Head Bolt Grease

[cadman60]

I'm replacing a head gasket on a 8hp horz. shaft B&S engine that has an aluminum block. My B&S manual says "A graphite grease or part number 93963, (which is no longer available), should be used on aluminum cylinder screws." Would it be OK to use a little dab of Never-Seez on the head bolts? Engine numbers are below. TIA for your help.
Model # 190402
Type # 0992-01
Code # 78060611

Cadman60

[bgsengine]

I'm replacing a head gasket on a 8hp horz. shaft B&S engine that has an aluminum block. My B&S manual says "A graphite grease or part number 93963, (which is no longer available), should be used on aluminum cylinder screws." Would it be OK to use a little dab of Never-Seez on the head bolts? Engine numbers are below. TIA for your help.
Model # 190402
Type # 0992-01
Code # 78060611

Cadman60

That's what the graphite grease is, pretty much - 93963 is NLA because it used to contain Lead, among other compounds (It was a valve guide lubricant also) - more modern versions will contain Zinc or Copper - but it is all the same effect - however, make sure you NEVER get any on the bolt head or the mating surface of the cylinder head it fits to - you'll end up over-torquing - In fact we never use anything but a light drop of oil on clean and dry bolt threads - too much and you get a hydro-locked bolt (and less torque) - lubricant on the bolt head (or head surface it mates to) results in over-torquing and crushed gaskets. Only reason to use never-seez (or equivalents) would be if you have a high corrosion environment (for future removal of hardware) Never-Seez is just a brand name of a proprietary formula of anti-seize compound.

[cadman60]

Thanks bgsengine for the info. I was wondering if Never-Seez would affect bolt torque. This engine is on an old Gilson Snow Blower. Do you think putting a drop of oil on a clean, dry bolt that gets threaded into an aluminum block would be OK to do in my case? Should the need arise, I just want to make sure I can get those head bolts out. Thanks again for the info.

[bgsengine]

Thanks bgsengine for the info. I was wondering if Never-Seez would affect bolt torque. This engine is on an old Gilson Snow Blower. Do you think putting a drop of oil on a clean, dry bolt that gets threaded into an aluminum block would be OK to do in my case? Should the need arise, I just want to make sure I can get those head bolts out. Thanks again for the info.

for removal if you keep the machine clean and run it at least every 6 months or so, don't let mice build a nest (they go potty in there and that sh*t is highly corrosive) avoid high moisture environment (a dry shed is best for storage) then you won't need any anti seize at all and a drop of oil (hint: wet a rag in oil and wipe the oil on the threads) will do the job.

- I would only use anti seize compound if I new the machine was going to be in a severe environment (Oil Field trash pumps, industrial generators, construction jobs, etc.) and then I would reduce torque by about 20% from spec due to the effect that anti seize will have on torque.

- If I suspect the machine is going to be abused, I still don't bother - if the machine ends up in such bad shape that you bust a bolt trying to remove it, the rest of the machine is about due for replacement anyway.

[Arkie]

If the engine is worthwhile and not a old junkie on it's last leg I take little bit of extra special care with the heads bolts into a aluminum block and on automotive engines I usually use a tap to clean the holes in the block even if it's steel block.
Steel head bolts going into and coming out of a aluminum block I usually take the time to take the head bolts to a wire wheel I have on a bench grinder and clean the threads real good, take a thread tap and clean the holes in the block use air and clean out the holes (so as to make sure the bolts don't bottom out when torqueing) and apply little bit of anti-sieze to the threads of the head bolt and don't apply to much or it may hydro lock and not bottom out when torqueing and I pay special attention to the bolts that are close to the exhaust port. The ones by the exhaust port (high heat area) are usually the ones that corrode, sieze and strip out or twist off. I sometimes run these bolts into the block couple times so as to get good light smear of the anti-sieze on the threads before installing the head and to make sure they feel ok in the threads.
I also keep a heads up for a good careful feel when removing the bolts next to the exhaust ports and work them back and forth when removing so as to reduce the possibility of bringing out the aluminum threads with the bolt or a twist off when removing. If the very bottom end of the bolt's threads is galled (which is where it usually occurs on the ones by the exhaust ports) it will strip threads or twist off. If careful you can feel when its trying to bring out the threads. If a bolt don't want to come lose immediately take time peck on the head of the bolt few times so as to shock it loose. (and don't use a 1/2 inch or 3/4 inch drive break over during removal, use a smaller drive like 1/4 to 3/8 inch so a to get good feel) Little bit of patience in this area will pay off in the long run.

