TOPIC:

Checking the valve clearance on my 1980 KZ1000b Ltd.My Clymer manual,I know,get a FSM,but right now its all I got,lists the torque value for the valve cover bolts at 11 ft lbs.I think I remember reading a post somewhere that someone said "in lbs".Can someone give me the proper value here?Thanks in advance for any help here.

Here's a page (1st image below) from the 1981 - 1983 KZ1000 / KZ1100 Kawasaki Service Manual. It shows 87 INCH pounds. My KZ650 Kawasaki Service Manual shows 61 - 78 INCH pounds for those same 6mm 1.0 pitch fasteners (2nd image below). I always torque on the low side of that (61 INCH lbs.) to be safe. Ed

Correct tourque is using a small m6 ring spanner and pushing hard with your fingers - not hand, to feeling the bolt stretch.

These alloy heads are bastards for stripping threads, a lot of tourque wrenches are wildly inaccurate at low settings plus bolts that have been retightened many times before stretch and fatigue so are weaker. Helicoiling or drilling out broken bolts, been there many a time ...

Critical areas like big end bolts, cylinder head nuts and clutch centre nut, primary shaft, crankcase bolts etc but I never bother with a tourque wrench otherwise. Besides, I use stainless allen bolts that needs copper grease, so any 'dry' tourque settings would be innacurate.

If i did I'd replace with new high tesile steel bolts all around and get a small 1/4 low tourque wrench that is accurately calibrated.

Tyrell Corp wrote: ...........get a small 1/4 low torque wrench that is accurately calibrated.

Absolutely! When using a torque wrench on those 6mm bolts you must use a torque wrench calibrated in INCH pounds and it needs to have a low torque range. Torque wrenches are not accurate below 20% of their upper range, so using one calibrated in FOOT pounds can only lead to trouble. The CDI site in the link below mentions this fact. CDI is a Snap-On company, and they make high quality torque wrenches, so they know what they're talking about, Ed

www.cditorque.com/education.html#Safety

Yes,I have a low range small torque wrench in inch lbs with a dial.Also a larger inch lbs and another in ft lbs.Only reason I want to torque these bolts is to be sure I've got even pressure on the gasket.I suspected the ft lbs listed was kinda high for these bolts.It looks like there was some type of thread lock on the bolts when I took them off,a sort of grayish color.Any suggestions on using anything here?

Those bolts should go on dry and clean. Also, clean out the holes they thread into. I've seen problems when there's junk in the holes. Ed

650ed wrote: Those bolts should go on dry and clean. Also, clean out the holes they thread into. I've seen problems when there's junk in the holes. Ed

Hey Ed,

99.999 % of the time I am with you and your words of wisdom; but not this time....

I'll agree clean - yes, but dry? Where is that coming from? I ALWAYS lube engine fastener threads, and most chassis fasteners, especially into aluminum. Also, required lube on stainless steel threads - stainless steel threads seize and gall without lubrication - never seize is most recommended.

Kray-Z wrote:

650ed wrote: Those bolts should go on dry and clean. Also, clean out the holes they thread into. I've seen problems when there's junk in the holes. Ed

Hey Ed,

99.999 % of the time I am with you and your words of wisdom; but not this time....

I'll agree clean - yes, but dry? Where is that coming from? I ALWAYS lube engine fastener threads, and most chassis fasteners, especially into aluminum. Also, required lube on stainless steel threads - stainless steel threads seize and gall without lubrication - never seize is most recommended.

Directly from the Kawasaki Service Manual. Using any sort of lube makes the torque values in the manual incorrect. The manual states "All the values are for use with dry, solvent cleaned threads." I've done my KZ650 fasteners this way for 39 years and never had one strip or be too loose.

There are a few exceptions where the manual specifies a non-permanet locking agent, but there are only a few fasteners that require that.

Here's a link that addresses the effect lubricant has on torque values. I wouldn't use the numbers in it to calculate changes in torque settings, but it does show there is an effect if lube is used on the threads. Ed

www.engineeringtoolbox.com/torque-lubric...-effects-d_1693.html

Lets agree to disagree on this one....

Yes, that is in the FSM, above the table for general torque values...and no where else in the FSM as far as I know...

And I have all kinds of other FSM's that quite clearly call for lube on engine bolt threads...

I know all about fasteners, torque values, material science, stress and strain, modulus of elasticity, yield stress / strain, metal fatigue, ultimate stress, etc...I've spoken directly with some of the best engineers and fastener manufactures in the business (ARP, Caterpillar, Detroit Diesel, Toyota, Mercury, Bombardier, Carillo, Eagle, Milodon, etc.), assembled numerous gas and diesel engines worth over $100 000 (including 500 c.i. 1500 HP pro-stock and tractor pulling engines and 3000 HP diesels), and, quite honestly...

I'm going to continue lubricating engine fasteners

I also lube fasteners and ones with a critical torque spec I lube underneath the head as well, but be careful lubing fasteners with blind holes you can crack the part.

Kray-Z wrote: Lets agree to disagree on this one....

Yes, that is in the FSM, above the table for general torque values...and no where else in the FSM as far as I know...

And I have all kinds of other FSM's that quite clearly call for lube on engine bolt threads...

I know all about fasteners, torque values, material science, stress and strain, modulus of elasticity, yield stress / strain, metal fatigue, ultimate stress, etc...I've spoken directly with some of the best engineers and fastener manufactures in the business (ARP, Caterpillar, Detroit Diesel, Toyota, Mercury, Bombardier, Carillo, Eagle, Milodon, etc.), assembled numerous gas and diesel engines worth over $100 000 (including 500 c.i. 1500 HP pro-stock and tractor pulling engines and 3000 HP diesels), and, quite honestly...

I'm going to continue lubricating engine fasteners

No problem here. If the torque specs in a manual call for dry threads do you reduce the torque level when using lube? Ed

Ed,

When working on bikes or cars, I always set torque at the low or middle value when a range is given, low for smaller fasteners, middle for larger ones. For example if the range is 10-12 ft-lb, I'll set the wrench to 10. When the torque spec. exceeds 25 ft-lb, I go to the middle of the range. If only a single value is given, I use that value.

When I was building racing engines for a living, I must have put in more than a thousand sets of ARP main and head stud or bolt kits, not to mention thousands of rod bolts. I even had ARP make custom rod bolts, head, and main studs, and spoke with some of their engineers over the phone. Some of the things we talked about went against even their own published instructions on installation, like backing studs off 1/4 turn from the bottom. ARP is very insistent on the use of their thread lubricant, and it is very effective stuff.

Industrial and heavy equipment diesel engine assembly is also much more controlled than the average gasoline engine. The manuals for those would specify threads lubed with everything from engine oil of a specific weight to proprietary thread sealants and lockers, sometimes moly-di grease. Back in the day when Caterpillar was still manufactured entirely in the USA, they manufactured their own bolts, and all Cat bolts were grade 8 or higher. Most often the critical fasteners had multiple tightening sequences, usually starting out with two or three stages of torque wrench settings, finishing with a final turning angle measured with a special dial gauge. Since then I've done some research and testing on this subject and found that oiling the threads with motor oil doesn't increase overall bolt stress that much, but it sure does increase consistency in bolt tension. The biggest enemy here is galling and seizure of the threads. Aluminum and stainless steel are both very abrasive materials and have a relatively high degree of surface irregularity induced mechanical interlocking. A surprising piece of engine material trivia: a hard steel wrist pin in an aluminum piston bore - which part is subject to more wear? Answer is the steel pin actually wears more than the aluminum - strange but true.

I have to ask - when you are replacing valve shims - do you oil the cam bearing cap threads?