Cam cap bolts stripped

I haven't had too much trouble with the cap bolts, but it is very important to get out all of the oil from the hole (and any other crud that may be in there). Wick it out with a paper towel or rag rolled into a point. If the hole is filled with oil, it will prevent the bolt from entering, while at the same time make it feel really easy to turn. That combination will strip the hole. I think I use 7.5 to 8 ft-lbs (90 to 96 in-lbs) on the torque wrench. I also make sure the wrench is calibrated. (You can do it easily with a vice and some weights).

Similar problems can happen on the valve cover bolts, but there, it's important to make sure you dig out all of the little bits of sealant. Silicone has the same problem... no resistance to turning, but will not compress, so will lift the threads out like nothing. I usually find a small spring, stretch it out and put a small hook on the end like a dental tool, and use that to dig out the sealant.

A baby snot sucker works well. I have a few from the old days. Good for filling and adjusting fork levels. Use a tube on the end and get them gnat's ass.
Steve

Like Steve say's. No inch lb. torque wrench! I have never owned or used one in the past 40 years! I'm 57.
And I have had heads and cams apart not 100's but 1000"s of times!
You need the REAL heli-coil kit! Not the chinese harbor freight one! You get what you pay for!
These are special decimal drill bits! And a special tap!
Plus if you do these holes over, heli-coil inserts come in different lengths. always use the longest ones, (makes sense) more to grip!
I made my hand sensitive torque wrench 40 years ago! I cut a J H Williams B-52 ratchet down to fit my palm.
As Steve says you go by feel! And experience! Here is my kit, with the blue tape on the drill for a depth gauge. Like I say use the longest inserts you can get!
Then use your hand held torque device.
Of course just my opinion from 40 years of experience!
Good Luck! Do it right the 1st time!

I should have bought the kit like you and have that handy/dandy case too. :dry: I have them with my tap and die set. Now the top won't close. :dry:
Steve

And as I see response's. The most important thing is cleaning the holes out, of course. Brake clean spray with nozzle and compressed air (always wear safety glasses!!!) Then, either lithium grease or even vaseline and a "Q" tip, roll down in the threads, keep turning same direction, pull up with the crud you thought was clean after air and cleaner spray. Do this 2 or 3 times!
Good luck! Happy New Year!

z1kzonly wrote: ........
As Steve says you go by feel! And experience!

A lot of folks do this and if it works for you that's fine, but the main problem with this method is that before most folks have enough experience to develop the right "feel" they will strip out some threads. This is especially true of fasteners threaded into aluminum components. If one tightens a fastener by feel to what they believe is 95 inch pounds and then checks the toque using a proper torque wrench I suspect they my be surprised at how far off they are from being accurate. This is one reason that manufacturers of engines use tools that are calibrated for specific torque levels rather than relying on their employees tightening fasteners correctly though their sense of feel, and this is true even though an employee may fasten thousands of fasteners per week.

Using an inch pounds torque wrench on dry, clean threads can help prevent stripping out the threads or over-tightening a fastener while ensuring that the fastener is tight enough for the application.

The problem with using a foot pound torque wrench when the torque spec is given in inch pounds is that they typically are calibrated at a higher torque range. One can multiply the foot pounds setting by twelve to get inch pounds, but if the top of the foot pound range on the wrench is too high (and it usually is) the wrench will not be accurate at the low torque setting needed for the inch pound spec. This is because of the fact that click type torque wrenches are not accurate at settings that are less than 20% of the highest setting of the wrench's range. Ed

I TQ to 70in lbs make sure holes are clean then lightly oil threads why someone would use loctite is beyond me and asking for problems.

DFIGPZ wrote: I TQ to 70in lbs make sure holes are clean then lightly oil threads why someone would use loctite is beyond me and asking for problems.

Anyone who oils the threads needs to pay STRICT attention to the fact that you only torque to 70 inch pounds since keeping the torque setting low on oiled threads is a close match to using the higher torque settings with dry threads. If they oil the threads and then torque up to the specified torque settings (95-113 in lbs on the KZ650) they run a serious risk of stripping the threads. Ed

I think personally ill stick with the easiest control, get the threads clean and dry and rough it the proper spec, no worries about affect of oil or locktite., I really appreciate the conversation fellas.

Would time certs be better, most probably but.... expensive and requires special tools to insert correctly.
Heli Coils work just fine....

As for torque... BAH.... SNUG is the torque measurement to use...
Unless you have a truly calibrated high dollar Inch torque wrench at these low values,
Use SNUG otherwise you or someone else is going to strip them holes,... Happens all the time!

650ed wrote:

DFIGPZ wrote: I TQ to 70in lbs make sure holes are clean then lightly oil threads why someone would use loctite is beyond me and asking for problems.

Anyone who oils the threads needs to pay STRICT attention to the fact that you only torque to 70 inch pounds since keeping the torque setting low on oiled threads is a close match to using the higher torque settings with dry threads. If they oil the threads and then torque up to the specified torque settings (95-113 in lbs on the KZ650) they run a serious risk of stripping the threads. Ed

You run more risk ruining threads installing dry I am pretty sure aluminum is weaker than steel bolts but what do I know I have only done hundreds of them :dry:

See this all the time..... Just had to repair all 16 holes in a head. All got helicoils. You can't easily use time-certs on cam tower bolt holes. Helicoils are much easier for that application and will suffice.

Have had heads come in with broken off drill bits and broke off taps in the same hole. Those are always fun.

It's always the 4 bolt caps you see this with. Rarely do you see a 2 bolt cap with stripped out holes. THAT ought to tell you that dowel pins located on opposing corners of a 4 bolt cap require a little bit of attention when installing the caps. The problem that causes this is almost always binding on the dowel pins because of improper tightening and not paying attention to checking the pins for burrs, the cap for burrs and making sure the pin is in the head with the tapered end up.....and last but not least.... apply some oil to the dowel pins, the caps and the bolt threads.

As long as these motors are around there will be stripped cam tower bolt holes. That's as certain as the sun rising in the east.