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Discussion Starter · #1 ·
The no compression thread was getting long and i wasent getting any replys so I added this new thread.
The Pin on the front cam has sheared off. Does anyone know if this is replaceable?? Can you drill it out and replace it. Does the Whole cam have to be replaced???
 

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Alot depends on the amount of damage. If the camshaft registration hole has been opened up or elongated, you might be into a new cam. Ditto the pulley. Get a machinists opinion; they may be able to fabricate an insert to repair the damage.

Question is, what caused the pin to shear? The only other time I can recall this happening happened to Michel Fortier: he dropped a rag into the cam gears on the front bank (don't recall how he did this or why the engine was running with the cam cover off) and did a bunch of damage, including shearing this pin off. But that's because something got caught in the cam gears. Under normal conditions, this should never happen. Any chance there was an oil starvation problem? Have you taken the cam out of the head yet? If so, what do the journals and cam bores (in the head) look?

I asked about oil starvation because a seized camshaft might cause this...
 
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Discussion Starter · #3 ·
She was low on oil but not over heating...and not OUT of oil ..It died on an on ramp from one interstate to another about 40mph
Havent pulled the cam..but what I can see with the cover off dosent look bad.
I can drill out what is left in the cam end (I have a 90 deg. drill) but the ? is can I get the pin.
Damage to the pulley/Sprocket is very slight..almost not noticable.
 

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chuck46 said:
but what I can see with the cover off dosent look bad.
Yes, well... whats bad wont be seen until you pull the camshaft out. if the camshaft has indeed siezed, the cam journal has "melted" to the bearing. the engine doesnt have to be "out of oil" for this to happen and the heat that causes this may not even reach the temp gauge which gets its input from the coolant temperature sensor. in fact, i wouldnt even expect it to.

damage to the cam gears is minimal? thats good. hows the belt? also when (and if) you pull the cam, expect a bearing (or two) to stick to it. it might be on ther so good that you cant get it off with your hands. if it doesnt come off easily, dont force it... bearings and rings, etc. can be sharp...
 
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Discussion Starter · #5 ·
The cam hasn't seized. It was turning earlier when I was trying to figure out this hell of a problem. If anyone else has had this problem (pin shearing) let me know what you did to solve this. I'm still wondering if I can fabricate a pin to fix this. Also, as for the timing belt tentioner piston arm, I've heard from a mazda tech that if you can push in the piston with your hands, it is bad. Does anyone know if he means all the way in or just at all.
 
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Discussion Starter · #6 ·
$%#%^&^%$$!$&%^#$%#$%!!!!!!!!!!!!!!!!!!!!!!!
Well, today I pulled the front end cap and low and behold the camshaft melted to the head!!! turns out the hole that provides oil to the end of the cam (behind the sprocket) clogged up and starved the cam of oil. Obviously, the previous owner must have hated his MX.( I've had this car for only 3 months) What do you guys think, a new cam and head or a new KL-ZE! Does anyone think it will be worth it to replace the head and cam or do the full switch.
 

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i would say P&P or extrude hone the heads and throw in mild cams. the ZE will give you about the same. the only thing it gives you on the bottom end is 10:1 (and arguably stronger pistons/rods, but no one has proved this yet... so ive read). These mods will also make your intake function better...
 
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