I do.
I’ve been making crank scrapers by hand since the 80s.
With a file and a hacksaw blade, up hill, in the snow, both ways.
And I generally install head drain tubes to keep the drain back off the crank.
Oh, FYI...zero clearance Teflon baby!!!
https://www.crank-scrapers.com/
https://www.crank-scrapers.com/Volvo.html
Some things really shouldn’t be kept “in the cloud”.
Oh, as for the rods.
I trust the manufacture, the end size is a design choice...it DOES reduce mass. The bolts are probably fine...but there’s more than failure to worry about. They can stretch within the elastic limit, pulling the bearing away from the journal and bleeding local oil film...even a couple thou will kill a motor. All steels have essentially the same Young’s mod, so the only fix it size.
JVL May be an abrasive SOB but he does good work.
Yep, the peanut gallery is yapping ALWAYS about rod bolt failure.. That's because they have simplistic analytical tools and simplistic methods---Fail and good/bad..
Not thinking about elastic deformation in normal or "rather more amusing use"
Or asking really basic questions like say "What keeps the big end ROUND?" and "together"...
Or "is the big end always round?"
Some of us know the big end--and the resultant big end bearing clearance -----a mere .0012" to .0017" should ideally stay round...but under the big forces of combustion, it isn't always round nor under the mechanical stresses of "keeping the pistons from flying out of the block as piston approaches TDC on exhaust stroke going up only to be jerked back as crank passes thru TDC and begins intake stroke down movement..
Compressive and tension forces pretty crazy...and that the nice round holes in big and small end elongate.. Go oval...and as they go oval, reduce clearances and stress the fawk outta the things TRYING to prevent this ovalisation and prevent metal to metal contact (by breaking/disturbing the oil film)and : the rod bolts. (at the big end).
So anything that can KEEP the big end round or "rounder" if it can be done easily is a good thing....Stronger material for the rods is one, stronger material for the bolts is another and simple size...if we can (and sometimes we can't--no room) and so, since there IS room and since there ARE large bolts at a similar price as the smaller bolts, of course it would be better to simply chose the stronger ones--say to minimise ovality >>
For those that have more "normal' attention spans, here is a very interesting thesis on this subject by some Norwegian gutt
https://daim.idi.ntnu.no/masteroppgaver/017/17762/masteroppgave.pdf
"Abstract
A virtual testing tool has been created in the FEDEM software by the supervisor, together
with MXRR, which enables integrity analysis of the combustion engine, including
the connecting rod. However, this test bench does not include contact analysis of
the connecting rod. Such an analysis is therefore desired in order to establish the big
and small end ovality, thus take strategic steps towards increasing the integrity and performance
of the part.
This master thesis describes the approach and results of performing such an contact
analysis of the connecting rod. It explores the different simulations methods for this
problem, and aims at quantifying the occurrence of ovality, as well as comparing the
simulation methods. One linear and one nonlinear solver have been used to perform
the analyzes. Necessary and desirable simplifications has been made to improve the
analysis efficiency, such as a simplified bearing model. The contact parameters has
been carefully investigated to ensure a comprehensive and accurate analysis.
Further, a FEA template has been created in the Product Template Studios module
in NX. This template aims to streamline the production process of the connecting rod,
by making an intuitive GUI for easy simulation set-up. After the template analysis is
performed, valuable feedback is given to the user, such as contact pressure and deformation
plots
As I keep saying: if there room,
why not try and reduce loadings from reciprocation parts to lessen the stresses on the rod, pin, piston and crank? Less stress = longer life on the one hand or the moving of the safe rpm limit higher on the other hand...
Because of Volvos rather ancient basic architecture and the tall block, there is room.
Why not?