I don't know the answer as it relates to HP but just thinking out loud....the rod is like a rolling mass...a little harder to get moving but once up to speed it pulls harder than a lighter one. Maybe it benefits torque. Hollyfield has more torque than Trinidad. LOL.

 

I hear about rod failures but why?? What was the cause?? If it is at the piston pin was it a lack of oil?? Were the machines run with out the right amount of oil?? Some of the motors with rod failures have been torn down before. Was the rod damaged prior to being reinstalled?? How many stock bikes have broke a rod?? I am sure some have. There are probably around 70,000 raptors out there now, you have to take some have broken everything by know. Common sense says that carrilo is the way to go on one hand. People always find a weak link and try to improve on it. But if a carrillo rod weighs 100 more grams than what yamaha engineered in will that shorten the life on the lower end next?? Will it cause the bearings to go out?? You fix one problem and cause another one maybe. Why did carrilo make there rod 100 grams heavier?? What were there design parimiters. They have been a few broken carrillo rods. In the big picture 70000 quads vs 400 with carrillo rods looks like carrillo has a worse record.

Fortin gears have been known to break after being improved.

Blue- you might be right

Air- with a stock rod you would not be at 87HP unless you used Harry's dyno. lol Why did you not run it back up on Othins dyno and get a another free run. You know it would have made your day if you could have dynoed higher.

 

The important thing is balance. When you change the weight of the reciprocating mass, then you need to re-balance. It is true that an engine out of balance will be down on power as compared to a properly balanced condition. The weight of the rod, and its effect on horsepower is negligable as long as the balance is correct. You will never feel the difference at all as long as it was assembled correctly. The difference in responce is also so minute that you will never feel it. It is I suppose able to be measured, but so is the distance to the moon. Who cares, its a long way. Difference in responce, who cares, you will never feel the difference. Anyone who says they can feel the difference is in the wrong line of work. They should be rich as a human dyno, and accelerometer.

 

I think somebody has to be able to lighten a carrillo rod rebalance it and reforge it to put strenth back in it???

 

LOL Don't be putting that bad MOJO on me, my rod is fine.......well it was.[img]i/expressions/face-icon-small-shocked.gif[/img] I bet you meant wshrdskin right?
After reading a very good thread, on another forum or I would link it, I don't think you have much of a choice but too run the dual rate springs with a stage2 cam. A Hot Cams rep. said it would destroy an aluminum head do to harmonics.

skin, you know I am tearring down mine at the same time too( I just have soem catching up to do[img]i/expressions/face-icon-small-wink.gif[/img] ). This is also an issue for me, I truely don't want to be tearring it down again. I am NOT going to use a Carrilo rod for some of the reason mentioned on here.

If your worried about the weight of the rod take the extra amount of weight from the rod off of the fly wheel. BUT then it will be even more out of balance. As with EVERYTHING else in life, its a give and take. So I pose this question, Do you want to get it or do you want to GET IT?[img]i/expressions/face-icon-small-confused.gif[/img]

 

Well, I don't need new a new head. Mine suffered no damage. I do however need a new sleeve put in my cylinder or a new cylinder.
Rod
Possible crank
Piston
Cases
Labor to switch rod into crank and install crank and bearings from old cases into new cases.
Gasket set
Various lock washers etc

Probably more things I'm not thinking of right now.

 

The additional ounces is not gonna make a realistic difference in HP. I can't see the rod throwing balancing off for most Raptors.....but for a professionally built engine, balancing needs too be done anyway.

 

I can tell you after my 686 was built with a carrillo rod it broke the motor mounts due to a vibration issue,dont know if the extra weight of the carrilo had anything to do with it or not but my guess it wasnt balanced or balanced correctly, I know I wont be putting another 686 in my new 03.

 

Here's just a little something I found on balancing.

There is absolutely nothing on the planet as good as a free revving, well balanced engine, it keeps wear to a minimum, and helps keep fasteners and complete engines together over a much longer period of time.One gram,(the weight of a paperclip) may not seem like much static, in your hand, but put it in motion, and give it some radius and you'll be amazed at what it can weigh. For instance one gram at a 5" radius can weigh well over 100 pounds at just 6,000 RPM. An out of balance engine can consume parts like a shredder, and can even break exhaust fanges and engine mounts by sending harmonics throughout the vehicle, some that can even be felt in the drivers seat!

It came from this article if you care to read more.here

Opps wrong one but it's pretty good too.

 

My question again, Is it the ROD or The CRANK twisting that causes the rod to break? Has any broke a rod with a welded crank????????