Bernbaum Head bolts

[Oberstar]

Without looking at an image of exactly what I was buying, I bought a set of head bolts from Andy for my D24 motor(I assumed they would be NOS DPCD).  I have no doubt that they will work as intended.  However, I was a bit disheartened to see that they appear to be the Chevy 350 bolts a lot of guys were talking about.  Crud.  If I had known that was what was going to be sent, I bet I could have gotten them cheaper than $3 a piece plus shipping....

Not mad or angry- I asked for head bolts, and he sent them to me.  Good looking bolts that will be on that motor until my Grandkids need to remove them!

But anyway, the bolts already come with a whitish film on the threads that appears to be Teflon coating.  Can this be used in addition to my aircraft sealer, or should they be cleaned of all oil film and foreign material before my aircraft sealer?

[Lloyd]

I used a new head bolt set from AB as well. I called them and asked about the stuff and what it was, he told me that the flatheads required a sealer on the bolt threads so they had applied it for me - it should work fine but at my choice I could remove it and apply my own, which I did do and then cleaned all residue from the bolts mainly because the sealer I wanted to use stated that it needed to be applied to clean dry threads. Its also a good idea to clean out the bolt holes on the block with air, then run a tap down them, use a good degreaser and blow them out as well.

[classiccarjack]

Lloyd is right about cleaning up the bolts and bolt holes, and taping the holes in the block....

If you feel binding or hear sounds while torquing your head bolts, be sure to stop, remove the head bolts, and clean out and tap the holes in the block again. Improper torque equals leaks and head gasket failure.  Definitely not something to be rushed.  

I am sure that you already know this, but I just wanted to help prevent you from having any issues.  I had an employee once that learned this the hard way.

[Oberstar]

No, even if I knew, it's always good for it to be re-enforced!  Thank you!

I removed the Teflon paint from the threads, cleaned them with carb cleaner, and even went out and got some Copper Spray Gasket.  I whined about the $7 price, but want to ensure that I don't have to remove this head for a long time.

[Mike36]

For those without much experience at taping a hole, I will add this. Make sure you have a sharp tap. Do not use an old dull beat up one you found in the bottom of the drawer. Get everything you can out of the threaded hole using compressed air. A nozzle long enough to reach the bottom of the hole is best. Use a light oil on the tap. Turn tap at slow steady speed. I if very little resistance is felt, turn tap all the way to bottom of hole. Stop turning immediately when bottom of hole is reached. Back tap out, blow off with air, blow hole out with air until nothing is coming out of hole. If resistance is felt while tapping, go a little way in, remove tap from hole. Blow hole out with air, blow tap clean and re oil. Do this as many times as necessary until bottom of hole is reached. This may or may not be quite time consuming depending on the amount of crud in the threads. PAY ATTENTION: DO NOT GET IN A HURRY!!! Taps are very hard which means they are brittle!!! They have to be hard to cut steel. If you break one off in your engine, its NIGHT MARE CITY!!! Because of the hardness of the tap, they can be EXTREMELY difficult to remove when broken. Remember, cleanliness, light oil, do not force it. Accurate torque is achieved with a clean, lightly oiled thread.

 

 

[Frank Elder]

All of this is good information, you guys left out one out.....iron block, iron shavings.......after you blow out the hole go fishing with your telescoping magnet just in case the cutting oil has trapped smaller particles at the bottom of the hole.

 

[Don Coatney]

And in several of the head bolt holes the bottom of the hole is inside the internal water jacket of the block. Thus all the iron shavings and rust crud is now free to float around inside the water cavities of the engine. Use the magnet and a shop vacuum to suck as much of the stuff out as is possible before and after the blast of compressed air.

[Mike36]

20 hours ago, Frank Elder said:

All of this is good information, you guys left out one out.....iron block, iron shavings.......after you blow out the hole go fishing with your telescoping magnet just in case the cutting oil has trapped smaller particles at the bottom of the hole.

