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Re: motor is done... (1.BillyT)

Quote, originally posted by 1.BillyT »
Beautiful, isn't it...

Too bad I just pulled it out or one of the boxes of broken rods I have, from all of the motors I have blown up...

anything is possible...
and you didn't SRENGTHEN/MAGNAFLUX those "STOCK" rods?
 

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Re: motor is done... (1.BillyT)

blessed by Jesus and they only lasted that long?? wow. I really have to give mad propz to the billyT engineering dept for making those rods look so close to stock and for going ahead and gettin 'em blessed by the son of god while they were out.
WTG.
 

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Discussion Starter · #67 ·
Re: motor is done... (1.BillyT)

Quote, originally posted by 1.BillyT »
The rods were actually blessed by Jesus Christ himself.

My skin burns when I touch them.
 

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Discussion Starter · #68 ·
Re: motor is done... (1.BillyT)

You know, the funny thing about this, is that I have the rod cap too... and it is perfect. Absolutely perfect... I think the problem with this wasn't so much that the rod broke, but the rod bolts let go... that would explain the hole in the oil pan, the perfect rod end cap, and all of the ensuing destruction....
The last motor that let go, and pretty much all the other guys I have seen that posted pics of blown motors, all still had the rod attached to the crank. interesting....
 

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Re: motor is done... (1.BillyT)

Quote, originally posted by 1.BillyT »
You know, the funny thing about this, is that I have the rod cap too... and it is perfect. Absolutely perfect... I think the problem with this wasn't so much that the rod broke, but the rod bolts let go... that would explain the hole in the oil pan, the perfect rod end cap, and all of the ensuing destruction....
The last motor that let go, and pretty much all the other guys I have seen that posted pics of blown motors, all still had the rod attached to the crank. interesting....

wow man you deff. got connections to get JC to bless them rods!
Usually the biggest reason most rods give is the rod bolts not the rods themselves...as I am sure you know...and I am one of those people with a blown block with my rod big end on the crank still...

http://www.pittspeed.com/uploaded/val14.JPG
http://www.pittspeed.com/uploaded/val15.JPG
your's looks bent at the big end though (oval shape tells me that)..due to the pressue it received...so your rod bent...vs. mine broke/shattered
 

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Re: motor is done... (kilmer420)

you were revving the piss out of yours too. Surprised the rod bolt's didn't let go.
Many of the rod bolt failures on here could have been caused by bending a rod first. A bent rod puts a nasty shear load on the bolts that they would otherwise not have. With your power levels it probably didn't have enough time
 

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Re: motor is done... (1.BillyT)

Quote, originally posted by 1.BillyT »
You know, the funny thing about this, is that I have the rod cap too... and it is perfect. Absolutely perfect... I think the problem with this wasn't so much that the rod broke, but the rod bolts let go... that would explain the hole in the oil pan, the perfect rod end cap, and all of the ensuing destruction....
The last motor that let go, and pretty much all the other guys I have seen that posted pics of blown motors, all still had the rod attached to the crank. interesting....

that is interesting...
ive never had a broken rod bolt.
2 motors, 2 shattered rods, both engines have seen nitrous. both cyl number 1.
i know both of my engines have seen detonation on a damaging scale.
and if you didnt detonate and the rod isnt too chewed up to bad im sure it will tell the story...
who knows maybe the rods are stronger than we thought and the rod bolts are the true weak link... but im not going to find out. you guys can if you want.
 

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Re: motor is done... (need_a_VR6)

Quote, originally posted by need_a_VR6 »
So what I hear you saying is, "put ARP rod bolts in"

You guys missed what i was saying, so i drew a little diagram for you. I'm no artist, but it should get my point across.
as billy was so kind to demonstrate, connecting rods are under tremendous load. Believe it or not, tensile loads are typically worse than compression loads. When the piston is at top dead center it has to change direction very quickly. Accelerating this mass requires tremendous load at high RPM. Stock rods, and bolts are designed to be very strong in tension. In fact the bolts are only loaded in tension. Normally.
even under serious cyliner pressures the rod really only pushes on the crank, the botom cap doesn't do much, and the bolts are not working too hard.
So conclusion - rod bolt loads are highest under tension, when the piston is at TDC, and changing directions. This is more rpm dependent not big maaddd powwa yo dependent.
Ok, so that being said, what breaks rod bolts if they are only loaded from RPM and we arent reving much higher?
If you bend a rod from high cylinder pressures, then the load is not applied to the rod cap as it should be. It is applied at an angle. Loaded at an angle, there is a massive tensile load, as well as a new shear load applied to the bolts. With a massive load, only a few degrees can create a severe shear load. Engineers did not design for this, as their rods are straight (no pun) So this new combined load can cause a bolt failure where the original load did not. See figure 1.

note this is not an engineering free body diagram, but a much simplified version for the whoretex, so no nerds are allowed to critique.
So that beig said, it is very likely that the rods get bent from the above mentioned maad powah and then the bent rod loads the bolts in a way to cause one to shear and then a resulting margarita maker of an engine.
To prove this theory an analysis of the bolts - if not damaged too severly - could show if there was a tensile or a shear load on the bolts.
 
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