Drilling and tapping a hole
 

Help me settle another breakfast table bet with Don.

The question is this:

Laying aside the issue of access, would you consider yourself capable of drilling and tapping a hole in an engine component and willing to undertake the task for some reasonable benefit?

Bill

Yes. I have done it when eliminating the "freeze/expansion" plugs on the manifold.

I voted 'absolutely' as I have done this successfully. Being able to use a drill press for the drilling is a big plus, otherwise you need some sort of fixture to hold the drill (and tap) square. Doing it freehand is asking for trouble as the hole and threads are likely to be off alignment. Often the mating part can be used as a fixture with suitable bushings around the drill and tap.

"Absolutely" :)

I just recently did so when I enlarged my side plate from 3/8" NPT to 1/2" NPT.

I will confess I did the same as Al, and took the plate off and used my drill press & tapped the plate in a vice, so access and alignment were not factors.

However, I have also drilled the block in the boat to repair my failed 1/8" aft block drain and re-tap to 1/4". That was one of my first tasks when the old galvanized piece fell off the motor into my hand the first winter. :rolleyes:

The 23/32" drill bit for the 1/2" tap cost 3 times what the tap cost! :eek:

As this is a do it yourself forum, I would think drilling and tapping would be a basic skill. Sure, there are members who don't consider themselves mechanics but I read over and over their personal satisfaction as they discover they can do it.

For those who don't know or haven't drilled and tapped before, give it a try, it's not that hard.

Yes!
 

I was really apprehensive about tapping new threads into the engine block for new manifold studs. The old bolts had stripped the threads in the block.

I found it to be easy (soft metal on the block) and VERY rewarding.

Careful to go in straight, and not "screw"-up, things went well.

Using a helicoil and JB weld, now I have a well-seated manifold via studs.

-Rick

On my old engine, I did it by HAND - turning the tap with a wrench due to lack of access.

Of course this may help explain why I got a new engine :rolleyes:

Is this a poll for the rumored A4 fuel injector/supercharger kit?

Uh, no.

Bill

Absolutely.

I did it a couple times on my ongoing rebuild.

I made the Moyer Modification to the accessory drive, which involved plugging the existing oil drain hole by tapping it and JB Welding a screw in to permanently seal it off, and then drilling a new hole in a different location.

I also snapped off one of the exhaust manifold bolts, so I had to drill it out and re-tap the hole to install the Moyer studs.

I have no problem drilling and tapping holes - this is far from the first time I've done it.

I think you might find a "continuum" of do-it-yourself types here - some will do basic engine maintenance and simple upgrades, and then there are the crazy people like me who will take on the complete tear-down and rebuilding of the whole engine.

Part of the question is how many people who consider themselves "mechanically inclined" or "somewhat handy" have tap & die sets, or are willing the spend the money to buy them if they don't already have them. I have found that there's a certain point at which some guys decide it's not worth it to buy a certain tool they don't have, because they're very unlikely to use it again. Taps and dies seem to fall into this category for a lot of people.

Of course, if you're putting together a "kit," you could include the correct drill and tap in the kit.

Darn. :( :rolleyes: :D

By the way, I also cut threads on several studs. I somehow ended up with the wrong number of "long" head studs versus "normal" ones. I had too many of the studs meant for the lifting eye, which are about 1/8" longer than the regular head studs. So I had to cut about an extra 1/8" of thread and grind them 1/8" shorter - basically move the threaded section 1/8" up the stud and shorten the overall length of the stud to match the regular ones. No biggie. Worked just fine.

Many years ago, one of my most favorite jobs was as an apprentice electrician. I learned many, many valuable skills, but what I most remember from those days is you can do most anything with the proper tools, the proper knowledge, and the proper time. Drilling and tapping a hole isn't that difficult. Now drilling and tapping a hole in an exact spot might be something I would not be willing to invest the time and money in to do it myself. Generally speaking though, I would be comfortable drilling and tapping (in fact I'm installing a new mast gate and two eye straps this afternoon using drilled and tapped holes) if there were an appreciable tolerance for hole placement and a purchase of expensive equipment weren't required.

