Travis, $149 is a killer price for a set of CNC milled gears (as you well know) and I'm very interested in jumping on the group buy. However, I would still like to know what the spec for rotor tip clearance is going to be on the new gears. Mazda gives the spec as .02-.18mm with .20mm as a max. That is a fairly large range (the wider the clearance, the lower the oil pressure). Do you have a manufacturing target spec for rotor clearance (i.e., .10mm plus or minus .05 mm) and how does this compare to what has been measured in a new OEM pump?

I'd be willing to pay more than $149 for a set of gears if we could go through the extra step of checking clearances of a few new & used pumps and then paying the $300 fee to make a single prototype to the target spec which could be "proofed" by assembly in both a new & used pump body.

 

they should run a first article as a matter of course. sn95, you can go buy a new pump or just "borrow it" at the counter and measure it there maybe. also, the drawings are posted a few pages up if you want to check them.

 

WoW, getting stuff fabricated is easy it seems. I just took a scan of my **** and mailed the dimensions to a "rubber" guy I know. He said it'd be two months cause he's gonna have to buy a bigger machine to make them.

Ahem... sorry I'm late to this party. I have one question I haven't been able to get a straight answer too... and yes, I've searched. I know gear failure is due to crank flex somehow. I haven't been able to find the actual mechanism that specifically causes the gears to wear prematurely. I also haven't found how billet gears is gonna solve whyever they break.... so I have 2 questions.

Why specifically are the gears we're talking about here not going to fail?
Who needs these gears?

$150 is nothing in the long-term, but in the short term, it's half a set of tires.

 

Sam, they don't wear prematurely, they break into large pieces.
bang, boom, bam, dead!

The stock oil pump gears are are sintered steel, (Powered steel that is pressed and heated in a form *without melting*) This results in a weak/brittle internal structure. Starting at or near 300 RWHP, excessive crank flex and undamped harmonics destroy the oil pump gears.

Billet steel, on the other hand, will stand up to much more abuse. High RPMs contribute to crank flex and harmonics as well. Billet oil pump gears are commonly prescribed for high RPM applications in other engines.

That being said, you should look into having those rubber ***** of yours CNC from solid billets of viton. Its the only way to be sure they can stand up to Hustler's abuse. Crank flex in the bedroom is a bitch!

 

I'm following you.
I will also threadjack a little and ask the best way to eliminate crankflex? That's what harmonic dampners are for, right? Anything else required?

My next Miata will have a 300whp goal, so I'm definitely "in" on this buy in any case.

 

Get the bottom end balanced when you do your build up.

 

You hit the nail on the head. This community needs a inexpensive heavy duty harmonic damper. ATI is the only game in town and is quite spendy.

What's the reputation of elastic or fluid filled dampers from folks like C.A.T.? Maybe we can approach someone like them to produce an inexpensive damper?

 

I'd rather spend my money on $150 billet gears. Make a new thread for your ****. kthnx

 

Get the entire rotating assembly (first bottom end, then bottom end with pre-balanced flywheel and clutch) balanced at a speed over target max RPM. Add MBSP. Finally add ATI Damper.

 

I am in for $150 billet gears too. Dampers are relevant and complimentary because they attack the same problem from a different angle. Go be a jerk in the actual group buy thread.

 

This thread is about oil pump gears it wasn't about anything else until page 17. I'm not being a jerk yet.

 

there's no way to eliminate crank flex in a piston engine. you can only reduce it. the bottom line is that two pistons are moving up in the middle of the motor while two are moving down at the ends. even when balanced, it's only going to be perfectly opposing forces vertically since the weight of the pistons is not transferred sideways but the counterweights are.

but with more durable gears, it should be less of a problem.

 

Not to tip my hand, but would these work in a 1.8l gtx motor? :-)

And I'm still wondering - what's the difference between these and stock, dimensionally?

 

NOTHING IS DIFFERENT!!!!! Will work in any miata motor or equivalent B series motor with a long nose crank shaft.

 

Ok, so, this only shows my infinite laziness, but someone edit the first post to put a link to the group buy thread. :-)

 

Group buy is official to be a part order at www.boundaryengineering.com

 

**** you. you're 3-months too late. God damn mother ******* ****!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!

****.

 

can I just rip the oil pan off, or do I have to pull the crank to install this ****?


I'm so epically pissed off at myself for building that motor without these that I'm about to start throwing ****. Badass motor with ------ oil pump gears = gaysex.

 

yeah, but you have to drop the pan and that's not going to happen with the motor in the car.

 

Yep, you are correct. Forgot about that small detail. My bad.