Thanks for the link. However, according to their Racing Brochure , SPS rod bolts is between 220,000 and 260,000 psi, not 320,000 as you say.
Why can't SPS rod bolts be used with Porsche rods? Bolts are always the weaker point, not the rod itself... And early Porsche rods seldom fail.

If you don't think there is a shop that x rays 100 percent of their product you haven't shopped at SPS. One of the reasons these are the Worlds best bolt is that they are 100% X rayed, thats part of the reason they cost a whopping $25 ea for a typical Porsche rod bolt. These are the EXACT same kind of bolts used in fighter aircraft, where the pilots life depends on it.

If you want to win a race, and you do not do EVERYTHING that can be done you will not win consistantly. And yes Real racers DO use Carillo, it just ain't worth the alternate. Even 99 percent of vintage racers eventually end up with Carillo rods, because the others break and Carillo ones do not.

And yep I am a design engineer, 30 plus years experience, but must state I only have an MSEE not a mechanical degree. But I have done many failure analysis, for space programs, I do know real QC when I see it.

You are wrong about torque. Re torquing a bolt, is bad. Why, not only do you have the unrepeatability of the torque method, which can be off by as much as 100%, even with everything properly calibrated, you burnish the threads each time you tighten them. This means that the next time you apply torque your streatch the bolt even more, how much? as much as another 75 % or more!!!

The stretch method is extreemly accurate in setting the clamping force of the bolt, if you use torque you either are setting the clamping force to small, or streatching the bolt to much, possible breaking it. The maximum force a rod bolt sees is during tightening. ONce this has happened, its guarenteed to hold that much, by definition enough for all running conditions. HOw is this inferior to over or under tightening a bolt??

SPS makes a range of rod bolts for Porsche type rods. Only a Carillo rod can take advantage of the full capability of the rod bolts. Thats because the ROD must be designed to work with the bolt. Porsche ones (at least production ones ) are not. And only SPS makes rod bolts t hat can do 320,000 psi.
Contact SPS for info on these special materials. By the way its usually not the rod that fails,its the fastener. But they are interelated.
Here are some additional links

http://www.carrilloind.com/pdfs/10777_eprint.pdf

http://www.machinedesign.com/ASP/strArticleID/14487/strSite/MDSite/viewSelectedArticle.asp

Great info.

How much is a set of Carrillo rods (2.4/2.7)?

thanks

Jack,

That's a bit of a broad statement (I'm being PC here). Serious racers? What's a serious racer? Nearly ever porsche racer I know (PCA, SCCA, MWC, VSCDA, SVRA, NASA) uses stock rods. The ones that use Carillo, well they are the ones that rev to 8500RPM or just have more money than brains.

Doing everything that can be done would put every race motor in the $40k range. There's just no need for that.

I think you've erased the line between theory and practical application here. I never placed less than 2nd last year and ran over 20 events on my "not a real race motor", yet I didn't use Carillo rods, nor titanium valves, nor cross-drilled cranks.

What you might say is that if you push any component of the engine up to, or past, the design limits it outght to be upgraded to prevent premature failure. That means if you are revving your motor to 8000 RPM Carillo rods, lighter valves, etc are a good idea.

I've had people go so far as to tell me that because an engine isn't boat-tailed it's not a race motor. Why not? A motor does not have to be extreme to be a race motor. Nor does every component have to be titanium, shot-peened, x-rayed, chopped and channeled and lowered and louvered.

But hey, what do I know? We only do 20 races a year for the last 4 years and have only had one DNF due to motor failure. One that all the Carillo rods and ARP rod bolts in the world would not have fixed!

So, ask some of the guys that know waaaaay more than me, Weiner, Patrick, Kelley Moss, etc.. and I'm guessing they'll say that the stock rods are good to at least 7500RPM... in a race motor.

I'm still a little confused here, for some reason the racers i used to talk to recommended pauter over carillo. I know this isn't helping your arguement, but now i'm curious. So besides the rod bolts that carillo uses, what makes them better. I know pauter's are forged and use a crossing support design instead of that I beam design of most others.

We're getting off track here.

I wanna know how the stretch method detects a faulty bolt.

