Technical Adjustable reamers (were not the answer to my problem)

I have a problem with a set of headers I bought. The holes in the flange are supposed to be 3/8, but 4 of the 8 bolts required won't drop through the holes, so I need to enlarge them. I was thinking of the next drill size up in my battery powered drill might open them up, but I have pretty bad arthritis and have had some bad experience with drills "catching" in situations like this with unpleasant results. I came across "Adjustable Reamers" in my searches, and wonder in they might be the solution. They are over $20 each, so before I ordered one (or two), I thought I'd check here to see if anyone has had any experience with them. I figure I will probably need two, one 11/32" - 3/8" to open the hole up to 3/8, and then a 3/8" - 13/32" to make it just a little bigger.

Any advice before I spend the $50 plus on these? It's a bit of money to spend on a one-time, trivial task, but I would expect I'll run into this same problem in the future, so...

 

Could you borrow a drill with a handle also on the chuck end ? Many 1/2" drills have a clamp on handle or a pipe that will screw on.

 

Use a file.

 

I'd recommend using a step drill rather than adjustable reamers. First, adjustable reamers work best in a machined hole. Second, they won't remove much material in a single pass, you'll have to make multiple passes in each hole. Try taking too much and you'll break it. Step drills, while not really designed for thick material, will cut it and don't hang up like regular drills do. You'll probably have to drill from both sides though because the 'steps' won't be as thick as the flange.

As an alternative, use a tapered reamer with a long taper.

 

I have used adjustable reamers on occasion. I had a micrometer to measure the size I was adjusting to. I really think you should invest in an inexpensive set of step drills. They don't catch as much as standard drill bits and are pretty cheap for a one time use and maybe more. Steve types faster than me.

 

use a drill press.

 

somewhere a while back I saw a round file that fits in your sawzall. I knew I needed one, then forgot all about it.

 

I have already installed the headers on the engine, so the problem with all of these suggestions is access to the flange. These headers have individual flanges that go against the exhaust ports and were a bitch to get on; I'd rather spend the $50 than fight the installation again.

About step drills, I have always dismissed them as suitable for really thin materials only. I have only seen them in HSS. I quite using HSS regular bits years ago and went to M33 Cobalt and wouldn't go back. Besides the step at 3/8" probably being to short (the flanges are 5/16") I can't get at both sides. I think I'll go see if step drills are available in higher quality materials.

Thanks.

 

If you are drilling the hole just a little bigger (like 1/64", which is commonly the next size bigger), it should not catch. Drilling a few sizes larger, yeah, it will catch.

 

You could use a 1/4" straight carbide burr in a die grinder, but it's tough to keep the hole centered and round.

 

Find some young punk with good wrists and fingers to come over and drill the holes for you. I would offer my services as I am going through Brainerd on my way to the Twin Cities tonight, but the Misses has me on a tight schedule and short leash.

 

I'd try a tapered reamer.

 

anything like an adjustable or tapered reamer, or step bit, will have trouble because the headers are installed, there is no room behind them for the rest of the bit/reamer to go.

 

Exactly. Bite the bullet and remove them or use a standard drill bit or carbide burr.

 

Not if you use a ball nose burr, 3/8" dia. with the standard 1/4" shank works great, done it many times. HSS is adequate as long as you can control the rpm's, especially if they are rough cut holes, ie plasma.

 

I am finding there are things called "Bridge Reamers" and "Car Reamers" that are designed to do just this. They are in the $70 range in the size I want. Fastenal has them and they have a branch in Brainerd; I'll stop by and see what they have. "DDDENNY"- I like your idea; I'm gonna stop by our local "Tools-R-Us" and see what they have.

 

So you might spend $140 for reamers to do this? All the bridge reamers I know of are tapered reamers. Hows that going to work if you don't remove the headers?

 

use a Dremel, with a straight bit.

 

Rich, as I understand it "Bridge" and "Car" reamers have much less taper than standard tapered reamers. As to the prices; I am going by Fastenal to LOOK, not to BUY since it's on my way.

 

None of us like to go all the way back to the start but after running into a Fit issue it's often the best way to resolve the unseen issue correctly. How ya gonna feel if you bitch up the threads in the Head?
The Wizzard

 

Having arthritis, it wasn't easy to install the headers in the first place, was it? I can understand not wanting to go through it again

 

There are all kinds of tapered reamers. As there are several tapers. Morse. journo. Taper pin. And such. You can Google them. But any reamers meant to line up two through holes is going to be longer than what you want. I think you wish you could use a chucking reamer as it has the least lead in of any I know. But I think all the guys who recommended a carbide burr and a die grinder, had the answer. You only need to move the hole in one direction. Not make it bigger all around. They are cheap, assuming you have a grinder. And available most everywhere.

 

"Wizard" - Good point. Only I don't have to worry about it since I am talking about the flange the exhaust pipe bolts to. No threads, just holes. It's really not that big of a deal, I'm just exploring the possibilities because I have encountered this same problem before and would like to find an easy way to do it, that's all. Muscling it through with a bigger bit just doesn't cut it these days for me.

 

loosen the bolts you have in to give some clearance, maybe squeeze somthinin between the block and flange so it cant move around, then dremmel or carbide burr tool in a drill. only thing easy will be to get the neighbor kid to do it

 

So these holes are in the header flange to the down pipe? Not the bolts that hold the headers to the head?

 

Correct. I already have had an "adventure" with those and was looking for something easier for these. The downpipe flange holes are real easy to get to from one side.

Looking back, I see I was not clear enough about this. I said that I "already had them installed", but I can see now that is not clear enough to fully understand what I needed to do, Sorry.

 

Buy an angled die grinder from Harbor Freight, bout $15...pick up a decent burr cutter, either tapered or ball from an industrial tool supply house (not Harbor Freight) and open the holes as needed...when your done, put all this on your tool box for later use...its a tool you will use more often than you realize.

 

how about a metric bolt?

 

Blasphemy!