How to return to 1/4" bolts when someone resized for 5/16"

[RoadsterRich]

Sometime in the past someone has retapped the holes in the block which hold the water jacket on. The originals were 1/4"x20tpi (I have been told), they are now 5/16"x24tpi. What would the best method be for getting these back to the original 1/4x20, or is that not feasible? I picked up a pair of original water jacket covers only to find out that the 5/16x24 bolts won't fit through them. Obviously I could ream out the holes in the covers, but I would much prefer to return it to the original sized bolts. Bear in mind that the threaded portion is open at the back end to the water passages. That is to say the end of the bolts that hold the water jacket cover actually will be in contact with water, as such so will anything I use to revamp the threads. Any and all help is truely appreciated.<P>Thanks,<P>Rich

[Guest]

Rich ~ Your desire to return to original is admirable but is it necessary or worth the effort? I think you would have to first make the hole a lot larger in order to make it smaller. There may be some risk in that. I suggest seeking the advice of someone who REALLY knows and understands the procedure which would be involved. Then there may be a question as to water tightness after the job is done.<P>As usual, that is just my non professional opinion. I could be totally wrong. ~ hvs

[RoadsterRich]

Howard,<P>First off would I ever have points deducted for the wrong sized bolts while being judged? Secondly, it kills me to contemplate reaming out the holes in beautiful original water jacket covers. Thirdly I often get confused between, preservation, conservation, and perfection <P>Rich

[The Old Guy]

A 1/4-20 bolt uses a 9/32 drill for a clearance drill. The 1/4-20 heli-coil uses the 9/32for a tap drill. The 5/16-24 bolt uses the 9-32 drill for a tap drill, so it would seem that all you need is a 1/4-20 Helicoil tap and a hand full of Helicoils and you are home free!

[Guest]

If you try to retap it will not work because of the mismatched pitch of the threads. What you can use Rich is an insert called a Keensert. This is a heavy wall insert that has little pins that you drive in to lock it into position. You must drill oversize so make sure there is room for a 7/16-14 thread with a letter T drill used for a tap drill. Here a link that shows you what they look like; <A HREF="http://www.imperialinc.com/items.asp?item=0073040" TARGET=_blank>http://www.imperialinc.com/items.asp?item=0073040</A><p>[ 03-25-2002: Message edited by: 4 Jaw Chuck ]

[Guest]

It seems with all of this suggested drilling, tapping, filling, inserting and/or welding that there is a lot of room for trouble here.<P>I assumed that the block is 70+ year old cast iron with all of attendent aging, rusting and the like. If the 5/16 threaded holes in that block are good, you might not want to mess with a good thing.<P>I'm sure all of the suggestions offered are good ones but they can be fraught with peril.<P>I seriously doubt that a judge would recognize that the bolts should be 1/4 rather than 5/16. They will be there and look right. I cannot see anyone taking a deduction for that. You would be more likely to lose points for a rusted 1/4" bolt.<P>But again, that is just my opinion. ~ hvs<p>[ 03-25-2002: Message edited by: hvs ]

[Peter J.Heizmann]

Rich, the way I see it is your call totally.<P>Personally, I would not fool around with the block. Fe (iron) will oxidize to a point then act as a protectant. (Ever notice those guard rails along highways that are rust covered?).<P>I concur with what Howard is alluding to in that would you want to replace the block, or, open up the covers?<P>If a judge docks you points, he either has God-given micrometers in his eyes, or, he will actually use one.<P>A known, in my thoughts, are no one knows how much oxidation is on the I.D. of the block. If you start reaming, re-tapping, etc., who knows how much oxidation will chip off the I.D.? <P>Regards, Peter J.

[Guest]

Rich ~ Believe me, Peter J knows cast iron. It is his business. ~ hvs

[Guest elgin16]

I would fix it in one of three ways.<P>First you may get lucky and find a helicoil that will work.<P>Second I would put a 5/16 bolt in the holes and cut or grind them off flush then drill and tap a 1/4 inch hole down the center of them. I have used this technique on aluminum heads with real good results. <P>Third I would weld the holes shut and drill and tap a 1/4 hole.<P>For solution 2 and 3 be sure you have good taps, cheap one won?t cut hardened metal.

[Guest]

MAYBE YOU COULD MACHINE THE BOLT HEADS ON THE 5/16 BOLT TO THE SIZE USED ON 1/4 BOLTS<BR>{1/2 TO 7/16}FROM THE OUTSIDE WHO WOULD KNOW.

[Guest]

That's EXACTLY what I did to a guy's cross engine Franklin on the valve assembly bosses,plus the water pump on my '32 Nash.

