Carl Fausett

We have laid in a supply of Grade 8 specialized fasteners for engine rebuilds.

Given the current interest in Supercharging, Turbocharging, Nitrous, and stroking the 928 - we have followed with the development of our 650 HP and 950 HP clutch kits and now Fasteners to keep that Monster Motor together.

Our Head Studs are made for us by ARP - and no, they are not simply two 944 kits put together. We worked with ARP to make exactly the head studs needed for the 928, and we are the only folks that have them.

It is our opinion that some of the head gasket failures on Monster Motors can be attributed to head bolt stretch - the gasket itself shows the results, (and we are a dealer for the Cometic Stainless-steel gasket) - but the gasket may not be the only culprit.

Our Head Studs rae 50% stronger than OEM, and easily installed. More info on them is available here:
http://www.928m.com/parts/upperenginefasteners.php

NOTE: Porsche used head studs on all 928 engines through 1986. They changed to bolts for 1987 to 1995 to make R&R of the heads easier with the engine in the vehicle. But: head bolt threads in the aluminum block will not take many torques/retorques before they pull out. Install head studs now, so your torsional force is steel-on-steel at the nut - and save your block!

Carl Fausett

We also have the bottom end covered with extra-deep Grade 8 nuts that grab more threads on the main bearing studs and hold their torque better...
http://www.928m.com/parts/enginefasteners.php

Here again, we worked with ARP to get the right nut for the 928 connecting rods that are not only stronger than the stock nuts, but lessen your rotational mass as well. Not applicable to aftermarket rods - they will come with their own rod cap nuts.

Carl Fausett

By popular request - we worked out the right stud lengths and flanged hi-inerference locking nuts for the oil pans...
http://www.928m.com/parts/oilpanstudkit.php

The studs are Grade 5 steel in black phosphate finish, and a special length made just for us. The nuts are hardened, zinc plated, and have a wide flange on them to completely eliminate the need for washers. Each nut has an anti-vibration crimp at the top (called a "toplock") that is reusable and prevents the nut from vibrating loose.

m21sniper

You guys rock.

Keep the new parts comin'!

a4sfed928

I have a couple of questions that I have been struggling with over head fasterners. I was told the Porsche head studs were developed with a thermal expantion rate very close to the block material which was a difficult task due to steel Vs aluminum. These studs were supposed to maintain constant clamp load on the head gasket even with the high thermal expantion rate of aluminum. Now this "maintaining of clamp load" did not imply it lost clamp load but rather the clamp load would have a tendenancy to increase with increased temperatures causing the head gasket to crush too much which would lead to a failure. Is this a real issue and was this concidered in the material choice for these studs?

BC

Carl - have you addressed the need for the head studs to be a bit longer for post 89 heads?

Tony

great job Carl.

Imo000

Nice product but have one question. Would lighter connecting rod nuts throw the rotating assembly out of balance?

atb

Any chance of putting together a crankcase stud replacement kit?

Ketchmi

We have them Adam.

BC

Are they really required? After how many torques do you think the original girdle studs are bad?

Carl Fausett

I was just told by Dave Lomas at Motorsport that they too have the ARP head studs for the 928.

As to whether they will fit the 32v heads that require a little longer studs - yes.
The pics will show how much extra stud is unused for the 16v motors - that is the extra length that the 32v motors require.

As to whether that concern about the OEM bolts expanding at a rate similar to the Alusil is valid or not - there has been a barstool arguement for many years on the 944 forums about just that. The Alusil is a low-expansion aluminum alloy, so the expansion is not as great as "aluminum" to begin with.

Still - the concept that the deck height will change enough in a hot Alusil block to pull threas on the head studs is not without merit. ARP uses a controlled-expansion alloy in their studs - available in 2 different strengths. I chose to have ours made from the "softer" strength as its expansion rate is greater, for just this reason.

In my studies, I beleive those that have pulled the threads out of their block did it by installing studs into threaded ports where repeated application of head bolts had already damaged the threads. Not the studs fault.

As to whether we will offer the oil pan studs and flanged nuts as a kit: we do:
Here it is: http://www.928motorsports.com/parts/oilpanstudkit.php

borland

The dynamic balance of the crank is dependent on not only the connecting rods, but also the pistons, pins, rings. So the lighter nuts will not significantly change the center of gravity of the entire assembly.

borland
90' S4, Slate Metallic

BC

He is asking about the studs for the bottom half of the block, not the oil pan studs.

atb

Dave,

I'll have JT contact you. US Chrome really did a number on the outboard studs in removing them. The inboard (large diameter) studs look okay, but I'd prefer to replace them all if we need to replace half anyway.

-Adam