Cam Walk/Cam driven water pump

[bubbletop409]

I asked this question over in "Gear Head" but got no answer, so maybe one of you sharpies over here can help me. How do you prevent cam walk with a roller cam, when using a cam driven water pump? The drive tang for the pump is mounted where roller thrust bearing would normally go. Thanks for any suggestions.

[flattie]

You will have to shim between the cam and the drive. Check the end play with the water pump installed and then shim it as needed

[DetroitJim]

I've been running like that for years, just had to machine the tang and shoulder for the right clearance. No issues at all.

[ol guy]

Install a thrust plate. Then shim accordingly. That machined area at the front cam journal with two threaded bolt holes has been there since day one of the Mark -Five motor. Roller cams are prown to want to unscrew out of the block. Some motors never show a sign and some will drive forward. It depends on the ential machining of the block and what G.M. calls core shift. Best thing is talk to a cam grinder (and not some phone jockey ) and get a PRO'S idea on the correct cure. My 2-cents with change back. Mark

[bubbletop409]

Thanks for the suggestions guys, any other ideas? I knew the Mark IV blocks had the extra holes next to the front cam journal, but have never seen a picture of how that type of retention works.

[ol guy]

If you can find a picture of a ford big block that will splain how a thrust plate works. Ford saw the problem years ago and nipped in the bud buy designing the t/c and cam set up to deal with it before it became a problem.

[2manymustangs]

Can someone tell me how the water pump drive for a 460 ford works since there is only one screw that holds the fuel pump elipse/timing gear on? I haven't found any photo's yet and the chebby pics show that three screws hold it in place. I am wondering what keeps the water pump drive from spinning since it only has one screw to hold it on. I'm assuming that it can be used in conjunction with a fuel pump elipse.
Cam walk on a ford is not an issue, all thrust issues are contained by the front cam retainier and the shoulder on the back side of the timing gear. When the timing gear retainer is torqued up there is a controlled amount of end play (front end of cam, back side of timing gear) since the thrust plate is sandwiched between the two.

[sangervdrive]

I've been running like that for years, just had to machine the tang and shoulder for the right clearance. No issues at all.
Same thing that we did.