[Peter J.Heizmann]

stude8: Very interesting & informative. Never thought about the stainless bolt concept as I have never dealt with it on my car.<P>What I forgot to mention (and you indicate) is what "good, solid metal" is in the section size. An area of a casting that has a 1/2" wall thickness, or, above, would be more condusive to Rich's plan. I agree that the wall thickness where he is contemplating returning to original would be a gamble I would not want to take. A block, or, any casting, looks huge by the naked eye, BUT, it naturally varies depending on the contour.<P>Manifolds, blocks, etc., all have variations in wall thickness. Take a manifold. The mounting flange is obviously thick. The side walls of the contoured areas are, as you indicate, a lot thinner. There is the gamble. Human nature would be to think, well, if the mounting flange is 1/2 - 3/4 thick because I can see/measure it, never assume the same dimensions hold true for the whole part. <P>I am rambling, but, I have never seen any cored castings, utilizing green sand molding processes, that have the same thickness throughout, whether by intentional design or process variations. <P>Regards, Peter J.<P><BR>

[Guest]

Rich ~ Never let high tech engineering overrule common sense. <P>Again, let me say that there is probably no one on this forum who knows more about casting and castings that Peter Heizmann. It is his business. ~ hvs

[Guest]

Rich ~ Even if you grind or machine the heads down to 7/16 you will still have to enlarge the holes in the cover to allow the threaded part of the 5/16 bolt to pass through. Then the head will be slightly small for the hole. I seem to recall that you were hesitant about enlarging the holes in the new cover.<P>It seems to me that there are probably a lot of bolts to alter to make a change that no one will notice anyway. A 5/16 bolt with a head altered to that of a 1/4' bolt is as non authentic as the 5/16 bolt, so if absolute authenticity is your goal, that fix won't do it.<P>Trust me, the judges aren't that thorough or knowledgable that they will notice and deduct for the 5/16 bolts on your car. I normally judge your class, I have been judging for 34 years, and I would have no idea whether the bolts should be 1/4 or 5/16. Judges are more interested in things like spark plug finish, hose clamps, plastic wire, valve stems, etc than they are in bolts. The only time bolts cause concern is if they have stress marks on the heads and are on a pre WW II car, so just make sure there are no stress marks on the bolt heads. If it looks correct and is well done, it will never attract attention. ~ hvs

[Guest stude8]

Hello Rich:<BR>I would not fool with the block, I'll bet the wall thickness you are looking at is only 5/16" or 3/8". That is not enough for a Helicoil to be reliable and remember you really want a watertight situation here. I have dealt with the same problems on my 1930 President (Actually 3 different engines) and it has 36 water jacket cap screws (5/16-18) into the coolant cavity. Use stainless steel SAE screws so you can get them out in the future again. Most stainless hex screws have grade marks stamped on the heads that you will want to grind off on your belt sander, you can then sand them with 220 paper, a touch on the buffer and they will look like a good old screw but never rust again. Plan to use copper/white-lead crush washers under the heads to seal the water. You can get fresh 5/16 crush washers from Dave Murray 253-565-8598 he sells them for Pierce and President water jackets. Stainless screws from McMaster-Carr. Be sure to dope the threads with sealer because they always want to leak no matter how good a job you do. Stude8

[RoadsterRich]

In revisiting the block, after all this discussion, I fear my woes are much worse than originally thought. The section of the block the water jacket bolts go through has thinned dramatically both in the front to back of the bolt and the amount of material on top of the bolt towards the opening. In a few of the cases the upper part of the threads are actually exposed. Obviously the use of anything requiring enlarging the holes is absolutely out. The next issue is how do I handle the places where parts of the bolts thread going through the block are exposed? (basically it has corroded down through the block to the point it is open in to the threaded hole in the block from the top looking down, the backs of the bolts were always open in to the water jacket.<P>Any ideas on this one????<P>Rich

[The Old Guy]

Is it possible to make a piece from strapping that will go into the jacket with 1/4-20 holes ,so you could actually clamp the waterjacket cover to the block??

[Peter J.Heizmann]

Rich. <P>stude8 hit it right on the head. Pre-heating is critical to prevent crystallization of the carbides. Read his post and adhere to it.<P>Tomorrow, I will talk with one of our metallurgists for input on the best route for repairing. Don't quit. There are good methods. I'll get back. <P>Regards, Peter J.<p>[ 03-27-2002: Message edited by: Peter J Heizmann ]

[Guest stude8]

Rich: You might try some skillful Brazing to fill in exposed areas then chase threads out to the previous size. The strap idea just mentioned has potential but use Brass material to survive in the coolant atmosphere. You might "Tack" it in place with braze. You would want to preheat the area of the casting slowly and likewise let it cool slowly (Keep reheating modestly) to come down from the actual torch heat condition. I'll admit to failing a braze job on a thin wall exhaust manifold crack. It went so well until about 15 or 20 minutes during the cool down period it went "Clink" and recracked. Stude8

[fordee9r (Ron Springstead)]

How about using something like "JB Weld" or a similar epoxy product? I understand that, once cured, it can be drilled and tapped. Anyone have any experiences, good or bad, with these products? I've only used "JB" once, many moons ago to repair an elongated keyway on a crankshaft. After fully curing, I filed away the excess, installed the key and balancer and sent it down the road. Never heard back from the customer but I knew the truck was running for several months before he moved out of the area.