[bgsengine]

Little bit of patience in this area will pay off in the long run.

Yep.. that Bolt Zen (Luke, Become One With The Bolt) is one thing that really pays for itself but only ever comes through years of experience.. You rarely ever find a new tech that has that feel.. but you find a guy that has turned wrenches for 20 years, he's probably breaking far fewer bolts than a "newbie"

I'll also tell you that when I do have a bolt where such Zen is necessary, the bolt gets REPLACED after removal if there is anything anywhere available within its specification.. as it typically will have twisted a bit or stretched a bit (not really visibly so) by the time it comes out. another reason that power tools are very sparingly used.. grabbing the impact at first sign of a bolt that is a little too tight is not a good thing.

[tomw]

My 1st post, and it is a tip most may already know...

I use a file on bolt threads to cut a slight 'wedge' into the leading few threads. Size depends on the size of the bolt. The wedge is cut using the corner of a file, and will have the square edge facing the direction of rotation when tightening. The triangle shape formed by the file will be thicker at the tip of the bolt, and taper to nothing further up. It will look similar to a self-tapping bolt or screw.
I use one bolt like this to clean all the hole threads before assembly when I don't have a tap available(most of the time). The square edge of the wedge will allow any grit, goop and crud to have a place to gather when threading the bolt. I run it in a few turns, and then remove, clean the wedge and repeat. When I can run the bolt down the threads all the way without gathering more 'stuff', I know I have pretty clean threads so I can set the tightening torque with confidence. It really makes a difference on assembly. You can generally thread all the bolts down to contact by hand when the threads are cleaned this way.
tom

[bgsengine]

My 1st post, and it is a tip most may already know...

I use a file on bolt threads to cut a slight 'wedge' into the leading few threads. Size depends on the size of the bolt. The wedge is cut using the corner of a file, and will have the square edge facing the direction of rotation when tightening. The triangle shape formed by the file will be thicker at the tip of the bolt, and taper to nothing further up. It will look similar to a self-tapping bolt or screw.
I use one bolt like this to clean all the hole threads before assembly when I don't have a tap available(most of the time). The square edge of the wedge will allow any grit, goop and crud to have a place to gather when threading the bolt. I run it in a few turns, and then remove, clean the wedge and repeat. When I can run the bolt down the threads all the way without gathering more 'stuff', I know I have pretty clean threads so I can set the tightening torque with confidence. It really makes a difference on assembly. You can generally thread all the bolts down to contact by hand when the threads are cleaned this way.
tom

Good advice - I do that all the time too (and have even used that tip to fabricate my own self-threading bolts in a pinch)

[wristpin]

- I would only use anti seize compound if I new the machine was going to be in a severe environment (Oil Field trash pumps, industrial generators, construction jobs, etc.) and then I would reduce torque by about 20% from spec due to the effect that anti seize will have on torque. -.

Loctite has the same torque reducing effect.

[bgsengine]

- I would only use anti seize compound if I new the machine was going to be in a severe environment (Oil Field trash pumps, industrial generators, construction jobs, etc.) and then I would reduce torque by about 20% from spec due to the effect that anti seize will have on torque. -.

Loctite has the same torque reducing effect.

Not to mention it (Loctite) DOES make a very good anti-seize as well.