ok so I was installing new cams in my head and i was tightening the caps as directed in the service manual in 3 steps, well as i was tightening one of the bolts striped out, it didnt break off but actually stripped out the aluminum. I was using a torque wrench that reads in inch pounds not ft pounds just wanted to clear that up before someone asks.
question is, how would you go about fixing it? i was going to find a new head but I all ready have had this head machined for oversized valves and milled.
#130115, "RE: cam cap problem" In response to Reply # 0 Mar-22-10 06:08 PM by CODE4
Some of the more experienced guys will hopefully chime in on this, but I highly recommend using a Timesert over a helicoil. Much stronger & more reliable.
You could probably drill and tap the AL for the next size up (and drill the cam cap too).
What hole is it? An M6 or M8 bolt? I assume your head is already torqued down, so in the interest of keeping it there you could perform the repair there however make sure you are VERY careful to clean it up and remove any metal while working. Any stray shavings are dangerous.
Did you run a thread chaser through everything after the machine shop had it?
Additionally this is another reason I suggest using studs in any parent material of aluminum.
#130116, "RE: cam cap problem" In response to Reply # 1
the head isnt on the block yet because of this issue, i figured it would be way easier to fix off the block, its a m6 bolt the smaller one, i asked my shop guy if he chased all the threads and such and he said yes, i was assuming the bolt itself was damaged some how and caused it, either way......i gotta fix it.
i figured a helicoil would work fine seeing they are not torqued down that much i dunno i gotta figure out the size hiliciol i need and stuff yet too.
i need the bolt size pitch but cannot find it in any of the service manuals i must be missing it some were
#130117, "RE: cam cap problem" In response to Reply # 2 Mar-22-10 06:30 PM by CODE4
Once again I need to provide thread pitches and lengths.
DOHC Cam Caps - M6 x 1.00 x 35 - Qty 18 DOHC Cam Caps - M8 x 1.25 x 40 - Qty 6
Now I have a question for you - why were you torquing down the cam cap if the head was not installed?
And the Timesert is as easy to install as a helicoil, but much more reliable.
Originally posted by donnyb373 i was assuming the bolt itself was damaged some how and caused it
If you are performing a rebuild and reusing any hardware you need to examine the hardware as if you were a gynecologist. Otherwise you end up in situations like this, and spend more money getting yourself out of it.
#130118, "RE: cam cap problem" In response to Reply # 3
i was installing my custom grind cams, i dont need the cams removed to put the head on, got to love studs over bolts just cause of this. its how iv always done it this way i can install my intake manifold before i put the head on just to make it faster/easier
#130119, "RE: cam cap problem" In response to Reply # 4 Mar-22-10 06:38 PM by CODE4
How are you torquing the head down with the cams installed? Last I checked you could not accurately torque the head bolts (or nuts if using studs) with the cams installed. Installing the IM to the head has nothing to do with installing the cams prior to torquing the head down.
Additionally, if you had searched for the cam shaft cap bolt specs you would have found this post:
#130120, "RE: cam cap problem" In response to Reply # 5
iv done it this way using the moly lube and i always torque down to 85 ft # and after a couple hundred miles i go back and check and they are all torqued down fine.
#130121, "RE: cam cap problem" In response to Reply # 6 Mar-22-10 07:02 PM by CODE4
Maybe I am not being clear enough: how are you accessing the head bolts with the camshafts in place? Did you cut down a socket to fit? The camshafts are in the way of gaining direct access.
#130127, "RE: cam cap problem" In response to Reply # 8
Originally posted by donnyb373 using a hardened socket and a swivel i have no problems whatsoever
Yeah, the swivel takes some of the accuracy out of the torque number (depending on angle of swivel point etc. it will change the number. As well as the loss in the "mechanism" itself).
I use heli-coils in the cam cap hole (product of using old used heads). Be sure to use loctite on the coils and let it set before putting in the bolt.
Captain Caveman
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