Am I taking a risk

[killa03ex]

Am I taking a risk running a 12:1 compression piston on a stock rod? I've been told that I could possibly break my rod and I've been told not to worry about it please let me know cause I have all these parts that need to be put on and I need to know if I should buy a rod so I can get this together.

[Flyin-Low]

Breaking a rod could be real nasty, id suggest just buying an aftermarket one to be safe.

-Martin

[BORY]

i was told an 11:1 is pushing it for a stock rod

[NacsMXer]

Originally posted by killa03ex
Am I taking a risk running a 12:1 compression piston on a stock rod? I've been told that I could possibly break my rod and I've been told not to worry about it please let me know cause I have all these parts that need to be put on and I need to know if I should buy a rod so I can get this together.

Yes, you are running a risk of breaking the stock rod with 12:1 compression. It may break, it may not. You will have MUCH greater chances of breaking it with 12:1 comp. though. You would be at the upper limits at what the stock rod could handle, really venturing out of the "safe zone" if you will.

If it were me, I would be scared to do serious riding with that setup because that stock rod breaking would always be in the back of my mind.

IMO a HD rod is just cheap insurance against your motor literally grenading on you. This has happened to people on this site and they have posted the ugly pics of the destruction. 11:1 compression would be as high as I would take a stock rod myself :o

[QuadJunkies]

I have about 300 hours on a stoc rod on MY 440 kit and not one single bit of issues, as a matter of fact, I even posted the Rod and what it looked like when we done my rebuld this winter. ITs been raced many, many times.. Unless your on a Stroked motor,you should be MORE than fine to run that . I run a 12: l also.

[lafinrat]

If you want added insurance, buy a Carrillo. I'm a dealer and getting ready to order some tommorrow. PM me for a price. They retail for like $240. I'll get my price tommorrow.

Two other things come to mind when I read this thread

1. 99% of the people on here have no idea what the static compression is in their motor. Since they base it on what a box says and most don't know how to measure it, nor do they have the tools to do so. No disrespect, but that's a fact.

2. The origin of a correlation between static compression ratio and rod fatigue. Connecting rod failure is most commonly related to harmonics (from imbalance, detonation, etc), RPM, acceleration, and power production. If you're raising your compression via larger dome on the piston, the power difference between 11:1 and 12:1 will be negligable at best. So, basically a well-built 11:1 motor may break a rod long before a more basic 12:1 motor--as a result of increased power, and possibly RPM. Now there is always the sloppy 12:1 motor (i.e. loose clearances, big dome to make up for it) that may dentonate due to poor quench and ineffecient flame travel. That kind of motor will break a rod if detonation occurs, and no you don't always hear detonation or see evidence of it. Most times yes, but always no.

Ok. I'm done.

[killa03ex]

Well I have the money to buy a new rod but i was told by the friend of mine thats putting on th parts for me that putting in a new rod isnt only hard but it would be expensive to get put in by a dealership

[Chino]

Originally posted by QuadJunkies
I have about 300 hours on a stoc rod on MY 440 kit and not one single bit of issues, as a matter of fact, I even posted the Rod and what it looked like when we done my rebuld this winter. ITs been raced many, many times.. Unless your on a Stroked motor,you should be MORE than fine to run that . I run a 12: l also.

I agree, i'm running a 13:1 on a stock rod and have had zero issues thus far.

[440_Turtle]

Originally posted by killa03ex
Well I have the money to buy a new rod but i was told by the friend of mine thats putting on th parts for me that putting in a new rod isnt only hard but it would be expensive to get put in by a dealership

yes you are looking at splitting teh cases to get to the crankshaft. you might as well have them completeley refresh your engine while they got it all apart.

[killa03ex]

do you guys think it would be worth just buying a hotrods stroker crank with the rod and everything since i have enough for one?

[Flyin-Low]

If money isnt an issue, go for it.

-Martin

[killa03ex]

well I want to get the stroker crank and rod but will the JE piston I have already bought work with it? cause I dont really like wiseco pistons and I read somwhere that you have to use a special wiseco piston

[ohsobad_chevy]

Dude, definately spend the extra money now. You will be up @#$@ creek if you break that rod. Better to spend the money now than later, right....

