2.2 S conrods or Wossner conrods

[964-RSR]

Hello,

Is there an interest (performance) to install Wossner, Pauter, Carillo conrods in a 2.2S engine hot street or original 2.2S conrods are good enough ? RPM up to 7500

Thank you

[chris_seven]

We think 2.2S rods are a bit heavy - I am sure many people will disagree and I think Woessner rods are very good but relatively expensive.

We have just finished a 3-D model for some rods and have done the FEA analysis for 8250 rpm assuming 1969 911S Mahle Piston Weight.

They are being made in Sweden form 4340AQ Forgings are fully heat treated, shot peened etc, etc. and have ARP 2000 Bolts as standard and Aluminium Bronze small end bushes.

We have machined grooves to allow oil to the piston crown to try to avoid fitting squirters in early casings which I believe contravenes FIA rules.

The weight indicated by the model is 540 gms.

We plan to use them in a couple of FIA Appendix K Period F 2.0 litre engines.



I will try to post photographs when they are completed.

[304065]

Chris, really? Squirters forbidden in Appendix K? I wonder what the rationale is, seems to me that you can enhance longevity and run the piston a little cooler, but wonder whether a true performance increase is offered?

[chris_seven]

Originally Posted by 304065

Squirters forbidden in Appendix K? I wonder what the rationale is, seems to me that you can enhance longevity and run the piston a little cooler, but wonder whether a true performance increase is offered?

I think I need to try to be very clear.

Period F Cars are based on Homolgation Form 183 and non of the extensions to these papers can be applied without moving the car to Period G.

If this is the case then I think the question should be 'why do we believe squirters are acceptable' as they are clearly not a period feature of an early pre 1966 911.

I would agree that squirters are not specifically prohibited but to justify their inclusion in an engine on the basis that they only help reliability and don't give a performance gain isn't entirely a 'solid' arguement with regard to FIA regulations and the way that they can be interpreted.

Could we not argue that by cooling crowns we can run engines harder so that without squiters they would fail. This does then become an enhancement?

If we have to build engines that fully comply with Appendix K, I would be looking for a paragraph in the rules that specifically allows this modification rather than assuming its OK.

During the last couple of years I think we are seeing a hardening of attiudes and an increase demand that cars fully comply with all aspects fo Appendix K.

Mods that were not strictly allowed but that had been common practice are now being complained about and the wording of Appendix K is being strengthened in some key areas.

I think the opening statement of Appendix K is very clear:

'A set of rules to preserve the specifications of the period and prevent the modifications of performance and behaviour that could arise by the application of modern technology

I was at a meeting at the end of last year where the Historic Technical Committee decided to hold an open day to answer detailed questions concerning current attitudes to modifications and how these would be administered.

The opening statement of Apendix K was readout out at the start of the meeting and we were all informed that mods designed to significantly enhance reliability beyond preiod specification were equally as forbidden as performance boosting mods. As you can imagine much argument ensued but attitudes were quite unmoved.

The caveat was that new parts could be made using material substitutions permitted by Appendix K.

The squirter mods that I would agree have been used for some time, have I believe, been justified by the fact that Appendix J of the period specified lubrication systems as 'free'

The Technical Committee also pointed out that Paragraph 3.3.3 states:

Freedoms granted by Appendix J of the period does not confer complete freedom but rather authorises the use of components and/or modifications that were actually used in period on the particular make and model as a result of those period freedoms

I would be worried, in the current climate, to build an engine with squirters and then have it pulled apart and a 'Black Dot' applied to the HTP - hence this rod modification.

I am sorry to have banged on but there are several grey areas on some well known Appendix K cars and they are being increasingly looked at and debated.

I also accept that these rod changes could be seen in the same light but much less noticable than genuine squiters.

[gestalt1]

I've heard of this connecting rod modification before, is it as good as squirters?

[brettm69]

Originally Posted by gestalt1

I've heard of this connecting rod modification before, is it as good as squirters?

it's a common mod for the T4 engine.

[chris_seven]

I am sure squirters are the best idea but these mods are used on high end Subaru and quite a few other motors and I think a couple of 911 engine builders carry out this mod on early engines.

I just thought while we were making new rods, and having become nervous about having a motor stripped by an FIA Scrutineer, it wasn't a bad idea.

I would think for a street 2.0 litre they would be better than no squirters and much more cost effective than modifying the engine case.