Head Bolt Tools

Stuka Stunt Main Forum · 12 of 12 known posts recovered

Larry F · Dec 04, 2000 10:52 PM

Gang --

Nothing is more annoying than trying to remove a head bolt or backplate bolt, have the screwdriver rise in your hand, the bolt not move, and look down at your precious engine to find a silvery burr where there was once a pristine bolt. Aaach! It is painful!

None of you "good guys" have this problem, I am sure. The reason is you have better tools than us slackjaws. I have a variety of tools. My cute little Taskforce screwdriver kit has a #1 screwdriver that fits engine bolts like it knew the guy that made the bolt. You know, like they might have talked to each other. I mean, when you stick it into the bolt, it is there to stay. That is the fit I can't find anywhere else.

The problem with the Taskforce screwdriver is that it assumes that people who deal with small bolts have small hands <g>. The grip is a lousy 1/4" diameter. The fit is good, but the leverage is a little low.

Way back when I had a nice driver that had about an 1/8 dia stem, a squarish human size handle, and an ideal fit to the bolts as I described for the Taskforce.

I bought two #1 sizes tonight -- one from PepBoys (Kobalt), and one from Lowe's (Stanley), figuring I would return the one that didn't work. Neither work! I have looked at both tips with a magnifier, and with a little work with a jeweler's file, the tip might work out OK.

Now, all you guys that have good tools, give me model numbers so I can order the correct tool.

Larry F

Warren · Dec 04, 2000 11:34 PM

#1 source

Are you talking about straight slot or Phillips head screwdrivers?

I experience the most slippage problems with Phillips head drivers. And the problem is not only the 'fit', but the softness of the screwdriver tip. One slip, and the tip is damaged, and the problem will just snowball....get worse every time you use it. Have several Craftmans in this condition. You can dress them up on a bench grinder, but the soft tip will just get damaged again.

What I look for, is drivers with hardened tips....they usually look black. I just bought a good Phillips screwdriver at Home Depot. It is a 3/16" diameter, Klein Tools #603-38. It was about $5, which is expensive, but it is a pleasure to use, and no stripped tips. Grabs those head screws on an OS40 and pops them out like they were kiss'ng cousins. It also has a rubber grip (1 1/8" dia.) over the plastic handle, so it provides good leverage.

Check them out. You'll like them.

Cheers,

Warren

Brett Buck · Dec 05, 2000 01:00 AM

#2 source

LAST EDITED ON Dec-05-00 AT 12:37 PM (EST)

>None of you "good guys" have
>this problem, I am sure.
>The reason is you have
>better tools than us slackjaws.
>I have a variety of
>tools.

I pretty much have nothing that didn't come from Sears. What I do to get around the problem you describe is get rid of the slotted and Phillips screws and replace them with socket head bolts. The more common metric and SAE sizes are readily available. There are a few oddball sizes use on Supertigres that are pretty difficult to find. The bolts on a G21/46 are 3x.6 (as I recall) and those are pretty odd (much more coarse than the standard. They can be replaced by 5-40's.

Brett

jacobite · Dec 05, 2000 03:25 AM

#3 source

About Phillpp's screws, I may be wrong here but it may be the Phillip's heads are actually Pozidrive, I'm fairly sure this is true for Japanese Motor-cycles ( I had mostly British iron way back when...).
Phillips screwdrivers in Pozidrive screws will " cam-out " very easily.
Torx head screws would also be a good replacement.

Dave Moffitt

Brett Buck · Dec 05, 2000 12:40 PM

#5 source

>About Phillpp's screws, I may be
>wrong here but it may
>be the Phillip's heads are
>actually Pozidrive, I'm fairly sure
>this is true for Japanese
>Motor-cycles ( I had mostly
>British iron way back when...).

I was trying to remember the name! The Posidrive screws have a shallower angle, and a regular Phillips doesn't fit well at all. Regular Phillips screws actually work pretty well.

Brett

LNeumann · Dec 05, 2000 07:57 AM

#4 source

I much prefer the socket head bolts, also, which are, generally, easier to use and longer lasting. However, some engines, such as the 20/25 FP and Thunder Tiger 36 use a screw with a smaller head that uses a smaller allen wrench. This usually isn't a problem when new. I have had several used engines, however, where the bolts became frozen in use and the end result was stripped out allen wrenches and, sometimes, a stripped out bolt head.

Another warning: When (if) you replace the bolts on your engine, make sure you replace them with bolts of the same length as those used originally by the manufacturer. Shorter bolts, obviously, won't have as much to grab into. And longer bolts...oh, these look so desireable since the bolt holes on the engine appear to be longer than the bolts supplied, but... Well, the truth of the matter is the hole in the case is longer than the threads that are tapped. Although there are taps that will cut threads "almost" to the bottom of the hole, every tap has a certain taper at the bottom and will not cut threads all the way to the bottom. On our mass produced engines there is also a certain amount of tolerance as well in which the hole is made longer than the threads.

