FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: fairlaniac on August 01, 2019, 06:28:02 AM
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I have my '66 427 block I'm prepping and thought I change the welch plugs to NPT plugs. I might be able to set the block up on my drill press to get the front and rear plugs drilled. However the ones in the galley may need to be hand drilled. Never doing this before, can it be done with a hand drill? I have a junk '59 block I plan to try first to get the feel. I'm just picturing the cast iron wanting to chip or break away using the hand drill. Any tips from anyone who has actually performed this?
Thanks,
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Doug, all you need is a hand drill. The drilling is easy, tapping is a little more difficult, but only because you have to pay attention to depth with a pipe plug. Make sure the one behind the distributor is deep enough to not snag a distributor.
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I've seen where some people say to drill dry? I've always used cutting oil when cutting most metals. I would plan to do so unless convinced otherwise.
So not to create a huge debate on the plug behind the distributor. Due to the "trickiness" I plan to keep it a plug.
thanks,
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I've seen where some people say to drill dry? I've always used cutting oil when cutting most metals. I would plan to do so unless convinced otherwise.
So not to create a huge debate on the plug behind the distributor. Due to the "trickiness" I plan to keep it a plug.
thanks,
A little more info than what you asked for: ACE Hardware has the plugs, long tap and long drill bit to do a full oil galley modification. Personally I have used an old 18 volt Snap-On drill and WD40. My corded drills tend to grab. On that valley plug right behind the distributor I tap it about 1/8th turn at a time. The FPP procedure cautioned against distorting that area. I have only done 4 but the last two did not get the main to cam galley drilled or beveled out.. A few guys have said that is a weak area and they prefer to open up the bearing if they do anything.
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I'd buy a new tap for the job and definitely use oil. Tapered NPT taps can be a bugger if they're not sharp.
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I shop at www.mcmaster.com and get a work discount :-) I have 6 new 7/16" drill bits and 2 new NPT 1/4 taps. I agree, never use old dull bits or taps on "critical" work.
thanks!
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Doug , if your concern is the drill grabbing and pulling you to deep or worse breaking, just put a small flat on the cutting edge in the flute. Tapping should be no big deal, a tap handle gives you better control, but sometimes a Tee handle gives you better room to work. If you mark your tap so that you’ll leave about 7 threads (5 threads on a worn tap) above the hole that should get you in the ball park.
I have a 62 solid lifter block and my concerns were in the valley going down to #5 main with that dog leg so I just left mine alone with welch plugs and a couple of stake marks on them
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I hand tap in cast iron blocks using Tap Magic. If a bit of drill work is required, same fluid. Just work the tap easy and test the plug for depth periodically.
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Ranch, please tell more about the small flat method for keeping the drill from grabbing. What do you use to make it a file? Sounds like a very useful piece of information.
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Drill bits are too hard to file, best to do it on a bench grinder with a wheel that has good square corners. Basically it reduces the effort of the drill bit pulling itself into the metal, works great on cast iron and is a must do for brass and other like metals.
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It makes a much nicer job to use piloted core drills. The pilot centers the bit in the oil passage, and when using a hand drill, it will follow the drilled hole. Your larger hole will be centered and straight. You do need to check your depth as you are tapping. Be sure to clean really good and put some anti seize on your pipe plug for the depth check. If you are dry and get debris in the threads, it will lock up and make real problems trying to remove it. It takes a while to do it right. Don't attempt to run a pipe tap into the 9/16 straight thread in a 427. Those plugs are the same as the front lifter plugs in a 460....... easy to get.
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Be sure to clean really good and put some anti seize on your pipe plug for the depth check. If you are dry and get debris in the threads, it will lock up and make real problems trying to remove it.
Best tip right there. You do this wrong one time and you'll never do it again.
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A suggestion; or rant even :)
Typically the "hole" for a pressurized oil gallery in an engine block would be tapped with a NPSF (straight,fuel) tap and the plug would be a NPTF (tapered, fuel) This to automatically set the plugs at a specific depth, including flush if desired.