[Guest]

Keenserts are used in virtually every aircraft engine in use today, they can be ground down to any height you might require. Since they are a larger diameter than the original thread they will have a higher pull out strength than the original. Seal them in with high strength red loctite and they will not leak, the entire industry uses them and they can be purchased at any good bolt supplier. They are simple, strong and adaptable to virtually any situation, even if the casting is only an 3/16 of an inch thick in this area it will work just fine. Install leaving enough sticking out to grind off flush. Everybody uses them particularly for high torque bolts that go into aluminum.<p>[ 03-29-2002: Message edited by: 4 Jaw Chuck ]

[Guest]

If you plan on brazing heat the whole block slow to at least 150+ degrees that way you wont have hot and cold spots and you wont have to heat your brazing spot as long.This is best done with a empty block?This is how the old timmers did it and they seldom had cracks wen done.THERE is a product on the market called DEVCON, it contains metal and is made for different metals.I think Snapon tools sold it? We used it on industrial applications similar to yours and it puts JB weld to shame.If you need help using or finding it let me know.with this you dont have to take the block out or apart.Have anice day.

[Guest stutzdriver]

I am the sales manager of a company that manufactures the keylocking inserts in 3 styles. Heavy duty, Extra Heavy duty abd THINWALL. the thinwall has a 3/8-16 external thread. The inserts arw manufactured in Carbon Steel and Stainless. More information can be foundat our website <A HREF="http://www.jergensinc.com" TARGET=_blank>www.jergensinc.com</A> <P>Good ZLuck

[Guest Billy Landenberger]

Hi, I'm new, and I can't get back to where I was reading about returning used up snapon tools. A few guys were having trouble.

Maybe my wife has the knack but she just called Snapon home office and spoke to someone who asked what was wrong with the tool and what the model number is. He's sending a new one. No necessity  to return the worn out screwdriver. I'll know better when I get the new one, but that's what I have to add.

Their 800 number is: 877-762-7664. Good luck.

[Bhigdog]

Lots of blocks have holes through to the water jacket. Keep it simple by doing the easiest and least invasive fix first. Drill the pump holes out to accept 5/16 bolts. Slather the bolt threads with aviation Permatex and tighten down. It should be fine. If not move on to the next least invasive fix...................Bob

[joe_padavano]

1 hour ago, Bhigdog said:

Lots of blocks have holes through to the water jacket. Keep it simple by doing the easiest and least invasive fix first. Drill the pump holes out to accept 5/16 bolts. Slather the bolt threads with aviation Permatex and tighten down. It should be fine. If not move on to the next least invasive fix...................Bob

 

You do realize the thread to which you are responding is fifteen years old, right?  I hope the OP has fixed that engine by now.

[Bhigdog]

53 minutes ago, joe_padavano said:

 

You do realize the thread to which you are responding is fifteen years old, right?  I hope the OP has fixed that engine by now.

 

Oh Jeez. Thanks, Joe........................Bob (the fool with egg on his face)

[Rusty_OToole]

Just in case anyone cares... there is such a thing as a "bull head stud". It is one diameter on one end and a smaller diameter on the other. Suitable studs could have a 5/16 end  screwed into the block and a 1/4 sticking out. If fixed with Loctite should hold even in rusted areas. The plate can be held on with nuts and washers or Acorn nuts for a decorative effect.

[joe_padavano]

10 hours ago, Rusty_OToole said:

Just in case anyone cares... there is such a thing as a "bull head stud". It is one diameter on one end and a smaller diameter on the other. Suitable studs could have a 5/16 end  screwed into the block and a 1/4 sticking out. If fixed with Loctite should hold even in rusted areas. The plate can be held on with nuts and washers or Acorn nuts for a decorative effect.

 

That's actually a great idea, thanks.

 

To Bob, unfortunately, when a newbie dredges an ancient post up from the crypt, we don't always check the date.  Of course, it's not like I've ever responded to one of those...

[trini]

I had a similar problem on the 1928 Dodge Senior engine on one bolt thread I solved it by using a hel ciol kit It comes with a special size drill. I used a special washer to seal all the bolts from water leaks. These washers have rubber inserts around the inside holes A flat washer may be used behind if you like . These washers are sold by Techno Seals here in my area in Toronto Canada. I still have a few left. All depends on how much "meat" left in the block. If you decide to use carbon steel bolts, use copper slip grease. It works for me.

All the advice have merits, but the block  is the dictator. The cover on the water jacket was rusted , lots of holes inside and a few was leaking. I sand blasted and soldered the holes from inside and had it powder coated.