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Broke intake cam during install

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WOTDSM

15+ Year Contributor
167
0
Dec 3, 2006
Detroit, Michigan
Hey guys. I'm in the process of doing valve seal job on my 1G. Got everything back together and I was starting to install the intake cam and heard a loud snap. :ohdamn::notgood::mad:

Busted the intake cam right in half. Luckily my buddy has a spare set of cams from his 1G. We heard a small pop when we were doing the exhaust cam too but there is no sign of a fracture, we're using his exhaust cam anyways just in case.

Should I install the cams without rockers in them, at least the ones that are being pushed open? Or should I keep the rockers in and just do a couple turns per cap till I hit 15 ft.lbs.? Also, should I be worried about using used cams in my motor? I've heard that cams are somewhat mated to the motor that they came in from the factory, since they're scored on the cap surfaces.

Thanks for the help guys.
 
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Just installing it!!! Put the cam in, put the cam caps in finger tight, started turning the bolt on what I thought was supposed to be the first one to start torquing and it snapped.
 
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Wow. Well I'll definitely be more careful with the new (used) one. I wonder if it wasn't seated properly or something.

Do you guys take out the CAS when removing cams? I left mine in. Perhaps that had something to do with it?
 
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Head was on engine.

Lay cam in the seat, install all caps with a few threads engaged, finger tighten the first cap (near #3 cylinder), finger tighten the rest of the caps in sequence, begin to tighten #3 cap to spec, SNAP.
 
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Lay it in the engine and torque from the middle out, after all are turned down till cap is flush with the head. cam caps must be in the exact spot and direction they cam off.
Also torque spec is only 168inch/pounds. About 14/lbs I believe. What are you towering with?
 
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Don't even think about tightening to spec right off the bat. Tighten all the bolts in STEPS, to keep everything even as possible. Do that until the cam is fully seated, THEN torque. It ends up having the same effect as placing 2x4's on each end of the cam then pushing down all in the middle. General rule of thumb, especially with heavy springs involved, but I believe it's also outlined in the FSM.
 
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I promise it happened! I wouldn't benefit at all from lying to you guys!

I think I just put too much torque on to the one cap without stepping the other ones down first.
 
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There is another factor that either you ate leaving out or most likely you are unaware of.

It's possible the cam stick wasn't seated in properly (sitting at an angle) and when tightened caused a stress point.

Did you finger tighten the caps and rotate the cam to ensure free movement?
 
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Well luckily my buddy had a spare set of cams out of his 90.

Thank GOD!!!

Stepped the bolts by one full turn at a time in the sequence laid out by the FSM and it worked just fine.

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PHEW!!! Kind of bummed though that I didn't have to do a forced upgrade to BC 272s! Lol
 
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i would turn it over a few times just to make sure nothing got bent while you have it open to look at everything
 
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I will turn it over tomorrow a few times. What would be the indicator of something being bent?

I did replace both cams with my buddy's set just in case there was a hairline fracture or something.
 
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I'm guessing you dident bleed the lifters before the install which would put more pressure on the cam and when installing caps you have to tighten them a few turns at a time untill all the caps are flush. If you tighten just one at a time it will bend and break a cam.
 
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I didn't do anything to the lifters besides taking a couple out to make room for the spring compressor.

I also primed the oil pump and oil squirted out of all 16 lifters.


***EDIT***
Now that I think about it, the cam was at a hella JDM angle before torquing... That's got to be why it broke.


******EDIT #2******
I got confused about priming and bleeding. You guys meant I needed to bleed the lifters so there was no oil in it so they could collapse when the rockers pressed on them. Got it. I'll remember that for next time!
 
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You really didn't even need to prime the engine for that job, just hit the key and youre good to go. Now you have to worry about a valve being ever so slightly bent.
 
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Why would a valve be bent?!

I didn't really prime the pump... I just spun it with a drill enough to get pressure to the head because the cams I used were bone dry and were out of the motor for 3-4 years.
 
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Wouldn't be just one, would be 4, right? Would be hard to bend 4 valves at the same time while torquing a cam cap. Then again it would be hard to snap a cam whilst doing the same LOL
 
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