Technical Ford Flathead Head Bolt Question

If this was my engine I would do a little bit more research on where to get the proper head bolts. Why don't you go over to the Ford Barn and ask Gary at GOSFAST or Bored&Stroked and ask either of them where they get their head bolts from. I'm quite sure either would be very forthcoming. Getting those heads properly torqued down is extremely important and I'm not confident that those made in Taiwan Hillman bolts are going to work out just the best for you. I have a feeling that they are gradually going to keep on losing their torque settings. I got my 59A engine done at Brothers Custom in Detroit. Fantastic job and works perfectly. Bill wanted to use studs and I fully agree with him. The completed engine was run on a test stand off and on for 2 months or more and torqued and then torqued again until it held for good on the final torque. I installed the engine in my 1929 coupe and to date I have never had a problem. No seepage and runs great. I also have a C69A engine as well and I believe they were a truck engine. The one I have has the 2 piece oil pan with the big clean out plate on the bottom. Super rare oil pan. I think you owe it to yourself to some checking on the availability of the proper head bolts before you get in too deep with those Hillman bolts.

 

I may have missed something in these posts but if you are looking for head bolts, I picked some up from Caterpillar. I got hardened washers also there. They have a good selection and are grade 8. I don't remember the head size of the bolts.

 

ARP is probably what a lot of builders use. $$$ here.

 

I put a request on "The Ford Barn" and got all of the 8BA head bolts I could ever have wanted for shipping. I had to discard a few, but I'm set for life.

Again, does anyone know if the rolled threads in the early blocks are cut to the same specs as 8BA's?

 

I'm not familiar with the early blocks, but it doesn't seem to make sense to roll threads in castings. Thread rolling involves deforming and reshaping the metal, which is not something that cast iron accommodates well.
Have you got that info from a reliable source?

 

The stud holes don’t have rolled threads, they are just a tighter thread than normal tolerances.

 

"Back Inna Day" when I was the junior member of a stock car racing team, we haunted the salvage yards and scrap yards scouting for an 8BA that was damaged beyond repair. If that engine still had the head bolts, they were gone when we left!

 

Alchemy is right,

Ford used a tighter thread cut tolerance.
You can still buy taps and dies that are this way.
Our tool room at work has these for different jobs they do.
Depending on the job or work piece,,,,,the threads will be cut tighter or looser ,,,so after heat treat,,,the hole threads are still correct.
Tool steel holes change size after being hardened.
You can purchase oversized taps and dies,,,or undersized ,,,,in different increments.
So,,,you could purchase an undersized tap,,and chase the threads if you had to.
But,,,it would probably do just as well to purchase a new bolt,,,cut you a groove into the threads and use it as a thread cleaner / chaser.

And I cannot imagine that cast iron would allow itself to have threads rolled into it.
Steel yes,,iron no.
I don’t have any evidence of this,,,,only my experience with iron.

Oh yes,,when I was working with my Dad on our heavy equipment,,,,he swore by Cat bolts. They use to claim that Caterpillar bolts were harder than grade 8,,,i cant swear to that,,,just that they were excellent bolts and caught a lot of abuse.

Tommy

 

Picked my stuff I ordered from Roy Nacewicz/ Third Gen Automotive and stopped by TSC in Ogdensburg. They won't order my bolts as a guy had told me on the phone the other day. They told me to leave me name/number with the items I want to order, and when the sales guy from Hillman drops by in a month, he'll give me a call. I won't hold my breath. I purchased the few bolts they had in stk, and checked a TSC store on the Canadian side on the way back home. Of course the Canadian TSC doesn't carry the Hillman Gr8 black oxide, but they and the Lowes store in Ogdensburg did carry Hillman Gr8 bolts in Zinc Chromate finish, but those bolts don't have the flanged head, and we're not stocked in 2.75" lengths.
Again, kinda of frustrating, but the washers from Roy fit these fanged head bolts perfectly.

 

Ziggster,
Those are good looking bolts to me,,,I like them.
Keep looking.
Have you considered looking into Grainger,,or MSC,,,they carry a lot of stuff as well.

Tommy

 

Thanks. I like them as well. Reading up on the Hillman Group, they are pretty big, and supply many of the box box stores with a myriad of different brands. Couldn't find if they are made here in NA, but they do have two manufacturing plants here.
Fastnel sells what I need, so I'll check with them as well, and our Caterpillar dealer here in town.

 

The head in the picture is from an early engine(pre 49) and those engines used studs. I bought the correct studs from Roy N. sometime back so I don't know if they are still available since Roy died earlier this year. They fit correctly in my 59A . I don't know what your machinist was thinking about recommending that you use bolts, but the use of studs in engines is considered to be superior as the twisting action while tightening a nut on a stud is less stress on the block. I would give up on the bolts and buy the studs.https://arp-bolts.com/kits/make.php?_Make=408&_EngModelID=*

 

I tried, he won't listen.

 

I don't hear much at those prices either.

 

The engine in my sedan uses the Speedway stud kit which cost around $100. It holds torque just fine, never had a stretching problem.

 

The engine in my coupe uses the original head bolts which cost me next to nothing. They hold torque just fine, never had a stretching problem.

 

What I still don't understand, and what no one had explained is why do I have three different length bolts which all protrude from the head the same amount. The Speedway stud kit offers only two stud lengths, which makes me think once installed with the stk heads, the amount of protrusion from the head surface will be different in some locations. Honestly, I never thought I would be spending thus much time talking about head bolts, but it seems I can't be the only one who has had to deal with these questions.

