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Tap size????? #435011
08/11/09 06:39 PM
08/11/09 06:39 PM
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Deerfield, Ohio
70dusterjohn Offline OP
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Help me out here, I need a 1/4 by 24 or 32.. by all I can find is 8 by 32 or 10 by 32.. What do these sizes mean.. What the heck am I doing???? I'm Lost need help PLEASE...

Re: Tap size????? [Re: 70dusterjohn] #435012
08/11/09 06:42 PM
08/11/09 06:42 PM
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On the south side of Nowhere
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S/ST 3040 Offline
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8-32(.164") amd 10-32(.190") are machine thread screws.

Re: Tap size????? [Re: 70dusterjohn] #435013
08/11/09 06:43 PM
08/11/09 06:43 PM
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Newfoundland
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codfish Offline
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What are you working on?

1/4 by 24, means 1/4" diameter, and 24 threads per inch. And then there are pipe threads.

codfish

Re: Tap size????? [Re: 70dusterjohn] #435014
08/11/09 06:43 PM
08/11/09 06:43 PM
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Florida
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scratchnfotraction Offline
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would you be looking for a 1/4-20 tap?

thats whats most common

plus,I dont know what you doing either..LOL

Re: Tap size????? [Re: scratchnfotraction] #435015
08/11/09 06:48 PM
08/11/09 06:48 PM
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Lake Charles,Louisiana
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BILLYJAY Offline
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john, the tap size they were talking about for the oil restrictors was 1/4 x 32 but those being so hard to find they said thats they used a 1/4 x 24.. and screwed them in tight and that they would stay considering the application..

5411321-009.JPG (27 downloads)
Re: Tap size????? [Re: BILLYJAY] #435016
08/11/09 07:00 PM
08/11/09 07:00 PM
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W. Kentucky
justinp61 Offline
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http://www.mcmaster.com/#taps/=35b5hr

Click on the "select inch size" and click on the one you need.

Re: Tap size????? [Re: BILLYJAY] #435017
08/11/09 07:28 PM
08/11/09 07:28 PM
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Deerfield, Ohio
70dusterjohn Offline OP
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Okay, so I found the tap all is good.. But I pull the fitting out of the head and there is no way that I can tap it without first drilling it out.. Is that normal.. and if so what size drill do I need to use... This is for the oil lines in the Indy heads.. To put the holley jet in it.. Thanks guys..

Re: Tap size????? [Re: 70dusterjohn] #435018
08/11/09 07:34 PM
08/11/09 07:34 PM
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Deerfield, Ohio
70dusterjohn Offline OP
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Anyone..

Re: Tap size????? [Re: 70dusterjohn] #435019
08/11/09 08:19 PM
08/11/09 08:19 PM
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Lake Charles,Louisiana
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BILLYJAY Offline
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YES,. you have to drill first then tap unless the hole you are retapping is close to size with the hole already there..(not in this case)there is a chart that will tell you what size hole to drill for the size tap you are going to use.. maybe someone here will chim in with that info.. i dont have it unless you google it....

Re: Tap size????? [Re: 70dusterjohn] #435020
08/11/09 08:26 PM
08/11/09 08:26 PM
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Hot 340 Offline
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ok. What tap size are you tapping? You need to state this to know what drill size to use. 1/4-20 uses a 13/64 drill size to tap, 1/4-28 uses a .213(#3)drill.

Re: Tap size????? [Re: 70dusterjohn] #435021
08/11/09 08:34 PM
08/11/09 08:34 PM
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north of coder
moparx Online content
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1/4 x 24 tap drill is : #4
1/4 x 27 tap drill is : #3
1/4 x 32 tap drill is : 7/32


Re: Tap size????? [Re: BILLYJAY] #435022
08/11/09 08:39 PM
08/11/09 08:39 PM
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NC
440Jim Offline
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Trust me on this one, I do this all the time.

