WHat size drill bit for a 3/8 NPT tap? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Reply
 
 
 
LinkBack Thread Tools
Old 10-20-2007, 02:59 PM   #1
Elite Member
Thread Starter
iTrader: (12)
 
Join Date: Jan 2007
Location: Hermosa Beach, CA
Posts: 2,575
Total Cats: 11
Default WHat size drill bit for a 3/8 NPT tap?

What size drill bit do I need to get for a 3/8 NPT tap?
cardriverx is offline   Reply With Quote
Old 10-20-2007, 03:01 PM   #2
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,147
Total Cats: 6
Default

9/16
cjernigan is offline   Reply With Quote
Old 10-20-2007, 04:48 PM   #3
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99
Default

37/64" would be ideal.
Ben is offline   Reply With Quote
Old 10-20-2007, 04:54 PM   #4
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,147
Total Cats: 6
Default

Man 64s bits are such a PITA to find though in comparison.
cjernigan is offline   Reply With Quote
Old 10-20-2007, 07:18 PM   #5
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,833
Total Cats: 1,786
Default

1/2" + .07" :gay:
Braineack is offline   Reply With Quote
Old 10-20-2007, 09:01 PM   #6
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,914
Default

Quote:
Originally Posted by cjernigan View Post
Man 64s bits are such a PITA to find though in comparison.
http://www.use-enco.com/CGI/INSRIT?P...PARTPG=INLMK32
Joe Perez is offline   Reply With Quote
Old 10-21-2007, 03:40 AM   #7
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,357
Total Cats: 1,322
Default

www.google.com

we have some noob-*** ************* on this forum. Phillip, you're slackin, buddy.
Savington is offline   Reply With Quote
Old 10-21-2007, 07:08 PM   #8
Elite Member
Thread Starter
iTrader: (12)
 
Join Date: Jan 2007
Location: Hermosa Beach, CA
Posts: 2,575
Total Cats: 11
Default

I used a 9/16. Thanks guys!
cardriverx is offline   Reply With Quote
Old 10-22-2007, 10:40 AM   #9
Elite Member
iTrader: (9)
 
Saml01's Avatar
 
Join Date: Jul 2007
Location: NYC
Posts: 5,730
Total Cats: 2
Default

Can I please get some education on drilling and tapping.

What is the relationship between the sizes when picking the fitting, the tap, and the drill bit?
Saml01 is offline   Reply With Quote
Old 10-22-2007, 10:46 AM   #10
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,833
Total Cats: 1,786
Default

google "drill tap size chart"

drill the hole too big and your threads might not be large enough, too small and the tap might not even fit in the hole!
Braineack is offline   Reply With Quote
Old 10-22-2007, 11:00 AM   #11
Elite Member
iTrader: (9)
 
Saml01's Avatar
 
Join Date: Jul 2007
Location: NYC
Posts: 5,730
Total Cats: 2
Default

Quote:
Originally Posted by Braineack View Post
google "drill tap size chart"

drill the hole too big and your threads might not be large enough, too small and the tap might not even fit in the hole!
http://www.icrank.com/cgi-bin/pagema...rt_npt.htm&t=2

3/8-18? So the drill bit is a 9/16. How is the tap selected?
Saml01 is offline   Reply With Quote
Old 10-22-2007, 11:15 AM   #12
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,833
Total Cats: 1,786
Default

if you got a 3/8 npt fitting, then you want a 3/8 npt tap. then it's just choosing the appropriate drill bit for the tap.
Braineack is offline   Reply With Quote
Old 10-22-2007, 11:36 AM   #13
Elite Member
iTrader: (9)
 
Saml01's Avatar
 
Join Date: Jul 2007
Location: NYC
Posts: 5,730
Total Cats: 2
Default

Quote:
Originally Posted by Braineack View Post
if you got a 3/8 npt fitting, then you want a 3/8 npt tap. then it's just choosing the appropriate drill bit for the tap.
Thats sweet.
Thanks man.
Saml01 is offline   Reply With Quote
Old 10-22-2007, 10:43 PM   #14
Elite Member
iTrader: (9)
 
Saml01's Avatar
 
Join Date: Jul 2007
Location: NYC
Posts: 5,730
Total Cats: 2
Default

Question. I was reading in the MS forum that the IAT sensor also uses a 3/8 NPT.

