2zz Stock Oil Pump Gear Vs 2zz Circuitworx Size

[cool_apple]

My 2zz spyder is in the shop for some upgrades. Hit a snag on the oil pump gear.
We discovered that the curcuitwork oil pump gear is larger than stock 2zz. He feels it will have problems rotating smoothly in the stock 2zz housing.

I havent found any threads on this (problems) & assumed it was plug & play swap

He recommended the curcuitwork be trimmed to size (difference vs stock) before fitting into housing.

i got a set of circuitworx from MWR


Stock2zz Oil Pump Gear showing ~ 8.94mm


Circuitworx2zz Oil Pump Gear showing ~ 9.03mm


thoughts? recommendation?
i wonder why the difference, intended or fault?

another note. we noticed minor scaring on stock 2zz oil pump gear housing. should 2zz owners be worried?
Esp those who drive hard. Some of us seen images of the breakage of some 2zz celicas.
My Engine has done only 9500km++ (7200km shown on salvaged celica odometer & the rest after spyder swap.)



could it be lack of oil that causes this ? scarring on walls or pressure is really that great?



New 2zz oil pump gear housing part no

[zuoom]

<div class='quotetop'>QUOTE </div>

Generally our gears are .001" to .0015" thicker than the stock gears because
it gives a more precision fit in the housings. On the particular gear I
measured this morning it ranged from .0003" to .0007" thicker than the
factory gear. On our next batch of them we make we are going to go dead on
with factory specs and hopefully not have this problem in the future.
Usually in the past the factory housings have a few very small burrs and can
cause minor binding issues because of the burrs in the housing. In the past
the issue with the binding has been solved by sanding the burrs out of the
housing with 1000 grit sandpaper. If you have any other issues of this
nature please contact me and we will get the issue resolved.

Thank you,
Daniel Jones
CircuitWorx[/b]

this is what i got when i asked them about it. hope it helps.

[cool_apple]

<div class='quotetop'>QUOTE (zuoom @ Dec 10 2007, 10:57 PM) <{POST_SNAPBACK}></div>

<div class='quotetop'>QUOTE

Generally our gears are .001" to .0015" thicker than the stock gears because
it gives a more precision fit in the housings. On the particular gear I
measured this morning it ranged from .0003" to .0007" thicker than the
factory gear. On our next batch of them we make we are going to go dead on
with factory specs and hopefully not have this problem in the future.
Usually in the past the factory housings have a few very small burrs and can
cause minor binding issues because of the burrs in the housing. In the past
the issue with the binding has been solved by sanding the burrs out of the
housing with 1000 grit sandpaper. If you have any other issues of this
nature please contact me and we will get the issue resolved.

Thank you,
Daniel Jones
CircuitWorx[/b]

this is what i got when i asked them about it. hope it helps.
[/b][/quote]


sorry for not updating this. anyway thanks, got word form matt (MWR).
returning item for investigation/change.

[dustylax]

im going to have to talk to them before we put our order in at the shop soon. The 2zz gears should be done this week i think, so hopefully this new batch is right on spec.

[rcntype]

Thats a difference of .00276 IN. I know engines are tight tolerance things but for something like that come on, maybe for other things like bearing.

Also why don't you try maybe 4 or 5 points of measurements all around the gear vs. the same on the stock gear.

I use to work at a manufacture, where i use to spec out parts. Although these parts were not super tight tolerance but i always tried to keep it within a tenth of a mm.

[LittleRocket]

<div class='quotetop'>QUOTE (rcntype @ Dec 12 2007, 01:33 AM) <{POST_SNAPBACK}></div>

Thats a difference of .00276 IN. I know engines are tight tolerance things but for something like that come on, maybe for other things like bearing.

Also why don't you try maybe 4 or 5 points of measurements all around the gear vs. the same on the stock gear.

I use to work at a manufacture, where i use to spec out parts. Although these parts were not super tight tolerance but i always tried to keep it within a tenth of a mm.[/b]

There are celarance specs in the bgb. Just follow them. If they are out of spec then don't use them.

