The Big Rod Discussion!

[Subliminal]

Carillo owns K1.

The rods at TU are made by K1 (which is now owned by Carillo)
The rods at FWDP are made by Carillo, not by K1 (which is now owned by Carillo.

[turbovanman²]

K1 rods will meet or exceed any thing you can throw at them.

[JamesL]

K1 rods will meet or exceed any thing you can throw at them.

And for a little less money Eagles will hold up to 650 HP.

[turbovanman²]

And for a little less money Eagles will hold up to 650 HP.

That too.

[Austrian Dodge]

why do you guys rate rods by HP? it's not a certain HP level that makes a rod fail.
Can't remember who, but someone did a very good post containing the tech. info whats the most stress on rods.

[mpgmike]

why do you guys rate rods by HP? it's not a certain HP level that makes a rod fail.

It's like rating cylinder heads by flow numbers. It quantifies them and puts a number on them. (So does dyno testing, but I digress.)

Mike

[8valves]

RPM is usually the most related to rod failures, although brute power can break a rod, key word being break. The bend is more of a signifier of more rpm than it was capable of. That's a pretty simple way of looking at it.

Are your Carrillo's going to be their A beam design, or something else?

[TurboGLH]

.....Having said that, Carrillo wouldn't buy just any rod company. Couple that with Tom’s credentials and you can trust he has a solid product. Feel free to email him Tom Molnar at K1 tom.m@k1technologies.com or Susan Williams susan.w@k1technologies.com if you have any questions. He is a very amiable individual. Kudos to TU for getting this companies product to the TD market first! Perhaps the TD community will benefit further with pricing should K1 find the need to increase production.

I know that the bad feelings between both companies will never subside, but cudo's for being a professional. I'd like to see this more often, but I'm practical and would settle for less public animosity from both sides.

[Directconnection]

RPM is usually the most related to rod failures, although brute power can break a rod, key word being break. The bend is more of a signifier of more rpm than it was capable of. That's a pretty simple way of looking at it.

Are your Carrillo's going to be their A beam design, or something else?

I think you got it the other way around. Compressive forces aka power is what bends rods including heavy detonation like what we saw with Larry's
T-III a few years back. High rpms is what breaks rods like overrevving, or revving too high for a heavy piston, rod and more like high piston velocites. But in the big time drag racing engines (V-8s with 700+hp) they usually toss rods at the big end due to letting out of the throttle. I hear this alot from the guys that race. Running WOT at max rpm through te traps, then lifting is when a rod goes boom. It's the stretching of the rods and same principle for people that engine brake alot as well.

The eagle h-beam I mentioned about that broke was due mostly in part to the heavy bobweight combo of the piston and piston velocity and the fact that the guy was severely overrevving his engine (windowed one of those nice aluminum Indy Max blocks as well)

Sorry to get off topic again, James. Rating the rod for a given HP is not a bad thing. Easier for people to understand vs. a large techinical breakdown of max. rpm vs stroke vs rod ratio vs piston, pin, ring weight etc vs modulus of elasticity analysis of rod bolt in question etc...

[8valves]

I think you got it the other way around. Compressive forces aka power is what bends rods including heavy detonation like what we saw with Larry's
T-III a few years back. High rpms is what breaks rods like overrevving, or revving too high for a heavy piston, rod and more like high piston velocites. But in the big time drag racing engines (V-8s with 700+hp) they usually toss rods at the big end due to letting out of the throttle. I hear this alot from the guys that race. Running WOT at max rpm through te traps, then lifting is when a rod goes boom. It's the stretching of the rods and same principle for people that engine brake alot as well.

The eagle h-beam I mentioned about that broke was due mostly in part to the heavy bobweight combo of the piston and piston velocity and the fact that the guy was severely overrevving his engine (windowed one of those nice aluminum Indy Max blocks as well)

Sorry to get off topic again, James. Rating the rod for a given HP is not a bad thing. Easier for people to understand vs. a large techinical breakdown of max. rpm vs stroke vs rod ratio vs piston, pin, ring weight etc vs modulus of elasticity analysis of rod bolt in question etc...

