F1 pankl conrod

[Darren Parkinson]

Hi Guys. Hope this information helps all concerned.



Dear Darren,



thank you for your e-mail.

I guess you mean the groove in the split line – cap side.

This groove was made in the earlier days before we manufactured serrations in the split line.



The groove more or less has the following reason:

For connecting rods, especially on high revs, we machined this groove in order to increase the surface pressure in the split line.

Of course the surface pressure increases, when the surface gets smaller.

Therefore we protect the conrod from gapping in the split line.



Today, on newer rods we basically do not make this anymore, because we now are machining serrations.



Hope this helps.



Best regards,

Oliver



Oliver Wolkner
Technical Sales Racing

Pankl Engine Systems GmbH & Co KG
A member of Pankl Racing Systems
Kaltschmidstrasse 2-6
A- 8600 Bruck an der Mur

phone: +43 (0) 3862 51 250 206
mobile: +43 (0) 664 821 9984
fax: +43 (0) 3862 51 250 290
e-mail: oliver.wolkner@pankl.com
http://www.pankl.com

[Formula None]

Thanks Darren, very interesting, although maybe the kind sales rep doesn't want his contact info out there for the world to see.

Same thing riff raff & F1_eng were saying earlier in the thread. Thanks to both.

Regarding the serrated split line he mentioned:

[mep]

yes,
thanks to Darren Parkinson and special thanks to the guy from Pankl.
For me this kind reply creates a positive image of this company.

[PlatinumZealot]

Thanks Darren, very interesting, although maybe the kind sales rep doesn't want his contact info out there for the world to see.

Oh yes they do.. they would give you their home address of they could.

[PlatinumZealot]

So riff-raff got it right after all. And look how far I went down the bolt road. but no harm in exploratory discussion.

[PlatinumZealot]

Wrong!

The groove in the cap to con-rod mating surface is used to alter the magnitude of the fluctuating load component in the bolt.
The ratio of the total fluctuating load taken by the bolt is dependant on the relative stiffnesses between the two components.

I am not going to say anymore as I feel that is enough information for people to do more research if they wish.

[riff_raff]

Darren,

Thanks for posting your response from Pankl.

Accommodating shear loads through a separable joint without fretting is always tricky. All approaches, whether serrations, shoulders, pins, ring dowels, etc. must be carefully designed.

I design aircraft propulsion systems, and we run into similar torque/shear joint design situations as this conrod. The typical approach is to use a self-aligning toothed face joint called a "curvic coupling".

[1980]

Hi everyone..

Interesting discussion....
I've been designing a strange conrod which has huge alternating stress (between 110-140 MPa) on the bolts. Normal M10 bolts (12.9 grade) have got an alternating stress limit of ~70 MPa for a bolt loaded to 70% of the yield.
Has anyone got an idea, which bolts can tolerate such high alternating stresses. What kind of bolts do they use for F1 conrods?
Any help would be apprreciated.

Cheers

[PlatinumZealot]

Just curious, How much % stronger material would work in your case?

[1980]

That's what I wondered. But a source from Pankl says that it's very much possible.

[marcush.]

I think the guys at ARP in the US will be a good adress and as far as my experience goes they are prepared to help and do small special production runs.

[hardingfv32]

How is the big end of the rod machined as an oval?

Brian

[elmerfud]

I have 1 of those rods from ebay as well, i am under the impression that gap in the slpit line is to collapse the edge of the bearing bore in order to cause failure when torque is applied to the bolts - i have seen these tricks on a few ex f1 parts.
There was an 'old' 053 ferrari v10 which a guy made a coffee table from and it had been taken to with a hammer at many critical areas.

[PlatinumZealot]

Nope, that wasn't the reason. That was discussed at length. The answer is posted by "Darren Parkinson" at the top of this page.

[Brian.G]

Hi Guys. Hope this information helps all concerned.



Dear Darren,



thank you for your e-mail.

I guess you mean the groove in the split line – cap side.

This groove was made in the earlier days before we manufactured serrations in the split line.



The groove more or less has the following reason:

For connecting rods, especially on high revs, we machined this groove in order to increase the surface pressure in the split line.

Of course the surface pressure increases, when the surface gets smaller.

Therefore we protect the conrod from gapping in the split line.



Today, on newer rods we basically do not make this anymore, because we now are machining serrations.



Hope this helps.



Best regards,

Oliver



Oliver Wolkner
Technical Sales Racing

Pankl Engine Systems GmbH & Co KG
A member of Pankl Racing Systems
Kaltschmidstrasse 2-6
A- 8600 Bruck an der Mur

phone: +43 (0) 3862 51 250 206
mobile: +43 (0) 664 821 9984
fax: +43 (0) 3862 51 250 290
e-mail: oliver.wolkner@pankl.com
http://www.pankl.com

My third post on page one>

Im thinking to maximise contact force in those particular areas.

''Im thinking'' simply because everyone has their own opinion

Well done on contacting them all the same, just to be sure,

Regards,

BG