Head stud replacement - SC

[safe]

Originally Posted by motogman

I am down to removing the dilivar studs and have some more questions...

It seems the Loctite on the studs needs heat to loosen them up. How much heat and what is the best way to do the heating. What Loctite product is used for the head studs?

My first try was an electric heat gun but this did not do much to warm the aluminum case. I think I need to use the propane torch but I am a bit concerned to over heat the case. What has worked for others - please share you experience.

Get a map torch. Easy peasy.

[mikedsilva]

Originally Posted by motogman

I am down to removing the dilivar studs and have some more questions...

It seems the Loctite on the studs needs heat to loosen them up. How much heat and what is the best way to do the heating. What Loctite product is used for the head studs?

My first try was an electric heat gun but this did not do much to warm the aluminum case. I think I need to use the propane torch but I am a bit concerned to over heat the case. What has worked for others - please share you experience.

I use a simple mapp gas torch from the local hardware store. The flame is directed to the aluminium case around the stud. I use double nuts on the studs too..
After heating for 20 or so seconds, I try to turn the stud while also applying heat.. once the stud starts to move, I turn off the heat and quickly work to undo the stud. I find if I let it cool down too much, it becomes difficult to undo.

[mepstein]

I use mapp but hit the cylinder wall and area around the stud for 2 minutes. If it doesn't turn easily, another minute or two. I use a collet tool. Much faster than double nutting but I was doing this at the shop so time was important. The heat doesn't hurt the case at all. Fastest is to have one person heating and one unscrewing. I've done a couple dozen engine cases this way.
I believe a lot of heat is actually easier on the threads than unscrewing it cold and I've never broken a stud or stripped threads this way.

[ahh911]

To follow up, see the tools and help necessary for "easy removal". I had 12 year old son working the map, every 10 -20 second count I'd try the bolts, he'd keep applying, when they started to turn then he'd pull the flame further back, it was as he put it "easy peasy". I've linked the exact sizes and map torch that works fantastic, home depot and amazon, or canadian tire, or whatever your local car parts place is.

Broken Head Studs

Phil

[Jeff Alton]

Has anyone seen a broken steel head stud? We never have. But have seen plenty (countless) broken Dilivar studs. That said, never have we seen a broken 993tt dilivar stud. However, for the price of 24 993 Dilivar studs, you can get a complete Raceware or ARP kit that includes new washers and nuts. Or, you could purchase a new Supertech stud kit (includes nuts and washers) for about 60% of the price of 24 new 993TT dilivar studs without nuts and washers.

Now, we have never used the Supertech kits, our go to is ARP on a peformance build, or all steel on a stockish rebuild. That said, all reviews of the Supertech studs is 100% positive. By all accounts they are a great choice. Why spend double on a set of 993TT dilivar?

Now as engine builders, we like to stick with what we know. So if you have a system that works, stick to it. Despite using either factory steel, or ARP or Raceware. We will likely give the Supertech parts a try.

At 95mm, 97mm or 98mm we would never consider 24 dilivar studs, unless we are talking about the 993TT ones...

Cheers

[motogman]

A slightly off the wall question...

Are the same head studs used in the SC 3.0 L motor an in the 3.2 L Carrera motor?

I think between these the crank went from 70.4 to 74.4 mm but it looks like the cylinder height group dimensions are the same and the head stud part numbers are the same.

The piston diameter appears the same so the 4mm increased stroke was taken up in the same sized cylinders which would mean the head stud lengths are the same? Yes?

[Henry Schmidt]

Originally Posted by motogman

A slightly off the wall question...

Are the same head studs used in the SC 3.0 L motor an in the 3.2 L Carrera motor?

I think between these the crank went from 70.4 to 74.4 mm but it looks like the cylinder height group dimensions are the same and the head stud part numbers are the same.

The piston diameter appears the same so the 4mm increased stroke was taken up in the same sized cylinders which would mean the head stud lengths are the same? Yes?

Head studs are the same.