suggestions - cam tower oil spray bar needs a slight position adjustment

bigred23 · 07:26 PM

I am at the end of an SC engine rebuild, and made a nice discovery while tightening the oil plug (the one with the small pin on the end) into the cam tower near the #6 cylinder...it wouldn't screw-in all the way! Turns out, the spray bar needs to be shifted ~1/16" toward the flywheel side and slightly upwards in order for the pin to engage the hole at the end of the spray bar.

What am I in for here?!? I am literally in the last assembly section of Wayne's book. Do I need to pull the plug? Is it then possible to 'pull' the spray bar into position from the flywheel side? (I shudder to think about having to disassemble the chain housing, cam, etc. so I could then tap the spray bar into position from the pulley side). Would the spray bar remain in position (it's close) if I were to remove the pin from the plug (aye...cringe)?

Best,
Paul

Flat6pac · 10-22-2017, 02:51 AM

Pull the pin screw and intake valve cover. With a pair of small needle nose pliers you can grab the tube and rotate. Probably once you have the rotational alignment the pin screw will align the tube.
Bruce

bigred23 · 10-22-2017, 09:31 AM

That’s what I was hoping for, but the spray bar fit in the cam tower is tight and will not budge. And I don’t want to press my luck given the tube is soft aluminum...

2jmotorsports · 2jmotorsports's Garage

For clarification in this thread and future reference, when you remove the spray bar plug, is there something keeping the spray bar keyed/clocked in the correct orientation?

bigred23 · 10-23-2017, 04:14 PM

From what I've read, it seems some spray bars are quite 'easy' to maneuver around in the cam tower (without threaded indexing plug installed), while others (including mine) can be quite tight. So, to answer your question, and as originally designed, the indexing plug needs to be in place for the spray bar to stay in position.

In my situation, I will likely have to remove the small aluminum end plugs from the cam tower in order to tap out the spray bar and reposition so that the original indexing plug can be installed properly.

KTL · 10-24-2017, 10:14 AM

I think the tubes are originally "glued" in place after installation. I've handled a number of these cam housings and many of them have shown a brown (probably oil stained) material around the locations where the tube passes through the housing. Some of the tubes i've removed are quite difficult to get out and the tube gets a little scarred when coming out. I also feel like there's opportunity for leakage around these passages after the tube has been disturbed, so I only take out the tubes if absolutely necessary.

When I reinstall the tubes, I make sure of the clocking position and use a drill bit or a hex key thru the large cross-hole near the end of the tube to maintain the clocking as I tap the tube in. As the tube goes deeper and deeper into the cam housing, there's more tube surface area in contact with the housing and that makes it harder to turn. So by the time the tube is nearly all the way in, it can be quite difficult to rotate.

So I have to agree with your perspective in that you should remove the aluminum end plugs and drive the tube out. Not what you wanted to hear but it's the safest way to go. If it turns out that you have trouble with the tube and it gets damaged, let me know. I have a few of these tubes (and valve cover studs) that I pirated from junk housings that were damaged beyond repair and were donated to people needing them for making a cylinder head machining fixture.

bigred23 · 10-24-2017, 01:43 PM

Thanks, Kevin. Would you recommend applying glue (red loctite, or similar) around the areas where it is hidden inside the housing once the new spray bar is installed?

And if there is more clearance between the spray bar and housing without glue, is oil bypass a concern? There would be no leak paths so that oil would get in the non-oil areas, correct?

cgarr · cgarr's Garage

The (glue) might be the 574 from what I have seen of spray tubes.

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KTL · 10-25-2017, 07:48 AM

Yep Craig brings up a good point. The brown does look like really thin 574 orange sealant.

Problem with applying sealer here is that there are a few places where the tube is really hard to reach where it goes thru the housing. I don't know how they were originally sealed at those locations. And i'd be afraid of possibly plugging up the oil delivery hole if you apply it to the tube before it goes into the housing

The oil bypass concern is more about losing oil that should be getting to the bearing bores or the pin holes that squirt the rocker arms and valve springs. Because oil lost there is not leaking into anywhere the oil shouldn't be, as in a dry area. It's just that it's not being directly delivered to either the cam bearings or the pin holes.