If it's got to be on the gnat's ass, I might pass. Same day, same way, I'm okay.

[Off topic]
Tom,
As you spent some time in the electrical industry you should be familiar with NOALOX. I strongly recommend slobbering it on the machine screws before installation. It virtually eliminates corrosion and dissimilar metals problems between the stainless screws and the aluminum mast in the future.

Neil, that is a great point that many folks don't consider (or even realize). Noalox is probably the best out there. OxGard is also good and readily available. The reason I am redrilling and retapping the mast gate is because the PO didn't use an antioxidant and the screws corroded and broke off.

If I feel like it!
 

Drilling and tapping is fine if you have the gear. That said, there are times when I just don't feel like doing it. If there is another aspect of the job to be done I might drop it off at a machine shop and have them do it. Can I do it.. yes, I have the gear, but I might not always feel like it. I usually fix my own vehicles also but there are times I don't feel like it and drop it off...same idea.

Well, as some of you know, I learned the hard way how to do it the right way. :rolleyes:

Yep
 

I've been drilling and tapping since I was a wee nipper. My Dad & Grandfather didn't believe in child labor laws:eek:. I started workig in a "garage~car lot" that my Grandfather ran when I was 8, mostly sweeping and washing cars. By the time I was 10 I was cleaning parts (including carbs) and doing some minor disassembly. I was doing tuneups and adjusting valves by 12 and running machines for brakes and valve grinding. With the afore mentioned experience came drilling and tapping for repair and fabrication, not sure exactly when.
I pretty much have no fear tackling anything mechanical, due to the experience they gave me.

Here's a question~~How many can pour babbit and scrape a bearing? I still have the tools but it's been probably 25 years since I have done so.

Dave Neptune:cool:

Having an avid interest in antique machinery, and owning a 1700-pound, 36" bandsaw dating from about 1910, and a few other pieces of old machines, I am familiar with what babbitt bearings are and how one pours them and scrapes them. I have read all about it and have seen it done close up, but never have actually done it myself.

Yet.

That bandsaw I mentioned is awaiting a full restoration. I have not yet closely inspected the babbitt bearings. When I disassembled the machine to transport it home, I gave them a quick a look, and they looked pretty good overall, so I might not have to melt them out and re-pour. But the bottom one might need a little attention. If so, I have a buddy who has built himself a very cool lineshaft-driven blacksmith shop, with his newest machine dating from probably some time in the early 1930s. They're all babbitt bearings, and he knows how to pour them, so I would enlist his assistance if it turns out to be necessary.

Ah yes, scraping bearings - two stories.
First was a bearing (16+ inch shaft) that I dispositioned to be scraped. Someone misread my disposition and the bearing was scrapped. Took us a while to track down the 'scrap' and have it 'scraped'.
Second was a giant lathe that had been refurbished with new poured babbit bearings. The guy doing the scraping of the headstock bearings used the actual headstock rather than an oversize mandrel to do the scraping. Lathe ran about 20 minutes before seizing up tight.

Yes..........

I'm embarrassed to say that my engineering education is so dated that one of the ways we were taught to measure the "value" of machinery was by its weight. Heavier=better.

Of course, we were looking up logs, carrying around slide rules (a badge of honor), etc. at the time. Ours was the first class not required to do drawings in ink.

Bill

Oooh, that brings back memories. I still have my bamboo Pickett.

I also believe learning CAD is much easier if you've come from a T-square background. In fact, up until maybe the late 70's I had a cabled straightedge drafting table after which I graduated to a mechanical drafting arm. Now they're museum pieces as am I.

Scum bags, triangles, compass, circle and ellipse guides, eraser shield, slide rule, I had experience with all of that stuff but I swear NO POCKET PROTECTOR! NEVER!!

The first electric calculator I ever saw was in a physics class in my second year of college. It was the size of a phone book and cost $800 (over $2K in today's money). Where's my Geritol? Any of you whippersnappers even know what Geritol is?

And did you watch Jack LaLanne every morning on KCOP? ;)

Don't forget Lawrence Welk and Mitch Miller!