[cool_apple]

<div class='quotetop'>QUOTE (rcntype @ Dec 12 2007, 12:33 AM) <{POST_SNAPBACK}></div>

Thats a difference of .00276 IN. I know engines are tight tolerance things but for something like that come on, maybe for other things like bearing.

Also why don't you try maybe 4 or 5 points of measurements all around the gear vs. the same on the stock gear.

I use to work at a manufacture, where i use to spec out parts. Although these parts were not super tight tolerance but i always tried to keep it within a tenth of a mm.[/b]

2zz engines here is still rare & expensive.

the shop cant guarantee it wont go wrong, even if he trims/grind it. i cant hold him if the worse case happens.

too many hiccups, i cant risk it.

[dustylax]

just hold your seat for now, i'll call curcuit worx in the morning and give them your measurements and get back to you. You should be fine w/what you have, has he/you put it together and tried to spin it by hand ?

[cool_apple]

<div class='quotetop'>QUOTE (dustylax @ Dec 13 2007, 12:06 AM) <{POST_SNAPBACK}></div>

just hold your seat for now, i'll call curcuit worx in the morning and give them your measurements and get back to you. You should be fine w/what you have, has he/you put it together and tried to spin it by hand ?[/b]

yup, onto a new oil pump gear housing (by hand ~ mechanic). the curcuit worx seems to jam up/hesitant upon rotating, even lube.

[zuoom]

we had a case of the circuitworx gear shattering upon starting up (within 5 minutes).
wonder if the extra width was the reason.

have forwarded this to Circuitworx, and to MWR (where the gears was bought.)

[CeeDapp]

The Circuitworx gears seems to be made from a sintered material (from what I could gather from a set sent here.)
The grears that I saw seemed to be rather soft (no heat treatment) and powedry (sp?).
That cross section view kinda confirms what I thought. Sintered material does not have any grain to it and is in some regards is very similar to cast iron, although much different in make-up.
I always thought those gears should be made from some type of tool steel of a more stable compound.

[zuoom]

<div class='quotetop'>QUOTE (CeeDapp @ Jan 2 2008, 04:15 PM) <{POST_SNAPBACK}></div>

The Circuitworx gears seems to be made from a sintered material (from what I could gather from a set sent here.)
The grears that I saw seemed to be rather soft (no heat treatment) and powedry (sp?).
That cross section view kinda confirms what I thought. Sintered material does not have any grain to it and is in some regards is very similar to cast iron, although much different in make-up.
I always thought those gears should be made from some type of tool steel of a more stable compound.[/b]

that's what i thought so too.

in my line of work, i deal with cast n ductile iron metals. and this is similar to what happens when the metal is not nodulised (or not enough).

anyway, still waiting for their reply. otherwise, will proceed to polish the sample bits n have a look thru a 100x scope.

[CeeDapp]

<div class='quotetop'>QUOTE (zuoom @ Jan 2 2008, 09:45 PM) <{POST_SNAPBACK}></div>

<div class='quotetop'>QUOTE (CeeDapp @ Jan 2 2008, 04:15 PM) <{POST_SNAPBACK}>

The Circuitworx gears seems to be made from a sintered material (from what I could gather from a set sent here.)
The grears that I saw seemed to be rather soft (no heat treatment) and powedry (sp?).
That cross section view kinda confirms what I thought. Sintered material does not have any grain to it and is in some regards is very similar to cast iron, although much different in make-up.
I always thought those gears should be made from some type of tool steel of a more stable compound.[/b]

that's what i thought so too.

in my line of work, i deal with cast n ductile iron metals. and this is similar to what happens when the metal is not nodulised (or not enough).

anyway, still waiting for their reply. otherwise, will proceed to polish the sample bits n have a look thru a 100x scope.
[/b][/quote]

I would be willing to bet that if you checked hardness the surface wouldn't be more than 3-4 ponit higher than the core. And I don't think they are much more than 38 Rc. Would be interesting if you could check those numbers though!

[zuoom]

we use BH for hardness. hmm, will do that also.

cross posted via : http://newcelica.org/forums/showthread.php?t=262791