You bring up good points for sure. The few rods failures I have seen in person, none in the TM scene, were rpm related and caused a bend. I will also state that two of the failures were an aluminum rodded hemi pulling truck engine, that could also alter the situation.

Ah well. Simplicity is the way to go probably

[Chris W]

Kudos to TU for getting this companies product to the TD market first!

Thanks for the compliment James Happy Easter to you and your family

it's not a certain HP level that makes a rod fail. Can't remember who, but someone did a very good post containing the tech. info whats the most stress on rods.

I'm not sure where that post is, but, unless the rod is grossly under designed, it will not break due to HP. Because power is produced from the expanding gasses pushing down on the piston, there is a compressive (pushing) load on the rod. If a rod broke due to power, it would be crushed. The fact is, rods are broken due to being pulled in two. This high tension (pulling) load is highest at TDC on the exhaust stroke when the piston is trying to go through the cylinder head and the crank tries to pull it back down. The reason it is highest at this point is because the other time the piston is at TDC is on the compression stroke and the piston is being pushed back down by the gas loads of the compressed air/fuel mixture. To the best of my knowledge, there is no power being created on the exhaust stroke so rating rods by power is simply not applicable. Most people including most rod manufacturers do not realize this. Fortunately for us, turbocharged engines do provide "some" backpressure on the exhaust stroke reducing that stretching force on the rods.

Chris-TU

[Frank]

Moved posts from the various threads in the vendors section. This is too be a nice collimation of posts and lets keep it awesome! Thanks!

[turbovanman²]

lets keep it awesome!

[Directconnection]

You bring up good points for sure. The few rods failures I have seen in person, none in the TM scene, were rpm related and caused a bend. I will also state that two of the failures were an aluminum rodded hemi pulling truck engine, that could also alter the situation.

Ah well. Simplicity is the way to go probably

Did the rod bend due to over-revving and the piston crashing the chamber?

[TurboJerry]

The most stress is when the piston has to go from TDC and be *yanked* down by the rod during the overlap period. Boost takes some of this stress away in a forced induction engine. Too much cylinder pressure at a low rpm (below 3000 rpm) in most cases will bend a rod from the force involved. Like hitting a high hp nitrous system at low rpm will bend a rod for sure in most cases. Also the rod bolts are usually first to go at high rpm. properly prepared rods usually won't crack.

[turbovanman²]

The most stress is when the piston has to go from TDC and be *yanked* down by the rod during the overlap period. Boost takes some of this stress away in a forced induction engine. Too much cylinder pressure at a low rpm (below 3000 rpm) in most cases will bend a rod from the force involved. Like hitting a high hp nitrous system at low rpm will bend a rod for sure in most cases. Also the rod bolts are usually first to go at high rpm. properly prepared rods usually won't crack.

Thats what I have heard and read. I won't let anyone dyno my bike or vehicles that goes to WOT then just pulls the clutch in,

[Ondonti]

well a stronger rod can mean the difference between detonation bending a rod and simply needing to replace a bearing. I know we would all like to have a "perfect" tune that never has a hiccup but....thats not always realistic.

[Chris W]

The most stress is when the piston has to go from TDC and be *yanked* down by the rod during the overlap period. Boost takes some of this stress away in a forced induction engine. Too much cylinder pressure at a low rpm (below 3000 rpm) in most cases will bend a rod from the force involved. Like hitting a high hp nitrous system at low rpm will bend a rod for sure in most cases. Also the rod bolts are usually first to go at high rpm. properly prepared rods usually won't crack.

Exactly!! Sounds like an echo of the words I just wrote above Jerry

I can think of one instance where horsepower will definitely bend a rod and that's if a cylinder is hydro locked.

Chris-TU

[Tony Hanna]

I can think of one instance where horsepower will definitely bend a rod and that's if a cylinder is hydro locked.
Chris-TU

I've seen this first hand.
Doesn't take much, you can do it with the starter.

[2.216VTurbo]

So does anyone have any first hand experience with the Mechart rods? I have a set of them in a spare 8V motor that was built many years ago... Not sure if I should pull them at some point and press them back into service on another motor or not I've heard they were crack prone but again, only what I heard, never seen any break.