Carrillo rods

Can someone tell me the difference between A & H beam Carrillo rods, apart from the price. Is the H rod stronger, last longer???

H is stronger but A works fine.
http://www.carrilloind.com/WhatsNew/...8/Default.aspx

Originally Posted by weecorey

Can someone tell me the difference between A & H beam Carrillo rods, apart from the price. Is the H rod stronger, last longer???

The Carrillo H-Rod is stronger, lasts longer, costs more,

Have a good look at the Falicon Rods, they are sweet,

if you are building an engine and you need a pair of either sent over, let me know,

I have had all of the three choices, If I went Carrillo, I would go H,

Personally I would go Falicon, have the crank balanced, lightened and matched to the rods and pistons. I had the extra oil channel put in and the cryo treatment done,

Very nice results and with the crank out anyway the extra $ were worth it to me,

Enjoy the ride, and best regards,
Blair

Falicon rods are ok but make sure you don't run in to old left over stock. they break like this one.

Got a picture of the crank that went with it?

Can happen just the same with Carrillo,

No guarantees with any of them,

Enjoy the ride, and best regards,
Blair

I guess you are expert when it comes to this. I only know how to post pictures
Here, expert, find something else wrong in this motor other than rod snapped around bolt, know issue with early falicon rods.

Don't be sensitive, I was just kidding with you,

We all know that when rods go they often take the crank or more with them,

Enjoy the ride, and best regards,
Blair

All you know is how to spam around on forums.

[embee]

Just to throw in some generalisations about rod failure mechanisms.

Probably the most common failure modes are associated with the big end joint, either bolts failing or the cap or rod failing near to the bolt boss. When on the exhaust stroke there is effectively no gas pressure so all the inertia forces due to accelerating the rod and piston are taken in tension at the bolts.

These forces can be very big, and go with the square of engine speed. The significance of that becomes apparent with just a few sums, at 11k rpm the forces are 50% greater than at 9k (11x11=121, 9x9=81). The joint is often designed with marginal safety factor at max rpm in order to keep mass to a minimum, so overspeed relative to design criteria is like playing russian roulette, it's only a question of when not if.

The b/e joint can come very close to separation instantaneously, and this can lead to movement of the bearing shells with loss of clamp load.

Most failures are due to fatigue, which comes from cycling the stresses high/low. Most steels have well defined fatigue characteristics so can be designed not to fail, but the safety margin adds weight so the design is closely tied to a maximum engine speed.

Overspeed will usually lead to a fatigue failure of either the cap eye section near the bolt typically, or the bolt itself, or more rarely the rod eye. Inspection of the fractured surfaces will usually tell you which has suffered a fatigue failure, showing "tide" marks in typical fatigue fracture fashion then a catastrophic break, like this


If a bolt goes, the cap bends over and either snaps itself or commonly bends and breaks the other bolt or even the rod eye. Of course all the components get bashed around as they exit the crankcase usually, so you have to learn to track down the real culprit. Collateral breaks usually don't show the fatigue characteristics, and are usually just a jagged type catastrophic fracture.

I recently was involved in a development project where a V8 was uprated and the max speed was increased from 7k to 7300, the theory said the rods would be OK (just) but in practice they failed consistently at between 100-130hrs of high speed cycling test (i.e. a consistent nuber of fatigue cycles). In that case it was the detail of the cap design next to the bolt boss which was the weak point.

Fracture of a bolt/cap/rod isn't necessarily any reflection of the "quality" of the rod design/manufacture, it can be simply that it's been run above its design speed. You say what your max speed will be and I'm sure Carrillo will give you a safe rod.

Buckling failures of the rod are not unknown but are uncommon and usually only seen in very high performance cutting edge designs. Bent rods often result from hydraulic locking or failure to allow for stretch in the rod. Incidentally the uprated V8 stretch allowance was so close that the piston part number which was etched into the crown was transferred to the head squish area and was clearly legible, now that's close.

HTH in some way.

[yorkie_chris]

Originally Posted by zadar

find something else wrong in this motor

It's f***ed. HTH