The "plugs" are special "fuel, dry seal type" and available in several profiles (regular, short, and SAE extra short) and two different tapers 3/4" per foot or 7/8" per foot depending on the desired protrusion.
The correct taps and plugs are easily sourced, but they will never be in a "hardware store". The tap drill sizes can also vary from plumbing stuff depending on the finished tap size, best to check this carefully.
The pilot drill suggestion from CaptCobrajet is great...
This is not water pipe threads... the thread form is completely different.
more here https://www.huyett.com/getmedia/3dedc73c-15c5-4828-9a13-73316622d6ba/GF-ThreadDesignGuide.pdf.aspx?ext=.pdf
Although it can be made to work, in my opinion a good way to screw-up a good block is to use hardware store water pipe taps and plugs...
(Cast iron is machined dry, there is enough graphite in the alloy to work as a lubricant. Using lubricants to tap cast iron can lead to interference or jamming of the tap).
Edit for clarity;
These are all considered "pipe" threads and there are many variations.
An explaination of the difference between "water pipe" and "fuel" thread forms is well explained here.
https://www.ring-plug-thread-gages.com/ti-NPT-vs-NPTF.htm
The difference being the very tip of the thread form having a different interference than the taper itself and a difference in precision, or class fit.
(In production work it can be impractical to form a tapered thread to a specific depth. A 1/4 revolution of the tap will be a much greater difference in plug depth. Expensive to control that when you are doing hundreds in a day. Hence a uniform dia straight thread female, and a tapered male plug.)
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This is not water pipe threads... the thread form is completely different.
more here https://www.huyett.com/getmedia/3dedc73c-15c5-4828-9a13-73316622d6ba/GF-ThreadDesignGuide.pdf.aspx?ext=.pdf
Although it can be made to work, in my opinion a good way to screw-up a good block is to use hardware store water pipe taps and plugs...
(Cast iron is machined dry, there is enough graphite in the alloy to work as a lubricant. Using lubricants to tap cast iron can lead to interference or jamming of the tap).
That is actually good advice assuming someone would walk in and pickup the first thing they see. Best to have a machinist pick it out for you if your not sure. Survival used to have the plug kits. I wouldn't remember the correct names of the Allen head plugs I used, my last one was 5 years and 23,000 miles ago.
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C6AE,
Thanks for the excellent info. I didn’t know any of that about the type of threads and plugs used in engine blocks. That’s what I love about this forum. There are a bunch of members with vast knowledge of relatively obscure but totally relevant topics.
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Amen to this forum of gurus. I'm almost 74 and still learning- that's why I visit here all the time and ask sometimes stupid questions because I know someone will set me straight.
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There is your plug kit. Ford used pipe, not fuel threads. I used WD40 as a lubricant for the drill. My Milwaukee will break your wrist if you don't keep a hold of it.
Here is the plug kit. -Keith
http://stores.precisionoilpumps.com/ford-fe-390-428-427-oil-galley-plug-kit-iron-390-cj-lr-heads/
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When your block comes back from a good washing out and you go to place your plugs. I would use a dab of Loctite 567 Thread Sealant or Teflon Tape. In either case don't let it get on the face of the plug that's in the block I usually stay a good one thread back with either, you don't want any contamination getting loose in your oiling system. If you sharpen your drill like I mentioned you shouldn't worry about it grabbing. Lubing your drill and tap in unnecessary, a little air pressure to clear any chips is all you should need. Take your time and when your done you'll say to yourself "that was easy" :)
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Thank you all.
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I happen to be doing this work now. When I run a steel rod through the main oil galley, it hits some obstruction near the middle. I haven't done this job for quite a while and I do have a long drill bit so is it recommended that I run this bit in and get rid of the "step" or whatever that is in the middle of the galley?
