both get "deformed" from the excessive stress caused from loose clearances. Maybe thats just a different equation from that strength equation in that wiki-link you posted?

With loose clearances I do suppose that it would get further more "loose" (even larger clearance) from the slamming action. But one thing you may be able to answer: on the basis of something needing to be harder than the other to be able to "deform" I can think to relate it to the plastic trim putting scratches in my door window on my 86 chevy truck. The plastic mold is softer than the glass for sure yet still scratches it to hell.

Im no engineer tho. Just looking and wording this stuff as my brain thinks it up. :S so forgive me haha. In the end I think were all on the same page here.

[jdms13rhd]

Yes, a splined connection would be best. But, your manufacturing costs increase.

what he said.

In part with the clearance issue it may also be that harmonics and the 2 flat design drive dont go well with each other. 2JZ engines dont have that problem and Id like to see a simple, affordable solution to equal the reliability of a JZ engine with the splines style drive wet pump. I could be totally wrong on that tho. Its just a thought really. Only one way to find out and thats to try it out.

[archaeic_bloke]

I was merely suggestiing that deformation could be going on here...

Allen, you and I (even from 2 years ago) have always both argued that it was never the short nose drive collar that was the problem, but instead its the large clearance between oil pump inner driven gear, and the collar on the crank. which, when bouncing off the rev limiter causes that repeated bashing front and back as the oil pump spins freely for a micro second, and then slams into the crank repeatedly.

we both agree there! But I still maintain there is deformation occuring on the crank, my theory of softer metals being the cause I now believe was wrong, as you pointed out, there must be a reason its happening in the first place, and thats because of clearance! but definitley the bashing between crank and oil pump causes deformation, just look at the photos... but I was backwards in suggesting that deformation may cause pump failure.

the last thing I'm still hanging on to is my own personal expeirence. heres what I know to be true 100%
- I bought a brand new R34 crank
- I bought a brand new N1 oil pump

Sitting at home, i took the crank and put it on my work bench... I then took the oil pump and attempted to slide it onto the crank. at first it did not go on and I freaked out thinking something must be wrong...
So I measured the inner diameter of the oil pump gear flat spot to flat spot (stupidly didn't write it down of course!) and I measured the outer diameter of the crank drive collar, again flat to flat, and it was exactly the same.
So after speaking with my engine builder he said that was normal of a new crank and oil pump, and its almost press-fit. the clearance on it was soo tight that it has to be installed perfectly straight, even the slightest tilt from perfect 90 degree perpendicular will cause it to bind during installation.

there was a guy on the forums (won't say name) who had a nice oil pump and crank and tried to force the oil pump onto the crank using a sledge hammer.... probably because he too had a super tight fitting clearance like me... so I know I'm not the only one here who had that.


but like I said, if you can get a new R34 crank, and the N1 oil pump and use the feeler gauges to measure the clearance, I think you'd find that to be the best solution.

[gtrjon]

i hope so lol josh i followed you exactly and bought a brand new r34 crank. i am going to measure it with my n1 pump i have already talked to allen and we are going to see the clearences if they are too large i will be getting a collar off him

[Black BNR32]

we're all on the same page, just that 'deformation' isn't quite the right term me thinks

hey josh, a near press fit is what i would expect, so i agree with your builder.

most will already know, but you can (should) heat your pump gear and/or cool your collar/shaft to make installation easier. you will gain a couple thou of clearance easilly. at least that's how press fit bearings are installed.

[GTRADDICT]

we're all on the same page, just that 'deformation' isn't quite the right term me thinks

hey josh, a near press fit is what i would expect, so i agree with your builder.

most will already know, but you can (should) heat your pump gear and/or cool your collar/shaft to make installation easier. you will gain a couple thou of clearance easilly. at least that's how press fit bearings are installed.

+1 same a sleeving.

[jdms13rhd]

the last thing I'm still hanging on to is my own personal expeirence. heres what I know to be true 100%
- I bought a brand new R34 crank
- I bought a brand new N1 oil pump

Sitting at home, i took the crank and put it on my work bench... I then took the oil pump and attempted to slide it onto the crank. at first it did not go on and I freaked out thinking something must be wrong...
So I measured the inner diameter of the oil pump gear flat spot to flat spot (stupidly didn't write it down of course!) and I measured the outer diameter of the crank drive collar, again flat to flat, and it was exactly the same.
So after speaking with my engine builder he said that was normal of a new crank and oil pump, and its almost press-fit. the clearance on it was soo tight that it has to be installed perfectly straight, even the slightest tilt from perfect 90 degree perpendicular will cause it to bind during installation.

You know, im still hung up on that as well. Ive seen only a couple r34 cranks and who really knows if they were r34. Thats just what I was told they were. Maybe I take some gears over to Jon and see how they fit on his R34 crank. Maybe that nissan had only some select cranks that were fixed? Its just weird that Nissan would go from a narrow-loose drive to a wide-loose drive to a wide-tight drive and that the reimax gears have a larger ID than the OEM pumps. Anyone on here know what year/engine the gears were produced?. Any of you guys know if the part numbers on different year R34 cranks are the same? Or if the 34 and 33 are the same number??? I've never looked into that.

Jon, next time your heading to Alans shop, give me a ring. I'll pop by with an oe pump and one of my collars. we can measure and see.

I do know that slipping the pump over the crank can be a little tedious sometimes. Only way to measure is to remove the gears. I usually measures the clearances with Two tools. Thats why my numbers at times are a full tho off of the measurements in this thread because they are not in ten tho intervals. I just wanted a centered measurement. Doesnt really make any difference tho.

[archaeic_bloke]

I have an interesting story to tell you about...

This past summer I worked in a machine shop, where a learned quite a bit about machining techniques... we had a batch of 35 brass sleeves which act as bushings around 35 stainless steel rods. They are used for elevation shafts on the machines we were building. Anyways, the machinist who I was watching did the first 3 unites and they came out perfect, the fourth was off by a few thou and then wouldn't fit into the brass sleeve. we were trying to find out why, because the lathe was set perfectly the same! it didn't make sense... until we realized that the hardened steel shafts, had worn down the milling bit and caused the shafts to be off by the amount the bit had worn down.

I wonder if the variance in cranks could be attributed to machining variances... like maybe nissan uses a wide tolerance for acceptable crank sizes...causing some to be too loose, and some to be super tight, just a thought.

anyways, heres some photos I dug up of my own N1 pump

Crank




lastly it may be worth considering the crank ratings as an indicator of this machining tolerance...see the numbers stamped onto the journal....