replace or re-use rod bolts

Mitch is sending me one. If we get ambitious we may make some. I'll have them analyzed for material if we do.

 

Why titanium is better in this sense than steel is it not?

 

Titanium has a higher strength to weight ratio than steel but isn't strong enough to replace a 12.9 steel fastener. You would need to upsize it which would mean new rods as well, if even possible.

Also should technically rebalance the crank.

If any replacements are made, best to exactly duplicate the originals in my opinion.

 

I've not looked - I assume you mean the tensile strengh is less in Ti than Steel?

It's clear from the photo these are torque to yield fasters although not stated anywhere I can find. Needless to say the clamp load is critical.

 

Ducati has also been using Pankl titanium connecting rods on their motors. Their rule is you are allowed to torque a new bolt to spec 3 times, after that it needs to be replaced.

If you are rebuilding a motor, I can't think of a worse place to scrimp unless you like big holes in the side of your engine block.

The Ducati rod bolts cost $370 each:
https://www.ducatiomaha.com/products/77911141a

So your Ferrari rod bolts are actually a bargain.

 

The SPS fasteners that look about the same are not single-use TTY.

 

They look similar to the 355 pieces. Maybe you can save some bucks by running the Ferrari version. (I just wanted to say that because it's doubful that phrase has been used very often, if at all).
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Mitch - I don't know the Rockwell hardness of a 12.9 off the top of my head but it's still ductile. If it was something like 50-60 Rc, it would not be ductile and would break when stretched.

While the threads are M10, the bolt is necked down - so that diameter is going to see the stretch.

All fasteners work by stretching - that is how they achieve a clamp load as they want to return to their natural state and pull back (hence, clamp)

Given the one-time use, it's clear they must be torque to yield. If not, no reason they could not be used again.

 

Its very hard to believe that they would be one-time use bolts, otherwise when assembling engine you would need to go through couple sets of bolts as you need to measure bearing clearances and so on.

 

It's very hard to believe more than a few things that Ferrari does.

 

Hard to absolutely verify over all time since the end of the war and Enzo cut out on his own....however, I'll warrant you are entirely correct....

"You can save some bucks by running the Ferrari version."

...has never been said or written. That is one of the most improbable sentences I think I've ever read.

Congrats!!

 

Manufacturers never preassemble anything so they dont care.


Many manufacturers use one time use bolts. Many engines require replacement of all head bolts whenever the head is off. By most industry standards nylock or any locking nut is a one time use.

Just because you are unfamiliar with it doesn't mean it isn't done or as in this case it is actually quite common.

 

Not saying it's right but 2 issues here:

1) The crazy cost of these - but yeah, I will replace them coz it's the right thing to do and I don't want windows in my motor per your advice And, the old ones can be used to check bearing clearances...

2) The nylock argument has been made before and I agree if it's critical, I'm replacing them but I'm not replacing them when used in non-critical applications like my air boxes. You can tell when they are done for those purposes.

 

My point is many of these things are quite common. As is regular timing belt replacement or a lot of other things. When it is cheap to do, no one cares, no one argues and most do not even know. When it is done on a Ferrari and now it costs thousands instead of $100 everyone questions it as though it is something new, or argues it as a way for the dealers to make more money or similarly stupid positions.

I have worked on these for over 40 years. I have been aware of them and read about them for about 10 years prior to that. In that time I cannot ever recall a single legitimate claim that anything about them is reasonably priced or that they are cheap to own and operate and yet so many become indignant, surprised or worse when they live up to that well earned reputation.

The bolts like many other parts are unreasonable and stupid expensive but no one should be surprised and it doesn't change the fact they still need to be replaced and it is a pretty industry standard procedure.

 

I don't disagree but will add that innovation comes from out of the box thinking and not just accepting what's been done in the past.

Sometimes, however, the answer is - do what's been done. But, sometimes, it's not

 

Plastic head bolts LOL

 

You seem to have missed it but the entire message was in answer JH48's assertions


I could give a **** if you want to make bolts but he is just wrong.

 

I didn't miss anything - just continuing the discussion

 

Intuitively I think what an excellent Ferrari mechanic who was factory trained does is probably the right thing TO do. If they replace 'em, then we should too.

Want to run the risk of a catastrophic engine failure for $1600? Go for it, but I'd play the sure thing and replace them. Betting $1600 to avoid a potentially $30K and up failure seems like the smart thing to do.

Given the experience Brian brings to the table, I'm betting on him. I can't imagine running the risk for under $2K.

Sometimes I think we all get cheap at the wrong time. Want to save a buck? Run the car on regular instead of premium. But I betcha no one here would do that. And assuming 12 miles to the gallon and an eighty cent delta on premium, you could save a bundle, but you won't . Reuse one time use nuts and bolts? SURE!!!

No thanks,

D

 

Yes, i understand it and if i would need to rebuild an engine to customer, theres no chance i would not change bolts if suggested. Its just too risky. If i was doing my own rebuild, i would definetly measure strech like Mike advised before purchasing new bolts

And like dave said, its possible to use old bolts in pre assembly if in doubt new ones dont stand it

 

A standard black Allen head bolt is 12.9 spec material so it makes you wonder whats so special

 

I just looked up the hardness for a 12.9 class - it's 39-44 Rockwell C which is tough, yet ductile.

What is special is the alloy and heat treating to obtain the specific min proof stregth and tensile strength.

Here is and excellent document.
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Not picking on anyone but I am just glad I got my car while it was under warranty knowing someone did not try to save a buck.

I dont allways agree with everyone on here but why risk it. For all we know and I have seen the videos of Ferrari scrapping engine blocks, heads, cams, etc etc the list goes on.

For all we knew they throw out bolts, maybe they test them all once and then use and discard the ones that fail.

I agree with the outside the box thinking but in this case the discussion is useless because if you try to save a few bucks in this instant I would be very concerned about what else you scrimped on.

As Brian used to say please post your vin so we can all identify the car.

This is just wrong.