 

Did you run this by the Engine Re-builder who did the work on the block?

 

He suggested bolts as well, but didn't know enough about the variations of heads/engines. I'll check again when he gets back after va action in the new year about extra Ford bolts. I'm going to review all options.

 

Ziggster,
If you want to use bolts,,,there will not be a problem.
Some guys are just pointing out that you might experience some leaking because of the wet bolt holes.
My 49 Mercury had bolts from the factory,,,however,,I’m gonna go back with studs because I cant stand anything trying to leak.
Also,,,studs always seem to distribute the load more evenly,,at least that is what I have always understood from the data.
The bolts you have seem like good quality,,,,go for it.

To be honest I was worried about the cost of studs,,,but after I looked at buying good bolts and washers,,,the price was almost the same.
6 of one,,,half a dozen of the other.

Also,, now,,,I plan on reusing the stock heads as well.
I was worried about over heating with the stockers,,but after some post lately on the Hamb,,,I believe stock will cool just fine.

Good luck.

Tommy

 

On my 8BA there are normally two different length bolts, but, if there are exhaust deflectors installed for the center exhaust, the bolt above it will be shorter than any of the rest. That would give you three different sizes.

 

Yep, cost of studs vs bolts is about the same, so that really isn't the issue for me. Mostly, I like the look of bolts vs studs with the nuts on top. I'm not using any chrome covers either.
Not using any exhaust deflector either. The length of the three different bolts is to accommodate the head thickness where the various bolts go, because they all protrude the same amount if you go back and look at one of my pics.
Do folks cut the studs to get them all flush with the top of the nuts, or is that what the caps are for?

 

Well,,,I don’t blame you,,,,if you want bolts,,,that is what I would do.
What about skipping the middle length ?
Since those screw into wet holes,,,they would just protrude a slight amount into the water jacket,,,or you could trim the length a little,,no problem?
I’m sure the issue is getting them found and purchased,,,I hope you can find them.

Oh yeah,,,,I needed some hardened washers for my main cap bolts.
I found ARP ones on Amazon,,,in a 10 pack,,,,the right size,,with a chamfered side.
Like about 9 bucks a pack,,,work great,,,and they are black coating like your bolts. Just an idea .

Tommy

 

He wants to use bolts & you want studs. Who is footing the money for the bill??? Your money & your engine.

 

As far a bolt length. You have three different length bolts and they protrude from the head equally. Then you have the correct length for those heads. Aftermarket heads often only need two lengths. Often the stud or bolt kits will be for aftermarket heads. Used whatever length you need. I bought bolts the length that I needed.

 

This thread has evolved into the realm of "making a mountain out of a mole hill"!

 

I have built a lot of engines and have never had a problem with used original head bolts.

 

Just some additional info and an update. I looked at the ARP bolts on the AllenFasteners.com site. They list two different types, depending on whether you want a 7/16" wrenching hex, or a 1/2" wrenching hex.

ARP 7/16-14 Hex Black Oxide Flange Bolt 7/16 Wrenching
Product ID: 0506
Flange Dia: 0.672"
Price: $3.08 (base for 1" long)

ARP 7/16-14 Hex Black Oxide Flange Bolt 1/2 Wrenching
Product ID: 0506A
Flange Dia: 0.738"
Price: $2.80 (base for 1.5" long)

Both these flange diameters are smaller than the typical spot face diameter machined into the stock heads I have (C7RA). The spot face diameter is approx. 0.850".

The flat hardened washers I purchased from Roy Nacewicz for
use with original style nuts for use on aluminum heads are 0.919" in diameter (P/N R-092-B). Even though I don't plan on using aluminum heads at this point, they are a good match for the machined spot face in the head, even though they are slightly oversized.

The Hillman flange head bolts have the following dimensions:

Hex head: 5/8"
Flange diameter: 0.890"

The stock Ford bolt has a hex head of 11/16"

When I first checked the ARP bolts, I was going to order them, as I'm getting tired of this, but the flange dia and the hex dia are just too small looking in my opinion. I called TSC in Ogdensburg, NY a few days ago to follow up, and the Hillman rep did take my "order", but I'll have to wait another month to see what comes in. The mole hill continues to get larger. Lol..

 

An update of sorts. Dropped by the TSC store in Ogdensburg yesterday to check up on my "order" while picking up some other stuff I had ordered elsewhere which is shipped to the freight forwarder near them. They said the parts should be in this coming week, so we will shall see.
I'll say this though. There is a marked difference in the sales staff I find in the USA and Canada. The staff I find in the states, and doesn't seem to matter what type of store or business or what state, are so much more helpful and friendlier than they are here in Canada. Afterwards, I drove down to Watertown, NY, about an hours drive away to pick up a sand blast cabinet at the Harbor Fright store. I had them put it on hold while I was in Ogdensburg. When I showed up, I mentioned I had called about the cabinet and within a minute, the cashier had called another staff member, who then called another staff member in the warehouse, who brought it out on a dolly, and to my car. This all happened within a few minutes, and with a bunch of genuine smiling faces. I can assure you, my experience in Canada, at the local Princess Auto, would not have been the same.

 

Can't help but wonder why Canadian experience is not as pleasant.
Business is business, one would think.