I currently have a Tower 40 in my shop on which the owner (I assume) replaced the head bolts with slightly longer bolts. In theory, it sounded good. In practice, every one of the head bolts was stripped out because it bottomed out before it tightened up. I can retap the case for 5-40 bolts and try to save the case, which I shall attempt to do because it has been converted to ball bearings, but we need to issue the warning. Do not replace the bolts with anything other than the same length used by the manufacturer.

Leonard Neumann

Larry F · Dec 05, 2000 12:44 PM

#6 source

Thanks to All!

Warren -- Found the Klein. Actually it is 603-3, not 603-38. The number after the hyphen, I found, is the length! It works as well as you said. The Klein is in the field box. The 603 appears to be the key descriptor. The Klein tip looks the pretty much the same under the magnifier as the TaskForce.

Brett -- Yeah, seems odd that OEM engines come with Phillips. I will eventually swap them out, with Leonard's caveats. I have allen engine mounting bolts, and you are right.

Jacobite -- I believe you are correct that a true Phillips is more pointy ended than the drivers we are discussing. I can't find anyone that knows the correct name.

Leonard -- Thanks for the warning. I'll be darned careful when I do make the switch. I remember on some engines that the head was tapped all the way through, you could break off a cooling fin with too long a bolt. But as you know, my memory is not the best.

Larry F

Chuck McLanis · Dec 05, 2000 07:47 PM

#7 source

Go to your local auto fixit place and buy a small tube of the finest valve grinding compound they have .A small dab pushed into the grooves gives the bit all the bite there is to get. Actually from time to time there is a product called Screw-Loose or some such thing just for this purpose that appears on the market, it's valve grinding compound also. Try this! CMcL

geoffgg · Dec 23, 2000 04:46 AM

#8 source

A long time back in my distant past, when I studied mechanical engineering, I was taught that there is a practical limit beyond additional thread engagement was nothing more than window dressing. I seem to recall that the minimum was about 1.5 times the bolt diameter and the maximum was not that much more. So fitting 4-40 bolts much longer than 1/4" long cannot be justified from the engineering viewpoint. As I said, I cannot remember the exact figure, perhaps a younger engineer can help out here.

Cheers, Geoff

denlip · Dec 24, 2000 06:27 PM

#9 source

I'll not add a great deal to this discussion, but allen screws are an industrial convenience. The trouble is there are several different types of the critters. Some are actually made to fit a certain brand of driver.
Years ago Duke Fox had written a column in one of his adds and stated that he used Proteus drivers exclusively and alluded that his screws were made for those drivers. I had bought several from Fox then and they had fit all his screws perfectly.
In Japaneese engines they are Japaneese standard screws and our phillips will not fit correctly thats why they roll out of them to our great aggrivation. Helicopter supply houses sell good drivers for these as does KSJ
English and European had wider bases and use pugs.
The whole point of this is its not the screw, it's the tool that is important. Sears may sell them but you won't know because they don't label them. You really need to go to a good supply house to get special tools. Which of course makes a good case for allen bolts. simple, direct and available

Steve Helmick · Jan 06, 2001 06:27 PM

#10 source

Perhaps the screwdriver or screw is a "Reed & Prince", which looks like a Phillips, but is more pointed and the blades are tapered in thickness. If you need to tap holes deeper, or have a slightly buggered thread, I am a believer in "Roll Taps", AKA "Form Taps". I would guess that most crankcase threads are done with roll taps at the factory, at least I certainly would. The hole needs to be drilled bigger than for a cutting type of tap, ask for a chart where you get the taps. They will only work on maleable materials, and a good lube is needed. Also, they don't make chips to pack into the hole and tap flutes, and since they don't have flutes, they are much stronger due to increase cross sectional area. STP should work fine as a tapping lube. The nice thing is that roll taps reform the material that is there, so you may be able to go to a smaller screw than you thought. My introduction to roll taps was power tapping 100 holes through 1/4" thick 304 Stainless with a single 4-40 roll tap, without a problem. Couldn't get any kind of cutting tap through one hole.
They are designed for power tapping, and are a bit difficult to get started for hand tapping, but will work. G'luck, Steve

Larry F · Jan 06, 2001 10:29 PM

#11 source

Steve --

Thank you. THANK YOU, and Thank you very much. For the life of me I could not remember "Reed and Prince", and I have not been able to sleep soundly for over a month.

Knowing that doesn't make the head bolts easier to get out or put in. But remembering the name made my day. Really, thanks a bunch!

Larry F