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When your block comes back from a good washing out and you go to place your plugs. I would use a dab of Loctite 567 Thread Sealant or Teflon Tape. In either case don't let it get on the face of the plug that's in the block I usually stay a good one thread back with either, you don't want any contamination getting loose in your oiling system. If you sharpen your drill like I mentioned you shouldn't worry about it grabbing. Lubing your drill and tap in unnecessary, a little air pressure to clear any chips is all you should need. Take your time and when your done you'll say to yourself "that was easy" :)
I did electrical work in the oil industry during the summers with my father. Arco/Shell/Chevron. I used to thread heavy pipe. I know you're a millwright so you know what I speak of. I have always used a lubricant primarily because iron is brittle by nature and time and heat cycles just make it worse. What I was told by builders in the past like Greg Forman and others was that never use pipe tape on the plugs as often it winds up in the oil gallery and ingested through the engine. I have always used the liquid PTFE sealer. As far as the chips I also use a magnetic extendable pick up tool to help collect the chips then I use hot soapy water , a rifle cleaning rod and a .50 caliber brass bore brush. I scrub the hell out of the gallery with the brush and soapy water and then use a high pressure hose nozzle and blow water through it. Then I do it a second time.
Cleanliness is next to Godliness when it comes to cleaning a block. Any remnants will likely wind up in the bearings.
-Keith
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I happen to be doing this work now. When I run a steel rod through the main oil galley, it hits some obstruction near the middle. I haven't done this job for quite a while and I do have a long drill bit so is it recommended that I run this bit in and get rid of the "step" or whatever that is in the middle of the galley?
I assume you're referring to the top center gallery? There is a restriction cast in the gallery that diverts oil to the lifters. Some drill them out as it also supplied the #5 bearing at the rear of the block.
Keith
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In regard to the 'step' in the MIDDLE of the gallery, it's there since the production machining of the block was done from both ends with the drill from each end going half way. It is very worthwhile to look through the gallery and if there is significant mismatch, take the time to use a cutter that'll straighten things out.
Here in the Detroit area, I was lucky to find a cutter source that was winding down and selling out. I found several reamers that were a close-enough diameter and the owner cut the ends to make them work for just this purpose. Since they had straight flutes there was no 'pulling' at all but they were very useful for correcting mismatch. Go for it!!!
KS
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Keith, I'm know what you are saying about Teflon Tape and that is a good rule for the inexperienced. So that is why I replied that you start at least one thread back and of course you have to wind it around in the correct direction. I retired from a local refinery and most if not all pipes we threaded were Steel, black iron pipe is nothing more than a steel pipe with black paint on it. When you were threading pipe in a rigid Pipe threader they have a cutting oil supply to the dies, did you notice how the chip from cutting was 'stringy', that's steel, if it flaked off in tiny little chips that is cast iron, and you don't see much of that any more. Pipe wrenches leave their teeth marks in steel where as a wrench can break cast iron, you've seen chain pipe cutters? works good on cast iron but not on steel. Soil pipes in older homes have cast iron (no pressure)
All machine work should be done before a thorough cleaning and that includes drilling and tapping. and you are correct about clean, No such thing as too clean.....JMO
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Thank you Keith and KS. I can get a rifle cleaning rod through it no problem so there can't be much of a mismatch. My larger rod that almost fills the entry hole won't go though. I will study it more closely then decide what to do.
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I don't know how much help I was. However, working with iron and doing the plugs three times on FEs. You'll notice that if you elect to make the changes by drilling out the oil passage from the adapter to the pump that the iron turns almost to a powder. Even with a tri-flute bit it still bites a little bit. Step drilling helps some. Just make sure you use hot soapy water and scrub the hell out of all the galleries when you're done. Like I said, I use a small magnetic pick up to clean up some of the large chips as I work. Bore brush, hot soapy water. WD40 or CRC equivalent. Machined surfaces. They flash rust, even the lifter bores.
-Keith