FWIW, I spoke with an ARP guy this past weekend at the SEMA show here in town. I asked THE question regarding tightening their rod bolts. He says words to the effect:

Using a stretch gauge is the most accurate method of tightening their rod bolts. That said, a torque wrench is also okay. He recommended tightening and loosening the fastener five times before final torquing. In their test with a torque wrench (probably an accurate one) and their moly-based thread lube, they are able to stretch the fastener to about the same specs.

How about anti-seize? They don't know as there are several brands. They have only tested using their thread lube, and their torque specs are based on using their lube.

If torque wrench inaccuracy is bothering you, use a beam-type torque wrench. Calibration is easy. Just bend the pointer so it points to zero and read so there is no parallax error (look directly down at the scale).

Mind you. The above tightening info only applies to ARP rod bolts.

Hope this helps,
Sherwood

Definition of"serious" racer- has more money than brains.

Serious racers ALWAYS rev their engines past 8500rpm, thatswhy the ones without more money than brains cannot be called serious racers, thats cause they blew up their engine and cannot afford to replace it.

Serious racers spend money, lots of it, thats how you seperate "serious" from fanatic or saturday afternoon PCA types. How much money did you win racing? Do you have a professional pit crew of 5 or more?, Spend more than $1million per year?, If not you just arn't all that serious.

Hmmm... Jack,

So by "serious" you now mean "someone else pays the bills", or perhaps "very wealthy" ... Well yeah, if someone else were paying the bills, I'd be using Carillo rods too... ...and I'd be more "Serious" about it.

Interesting statistic that you mention "Even 99 percent of vintage racers eventually end up with Carillo rods, because the others break and Carillo ones do not." I know a fair number of vintage racers (lets say 150 for round numbers, and 30 Porsche vintage guys), and maybe 2 or 3 use Carillo...

I'm not real sure about your statistic there...

With all due respect, and at the risk of offending anyone accidentally, I aint buying this at all.

Unless these bolts are designed to be tightened to yield, you can torque them multiple times. If the lubrication is maintained and consistant you should be able to maintain repeatability to 10% as long as the fastener is not taken anywhere near yield. Yes, I do mechanical stuff for a living and have over $80,000 of torquing equipment in my shop.
A decent ME would design them to be taken no farther than 70% of yield unless it is a really special application.

The most anal procedure I've ever had to use was at a local nuke plant.
On turbine overhauls every case stud was removed and the ends shaved flat and parallel.
when it came time to fasten them they used an ultrasound machine hooked up to a lap top that recorded the exact stretch. Talk about overkill and a waste of money.

Well, I ain't very wealthy, but sometimes I like insurance. Like for the small difference in cost of Carillo rods vs whatever.It means It just don't break, at least because of rods or rod bolts (oneof the main causes of failure next to lube failure) or it does break and there goes another umteem bucks, much much more than the diff in cost of the rods, I will take the Carillo rods anyday.

I guess it boils down to our faith in the stock rods... For once, I'm the optimist. :)

I like stock Porsche rods, as long as they are the Titanium ones Porsche uses in its race cars.

Do you use them in a racecar? These have a fairly frequent failure rate if used for long periods due to embrittlement. Spendy replacing them that often...

That may be why Carillo is still numero ONE. Think about it, if you put umpteen bucks into your engine, and for WHAT maybe a couple of hunded bucks at most, you do not use the BEST rods available. Sounds like a false echonomy to me. For most of you all, the ones that do not do your own engines, its TOTALLY insignificant in the total cost of your rebuild to use Carillo vs anything else.

Do I hear ANYONE who can diss a Carillo rod??? With good evidance? I don't think so.

Did you get my PM Jack? (About the failed Carrillo rods.)
-Chris

Coupla hundred for Carillo rods?!

I'd like to find that price!

Thats the DIFFERENCE in cost not the total cost

What range of torque wrench is he using 0-150 , 20-80, 0-100,
with a clicker type theyre accuracy changes from one end of scale to the other. For instance I wouldnt use a 0-150 to torque 35ftlbs accurrately. SnapOn even publishes this with theyre torque wrenches.
I use a torque wrench and stretch gauge. torque wrench will get you real close to the stretch if you lube properly. also use the proper torque wrench. plus its a great double check.

914/6...

IN this case the bolt had definitely failed. You could easily see where the bolt had necked down and was failing.

The lesson I learned from this is that you should probaby use the stretch method in combintation with a torque wrench. If the stretch is reached without hitting somewhere near the suggested torque levels, there could be a problem.