Short Stroke Con Rod Preferences
 

OK, I'm not one to subscribe to engineering as a popularity contest, but this subject seems to lend itself to a survey.

To my knowledge there are at least 4 different connecting rod options when building a 66 mm stroke engine. Which do people feel most comfortable with. Assume that the engine will be a DE or race engine, so it will be seeing harder then street use. After you've voted, feel free to elaborate on your decision and why.

Thanks!
SmileWavy

Im a big Pauter fan...

I did have some 2.2 rods once gone over by a really reputable machine shop once, when I got them back they were things of beauty, balanced, shot peened, polished, etc.

My friends shop uses pauter almost exclusively. Carillo has too much of an attitude to deal with, and there product cant be that much better than Pauters to have to deal with that kind of bull****

Oh those stock rods that the local chebby guy did are still pieces of art

John, If you decide to go with stock rods. Lindskog Balancing in Boxborough (Boxboro?) does shotpeening as well as balancing.
-Chris

If your object of making a shortstroke motor is to have a rev happy motor then it would seem the lightweight rods could be a big advantage.

So who makes the lightest rods, strength being equal?

Re: Short Stroke Con Rod Preferences
 

Hi John:

I too, don't subscribe to popularity contests in lieu of good engineering and long-term experience,....:)

You did not say anything about peak and sustained RPM and that truly defines the choice. FWIW, we use Pauter rods in any engine that will see sustained 7000+ RPM operation.

Some of our clumsy customers have missed shifts leading to well above 10K RPM peaks and those Pauters didn't budge a bit.

I'm with Tim on using Carrillos: I used to use them starting in 1976 but they are no better than Pauters, they are more expensive; they have lousy customer support & service, and their windage characteristics are questionable in a 911 motor, compared to the Pauter product.

How do the Pauter's compare to the factory 2.2 rods? Would you use Pauters in a street motor, or only in an engine that was torn down and inspected every year or two?

Lets say you are going through tremendous expense and time to build a hi-po 3.6....... would these Pauter rods be a good investment?? What am I gainning? Are they lighter, better bolts? What are all the advantages?? Help me spend $$$

Jeff

Forgive the fact that I have never personally broken arod..but have pulled down plenty of broken motors..and cracktested hundreds of rods..

In my ignorance therefore, I would say that Porsche rods do not break from overrev nor fatigue crack unless they have been damaged....has anyone seen a fatigue crack?

The big end does go oval as usual...

Rod failures are common however, and in my humble opinion are attributable to lubrication failure..

I do know that Grady and some others like the 911" 2.2" rod over the 901" 2L", and they do have a stiffer big end..but are much heavier..

I'll get some numbers ..

Kind regards
David

This thread has some comparative weights for the 2.0 and 2.2 rods. I don't have any Pauters or Corrillos to weigh.

Steve; I purposely didn't specify a rev range when I started this thread last year, but just defined track/DE use. I guess you could interpet that to mean red-line between 7000 and 8000, with a rev range between 5000 and ~7500 RPM with occasional foreys up to 8000 RPM. My real intention was to define a situation beyond street. I think that we'd all agree that the Pauters and Corrillos are overkill for street use with a street red-line, while the stock units (with shot peening and balancing) would most likely be adequate for street use, even in an S spec motor.

The subject of rods is somewhat misleading. The weakest point in an engine is the rod bolts, not the rod. The problem is to come up with a way to use the very best rod bolts that man can make. Thats the main secret to Carillo rods. Forget the attitude thing, its a cross between bad customer service and envy. Carillo is the best because it uses the best rod bolt in the world, by far and the rod is an intergal part of the rod bolt design. Carillo does several other things that others may or may not do. They 100 % xray and inspect all the rods. Someone making a very good rod, that does not do this is gambling with your money that their rod will not break. Want to join an engine lottery??