Set screw size for orifice in top of block BB. - Moparts Forums

Register Log In Moparts Forums Unlawfl's Race & Engine Tech Set screw size for orifice in top of block BB.

Print Thread

Set screw size for orifice in top of block BB. #1384111 02/09/13 06:11 PM 02/09/13 06:11 PM
Joined: Nov 2003 Posts: 7,348 Mt.Vernon ,Ohio VernMotor OP master
VernMotor OP master Joined: Nov 2003 Posts: 7,348 Mt.Vernon ,Ohio	It looks like a I need 9/32 set screw ? 9/32 is .2812 and hole is .270... what tap would I use ? This is for the top of the block to cy heads oil feed for the rockers. I going to put a .080 hole in them. had .100 in the other motor and seems like a bit much.

Re: Set screw size for orifice in top of block BB. [Re: VernMotor] #1384112 02/09/13 08:25 PM 02/09/13 08:25 PM
Joined: Oct 2005 Posts: 8,879 Ontario, Canada S Stanton Don't question me!
Stanton Don't question me! S Joined: Oct 2005 Posts: 8,879 Ontario, Canada	seems to me that for a 9/32 set screw you'd want a 9/32 tap - with the pitch to correspond to the set screw as well i.e. 9/32 nc or 9/32 nf FWIW the recommendation seems to be a .060 hole, although a 1/16 bit is more common and I didn't think .002 would make much difference

Re: Set screw size for orifice in top of block BB. [Re: Stanton] #1384113 02/09/13 08:28 PM 02/09/13 08:28 PM
Joined: Nov 2003 Posts: 7,348 Mt.Vernon ,Ohio VernMotor OP master
VernMotor OP master Joined: Nov 2003 Posts: 7,348 Mt.Vernon ,Ohio	So set screws are NF or NC and not NPT.. I was not sure.

Re: Set screw size for orifice in top of block BB. [Re: VernMotor] #1384114 02/09/13 09:12 PM 02/09/13 09:12 PM
Joined: May 2004 Posts: 5,123 Warrenton, VA RoadRunnerJD master
RoadRunnerJD master Joined: May 2004 Posts: 5,123 Warrenton, VA	.080 won't be any problem but if you are trying to restrict the passages, .060 will be fine. That's what I have always run and no problem even with roller rockers.

Re: Set screw size for orifice in top of block BB. [Re: RoadRunnerJD] #1384115 02/10/13 12:30 AM 02/10/13 12:30 AM
Joined: Jan 2013 Posts: 174 H hustlin hoosier member
hustlin hoosier member H Joined: Jan 2013 Posts: 174	9/32 is not a standard size you have something other than an sae thread it might be 1/16 pipe or metric .280 would be 7 mm. I have been atool & die maker for over 40 yrs and have never run across a 9/32 screw . If it were a "number screw" the formula to detemine a number screww size as follows 0 is.060 for every number you add .013 in such as a 10-32 , 0 is .060 , 10 times .013 is .130 add the 2 together is .190 that is the major dia of a 10-32 screw at 100% thread. But I think you really have a 1/16th pipe thread. The problem is I am not a plumber I am a toolmaker.

Re: Set screw size for orifice in top of block BB. [Re: hustlin hoosier] #1384116 02/10/13 01:29 AM 02/10/13 01:29 AM
Joined: Oct 2005 Posts: 8,879 Ontario, Canada S Stanton Don't question me!
Stanton Don't question me! S Joined: Oct 2005 Posts: 8,879 Ontario, Canada	Well I don't know where that .270 hole came from ... I seem to recall those oil passages in my block were only around 1/8 and I used 1/4 set screws.

Re: Set screw size for orifice in top of block BB. [Re: VernMotor] #1384117 02/10/13 02:22 AM 02/10/13 02:22 AM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	.242 is the drill size to tap for a 1/16 pipe plug (or letter bit C)... .332 is the drill size for a 1/8 pipe plug(or letter Q).... both of taps have a 27 threads per inch(1/16 and 1/8).. if its threaded now and you have a .270 it MIGHT be 1/16 NPT... that would be like .014 per side but since pipe is a taper it might be that much.... that could be what your looking at Jamie.... see if its a tapered hole Last edited by MR_P_BODY; 02/10/13 02:25 AM.

Re: Set screw size for orifice in top of block BB. [Re: MR_P_BODY] #1384118 02/10/13 02:31 AM 02/10/13 02:31 AM
Joined: Jan 2003 Posts: 16,376 D dogdays I Live Here
dogdays I Live Here D Joined: Jan 2003 Posts: 16,376	If it's a factory hole for fluid flow it's NPT. If it's for holding things together it's UNC. These are what I've observed. R.

