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-   -   Sintered steel oil pump gears (https://www.miataturbo.net/general-miata-chat-9/sintered-steel-oil-pump-gears-13696/)

Ben 10-29-2007 03:11 PM


Originally Posted by Loki047 (Post 168594)
Im thinking we look at options to improve the stock gears that will not require re machining.

:rly:
Hmm, I thought that was the purpose of this thread... :)

cjernigan 10-29-2007 03:13 PM

I have access to a materials testing lab if you want hardness tests done.

Loki047 10-29-2007 03:18 PM

I would like them done if we can get someone to donate a gear, we can't really decide on what to do if we dont have a baseline.

Ben 10-29-2007 03:20 PM

CJ--will the lab's report state metalurgy?

neogenesis2004 10-29-2007 03:20 PM

I'll look but im pretty sure I threw away the ebay oil pump gears, they should be close enough to stock quality.

Loki047 10-29-2007 03:21 PM


Originally Posted by Ben (Post 168597)
:rly:
Hmm, I thought that was the purpose of this thread... :)

:gtfo:

Get back in the HSV thread and forget about this gear pump shit. Use a straw and an ardvark. Problem solved.

Loki047 10-29-2007 03:23 PM


Originally Posted by Ben (Post 168603)
CJ--will the lab's report state metalurgy?

Well if we know the metal and the hardness at different depths, and pictures if you got em onces its sliced we should be able to get a good idea of whats happening.

Personally, i dont care what they did to the original gear, i care what the gear ended up being.

Actually Im wrong. A carbon content would be nice, but we should be able to piece it together with some pictures and hardness tests

neogenesis2004 10-29-2007 03:26 PM

I can't find the gears....too bad, they were fun to play with.

Ben 10-29-2007 03:26 PM

That's cool. Maybe we can get stealth97's old oil pump gears. I think I'm closer to his car than he is, so I can hold hostages. :)

If you've seen my dyno run vid on youtube, his car is in front of mine, right side.

cjernigan 10-29-2007 03:29 PM

Not sure exactly what information they can provide. I do know they can do brinell hardness tests. Which would be possible on the outside of the gear and the inside. Not sure what the recommended method for cutting the gear would be though i'm sure they would know. I'm in metallurgy right now, only reason i know we have these labs. Hell we also have an SEM machine, electron microscopes are badass, tell you what.
They can also etch part of the piece and test the hardness of individual grains. Judging by the hardness of the inside and outside, i bet they would be able to tell what the base metal is as well as the heat treatment. Should be pretty simple stuff for the most part.

cjernigan 10-29-2007 03:31 PM


Originally Posted by neogenesis2004 (Post 168610)
I can't find the gears....too bad, they were fun to play with.

I've always wanted to hold a mazda rotor in the cylinder so i could spin it around the eppitrochoidal axis. Sure is a weird shape. Glad i never got into rotaries.

bripab007 10-29-2007 03:55 PM


Originally Posted by patsmx5 (Post 168504)
Crankshaft flex is what causes them to shatter, as they are quite brittle compared to a cast gear. It's not the power the pump takes to drive it that breaks the gear.

What are the causes of crankshaft flex? Weak main bearing/caps/fasteners?

Would not crankshaft flex be exacerbated by both RPM and torque, especially on in inline-4 cylinder with no extra balancing shafts?

Loki047 10-29-2007 03:58 PM

we use EDM because it doesn't change the hardness when you cut it (it does slightly but nothing worth noting), water jet, i guess a band saw but its so uneven. Ask your machine guy, usually they have something worth while.

Loki047 10-29-2007 03:59 PM


Originally Posted by Brian (Post 168625)
Would not crankshaft flex be exacerbated by both RPM and torque, especially on in inline-4 cylinder with no extra balancing shafts?

It definitely would, thats sorta why we all agree that your a dick... I mean that the oil pump needs some work done :dancegay:

y8s 10-29-2007 05:30 PM


Originally Posted by Loki047 (Post 168628)
we use EDM because it doesn't change the hardness when you cut it (it does slightly but nothing worth noting), water jet, i guess a band saw but its so uneven. Ask your machine guy, usually they have something worth while.

you can always anneal and heat treat if you dont like the surface effects of the cutting method. i mean you're gonna do those anyway to get the final product.

Loki047 10-29-2007 05:42 PM

well thats what ideally we would avoid.

Any of those would change the hardness of the metel and theres no point in doing a hardness test.

Stealth97 10-29-2007 08:19 PM


Originally Posted by Ben (Post 168611)
That's cool. Maybe we can get stealth97's old oil pump gears. I think I'm closer to his car than he is, so I can hold hostages. :)

If you've seen my dyno run vid on youtube, his car is in front of mine, right side.

hey now, I offered the ones on my floor, not in, my car :nono:

I just need a hand getting the timing gear off. the whole crank with OP attached is laying on my floor. Even after torch work, and taking three chunks out of it with my prybar, I only got it to move just enough to pull the crank out. If anyone wants it for testing youre welcome to it.

neogenesis2004 10-29-2007 10:48 PM

sledge hammer? I doubt the gears need to be mint to get the testing you guys want done.

jif 10-30-2007 05:16 AM

oil pump failure...
 
FYI - this is what the powerlist had to offer about oil pump failures (in 2005) ...
>
Out of the 469 PowerList members (and I would presume the highest per capita number of built motors in all of Miatadom) only 4 built motors have gone south. And all four were oil pump failures. And all four were using the OEM oil pump. And all four were far exceeding OEM design redline of 7,200rpms.

So, morale of the story may simply be: Don't over rev. the BP.

I ask the question originally to gauge the collective wisdom on how much boost a built motor can safely see. It sounds like RPMs (and oil pumps) should be more of a concern. Does anyone know of BP over-boost failure?

Jim in Tucson

#1
I destroyed 3 built engines. In all cases the Oil Pump shattered and smoked the
crank and bearings.. Never lost one due to boost, or tuning (I tune my own
engines and take a great deal of time) My highest hp was 489hp and that was
with Turbo and Nitrous on that motor. I hope to crack 500hp with my newest
engine revision. 9000rpm? I found that 8100rpm was the breaking point..
7800-8000 and I never broke one..
Marc

#2
my highest powered NA was 170 RWHP with a 8500 redline failed due to a
failed oil pump.
Greg

bripab007 10-30-2007 08:12 AM


Originally Posted by Loki047 (Post 168629)
It definitely would, thats sorta why we all agree that your a dick... I mean that the oil pump needs some work done :dancegay:

So eloquent; you've got a way with words...must really impress the ladies...

So, anyway, does anyone think this can be done for less than the $500 asking price of the M.net fella?


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