Milling/Shortening Cylinders

[Hillside Motorcycle]

The studs aren't/weren't the issue, but rather the poor quality case material, usually casing a fracture in the 90* corner behind the rear tappet block, migrating up to the cylinder stud holes, and in other instances, the cylinder stud case threads are only pulled.

[thumper 823]

Unless you have a well-rounded education in metallurgy, one will scoff at fastener stretch.
It is real folks, and like already said -once the rubber is gone,  the steel it is now just a static pull and quite worthless.
If seeing is believing, walk into a "Reliable "  diesel shop and ask for head bolt stretch gauge and used head bolts.
They should have an ample supply. You can actually see how far a bolt will stretch.
I have found it is much cheaper to replace strategic fasteners then even take the time measuring them.
Do you want to replace threads in the case?
Or the studs.
Personally, I use a brand name with a great reputation.
I HATE redos.

[Deye76]

"I have found it is much cheaper to replace strategic fasteners then even take the time measuring them."

I never understood guys spending 12-15 hundred on a flywheel assy., another 6 or 7 hundred on cylinders/pistons, then another grand on heads & cam, only to cheap out and reuse fasteners.

[HD/Wrench]

I sold and installed a lot of Evo S&S cases between '90 and about '96. Late 80's and earlier 90's HD cases had issues, porosity, studs pulling out, deck surfaces not square or flat. I think they had some many bikes in demand, they had anyone and everyone making cases and heads.

I feel the largest issue is the case.. I know that they can create issues. If the stud is not rusted I leave them alone. been down the road of replacing them only to have them pull right out of the case. Install tyme sert  yep it pulls that out as well . For what ever reason many times I feel you are better to leave them alone .   If you get to that point , time for a set of S&S cases and move on.

The case issue ran for years and as already stated common for this issue and then as Scott pointed out the case cracking behind the tappet block.. Lost count of how may came in for gasket repair for a leak and its the case that is cracked ..

HD studs are pretty tough all in all and not a common issue to have one break . at least not as common as the stud pulling out of the case .   Slippery slope for sure

[thumper 823]

Like all things they stretch and wear out
The bolt / studs, loses its elasticity and becomes a static pull over time or just shears off.
It is good practice to replace them if in doubt

[farmall]

If you damage the case threads, threaded inserts are cheap and an upgrade, hence their use on aircraft with much higher time between overhauls than motorcycle engines. Skip coil inserts and use a barrel insert instead. There are quite a variety and many are designed to install using a standard tap. Tape off with painters tape (clean with contact cleaner first so no oil prevents tape adhesion) and no chips will go in the engine.

McMaster-Carr, MSC etc industrial suppliers have many examples, but I'd use them to find the part then search maker and part number or name to save money. The big boy industrial suppliers serve the "need it NOW" market which can't afford to wait and price accordingly. Their excellent catalogs make great bathroom reading...

[thumper 823]

What is the installed thickness of Hayden gaskets?
I looked at their page and no specs.

[farmall]

I got a Hayden kit and the brass tubes (AKA pigtails but I've never seen a hog with a tail like that!) are the important part. They sell gaskets with the kit to avoid owners having to punch holes in a stock gasket.

You can use the Hayden gaskets as templates with a Sharpie to mark other gaskets then punch holes as you prefer.