Author Topic: Project "Phoenix Rise" (Read 15632 times)

Jerry Hall · « **Reply #15 on:** June 02, 2016, 04:15:57 PM »

Quote from: Tbone07;67993

Was the crank the culprit for the explosion? Was it trued and/or welded?

Truing and welding the crank will not prevent this type of failure. This type of failure is related to: cross-section too small at point of failure, heat treat, type of material or pilot error.

This is not the first time I have seen this type of failure at the small end of the rod.

A 250 piston assembly (piston, rings, pin, bearing and clips) usually weighs in at around 300 gm. A 330-350 piston assembly usually weighs in around 350 to 380 gm.

I personally believe that the connecting rods (OEM, Hot Rod and the other aftermarket rods) were not designed to carry the loads that can be placed on these rods with big bore pistons with the current cylinder and pipe technology of some good engine builders.

The additional weight of a big bore piston and the increase in acceleration produced by adding 4mm to the stroke, increases the tension in the connecting rod over 25% at 9000 RPM over the original design intent.

Missing a shift, or down shifting when an up shift was intended can easily send the RPM well over 10,000 RPM.

The additional weight of a big bore piston and the increase in acceleration produced by a 4mm stroker, increases the tension in the connecting rod over 40% at 10,000 RPM over the original design intent.

We used the OEM CR250 Con Rods to rebuild the TRX 250 R cranks when they were still available. The OEM CR250 rods had a thicker cross-section everywhere as compared to the TRX 250R OEM rods and never broke in the 250 shifter kart engines that we use to build that spent a lot of time above 10,000 RPM.

christph · « **Reply #16 on:** June 02, 2016, 06:14:49 PM »

Wow, the force necessary to bend a rod like that must be incredible.

Jerry Hall · « **Reply #17 on:** June 02, 2016, 08:01:34 PM »

Quote from: christph;68011

Wow, the force necessary to bend a rod like that must be incredible.

The rod broke first. Then the kinetic energy stored in the rotating components of the engine and drive train, as well the mass of the bike and rider at speed was used to bend the rod after it became detached from the piston.

rablack21 · « **Reply #18 on:** June 03, 2016, 08:19:49 AM »

Quote from: Jerry Hall;68012

The rod broke first. Then the kinetic energy stored in the rotating components of the engine and drive train, as well the mass of the bike and rider at speed was used to bend the rod after it became detached from the piston.

Normally, yes. However, in this case, it was just pure kinetic energy from rotating components. The quad was sitting still when it blew. I was on the starting gate at one of my mx races. It blew right as the gate dropped.

rablack21 · « **Reply #19 on:** June 03, 2016, 08:24:59 AM »

Quote from: zcarlson12;67989

Looks like a great start Ryan. Those cases are sweet! Pics of the pipe please!

Here ya go Zak.

christph · « **Reply #20 on:** June 03, 2016, 11:34:03 PM »

Damn, that is a bad-ass looking pipe. Is that their 350G model?

thesmith87250r · « **Reply #21 on:** June 03, 2016, 11:48:27 PM »

yes it is says so in 2nd post.

F-Red · « **Reply #22 on:** June 04, 2016, 09:27:54 AM »

Them pipes are sweet. I have the raw version and let me tell you, what a difference it makes on the big bores.

Big_Mike · « **Reply #23 on:** June 04, 2016, 11:17:34 PM »

I have seen rods turned into spaghetti like that from the cylinder being hydro-locked, that would do that kind of damage to a connecting rod too...

Michael88R · « **Reply #24 on:** June 05, 2016, 02:09:34 PM »

Sorry to hear about the explosion. Glad ur rebuilding her. Looks like a good start. That pipe is sick. I've been wanting an led engine but very $$$$. Too many toys. Not enough money.

What pipe were u running before?

rablack21 · « **Reply #25 on:** June 06, 2016, 08:15:22 AM »

Quote from: Michael88R;68092

Sorry to hear about the explosion. Glad ur rebuilding her. Looks like a good start. That pipe is sick. I've been wanting an led engine but very $$$$. Too many toys. Not enough money.

What pipe were u running before?

You are not kidding! I shed a few tears and drank a few beers after I ordered that pipe and silencer.
I was previously running an ESR TRX 5B pipe. I liked it very well. Wanted to see what this one could do.

Skeans1 · « **Reply #26 on:** June 06, 2016, 08:30:05 AM »

Quote from: rablack21;68098

You are not kidding! I shed a few tears and drank a few beers after I ordered that pipe and silencer.
I was previously running an ESR TRX 5B pipe. I liked it very well. Wanted to see what this one could do.

They aren't all that bad Ryan 750 in chrome isn't that bad at all, I was around that price from Matt Shearer for a raw price.

rablack21 · « **Reply #27 on:** June 06, 2016, 09:09:43 AM »

Quote from: Skeans1;68099

They aren't all that bad Ryan 750 in chrome isn't that bad at all, I was around that price from Matt Shearer for a raw price.

$800 for the chrome pipe. Shipping and everything was $930. That's a lot of dough. That is among the highest priced pipes of all the manufacturers.

Skeans1 · « **Reply #28 on:** June 06, 2016, 09:14:11 AM »

Quote from: rablack21;68100

$800 for the chrome pipe. Shipping and everything was $930. That's a lot of dough. That is among the highest priced pipes of all the manufacturers.

He's showing 550 for a chrome G pipe and 200 for silencer, a hall pipe pipe for a zilla raw was 950 shipped.

rablack21 · « **Reply #29 on:** June 06, 2016, 09:19:27 AM »

Quote from: Skeans1;68101

He's showing 550 for a chrome G pipe and 200 for silencer, a hall pipe pipe for a zilla raw was 950 shipped.

My mistake. It wasn't 800 for the pipe by itself. I do know it was $930 with shipping and everything, don't care what his website says. I thought we were discussing 250R pipe prices? The pipe you mentioned is not for a 250R engine. So yes, among 250r pipes, this LED pipe is among the highest.