Traveling rocker shafts

Craig Stevens · 10-25-2003, 09:53 AM

This morning I pulled the upper & lower valve covers from my stock 3.0 SC to replace leaking gaskets. all the head studs were in good shape,but 4 of the rocker shafts could be moved in & out by hand. tried to tighten them but no joy, The engine was rebuilt, top & bottom about 3500 miles ago, & has leaked since the rebuild. I have had it back to the mech. many times. The engine still leaks from the valve cover area. I found the seals on the rocker shafts to be in good shape. I also found chunks of sillicone rubber . it appeared the the mech tried to seal the end of the shafts with rubber.( the jerk!!) I ordered 4 new shaft assy. My question is, can the cam shaft case be drilled & an allen screw be put in to keep the shafts from walking? Has anyone ever tried this? what repercussions could this cause. After replacing the rocker shafts, each at TDC do the valves need to be adjusted? Craig

john walker's workshop · 10-25-2003, 11:12 AM

the loose shafts have probably worn the cam tower bores to a point where the cam tower needs to be replaced. new shafts probably won't tighten either, but it's worth a try i guess. forget the set screw idea.

Wayne 962 · Wayne 962's Garage

Yeah, what John said - sounds like you need new cam towers.

There are shoddy ways to get these to stick in there, but I don't really recommend any of them...

-Wayne

Craig Stevens · 10-25-2003, 11:29 AM

Thanks, John & Wayne. I have a DE at Sebring in 2 weeks. I don't have time to replace the towers in that time frame. any suggestions for the short term? Can the towers be rebuilt? what are my options for replacement, new ,used? Thanks again, Craig

Wayne 962 · Wayne 962's Garage

No, the cam towers are shot. Short Term ONLY! - take out the loose rockers and rough up the edges a bit with a pair of vice grips and/or a vice. Keep in mind that installing these back into your cam towers will be a one-time thing - the cam towers will be destroyed. However, they are already destroyed by being too loose, so you really have nothing to lose. Use the RSR rocker seals - as that might help them to stay in place a little bit.

I guess you can try your allen screw thing - if you're going to be tearing down the engine and replacing your cam towers immediately after your DE event...

-Wayne

Get ready to do a teardown right after your DE...

Craig Stevens · 10-25-2003, 12:10 PM

Thanks Wayne, I guess I will be looking for a used set of towers. $2000 per side is not in my budget. I am going to try the allen screw tem fix in the intrum with new RSR seals. I will have to check my engine book for th exact sleeve sizes in the tower. when looking for a good used towers Thanks again, Craig

Wayne 962 · Wayne 962's Garage

I have a set of used 3.0L towers if you're interested. One of the oil line tubes is a little mashed, but these can either be replaced with a new one ($40) or you can remove one from your old cam towers. I'm probably looking to get $300 which would include a full guarantee if any of the rocker shafts are no good (these came with a pile of parts that I got recently) and would include shipping as well. If you buy a used set from someone or on eBay - there's no guarantees that they will be good.

These are stored in the back of my garage - let me know if you're interested. I have not inspected them intensely, but they looked fairly good to me (except, of course for the bent oil tube, which was from a rocker breaking, I believe).

-Wayne

Craig Stevens · 10-25-2003, 06:24 PM

Wayne, I am interested. would it be possible to check the towers to make sure they are in spec before they are sent? I will purchase new shafts, gaskets, & the rest of materials needed from Pelican. Thanks, Craig

Wayne 962 · Wayne 962's Garage

Quote:

Originally posted by Craig Stevens
Wayne, I am interested. would it be possible to check the towers to make sure they are in spec before they are sent?

Nope, I don't have time to do that, or even time to take them to my machine shop. I would barely have time to dig them out if you wanted them...

-Wayne

Craig Stevens · 10-25-2003, 06:52 PM

I understand your time constraints. you said that you would guarantee them to be in spec. That's good enough for me. when you have time to dig them out, I would like them. how would you prefer payment? Craig

5axis · 10-25-2003, 10:50 PM

Why forget the set screw idea? It would not take to much to replace the shafts with a hardened pin and then grind a V in the pin for a screw location so that it would not interfere with the RSR seals. The tower would be a easy sine plate setup on a mill.

Wayne 962 · Wayne 962's Garage

Quote:

Originally posted by 5axis
Why forget the set screw idea? It would not take to much to replace the shafts with a hardened pin and then grind a V in the pin for a screw location so that it would not interfere with the RSR seals. The tower would be a easy sine plate setup on a mill.

If you have to remove the cam towers anyways, why not do it correctly? Who knows if the set screws will work?

-Wayne

ChrisBennet · ChrisBennet's Garage

Craig, I wouldn't be so fast to condem your mechanic for trying to seal it with silicone. A mechanic friend of mine uses the "silicone plug" in the ends of the rocker shaft hole for his rebuilds. The silicone can't can't go anywhere.
-Chris

Craig Stevens · 10-26-2003, 03:45 AM

Chris, what upsets me about the silicone is, through out the rebuild no expense was spared. When a part was found to be in question, it was replaced. The engine has leaked through the valve covers since the rebuild. It took 4 months for the first rebuild, & he has had several chances to repair the leaks.If the mechanic would have told me the towers were border line, I would have replaced them. Now the engine has to be dropped again for a top end. I guess what I'm really upset about is the money that I have set aside to build a spare tranny with airport gears & LSD is now being pushed back again. At least I have the resource of Wayne's Engine book to make sure the job is done correctly this time. Sorry for the rant, but it ticks me off to spend top dollar for average work. Craig

Wayne 962 · Wayne 962's Garage

Quote:

Originally posted by Craig Stevens
Sorry for the rant, but it ticks me off to spend top dollar for average work. Craig

Oooh, I can't stand that either. Like going to an expensive restaurant, and the food is horrible. Best way to avoid this is to take the time and do it yourself - that way, you will know it's being done right...

-Wayne

ChrisBennet · ChrisBennet's Garage

Quote:

Originally posted by Wayne at Pelican Parts
Oooh, I can't stand that either. Like going to an expensive restaurant, and the food is horrible. Best way to avoid this is to take the time and do it yourself - that way, you will know it's being done right...

-Wayne

Amen brother!
-Chris