Flow from grooved main bearing to big end

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Visualization and Measurement of Oil Flow in Transparent Oil Passage of Crankshaft

http://www.tytlabs.com/english/review/rev383epdf/e383_044suzuki.pdf

Pretty flash in that they made a section of crankshaft out of transparent polymer, and not only measured the oil pressure available to the crankpin, and estimated the volume, but were able to visually detect aeration in the journal drillings with a reduction in oil pressure.

Of note is the "I" versus "V" crank drillings...it's not your Grandaddy's cross drilled crank, but there is apparent merit in it.
 
My liberal arts math gave out around fig 4. So, the engineers are figuring out if a less processed crank will deliver a good enough oil flow? Using a lower power oil pump? Transparent crank is cool. I wonder how it stood up Or was the crank spun on outside power? Thanks for link. I have always admired Suzuki for their little utes. A thin oil was used to simulate operating temps. I wonder how thin? Thanks again.
 
So aeration or even complete oil starvation could happen at hot idle if the oil viscosity gets low enough?

50 kpa at hot idle doesn't seem that exotic...
 
I want to know to cross drill the crankshaft or not cross drill the crankshaft? Grooved bearings or not? Lots of oil is always better. The quest for fuel efficiency is charging at WOT.
 
Originally Posted By: Shannow
Google Books Link to MOFT with different groove arrangements

Note how grooving makes a bearing into "two" bearings, and reduces the minimum oil film thickness.
Back in the 1970s there was the debunking of the grooved bearings and the benefits of cross drilling cranks. I looked into this when building my boat engines. I built some long lasting 8,000 RPM 427 Chevrolet big block engines using stock parts machined and assembled properly. I had help from a long time friend who for a long time built the engines for this boat. link. He could build the engines well we built go carts, motorcycle engines and car engines as well. Ahhhh the good old days. Now I just want to buy a new vehicle before I need to do work on them ,, But I an too cheap to.
 
CT8,
I remember the days...1991, I noticed the inertia ring on my Holden 6's balancer was starting to move, which was usually a sign that numbers 2 or 5 piston was about to fail.

Commuting 75km each way, during the week I had a block and hypereutectic pistons delivered, a crank ground, bearings and special order cam grind (it was a regular, just not what the speed shops carried), and assembled the short during the evenings.

Friday night, dropped the coolant and oil still hot, and left to drain down overnight.

Saturday pulled the head off the old one (it was a fairly new head), lapped the valves, swapped the short and got the head on. Not enough lifter preload with the reground cam, so spent a couple hours Sunday morning filing the rocker pivots.

Fully intended to drive to work Monday, which I did.

Now nothing like that confidence/drive
 
Ah, the alloy rocker bridges on the 173/202 - what a dumb idea, another reason I prefered the 186 and other earlier red engines.
 
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