Re: Set screw size for orifice in top of block BB. [Re: dogdays] #1384119 02/10/13 02:51 AM 02/10/13 02:51 AM
Joined: Jun 2003 Posts: 52,972 Romeo MI MR_P_BODY Master
MR_P_BODY Master Joined: Jun 2003 Posts: 52,972 Romeo MI	Quote: If it's a factory hole for fluid flow it's NPT. If it's for holding things together it's UNC. These are what I've observed. R. I believe Jamie is trying to plug the oil supply hole coming up out of the deck surface.... I did my SM with a 1/16 NPT to close it off... I did the upper side of the head under the rock base(I went to PR oiling and the TD rocker base left a bit of the hole open... on my W-5s) so that hole isnt tapped for anything... its just a hole and I think its cast in EDIT Jamie... a .277 is the drill size for a 5/16 X 18 if you want the 50% thread factor(which can be used in iron) .277 is a J bit.... normally I use a F bit which is .244 but that is for 75% thread factor.... just giving you more to think about Last edited by MR_P_BODY; 02/10/13 03:19 AM.

Re: Set screw size for orifice in top of block BB. [Re: MR_P_BODY] #1384120 02/10/13 12:00 PM 02/10/13 12:00 PM
Joined: Nov 2003 Posts: 7,348 Mt.Vernon ,Ohio VernMotor OP master
VernMotor OP master Joined: Nov 2003 Posts: 7,348 Mt.Vernon ,Ohio	OK Thank you all. This is the info I was looking for. I try'ed to get the plugs/screws out of the old block to see what they are.. but could not. Did't try hard LOL. Been 3-4 years since I put them in and don't remember what I used. I will remeasure the hold again but I think Mr.P is right about using 5/16.. 9/32 confused me LOL.

Re: Set screw size for orifice in top of block BB. [Re: VernMotor] #1384121 02/10/13 12:40 PM 02/10/13 12:40 PM
Joined: Nov 2003 Posts: 7,348 Mt.Vernon ,Ohio VernMotor OP master
VernMotor OP master Joined: Nov 2003 Posts: 7,348 Mt.Vernon ,Ohio	Ok so a 1/4 tap will fall in the hole. 5/16 NF will work good and a 5/16 NC would need to drill a hair !

Re: Set screw size for orifice in top of block BB. [Re: VernMotor] #1384122 02/10/13 04:01 PM 02/10/13 04:01 PM
Joined: Nov 2003 Posts: 7,348 Mt.Vernon ,Ohio VernMotor OP master
VernMotor OP master Joined: Nov 2003 Posts: 7,348 Mt.Vernon ,Ohio	Went to the hardware store bought some set screws. they are so hard I can't drill them !! LOL have to find some cheap ones..

Re: Set screw size for orifice in top of block BB. [Re: VernMotor] #1384123 02/10/13 04:31 PM 02/10/13 04:31 PM
Joined: Oct 2003 Posts: 3,698 NE Oklahoma V Von master
Von master V Joined: Oct 2003 Posts: 3,698 NE Oklahoma	Quote: Went to the hardware store bought some set screws. they are so hard I can't drill them !! LOL have to find some cheap ones.. Did the same thing last weekend. Bought 2 set screws, just as you did. Drilled through the first without any issue. 2nd one, no dice. They came from the same box at the hardware store. Went back and bought all they had. None of the rest were soft. Finally gave up and drilled through one of the hardened suckers. Took a hour and 3 bits, but finally got through. 72 RR, Pump gas 440, 452s, 3800 lbs, Corked, ET Radials,. 11.33@117.72. Same car, bone stock 346s, 9.5 comp, baby solid. 12.24@110.

Re: Set screw size for orifice in top of block BB. [Re: Von] #1384124 02/11/13 03:44 AM 02/11/13 03:44 AM
Joined: Aug 2003 Posts: 43,213 Bend,OR USA C Cab_Burge I Win
Cab_Burge I Win C Joined: Aug 2003 Posts: 43,213 Bend,OR USA	Quote: Quote: Went to the hardware store bought some set screws. they are so hard I can't drill them !! LOL have to find some cheap ones.. Did the same thing last weekend. Bought 2 set screws, just as you did. Drilled through the first without any issue. 2nd one, no dice. They came from the same box at the hardware store. Went back and bought all they had. None of the rest were soft. Finally gave up and drilled through one of the hardened suckers. Took a hour and 3 bits, but finally got through. Two things, buy brass set screws to start with or deharden the steel ones by heating them up to cherry red(annealing them) and let them cool down to room temps. very slowly, or do you need to quench them in water to remove the temper or heat treating Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)

Re: Set screw size for orifice in top of block BB. [Re: VernMotor] #1384125 02/11/13 04:25 AM 02/11/13 04:25 AM
Joined: Jan 2004 Posts: 27,347 Today? Who Knows? 1_WILD_RT Management Trainee
1_WILD_RT Management Trainee Joined: Jan 2004 Posts: 27,347 Today? Who Knows?	I've seen it suggested here in the past to put the restrictors in the oil passage in the heads rather than the block so if you decide to tune the oil supply to the heads it can be changed without pulling the heads... "The Armies of our ancestors were lucky, in that they were not trailed by a second army of pencil pushers."

Moderated by Al_Alguire, Hotwheelsjr, moparts, not_a_charger, RangerDan440, tboomer

Hop To

Powered by UBB.threads™ PHP Forum Software 7.7.1