MrDrezzUp

I have done the heads on that car something like five times, and the valve springs many more times. I purchased/tried a variety of different spring compressors and the one that worked best for me (by a wide margin) was Tim's Valve Spring Tool. It seemed ironic to me that out of all of the different spring compressors I bought that such a simple looking tool worked so amazingly well.

1fastbob

Did the cam bolts actually back out? Looks like to me they broke off. Maybe this was all caused by a bad torque wrench. Maybe the bolts backed out, got caught and then broke off. Please clarify this.

Thanks

Bob

MrDrezzUp

The following pictures were taken after I removed the timing cover and nothing was touched or altered before the pictures were taken. In the first two pictures you can see how far one of the bolts had backed out.

https://picasaweb.google.com/lh/phot...eat=directlink

https://picasaweb.google.com/lh/phot...eat=directlink

After the broken components had been removed from the car I took a picture of the bolts themselves.

https://picasaweb.google.com/lh/phot...eat=directlink

I think the picture above provides a clue as to what happened. The bolts backed out (due to either lack of loctite, or lack of loctite plus possible misuse of torque wrench). As the bolts backed out, the cam shaft sprocket was no longer "clamped" to the camshaft and the camshaft sprocket started riding on the bolt shafts. Zoom in on the last picture and you can see where the camshaft sprocket was riding/wobbling on the bolt shafts.

What is a bit hard to figure out is what was the final straw. Did the camshaft bolts back out far enough that the camshaft sprocket had so much deflection and wobble that everything busted up? Or did the camshaft sprocket ride on the camshaft bolts until the bolts(s) broke? Regardless of what the final straw was, the bolts backing out appears to be the source of the issue.

MrDrezzUp

After rereading your question I think I better understand what you are asking. I think you are asking whether or not it was possible that the bolts were overtightened/strained with the torque wrench, and then broke off because of being over torqued? I do not believe the issue was that they were overtightened. I do not believe they were over tightened for two reasons. The first reason is because of the previous answer I have given (the pictures point to the bolts having backed out). The second reason is because when the bolts were being torqued I remember at the time that very little torque was used when tightening and I was surprised/worried at how little torque was being applied. In hindsight my concern was justified. :-)

nch209

Subscribed. What an awesome thread!!!

1fastbob

I understand...I am contemplating a cam swap and after reading about your situation and viewing the photos I became just a little nervous about the swap. It would not be good to go through all the time, trouble and cost of swapping cams to have it come apart. Somekind of locking plate or special washer or safety wire on the cam bolts would be comforting! I very much appreciate the response.

Thanks

Bob

MrDrezzUp

The cam swap is absolutely doable. Rest easy in knowing that the carnage you see here was caused purely by an error on my part!