?- Locking DOHC cams before head removal.

[94.GT.Wagon]

I'm doing head gaskets on the '97 GT that I just bought and this would be my first adventure this deep into anything other than american pushrod V-8s. First question, is it absolutely necessary to lock the cams before removing the timing belt and unbolting the heads? My gut tells me yes, but some of the pics I've seen in other threads show mostly built engines with no timing components on them yet and no obvious signs that the cams are locked in place. Second question, is there an effective shade-tree method for locking the cams without buying the expensive purpose-built tool? I'd thought about buying four really cheap sockets to fit the cam sprocket bolts and then welding a bar between each pair to keep things from turning. Thanks in advance for your wisdom.

[gijonas]

It can be done without the special tool.However your socket idea sounds pretty sweet,i would make a couple of those and keep them around!!

[fishbone79]

Yeah, I kinda like that socket idea... simple and effective.

[wtdash]

I don't see it addressed above, but yes, lock the cams or you might bend a valve.

I have heard that one side/head can be 'positioned' so it doesn't need locked and is not under tension, but don't quote me on it.

If you don't find a write-up here,
RS25.com, www.ultimatesubaru.org/forum/, and NASIOC.com probably have a thread on this.

EDIT: Found the link: http://home.comcast.net/~skipnospam/Hea ... ement.html (scroll to the bottom to move to the next page)

He mentions how to do this so the cams don't move.

[Matt Monson]

There's no reason to lock the cams as long as you bring it to TDC before you take off the tensioner and timing belt. Just keep your fingers clear of the cams as the loaded ones have a tendency to snap shut. If you search deep enough you'll find pictures of what my pinky looked like after it rolled between a couple of cam gears.