Torque wrench suggestions.

Messages
246
Location
Eastern U.S.
I'm getting ready to tackle the sparkplugs on our PT, and it's advised to torque them to proper specs (aluminum head I guess). So, I guess it's about time I invest in a decent torque wrench. Any advice on one of these things? Just looked at the Wiki article and got a headache...lol!
 

Rumble

Thread starter
Messages
246
Location
Eastern U.S.
 Originally Posted By: benjamming
What torque range do you want? This one is 20-100 ft-lb. Precision Instruments Split Beam 3/8" Drive An in-lb torque wrench would be better for spark plugs, 50-200 in-lb. We have a Snap-On at work that is this range. The Precision Instruments would take over from there.
The plugs require 13 lbs on this thing. Maybe I need something with a lower range. Steve: I've never torqued plugs before, but have installed many over the years. I guess this aluminum head makes me a little nervous. Plus, if I screw it up, my wife will kill me!
 
Messages
8,711
Location
Nothern USA
 Originally Posted By: TaterandNoodles
I prefer simple, durable and reliable beam style with a piece of tape to mark my setting.
+1 For occasional use by a DIY not wanting to spend more time calibrating a clicker than doing the job, a good choice. For 13 pound feet spark plugs you want something fairly low range.
 
Messages
9,679
Location
Central Coast, Calif.
never use the lower 20% of any torque wrench's rating. It is not considered accurate and sometimes don't even function at the very bottom. new plugs with a gasket should be torqued snug plus 1/2-3/4 turn. you will not strip out the head if you use this method as you are only compressing the gasket, not smashing the plug against the head to make a seal.
 
Messages
379
Location
Mi
I know Champion does call for an eigth of a turn when tightening their spark plugs requiring no torque wrench.I do not torque spark plugs,a huge waste of time and no one torques spark plugs most of the time.There is one that has a recall on their torque wrenches,Richard Abraham KG.The internal spring mechanism breaks,breaking the bolt and there has been no cases of injuries yet.
 

Rumble

Thread starter
Messages
246
Location
Eastern U.S.
 Originally Posted By: tom slick
never use the lower 20% of any torque wrench's rating. It is not considered accurate and sometimes don't even function at the very bottom. new plugs with a gasket should be torqued snug plus 1/2-3/4 turn. you will not strip out the head if you use this method as you are only compressing the gasket, not smashing the plug against the head to make a seal.
That's pretty much the system I've always used on plugs. Maybe I'm just freakin' over nothing.
 
Messages
264
Location
Rio Grande Valley
The SnapOn in inch pounds is ideal for PT plugs and according to NGK no anti sieze. Without torqing you stand a chance of blowing one out or sticking one badly.
 
Messages
9,679
Location
Central Coast, Calif.
 Originally Posted By: wafrederick1
I know Champion does call for an eigth of a turn when tightening their spark plugs requiring no torque wrench...
That instruction is for plugs with no gasket, such as an SBC application.
 
Messages
379
Location
Mi
I have never seen one blow out without torqueing them down.Change plugs on a Ford Triton 5.4,4.6 and the V10 before 100,000 miles.They are known for blowing out spark plugs badly and Ford charges $300.00 a hole repairing this.
 
Messages
6,070
Location
northern Alabama
 Originally Posted By: tom slick
new plugs with a gasket should be torqued snug plus 1/2-3/4 turn. you will not strip out the head if you use this method as you are only compressing the gasket, not smashing the plug against the head to make a seal.
Not sure if everyone is aware of what it means to be snug-tight. "The 2004 RCSC Specification defines a snug-tightened joint as a joint in which the bolts have been installed in accordance with Section 8.1.'Note that no specific level of installed tension is required to achieve this condition, which is commonly attained after a few impacts of an impact wrench or the full effort of an ironworker with an ordinary spud wrench. The plies should be in firm contact, a condition that means the plies are solidly seated against each other, but not necessarily in continuous contact.' It is a simple analogy to say that a snug-tight bolt is installed in much the same manner as the lug nut on the wheel of a car; each nut is turned to refusal and the pattern is cycled and repeated so that all fasteners are snug. Essentially, snug-tight bolts utilize the higher shear/bearing strength of high-strength bolts with installation procedures similar to those used for ASTM A307 common bolts, which are never fully tensioned." Reference
 
Messages
9,564
Location
Ontario, Canada
 Originally Posted By: tom slick
new plugs with a gasket should be torqued snug plus 1/2-3/4 turn. you will not strip out the head if you use this method as you are only compressing the gasket, not smashing the plug against the head to make a seal.
I use this method as well, you can feel the gasket compress and then when its starts to get a bit harder to turn its good. I had an old snowmobile with points ignition and aluminum heads. Pulled the plugs on that dozens of times with no stripping...
 
Messages
99
Location
Iowa
Your posted definition of snug-tight is useless in this application, the threads are not steel. Its kind of funny though. Imagine a the full effort of an iron worker with a spud wrench being less than 13 ft-lb torque.
 
Last edited:
Messages
6,070
Location
northern Alabama
That is the definition of snug whether or not it applies here doesn't matter. Notice the 2nd paragraph & the difference between joint & bolt. This is still somewhat of a fun, educational site.
 
Messages
99
Location
Iowa
Good site, definitely. Its in my bookmarks now. Thanks. I only commented in case there is someone out there who is so stupid that they find this thread and use an impact wrench to get their spark plugs 'snug tight'. Then continue tighten the plug another partial rev. as indicated by the instructions.
 
Messages
130
Location
NW Georgia
The RCSC specs are for structural steel joints using ASTM A307, A325 or A490 bolts. They do not apply to autos. The "snug tight" condition was spelled out this way due to engineers that did not understand the bolt code and kept insisting on fully tightening the bolts on a job when it was not required. A "SC" or slip critical bolt relies on the clamping force of the bolt to hold the plies (bolted parts) in place when a load is applied perpendicular to the line of the bolt. These bolts are required to be fully torqued and should only be used under cyclical loading conditions. An "N" bolt (bearing type with threads in the shear plane) or "X" bolt (bearing type with threads excluded from the shear plane) rely on the shear resistance of the bolt itself to resist a load that is applied perpendicular to the line of the bolt. These bolts can be fully torqued but it is only necessary to bring them to a snug tight condition to be effective. Note that all three types have the same value when loaded in a tension condition (in line with the bolt). This occurs at moment (rotational) or axial (tension/compression) loading conditions. Yes, I'm a little anal about this subject after detailing steel for 30+ years.
 
Top