As I'm getting ready to (finally!) re-assemble this old engine (Skoda Estelle/120 '70s, RWD, rear mounted engine), I needed/wanted to change a few studs, but basically all of the head studs are damaged somehow. So I went deeper and got made all studs used in this engine. Each original stud used for the head are 130mm long, with threads 25mm long on each side. However, the guy made them with threads lengths like twice that. I asked for larger studs, so I can cut them to the size I want. I can cut the extreme that goes screwed in the block, so the stud's flat area without thread sits well over the block surface, however the other threaded extreme (that gets the nut to secure the head) will get some thread running down the head holes. I think almost half of it.

The engine block is aluminium, the head is cast iron, the studs are hardened and "double" length nuts (20mm long). The studs are M10 x 1.25. The nuts will be torqued to 50-55Nm (36-40ft-lbs), according to the Haynes manual.

Question: is that posing any problematic issues? Or is it "ok enough"?

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  • I love your questions, keep 'em coming :)
    – Zaid
    Feb 21, 2017 at 8:31
  • Geographic fatalism is what forces me (us) to find alternatives. Feb 21, 2017 at 15:13

1 Answer 1


They will be fine - did something similar in the past. You say hardened, but did you get a sufficiently high grade steel? i.e. strong enough? It would be good practice to use a compound to prevent corrosion of the studs with the aluminium - otherwise they become extremely difficult to remove.

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