cam spray bar plug replacment
 

After removing the press fit plugs for the cam spray tubes and cleaning them I decided to replace the press fit plugs with threaded pipe plugs.

I used 1/8" NPT plugs. The hole is perfect for this tap size, no drilling was required.


http://forums.pelicanparts.com/uploa...1133672435.jpg


http://forums.pelicanparts.com/uploa...1133672476.jpg


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Thanks, Al. Great pictures!

Mike

Nice Alan, good to know:)

Alan,

What did you use to seal them with?

I used blue thread locker to seal the threads.

they're a tapered plug, so I took my time with the tap and made sure to only tap the hole deep enough to sink the plug just past flush. the plugs are very tight. I just used the thread locker for added protection.

Alan,

Thanks. I am just about to remove the plugs and clean the spray bars. I have done the regular plugs before, and I have the plain plugs at the ready, but the idea of being able to pop them out at some future time is intriguing.

That is really neat,
something that I have to do in the near future, thanks for sharing

Regards,

Jakes

Great idea! I've got an old cam tower I'll have to try it out on.
-Chris

I have been telling this to every one for years........I just get no respect around here
.Seriously its the best deal since dehydrated water !!

yes...I must give props to afterburn, he gave me the idea.

since I tear my engine down every other winter this was the only solution that made sense.

you will just luv it if you ever have to plull a tube in the car !!!

I can see the utility of this immediately; especially during the cleaning stages of a rebuild of cam-towers and heads! I will implement this trick on the 3.0L and 3.3L I’m currently rebuilding.

Thanks for sharing the great tip…

munchovie.

Did you do both ends?

can anyone tell the process of how to clean out this tube/spray bar?
probably need to remove BOTH ends of the tube to spray some solvent in there and then blow hi pressure compressed air thru the tube??
Bob

I'm going to drill and tap both ends then use my hoppes gun cleaning kit on it!

munchovie.

This was done on mine many years ago. I just finished a full on rebuild, and even after I had the cam towers professionally cleaned, I pulled out coked oil that was about the size of a quarter. Many people also use this to flush the spray bars while engine is still in the car.

I did both ends of the tower.

Be VERY carefull with the tubes and espically when drilling out the plugs. The tubes are VERY SOFT!!!! Also... the tubes are held in place by the oil hose fitting. Those must be removed to push the tube out.

DON'T USE ANYTHING ON THE END OF THE TUBE TO TRY TO PUSH IT OUT! You should be able to reach into the housing and grab the tube with your fingers and slide it out far enough to pull it out.

Hey Big Al,
did you use 1/8" drill to remove the plugs? If not, how did you remove the plugs? I just looked at my tower and man are these cap/hole area small!! They look pretty frail also??
did you drill the hole to a particular size before threading the hole?
what size tap? 1/8"?
is the threaded insert called a 1/8"NPT plug? so I can get the correct one at the big box?
Thx for answering some of my dumb questions, I just don't want to screw this up and ruin the spray bar pipe.
Thanks again for your help!
Bob

I just thought of another dumb question...when I remove the spray bar, in case it has become miss directed a/o wrongly installed, can you tell me where the spray bar holes need to be pointing, as in what/where should the oil be pissing on? the area where the rocker rides on the cam lobes?.
Bob

Cleaning the spray bar orifices takes a little patience. I took a pin (smaller than the size of the orifices), made a 90 degree bend about 3mm from the tip. Took the new tool and inserted in every orifice and turned the little arm on the tool around the inside to break off any sludge/coking that may have caused restrictions. Blew the tube out with injector cleaner, followed by compressed air. Then I soaked the spray bars in a solution of Dawn detergent and water. Sit for a few hours and have a beer or two, rinse the spray bars with water. Good as new!

The orifices should be pointing down towards the head. There are only two ways the spray bars can line up, orifices pointing up(incorrect) or pointing down(correct). When you are looking down on the cam tower, you will see plugs where the towers are drilled for the oil galleys the feed the camshaft bearings. First off, you must be sure to insert the spray bar into the tower so that these cam oil galleys line up to the orifices on the spray bar for the cam bearing orifices. Secondly, you must make sure the spray bar aligns properly so that when you reinstall the bolt/locating pin at the rear of the cam tower aligns with the hole in the spray bar.

