Stud girdles - any hard proof they work?

[markrinker]

I 'passed' on installing a stud girdle when replacing the engine in #2 last summer. Have wondered since if I made a mistake, especially since the '98 motor I replaced it with has the infamous large piston oilers.

Does anyone have hard proof these things work? Can an external brace actually save poor castings? I find it hard to believe when core shift due to torque and thermal expansion cycles is measured in thousandths of an inch - what are the tolerances of the bolt holes in the girdle to the fastners that hold it in place???

[G. Gearloose]

I suspect its function is reduce torsion on the webs, not really to add bulk strength.

Like how an I beam flexes and rolls over when stressed, control the torsion and its strength and stiffness improves.

[More Power]

We won't know with any degree of certainty till enough problem model year engines (that started out crack-free) have been in service for a number of years/Kmiles.

Personally, I think it might be a good idea, but if I just had to build an engine using a large oil spray block, I'd have splayed main caps installed.

I actually discussed this issue with Jamie Avant from The Diesel Depot a few days ago. They will begin testing this theory.

MP