I just measured the diameter of my e-shaft main journals and came up with 1.6910

Well I looked at my atkins spec sheet and they list it as 1.6918-1.6923

Does that 0.0008 difference mean my E-shaft journals are out of spec and useless or am I misunderstanding something? I know everything needs to be within spec but .0008 is kinda extreme. I'de like some other input on this b4 I buy a replacement e-shaft.

BTW this is in an FD And the measurements were made on the inside of the journals. I plan on replacing my main bearings anyway but I have no idea which ones to get.

They go as followed:

T=1.980MM Yellow
T=1.983MM Green
T=1.986MM Brown
T=1.989MM Black
T=1.992MM Blue
T=1.988MM Yellow
T=1.991MM Green
T=1.994MM Brown
T=1.997MM Black
T=2.000MM Blue

those are all the main bearings they have to choose from.

Can you guys help me out here?
Thanx in advance

 

Mazdatrix are just selling the largest ones.
According to them, if you wipe the bearings with a cloth, you just changed diameter.

.0008 isnt awhole lot, with 4 decimals it doesnt take much more than a little bodyheat to change the micrometer screw gauge.

 

Thanx Kim. Ok so the main journal diameter is ok? How do i know if that is the right bearing size for me? I guess because the diameter of the main journal is so small, the biggest bearing would be best? They are selling the 2mm Blue one. Is that the thicknes of the bearing?

Any other input?
I need to get these bearing ordered so i can put my motor tugether

 

Well, clearance is listed as 0.0031-0.0043" outside, 0.0051 Max.
0.0023-0.0031" Inside, 0.0043 Max.

What is your existing clearance? Just b/c your bearings show copper does not mean they are garbage. When clearance bearings for new engines on the lathe, I often take the bearings down until they show copper. I like to run a little more oil pressure and a little more clearance for higher rpms engines to prevent the bearing from sezing when the e-shaft flexes.

Check the clearance, and go from there.

Might also want to check what your current journal taper looks like...

 

Since the main journal is a little out of spec, i would go to a Mazda stealership and order the smallest bearing.
I was thinking rotorbearings when i wrote about the larger ones, hehe
If you going to run trackdays or otherwise high rpm(beyond stock redline) for longer periods of time, you should just get a new e-shaft.
I have no idea why they are calling them 2mm bearings, sorry

Are you getting a complete rebuild kit or reusing the original parts?

 

I'll check the bearing clearance and get back to you. i've never heard of anyone taking the bearings down to the copper. i always thought you wanted to avoid copper. And sence the copper in mine isn't showing equaly around the bearing i would think it is worn slitely uneven? I don't have access to a lathe nor the know how to use it for that matter. I think it would be in my best interest to get a new e-shaft.

I've already got the complete RA kit. But I bought some Mazda apex seal springs to use instead of the RA ones. I have already spec'd out my rotors housings and irons. had them ported by a local guy. I'm basicly needing new main bearings and i'll probablu try to find a new e-shaft also. more and more peeps are telling me thay are easy and cheap to come by.

This is my first rebuild and i am also going single so i wanna make sure everything is right without cutting corners.

Thanx for the help guys!

 

Avoid the copper.
I think we misunderstood eachother, By smaller I meant the ones with less clearance
The problem is solved by getting a new eshaft, new bearings from mazdatrix are one size only, both rotor and main.

 

just put the engine together and run it , you would be surprised how good you really are .

 

What problem does showing copper present?
What advantages does the bearing overlay offer to the oiling system?

If the clearance is good, leave it alone.

 

1: I just dont like it, the price of new bearings make me have that opinion
2: His shaft is a lilbit smaller than it should be common sense tells me to get the bearings with less clearance.

 

frt main: 1.6921
frt rotor: 2.9123
rr rotor: 2.9125
rr main: 1.6920

Ok with those diameters for the front and rear main journals. which one of the above main bearings do i need? I could figure out the clearance myself but i don't know the inside diameter of the bearings listed in my first post.

Thanx
Cyan

 

The difference between bearing sizes is too minimal to worry about choosing different sizes. This is why Mazdatrix only sells one size bearing.
Get the largest one: 2.00.
It'll put you back into stock clearance spec, although you haven't given us your existing clearance yet.

 

Thanx that answered my question

The only #s i have right now are of my e-shaft. I don't know the inside diameter of the bearings so i can't subtract the journal to get the clearance( i need new bearings BTW)

I will be ordering the 2.00 tomorrrow.
thanx for the help