F1 Conrods

[63l8qrrfy6]

Hmm green could be copper oxide which may hint at a copper coating.

Copper coatings are sometimes used with the purpose of reducing crown thermal gradients (effectively eliminating hotspots). The downside is a reduction in heat transfer through the crown thickness due to the imperfect thermal contact between Cu and Al.

[J.A.W.]

Research article on plasma sprayed piston crown coatings:
http://ijera.com/special_issue/NCERT-No ... 116122.pdf

[e36jon]

I took some additional images of the Pankl Cosworth TJ conrod that I have, focusing on the small-end coating we are speculating about. They are in the first post, in the V10 section. Hopefully they'll help us resolve what the coating might be...

[*]I found another Peugot V10 rod that I added to the first post.

[*]Also added some Cosworth DFV / DFR V8 rods.

[*]Added views of the 2000 Ferrari V10 rod.

[*]Added one view of a 1992 Ferrari V12 rod.

[*]Added section headers with dates. IE, "1995 - 2005, normally aspirated V10". Hopefully things are easier to navigate now...

Cheers,

Jon

[e36jon]

Greetings all

Just realized that my using 'edit' instead of new postings has hidden all of the changes over the last week. The post before this has a pretty complete list of what's changed, but all you need to do is check out the first post again as all of the new goodies are in there.

I think I am 'done' adding new rods at this point, as I can't find anything beyond what's posted. There are three Pankl rods that I couldn't link to a particular year / car, so any input there would be greatly appreciated.

Cheers,

Jon

[e36jon]

Greetings all

I might have solved the mystery (to me anyway) of one of the Pankl rods.


I've been wondering whether this was a 'real' rod or not:





I found this image today for the Renault RS27 V8 and it sure looks like the same rod to me:





Anyone with more info care to confirm or deny?

This is a piston from the same engine. Maybe. (If it's on the internet, it must be true, right?) This piston is unique in my limited experience with the detached / floating skirts. I've only seen one other that came close and it had a window cut into the non-thrust side skirt, which is tame compared to this. The pin location also seems quite low, but maybe that's a secondary effect of the thin bottom land? Maybe this was just a design exercise?





Compared to all of the other V8 pieces (See first post) both the Renault rod and piston are quite different. I find that really interesting as everyone is using roughly the same design tools, and in this case probably even the same manufacturers. So how did Renault end up going this way when everyone else went that way?

[63l8qrrfy6]

Porsche F1 piston and rod from the previous turbo era.

[e36jon]

Thanks for the addition Mudflap!

I have the rods and pistons on page one, but the section view of the piston is new to me. Hard to tell exactly what's happening there, but things sure look massive...

I also love those rods as they exemplify the 'organic-as-optimum' way of thinking. (The Renault V8 rods too.) I'm not saying it well, but the ideology is something along the lines of "If you're adding ribs you're doing it wrong".


Maybe we'll have new Porsche F1 parts to look at soon.

[riff_raff]

One thing to consider when you see engine parts like these with structural profiles/shapes that seem unusual, is that they are designed to provide a balanced stress distribution and/or a specific shape under operating conditions.

[e36jon]

Thanks for weighing in riff_raff.

I understand the concept of designing for the loaded case (I'm a Mechanical Engineer with 20+ years of experience). What makes me scratch my head is how different these Porsche rods are, and the Renault V8 rods too, from everything else that was contemporary. In the case of the Renault rods, which were manufactured by Pankl, there were several other engines using Pankl rods that were completely different. And that's even in light of Pankl's own hybrid H + I beam design (I assume that's Pankl's design since several teams used it.). Since both of the above cases were from championship winning engines I figure it wasn't the intern that designed them, and just didn't know better... And in both cases I believe the designs prior to these were conventional. Looking at the Ferrari turbo rod (with a grain of salt), it's also pretty conventional.

All that to say I find the unique designs interesting from the standpoint of what environment / personnel spawned them. In my experience, within large organisations, you don't just get to do something radical. Refinement wins over invention usually as it represents lower risk. So, I'd love to have a beer (or three) with the designers for the two rods in question. Care to join?

Cheers,

Jon

[63l8qrrfy6]

I have the rods and pistons on page one, but the section view of the piston is new to me. Hard to tell exactly what's happening there, but things sure look massive...

Nothing too exciting really, just a very diesel like gallery cooled Al piston.
Apologize for the poor quality pic, was taken with a mobile phone at the Porsche museum.

I also love those rods as they exemplify the 'organic-as-optimum' way of thinking. (The Renault V8 rods too.) I'm not saying it well, but the ideology is something along the lines of "If you're adding ribs you're doing it wrong".

To be fair I think recently modern FEA and topology optimization methods have shown that the ideal rod shank shape is quite far from the extravagant shapes we have seen in the past.
CAE use in F1 was still in its infancy in the V10 and even at the start of the V8 era (see the Honda papers) and designers relied more on 'feel'. In addition the large bore pistons had high moment of inertia and were prone to torsional resonance which drove most of those bonkers shank designs (aimed at increasing the polar moment of inertia) culminating in the welded rectangular cross section used by Honda.

The design of the big end side of the rod is much more involved as it directly affects the hydrodynamic performance of the bearing as well as the load distribution in the bolted joint - this is where most of the current research is focused on.

[e36jon]

Greetings Mudflap

I learn something every time you stop by...

You mentioned the big-end cap detailing as a point of interest back in your June 8 post and I've been paying attention to that area more when I am web surfing. Apart from the F1 madness shown here there are only a few rod makers using a center or crossing rib on the big end cap. These days you would hope that's due to use of FEA and not a 'me too' thing.

If you look at the Cosworth DFV / DFR rods in the first post they have all three flavors: flat, dual rib, and center rib. I don't know their chronological order. That was definitely well before FEA was available!

Cheers,

Jon

[63l8qrrfy6]

It does depend on many factors - for example a barrelled crank pin journal is more suitable for double rib caps since the bearing is not as sensitive to edge loading. Same goes for profiled bearings running on straight pins.

Mercedes/Ilmor have used some interesting rods with angled bolts for a while during the N/A era - it's a shame pictures can't be found online. The idea was to reduce the moment caused by the offset between the shank and the bolt axis which is sound but turned out very difficult to manufacture and assemble.

[roon]

...culminating in the welded rectangular cross section used by Honda.

Anyone have images or keywords for the papers?

[e36jon]

I love a challenge, so off to Google I went in search of Mercedes splayed bolt F1 rods. Yeah, not happening. I did find this though:



The folks I borrowed the image from have a nice discussion of why this is even an issue: http://arcracing.blogspot.com/2000/03/ ... esign.html Granted, it's from the pushrod V8 world but the principles are the same. Mostly.

Ran across this today as well. It's a MMC rod with a polymer coating aimed at the drag race crowd. It's 'almost to market' for four years now (Hence no link)... Anyway, shows the thinking Mudflap was referring to:



Doing the web search also pointed out the 'splayed 4-bolt main caps' used in these same engines, but for different reasons...

[e36jon]

Hey Roon

A link to the rod paper is also on page one right above the pics of the hollow Honda rod pics: http://www.f1-forecast.com/pdf/F1-Files ... P2_34e.pdf

They're behind a paywall at Honda (https://www.hondarandd.jp/summary.php?sid=23&lang=en) but have been bootlegged to the web in several places. The link above will let you get exact titles so you can do a more targeted search for bootleg copies.

Cheers,

Jon