 

Don, that is a good point I over looked. I believe a better solution would be to use a spiral fluted tap     On the holes that enter the water jacket. They are designed to pull the chips and cuttings OUT of the hole, towards the shank. Instead of pushing them ahead, as a standard tap does. Again, do not get in a hurry!

Edited April 9, 2017 by Mike36

[DJ194950]

One of my mentors -owner of a equipment rental co.- told me to put a heavy grease (like and old style bearing grease) on the tap when used in sensitive areas whether a newly tapped hole or cleaning one out and then Very regularly backing the tap out- cleaning if off-and reapply thick grease,repeat until done.

DJ

[Oberstar]

Installation of the new head gasket and bolts went well, no issues (as of yet).  Going to let the Aircraft Sealer set about 24hrs, and then fire it up and check for leaks.  If me and my Son have done the flathead right, the valve job should bring up the PSI of cylinder number 6 from 40 to at least 90.  My only concern right now is possible coolant leaks.  We'll deal with that if it arises....

It still feels weird putting nasty ol' Chevy bolts in a Chrysler powerplant!

[Jerry Roberts]

Remember to re - torque your head bolts  , they loosen up a lot . I do mine several times to be sure . 

[Flatie46]

2 hours ago, DJ194950 said:

One of my mentors -owner of a equipment rental co.- told me to put a heavy grease (like and old style bearing grease) on the tap when used in sensitive areas whether a newly tapped hole or cleaning one out and then Very regularly backing the tap out- cleaning if off-and reapply thick grease,repeat until done.

DJ

We use a product where I work called " Mike O Cut " No 87 . It's for lubing Taps, dies or drills. It's thick like honey and sticks to the tap, pretty good for pulling the shavings back out with the tap. I like it because it doesn't just run off the tap, stays with it.

 I agree with Mike36, an old dull tap or a new cheap one can really ruin your day.  

[rallyace]

If you are buying a new tap to chase threads in a blind hole, get a bottoming tap. There are two main types of tap, a taper or starter tap that has the first few threads ground on a taper to make starting the tap in a new hole easier and a bottoming tap which does not have a taper.  I use a bottoming tap when chasing threads as it will clean the threads a little deeper into the hole. You must be vigilant when using this type of tap as the hole will have been made with a taper tap and you can waste effort cutting the threads deeper than the original and also risk jamming and breaking the tap in the hole. I have no idea what the taper was on the original tap and using a bottoming tap assures me that I have cleaned all of the usable thread. I stop when I feel the tap start to cut at the bottom of the hole. As has been mentioned above, proper lubrication of the tap abd thoroughly cleaning out the hole after chasing the threads is paramount to doing the job correctly. Just my two cents worth.

[Plymouthy Adams]

15 minutes ago, rallyace said:

If you are buying a new tap to chase threads in a blind hole, get a bottoming tap. There are two main types of tap, a taper or starter tap that has the first few threads ground on a taper to make starting the tap in a new hole easier and a bottoming tap which does not have a taper.  I use a bottoming tap when chasing threads as it will clean the threads a little deeper into the hole. You must be vigilant when using this type of tap as the hole will have been made with a taper tap and you can waste effort cutting the threads deeper than the original and also risk jamming and breaking the tap in the hole. I have no idea what the taper was on the original tap and using a bottoming tap assures me that I have cleaned all of the usable thread. I stop when I feel the tap start to cut at the bottom of the hole. As has been mentioned above, proper lubrication of the tap abd thoroughly cleaning out the hole after chasing the threads is paramount to doing the job correctly. Just my two cents worth.

the use of the second or intermediate tap will reduce the risk of cutting new thread or breakage on reaching the bottom...

Edited April 11, 2017 by Plymouthy Adams

[Mike36]

I intentionally did not mention the bottoming tap because there is no chip clearance if a person goes too far in the hole, thereby snapping part of the tap off in the hole. I am sure there are those on here without extensive experience at tapping or cleaning previously threaded holes. When you are inexperienced at this, the danger of a broken tap is real, and something you will regret. A standard plug tap is all that is needed and is safer.