The Definitive "VVT swap into 90-97 chassis" Megathread.
#331
Along this same line of thinking, if I'm going to integrate crank sensory into a '94 block, I need to add a timing wheel. This is gonna change the stackup thickness of all the things bolted to the nose of the crank. Would I need to replace the pulley and/or boss with a NB specific equivalent? I have to think that something's thinner to accommodate for the timing wheel.
Edit: this answered my question. Boss changed in 96 when crank position wheel was introduced.
http://www.planet-miata.com/index.ph...ch-item&idn=89
Edit: this answered my question. Boss changed in 96 when crank position wheel was introduced.
http://www.planet-miata.com/index.ph...ch-item&idn=89
Last edited by wackbards; 11-24-2016 at 02:44 AM.
#332
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Along this same line of thinking, if I'm going to integrate crank sensory into a '94 block, I need to add a timing wheel. This is gonna change the stackup thickness of all the things bolted to the nose of the crank. Would I need to replace the pulley and/or boss with a NB specific equivalent? I have to think that something's thinner to accommodate for the timing wheel.
Edit: this answered my question. Boss changed in 96 when crank position wheel was introduced.
*Planet-Miata.com - Your #1 source for Mazda Miata new and used parts and accessories.
Edit: this answered my question. Boss changed in 96 when crank position wheel was introduced.
*Planet-Miata.com - Your #1 source for Mazda Miata new and used parts and accessories.
Correct you need the 96 or new boss.
#333
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Tap the hole, I bet it's the right diameter for m6x1 threads. Start tapping it, once it bottoms out, grind the tap flat on a bench grinder. Then tap the bottom of the hole. Kinda ruins a m6x1 tap, but it's still useful for chasing threads and if you're careful creating new ones. Plus they're only about $10.
#334
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The hole should be drilled correctly for M6x1.0. We had to do this on some of the very early BE pumps (like 6 years ago) before Travis started tapping them all at our request.
#335
Originally Posted by curly
Tap the hole, I bet it's the right diameter for m6x1 threads. Start tapping it, once it bottoms out, grind the tap flat on a bench grinder. Then tap the bottom of the hole. Kinda ruins a m6x1 tap, but it's still useful for chasing threads and if you're careful creating new ones. Plus they're only about $10.
#336
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Yes if you can find one that'll work. Generally when you add coating, different tips, or other features like spiral flutes and what not the price goes up.
$1.60:
https://www.walmart.com/ip/WESTWARD-...&wl13=&veh=sem
$17.22
https://www.zoro.com/osg-spiral-poin...Q&gclsrc=aw.ds
$1.60:
https://www.walmart.com/ip/WESTWARD-...&wl13=&veh=sem
$17.22
https://www.zoro.com/osg-spiral-poin...Q&gclsrc=aw.ds
#338
I do not understand the purpose of a spiral point plug tap. A spiral point tap is made the way it is to propel all the chips forward, generally used in through holes only. Using one in a blind hole will lead to tears.
Regardless, the second tap Curly posted is not a hand tap and should not be used as such. It's made for highly rigid tapping machines, it'll break if you look at it funny.
When you grind the point off a tap you need to be sure it's done perfectly perpendicular to the threads, it's possible to have too many thread starts with a three flute hand tap if you grind the end off at an angle. It will shred stuff, quick. I do not like doing it, at all.
I'd just use a normal tap and find a slightly shorter bolt. 1.5x bolt major diameter is plenty of engagement for something like that.
Regardless, the second tap Curly posted is not a hand tap and should not be used as such. It's made for highly rigid tapping machines, it'll break if you look at it funny.
When you grind the point off a tap you need to be sure it's done perfectly perpendicular to the threads, it's possible to have too many thread starts with a three flute hand tap if you grind the end off at an angle. It will shred stuff, quick. I do not like doing it, at all.
I'd just use a normal tap and find a slightly shorter bolt. 1.5x bolt major diameter is plenty of engagement for something like that.
#339
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Bottom taps aren't special or exotic. They are right next to the starter and plug taps for the same price. Grinding a tap flat with out the proper end chamfer is also stupid as it always leaves the last tooth or 2 super thin, and it usually breaks off in the bottom of the hole once it starts taking a chip load.
USA made M6x1 bottom tap for $7 shipped
USA made M6x1 bottom tap for $7 shipped