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Ream set....

4

496 BB

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Where did you get your ream set and is it accurate? Price?

I have a tiny drill bit set I got from Jegs but after measuring the small .019 - .025 it seems they are all the same size. Time for something more accurate I suppose. Not even sure if I trust the ones drilled from vendors anymore as Ive measured a few and they have been off as well.
 
496 BB said:
Where did you get your ream set and is it accurate? Price?

I have a tiny drill bit set I got from Jegs but after measuring the small .019 - .025 it seems they are all the same size. Time for something more accurate I suppose. Not even sure if I trust the ones drilled from vendors anymore as Ive measured a few and they have been off as well.
Click to expand...
the slightest blemish in a hole can cause a change in fuel flow. When you consider that fuel is something like 700 times denser than air you can understand why this is true. When I worked for Bob Truax, (the man who built Evil Knievel's Snake River Canyon rocket) we had some rocket engine injectors made by a company with a Swiss CNC lathe. When we flow tested the Jets using water, we found maybe 15 to 20 different flow rates. And this is with a precision Swiss lathe. You can imagine how much difference there would be using a drill.

MSC cells reamers in English and Metric. You can get sizes between round numbers such as .039" and .040". For instance, .0393". The area difference between .039 and .040 is about 5%, and a little more. That's a big change in flow. It's equal to five points on the air density gauge.

They're not cheap, but going first class seldom is.

Comments compliments criticisms and questions always welcome.
If the data does not support the theory, get a new theory.(Al Nunley)
 
Ok Im usually not one to cheap out but damn Im not trying to spend $500 on ream set. There has to be something else out there fairly accurate for less. Ebay??? Links??
 
I got a set of bits that are used for watch making. the sizes listed are not accurate but all of the bits are different sizes, you will just have to measure them and see what you have. I also got screwed by Jegs on the set of bit for carb work.
 
go to your nearest harbor frieght...look in the drill section for little drill bits in a plastic case....each drill has a different color plastic collar around it. i use them for building my scale models in the off season and some are fine as a hair....i twist them using my fingers becasue too much speed will melt the plastic, but these are for precision work...i think i paid like $7 or $8 for the set...i've even found them at flea markets....

here's a link for the ones at harbor freight: http://www.harborfreight.com/20-piece-solid-carbide-micro-bit-grab-bag-44924.html

here's a link for micro-mark: http://www.micromark.com/SearchResult.aspx?deptIdFilter=0&searchPhrase=drill+bits

somewhere on bob's there was a listing of what size the hole was and what the corrosponding inch size was (like a #32 hole is .021")...but i don't know what it was listed under...

just sayin!!!
 
Don't drill jets for size. As Al says, you need them reamed because one scratch in the bore will throw off the flow. Then you don't know what you have.

McMaster Carr sells reamers in .001" increments. Got to www.mcmaster.com I am sure they are not cheap, but you would buy them once, and if you took care of them, they would last a lifetime. So they are cheap in the long run.

Dave E.
 
I bought a precision drill bit set at the local hardware store, they were called welders drill bit set, for cleaning the tips on mig welders. These were #50 thru #100 or something like that, the smallest one was .020 and the biggest was .070, so they were perfect for carb jets and things like that for me, there were 15 bits in the set and they came with a pin vice that the tip screws off on, and is hollow so you have a place to store the bits inside the pin vice. Best $12 i ever spent, and i havent broke any yet because you twist the pin vice by hand, not a drill. They work great.
 
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