So thats the oil return, and the IAT that uses a 3/8 inch NPT. What else uses a 3/8 NPT. I ask because then its simpler for me to just get one, and use it for everything that needs to be screwed in.

While we are on the topic of fittings, is 3/8 enough for oil return?

Even better question, how do I know what size fittings the turbo needs? The oil feed is threaded while the return is not, and the water is threaded.
Saml01 is offline   Reply With Quote
Old 10-22-2007, 10:58 PM   #15
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,357
Total Cats: 1,322
Default

You can use it for the IAT, oil return, idle air valve fitting, and you might be able to get away with it for the BOV fitting as well, although 1/2NPT is preferred for that just due to size and airflow requirements.
Savington is offline   Reply With Quote
Old 10-22-2007, 11:33 PM   #16
Elite Member
iTrader: (9)
 
Saml01's Avatar
 
Join Date: Jul 2007
Location: NYC
Posts: 5,730
Total Cats: 2
Default

Quote:
Originally Posted by Savington View Post
You can use it for the IAT, oil return, idle air valve fitting, and you might be able to get away with it for the BOV fitting as well, although 1/2NPT is preferred for that just due to size and airflow requirements.
Im sorry, just to clarify, you mean the signal to the blow off valve?

Also, can I use it to put a fitting into the outlet from my compressor, it doesnt come with one and id like to keep the boost controller close to the turbo and the actuator.
Saml01 is offline   Reply With Quote
Old 10-23-2007, 12:13 AM   #17
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,914
Default

Quote:
Originally Posted by Saml01 View Post
While we are on the topic of fittings, is 3/8 enough for oil return?
Yes. I am using a 3/8 NPT to -10AN fitting, and it drains just fine. The actual amount of oil flowing through the turbo is amazingly small.
Joe Perez is offline   Reply With Quote
Old 10-23-2007, 10:04 AM   #18
Elite Member
Thread Starter
iTrader: (12)
 
Join Date: Jan 2007
Location: Hermosa Beach, CA
Posts: 2,575
Total Cats: 11
Default

Quote:
Originally Posted by Saml01 View Post
Im sorry, just to clarify, you mean the signal to the blow off valve?

Also, can I use it to put a fitting into the outlet from my compressor, it doesnt come with one and id like to keep the boost controller close to the turbo and the actuator.
He means where the BOV acually mounts on the pipe.
cardriverx is offline   Reply With Quote
Old 10-23-2007, 11:08 AM   #19
Elite Member
iTrader: (9)
 
Saml01's Avatar
 
Join Date: Jul 2007
Location: NYC
Posts: 5,730
Total Cats: 2
Default

Quote:
Originally Posted by cardriverx View Post
He means where the BOV acually mounts on the pipe.
Hmm, I cant picture this in my mind. But ok, ill take your word for it.
Saml01 is offline   Reply With Quote
Old 10-23-2007, 03:04 PM   #20
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,357
Total Cats: 1,322
Default

Yeah, where the BOV mounts. Instead of using a silicone coupler with a 1" fitting or something, I used a 1/2" NPT to 3/4" pipe thread fitting, some high-temp silicone sealant, and a small length of 1" heater hose. Coat the 3/4" threads with the silicone, push the 1" hose onto the threads, install BOV in the other end, run signal line up to the cruise control fitting, and let the silicone dry overnight, and you're done. It could leak like a ****, but I don't care because my car is running a MAP sensor.
Savington is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
1994 Spec Miata Race Car SM/SM2/SSM For Sale Quinn Cars for sale/trade 6 10-23-2016 08:58 AM
My solution for Oiltemp and Oilpressure input into Megasuirt (MS3) Zaphod MEGAsquirt 41 01-24-2016 01:25 PM
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
Moroso Air Oil Separator Catch Can Aroundcorner Miata parts for sale/trade 2 10-01-2015 04:20 PM
Another Alternator thread ihiryu General Miata Chat 9 09-28-2015 11:22 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 08:17 AM.