My 2 cents...

[aviator4]

The answer is no, your JE 12:1 piston won't work with the stroker crank.

As far as HAVING to use Wiseco piston... my HotRods crank kit came with a 10.5:1 CP piston (10.5:1 because the want people to be able to run pump gas) so there are some options available to you there.

I would say, after just doing this mod on my bike (stoker crank) and trying to press the old crank apart to see what the bearing looked like... forget a new rod... it's too much work and takes a 20 Ton press or better to get the thing off. Then you have to index the ballancers and yada yada... Just go for the crank kit. Don't forget to order new case bearings as well. It's a good idea to go ahead and replace 'em while you're in there. you're going to need a gasket kit as well. Might as well replace them all while you're in there too. This will give you a practically band new motor.

This mod is a LOT of work and requires attention to Detail to get it done right and have a reliable motor. Having a shop press and bearing seperators, is a MUST to get this done (oh, and don't try this without a Clymer or service manual). you wil l also need a crank installer. We used a 36mm deep impact socket and a new bolt and washer to "make" one - worked like a champ. I was very impressed with the HotRods crank, it spec'ed out EXACTLY where they said it would, the CP Piston came with it's own spec sheet and was dead on. The rings required only minor filing. This thing runs like a RAPED APE! Should have dyno numbers soon.

Some other important tools to have for this project (IMHO) that you don't find in just anyones garage:

Deadblow Hammer ... to help break seaals and seat things, DO NOT use a regular hammer here (or anywhere) on the engine
Inch/lb torque wrench, 20-200 in/lb is sufficient
Foot/lb torgue Wrench, up to 100 Ft. lb's works good.
Feeler Guage for setting valve lash/ checking clearances
Micrometer and bore guage (not mandatory, but nice to have if you're a stickler on detail, like me)
assembly lube or lithium grease
Parts cleaner - again, not mandatory, but sure beats buying 4 cases of break/carb cleaner!
brass wire brush or brass wire wheel for a grinder to clean up threads and stuff.


Good Luck!

[killa03ex]

wow:( , i was hoping to just get my cam and piston put on without having my whole motor redone. and I highly doubt my friend who was going to do this for me knows how to put in a whole new crank, plus it wont even work with the piston ive alreday bought:mad:

[04'400ex'er]

Splitting the cases is a far cry from freshining up a top end. If I were you and wanted to go the cheaper route I would go ahead and put in the parts that you have. BUT...I would not run an aftermarket rev box of any sort.

[redracer10]

yah definitly 11:1 are bad for rods 12:1 are twice as bad the bigger u get with a stock rod the faster the ruining.

[redracer10]

If you want added insurance, buy a Carrillo. I'm a dealer and getting ready to order some tommorrow. PM me for a price. They retail for like $240. I'll get my price tommorrow.

Two other things come to mind when I read this thread

1. 99% of the people on here have no idea what the static compression is in their motor. Since they base it on what a box says and most don't know how to measure it, nor do they have the tools to do so. No disrespect, but that's a fact.

2. The origin of a correlation between static compression ratio and rod fatigue. Connecting rod failure is most commonly related to harmonics (from imbalance, detonation, etc), RPM, acceleration, and power production. If you're raising your compression via larger dome on the piston, the power difference between 11:1 and 12:1 will be negligable at best. So, basically a well-built 11:1 motor may break a rod long before a more basic 12:1 motor--as a result of increased power, and possibly RPM. Now there is always the sloppy 12:1 motor (i.e. loose clearances, big dome to make up for it) that may dentonate due to poor quench and ineffecient flame travel. That kind of motor will break a rod if detonation occurs, and no you don't always hear detonation or see evidence of it. Most times yes, but always no.

Ok. I'm done.








I also think 99% of people really dont care about a single thing you just said!! I have a stock rod and I have a 14:1 piston and nothin happened yet. I guess the day somethin does I will have a buisness fix it.