Spray bar installation tip
 

Sorry if this is a little late, I had difficulty finding these photos.

This shows how to line up the spray bar. Note the holes in the tube, and the chain housing plugs. The plugs cover the hole which was drilled in the housing to get oil to the cam journals. If the spray bar holes are aligned with the housing plugs and the end hole in the bar is facing outward, there is only one way the bar will fit properly.

http://forums.pelicanparts.com/uploa...1197386546.jpg

Hope this helps.....

This way:

http://forums.pelicanparts.com/uploa...1197386625.jpg

NOT this way:


http://forums.pelicanparts.com/uploa...1197386703.jpg

Single holes up, double holes down.

http://forums.pelicanparts.com/911-engine-rebuilding-forum/180548-spray-bar-orientation.html?highlight=spray+bar+holes

Jim, those are good pictures of the big holes that feed the cam journals.

Are those plugs in the holes that feed the journals? Or is that a vestigal casting boss left over from centerlube?

thanks a lot everyone!! I will practice on a old tower first and see how it goes.
Many thanks here!!
Bob

Tweaks

Buy a 1/8" NPT pipe tap.

Buy 1/8" NPT pipe plugs. You can get them in iron, brass, or aluminum. I worry that aluminum plugs will be hard to remove (I had that problem with engine oil galley plugs), so brass seems a reasonable material.

To remove, drill a small hole that you can tap for a small machine screw. You aren't trying to drill out the plug, just create a way of grabbing it. And you aren't using your 1/8" tap either. You do have a metric tap set, right? And a junkbox with, say, 5mm bolts/machine screws?

I suppose you could use a slide hammer and your small machine screw. However, it is easy enough to make a puller. a) a socket or other short tube whose inside will clear the plug. b) a suitable washer or washers. c) a long enough machine screw. c) a nut for the screw.

Screw the nut onto the screw. Slide the washer on. Put the socket over the plug and insert the machine screw and screw it into the plug. Spin the nut down until everything is tight.

Hold the head of the machine screw fixed, and with a wrench tighten the nut. It should pull the plug out and into the socket. When things fall off you are done.

Maybe there are other, better, ways of doing this.

Walt Fricke

thanks Walt! Your timing is perfect as always since I plan to tackeling this experiement tomorrow as long as the christmas party this afternoon doesent get out of hand if you know what I mean ;-). Power tools with a fat hang over head usually dont mix well.

I will p/up some brass plugs today and go to sears to use an old gift card and hopefully they have slide hammers. It is amazing that I have been buying tools for the past 30 yrs and EVERY fix-it or repair job could and probably would/does come out better/best AFTER I buy another new tool. What happens to the guys that dont proceed as I do? Maybe they are more lucky than I and or more talented OR they already spent the fortune on tools...

I will post pics of my hopeful attempts tomorrow on this doing.

Bob

John,

Those are definitely plugs in the holes that were drilled though to feed the journals...... Two such holes for the 4-journal cams, only one hole for the 3-journal cam housings.

cam spray bar plug replacement
 

just received my plugs from mcmaster-carr.
1. I couldnt find from the thread whether to use the 6k psi steel plugs (shinney one on the right of 1st pic) or to use the 302 stainless steel ones?
2. The stainless ones were $0.50 ea. & the 6k psi steel ones were $1.05 ea.
3. I am also wondering which is the "stronger" metal so hex wont strip out? I don't recall being able to find a metal hardness spec but these looked like the best choices. The McMaster-carr part numbers are: Steel p/n 50925k231 & stainless p/n 4464k561
4. Which ones did you guys use and did you use any "goop" to prevent them getting stuck in cam tower so we can service the tube at a later time?
Thank you
Bob

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It may be different on different years and models.