1/4-32 National extra fine series. (or Unified Thread Standard)
Drill 7/32" (0.2188") then tap.
---------------------------------

1/4-28 National fine series.
Drill #3 (0.2130") then tap.
----------------------------------

1/4-20 National coarse series.
Drill #7 (0.2010") then tap. (13/64 is acceptable, but a slightly looser fit. not class 2).

http://www.physics.ncsu.edu/pearl/Tap_Drill_Chart.html


1993 Daytona, 5.50 at 130mph (1/8) 1.19 sixty ft (PG). Link to 572 B1 - Part 1
Re: Tap size????? [Re: 440Jim] #435023
08/11/09 10:04 PM
08/11/09 10:04 PM
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Deerfield, Ohio
70dusterjohn Offline OP
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Is there any pros or cons to doing this.. Here is my fear.. My oil pressure is at 85 to 90 pounds cold and 40 to 45 pounds hot, and if this will increase my pressure I'm affraid of the dreaded gasket on my miliodon oil pump.. I'm not having a problem with oil blowing out the breathers so should I do it or not...

Re: Tap size????? [Re: 70dusterjohn] #435024
08/11/09 10:08 PM
08/11/09 10:08 PM
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long island NY
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Ari440 Offline
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do it : ....... more oil to the mains


#70 jet in mine


1.39 9.85 - 137 mph
Re: Tap size????? [Re: Ari440] #435025
08/11/09 10:14 PM
08/11/09 10:14 PM
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Deerfield, Ohio
70dusterjohn Offline OP
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I'm just on the fence...

Re: Tap size????? [Re: 70dusterjohn] #435026
08/11/09 10:39 PM
08/11/09 10:39 PM
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Ontario, Canada
Dodgem Offline
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I just soldered my fittings in and drilled them .055 works fine. seems to be enough oil to the rockers when I pulled the covers off after a few 2 minutes runs?
Never seen much difference in oil pressure but I have the adjustable milidon relief spring regulator kit!
Guess I'll have to check the hot in gear pressure later.

Re: Tap size????? [Re: 70dusterjohn] #435027
08/11/09 11:43 PM
08/11/09 11:43 PM
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Bend,OR USA
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Cab_Burge Offline
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Quote:

I'm just on the fence...


Which brand and type rocker arms are you using now? If there bushed and non needle bearing roller rockers like T&D or Harland Sharps don't worry about it. If there needle bearing type roller rockers restrict them, .040 to .060


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Tap size????? [Re: Cab_Burge] #435028
08/12/09 01:15 AM
08/12/09 01:15 AM
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CA
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62SAVOY Offline
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1/4-32 tap and die can be gotten at some local hobby shops. This is the thread the glow powered models use for the glow plugs.

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXL774&P=7

Re: Tap size????? [Re: 70dusterjohn] #435029
08/12/09 10:22 AM
08/12/09 10:22 AM
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NC
440Jim Offline
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Quote:

Okay, so I found the tap all is good.. But I pull the fitting out of the head and there is no way that I can tap it without first drilling it out.. Is that normal.. and if so what size drill do I need to use... This is for the oil lines in the Indy heads.. To put the holley jet in it.. Thanks guys..


Sounds like you have not tapped metal before. Here is a tip, after drilling, chamfer (bevel) the entry. Start the tap straight into the hole (check carefully). When tapping, start by turning the tap 3-5 turns to get it started. Then back out 1 turn to break the chips. Then reverse every 1 turn or if the tap feels hard to turn. This avoids breaking taps, which is really easy with #6, #8. A looser drilled hole is less likely to break a tap, but makes threads with less strength.

3 common types of taps:
1) tapered - long lead (taper) for easier turning, but doesn't reach the bottom of the hole
2) bottoming - very little lead, harder to turn more difficult to start straight, but gets close to the bottom of the hole
3) plug - good compromise of above

Re: Tap size????? [Re: 440Jim] #435030
08/12/09 10:50 AM
08/12/09 10:50 AM
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Deerfield, Ohio
70dusterjohn Offline OP
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No I've used a Tap before.. I'm using the Indy Rockers for now But I have the Harlmsharpes from my other motor that I sold. Just haven't put them on yet.. I just feel if I'm not having a problem with oil control up top why should I mess with it.. Like if it ain't broke don't fix it type.. I don't know.. Maybe I'll order more fittings and mess with them..

Re: Tap size????? [Re: BILLYJAY] #435031
08/13/09 07:52 AM
08/13/09 07:52 AM
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New York
polyspheric Offline
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Glad you found it - BTW: 1/4-24 is very common on all 1976 and older Harley motors, so any dealer will have some hardware (but only a few have the tap or die).


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