Which crank does my 90 have?

1364 Views 12 Replies 6 Participants Last post by speedworkz, Dec 10, 2006

Discussion Starter · Nov 5, 2006

Check these pics:

http://homepage.mac.com/billwilner/PhotoAlbum8.html

Thanks,

Bill

1 - 13 of 13 Posts

Agent935

· #2 · Nov 5, 2006

Looks like a short nose too me. It should be anyway unless the engine was replaced. check the vin on the block. If it matches the car it's short nose.

Also the long nose has an additional spacer that goes between the accessory drive pulley and the timing pulley.

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Bryan

· #3 · Nov 5, 2006

Long-nose. You can tell by the 8 slots in the main pulley. Check out this article for more info

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Agent935

· #4 · Nov 5, 2006

I stand corrected!

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thedishesrdone

· #5 · Nov 5, 2006

i think the crank bolt is a different size too, i think the long nose is like a 21 or a 19, and the short nose is supposed to be a smaller head. but yeah that article on m.net will tell you.

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Bryan

· #6 · Nov 6, 2006

thedishesrdone @ Sun Nov 05 said:
i think the crank bolt is a different size too, i think the long nose is like a 21 or a 19, and the short nose is supposed to be a smaller head. but yeah that article on m.net will tell you.

I don't know what size the bolt is off the top of my head, but the long-nose has a wider shoulder.

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Nevadabob

· #7 · Nov 6, 2006

There is a larger difference between the ID of the bolt hole and the OD of the nose on the pictured crank than on the "light weight sports crankshaft" that normally is in a '90.

The first time I did my timing belt is was scary to see how thin the wall of the nose is on the short-nose crank. That said, I did 2 timing belt changes on the original '90 with no problems in 166k miles. The current '90 has the LWSC and I changed the timing belt at 90k, still running strong.

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Bryan

· #8 · Nov 6, 2006

Nevadabob @ Sun Nov 05 said:
There is a larger difference between the ID of the bolt hole and the OD of the nose on the pictured crank than on the "light weight sports crankshaft" that normally is in a '90.

The first time I did my timing belt is was scary to see how thin the wall of the nose is on the short-nose crank. That said, I did 2 timing belt changes on the original '90 with no problems in 166k miles. The current '90 has the LWSC and I changed the timing belt at 90k, still running strong.

As long as the job is done right, there's really nothing to fear. Having a long-nose crank DOES NOT protect you if the timing belt job is not done right--ask me how I know

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Discussion Starter · #9 · Nov 6, 2006

Bryan, How do you know?

:twisted:

Bryan @ Mon Nov 06 said:
Nevadabob @ Sun Nov 05 said:

There is a larger difference between the ID of the bolt hole and the OD of the nose on the pictured crank than on the "light weight sports crankshaft" that normally is in a '90.

The first time I did my timing belt is was scary to see how thin the wall of the nose is on the short-nose crank. That said, I did 2 timing belt changes on the original '90 with no problems in 166k miles. The current '90 has the LWSC and I changed the timing belt at 90k, still running strong.

Click to expand...

As long as the job is done right, there's really nothing to fear. Having a long-nose crank DOES NOT protect you if the timing belt job is not done right--ask me how I know

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Discussion Starter · #10 · Nov 6, 2006

The oil pan VIN matches the car, but the block has this weird stamped aluminum tag on it dated 10/24/2003, with a Mazda OEM part #B61P-02-300R.

Does anyone know what I've got here?:

http://homepage.mac.com/billwilner/PhotoAlbum9.html

See less See more

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Bryan

· #11 · Nov 6, 2006

:lol: Long story short, Junior sports a Loctite-fixed crank nose.

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roadsternut

· #12 · Nov 6, 2006

The engine number cut-off for the change in crank design is B6-127441.

Block details; the part number is correct for a 90-93 engine. This plate doesn't appear to be a Mazda factory plate; I'll hazard a guess its either a reconditioned block, or one imported as a used motor. I doubt this is a NB6 block; it will be a fair bit of work tro get a Mk1 head tro fit.

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speedworkz

· #13 · Dec 10, 2006

definitely a long nose. as stated before, the 8 windows on the crank pulley are an easy tell tale sign.

as for the oil pan and the VIN # i would assume it was switched with the old motor so the numbers would match.

new crate engines from mazda have no VIN's obviously and can have the pan switched or the VIN tag rivets from the old pan drilled and re-rivetted (is that a word?) back on to the new pan.

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