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At Putnam Park last weekend while awaiting the checkered flag and a hopeful mid pack finish, I lost good engine power with a sputter and today uncovered #4 intake rocker broken. This is not new to me but I am sick of pulling the head. I know many have done mods to be able to slide the rocker shafts out front or back and make this a much easier task. Does anyone have a write up or link to advice or a tutorial as to how this can be done?
Thanks in advance.
You can slide the rocker shaft out the front of the head through the holes in the cam gear. We did one at the Glen last year in about 45 minutes between qualifying and race. I don’t know of any write ups, but if you are familiar with the head and know your way around the M20 it should be pretty self explanatory. If you want a lot of detail message me back and I’ll do a write up for you and email privately.
Jeff C.
With some excellent help, we changed intake #4 in 35 minutes (starting with engine steaming hot) at Sebring.
Some folks have punched holes in the firewall to slide back when a front one goes, but we found this approach easy and fast enough that sliding the shaft all the way forward would not have been much more work regardless of which cylinder is affected.
It also does not require that you remove the timing belt, so that saves a ton of time.
The key that makes it easy is to get all the rockers off their respective cams. This takes the pressure off the shaft so that it’s not so hard to drive it forwards and back. Obviously there is no position you can rotate the engine to make this possible, but what you can do is selectively slide the rockers that are binding ‘off the cam’ into the neutral zone between intake and exhaust.
Our procedure was something like this:
[ul]
[li]Remove rocker shaft locating key, radiator and distributor cap[/li]
[li]Pick your targeted cam location (temporary) by rotating engine until the rocker shaft aligns with a hole in the cam gear.[/li]
[li]Determine which rockers are up on their cams and are causing pressure on the shaft[/li]
[li]Remove clips from the offending rockers[/li]
[li]Rotate engine just enough to slide these rockers into neutral zone[/li]
[li]Rotate engine back to target spot[/li]
[li]This should have all the pressure off the rocker shaft[/li]
[li]Using your favorite implements work the shaft forward until you can R&R the broken rocker[/li]
[li]Reinstall rocker shaft, align with key, install key[/li]
[li]Rotate engine as necessary to allow repositioning of the rockers you parked[/li]
[/ul]
Thanks for the help, I will let you know how it goes when/if I get to it in the next couple weeks.
Thanks again