AV8, 286, Bruce L, and other flatty lovers. Studs or bolts?

[Kevin Lee]

And why? Maybe I'm getting too fancy schmancy here but this engine is turning out to be so nice thus far that I don't want to do anything that might wreck it. Is it okay to run the original head bolts if all of the threads look nice? Looks like no corrosion present and they all came out fairly easily.

Sounds reasonable to reuse them but the problem comes when I switch to aluminum heads. Add a washer to prevent the bolts from biting into the head surface and it reduces the purchase on the block. A thin washer shouldn't kill anything, right? I am still on a budget here so reusing hardware would be nice, but I don't want to buy headgaskets twice and new hardware because of it.

What would you use and why? I've read some books, just looking for opinions.

[Smokin Joe]

Switching to aluminum heads usually means different lengths from stock. Also bolts being reused means that they've already been stressed once.

[4eva4banger]

I used longer stainless head studs on mine no worries

[Kevin Lee]

Pretty sure these heads are stock dimentions. Just aluminum "stock" heads.

I guess my question should be, "Any real reason I shouldn't reuse my head bolts and if so, should I replace them with more bolts or studs?......And why?

If you retorque your heads or replace a headgasket arent you using bolts that have already been stressed at least once? Just asking.

[Bruce Lancaster]

An issue here is the amount of retightening (lots) flatheads with aluminum heads need, grinding away at old, rusty, too shallow threads each time. Studs get set in there and stay. Bolts came along about three seconds after Henry died, when Ford hired lots of former GM beancounters and became a modern, cashflow oriented company instead of a primitive product oriented one.

[Kevin Lee]

That's a good enough "why" for me. It's down to the final hour or so. poncho should be here anytime with the goods.

[286merc]

If it came with studs use studs; if it came with bolts use bolts.
IMO studs are a PITA to get heads over, especially aluminum.

Ive yet to have a problem with bolts in an 8BA style block with fresh chased threads.

Maybe Ford should go back to studs in the 3.8 V6 but for a non racing flatty it makes no difference except ease of assembly.

Factory bolts can be used twice maximum. Be sure to seal them good with Permatex.

[Kilroy]

I'll tell you about my 8ba block...

At least 10 bolts that wouldn't come out when it was originally cracked for the rebuild. They eventually came out but the threads were slightly buggered in the process. The guy that had it before me chased the threads and put new bolts in. He ended up stripping all 10 bolt holes in the deck.

Now I bought the block from his builder with almost all the bolt holes helicoiled.

I think it's worth the other hassles to protect your block with studs. Just put in some permatex like 286 says, liberally on each stud.

Just my opinion...

P.S. Here's something else that should be discussed here...

After you get the old fasteners out, you need to clean up the threads, but I gather that Ford used special taps when they threaded the holes in the flatty and running a modern tap down the holes loosens up the holes a little.

So what's the best method for cleaning up the threads in a flatty?

[Tuck]

Grimlock

I reused most of the bolts on my flathead when I bolted on all the speed equipment. I just got some big washers to help spread out the pressure on the aluminum.

I heated a couple in removal and tossed em.
I have a drawer FULL of head bolts from 3 different flattys I dissasembled. NEED ANY?

Need one more acron?

I havent had any problems, I had the one bolt break off removeing the old heads but I took care of that...

I ran around and let it heat up and retorqued all the bolts again..

check yet again later and they were all right on...

didnt have any break
dont have any leaks
everything rocks...
and it didnt cost shit... just reused the old bolts.

The one thing I check was that they fit thru the head with the same amount of BOLT showing on the backside. So I wasnt short threading the new heads. EDMUNDS heads i bought were the same as stock as far as how much of the bolt protruded out the back side ya dig??

Now mind if I bring my dyno over tonight? I need help adjusting the ORYG so that I have brakes... The neighbor kids have a half pipe behind the garage and I wana KILL MYSELF friday night when the trash...


ROCK OUT
Tuck

[Bruce Lancaster]

On the block threads (and also banjo rear threads) I have heard but can't confirm that Ford used one of the tighter grades of tap (There is a nomenclature--class two, class B, something like that--check an industrial supply catalog) and that use of a normal thread depth tap will degrade fit. I suspect this is true--using even a new good brand tap does seem to add some wobble there. I lost the blasted citation on this. Naturally, I've tapped all the holes all my life and so has everyone else, so there are probably few blocks around that haven't been retapped...anyway, to be safe, I will in the future use .45 calibre clening brushes. Smokey Yunick's book has a long rant on how he sets up the studs both for solidity in the block and for squareness. And definitely check thread depth in the block--I think 7 or 8 turns worth--see how the stockers go if using bolts. With aluminum, different makers used different thicknesses, and you need a washer that's several threads deep, so you may well need new bolts anyway.

[Iceberg]

Red Hamilton of "Red's Headers" is pro studs. Our local PNW flathead guru Earl Floyd says bolts. I went with Earl's advise and used Caterpillar hardened head bolts. I've had no problems with my new Edelbrock heads.

[Kilroy]

Another thing to remember is that with aluminum heads, you torque and retorque the fasteners at a lower rating than with iron heads.

I'm using studs with my iron heads.

What's the feeling about using actual acorn nuts on studs? Do they hold torque well or are they more $/work than they're worth?

[burger]

Bruce,

Threads are classified like this:

UNC = UNified standard Course thread
UNF = UNified standard Fine thread.

1 = Loose fit
2 = Medium fit (Most threads are this classification)
3 = Tight fit

A = External thread
B = Internal thread

[Flatdog]

Studs are a hassle, but I WILL NOT do it any other way.Hope you dont have to learn the hard way.

[286merc]

Thanks for posting that Ed.
I had to have my "Tight Fit" special ordered some years ago. It is probably time for a new one so if anyone is having a problem finding a source let me know. Hopefully my supplier can still get them.

[burger]

286merc - how do i get in touch with you to get some zero rust? i've sent you a pm, but i haven't received a reply.


ed