I have an '87 930 and the only cam spray bar holes I can see with the motor in the car are pointing straight up.
Alot of oil shoots out of them... I mean with a cold motor just cranking on the starter motor a straight 1/8" thick stream of oil will shoot about 6 feet or more straight up in the air...
With the rocker cover on the oil stream bounces/ricochets or splatters off the inside of the the top rocker cover which is angled in such a way that the oil then splatters all over the valves, rockers, and cam lobes.
There may be more holes in the spray bar that I havn't seen though.

As far as flushing the spray bars to remove small coffee ground sized coked oil chunks that clog the holes... (this is common on a turbo that has had dino oil run in it)
I've never removed them, but you can flush them out so easily while they are in the car by simply removing the 17mm plug at the firewall end of the cam tower and putting some polyvinyl or rubber hose into the threaded hole that fits snugly and running it through the air pump hose hole or any other hole in the engine pan into a container under the car.
Next use a pin to dislodge any carbon particles that may be lodged in a spray bar hole, then crank the motor over on the starter motor and alot of oil will flush through the spray bar taking any junk with it and out the hose into the container under the car.
You can start it and let it idle too. In about 15 seconds of idleing you'll pump around 2 quarts out the end of the spray bar through the hose and into the container under the car.
I still have around 4bar of oil pressure at idle with a cold motor while doing this so low oil pressure while doing this is not a concern.

Then take the oil that you have collected and filter it through something or just let it sit long enough for the carbon particles to settle to the bottom, and carefully pour it back into the oil tank watching for the carbon particles at the bottom so you can stop and not pour them back into the engine oil.

This process takes very little time and works very well.
Afterwards I slide the cleaned top rocker cover back on the studs and crank it on the starter motor for a couple seconds, then go back and remove it and check to see the 3 oil patterns on it where oil shot straight up and bounced off it.

Here's a pic of the clear vinyl hose I used in the hole, the 17mm plug with locating pin that goes in the hole, and the oil pattern on the inside of the top rocker cover while I did this a few months ago.

hope this helps.
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Ok, I'm attempting this on a damaged tower. It took me 5 stops at hardware and auto parts stores just to find brass plugs. You can not use brass it will strip the allen head long before the plug is flush, about half way in the plug gets tight. I've ordered some stainless steel plugs from McMaster. Threading the hole I tried free hand, not a good option, as it threaded at a bit of a angle. Do you use a drill press or mill?

NPT threads are tapered. You must tap deeper to get the plugs to fit both tight and flush. If your plug is tight before the plug is flush then pull it out and run the tap a bit more. keep going little by little until the plug is flush and tight.

I got it, the tap is tapered not the plug (no I'm not a plummer). Successfully threaded and plugged the other side of test tower I moved on to an extra tower and threaded it also. I reamed the hole with a 21/64" drill bit and I used a port-align to start the tap. The threading leaves a burr at top I just used a de-burring ball to clean it. The brass plug could be used but if it gets to tight over time could be problem to remove so I'll use the stainless ones.

smart move as I used the stainless ones too as I posted above...

Thanks for posting that part number on the plugs, I didn't have much luck searching there site for the plugs.

bag on the right...302 ss...good luck!
Bob

Questions on a 11 year old post...

I'm thinking about using threaded plugs. Is using stainless plugs ok given the different expansion rates.. Several people have used them so at this point I would think someone could chime in.

If I go forward will these plugs and tap do the job?

https://www.amazon.com/Century-Drill-Tool-95201-Plug/dp/B004UUAMK4

https://www.amazon.com/Metalwork-Stainless-Steel-Fitting-Countersunk/dp/B07DDN298N

Gawd, has it been that long already?

Regarding any application to the threads.....I would use an anti-galling lubricant and NOT a sealer. Sealer might migrate from threads into tube when installing the plugs.

Here's another site that may have what you're looking for...
https://www.mcmaster.com/

Anti-galling lubricant such as?

I used Permatex, Aluminum anti-galling , anti-seize lubricant sparingly. US Part Number: 80078

Spray bar pipe plug at 3 o'clock:

http://forums.pelicanparts.com/uploa...1617997778.jpg

It's a 1/8" NPT plug. The required tap drill is specified for the plug size. Can look up.

Sherwood