shane661
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posted June 17, 2007 01:04 PM
Billet Stroker Cranks
I have heard of a lot of crank failures on stroker motors. I was wondering if anyone has experience with the billet cranks, and do they improve reliability as stated?
  
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entropy
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posted June 17, 2007 02:05 PM
Shane.
i don't know of a single weldup stroker crank which has failed.
Oiling probs resulting in rod bearing damage, YES, but crank failures???
I had a billet stroker which i lost to oiling probs, and am running a weldup(offset) now with no probs.
I've been running a stroker since 2001 (1361, 1375, 1427) and am thus interested in any failures you know of????
Karl
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shane661
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posted June 17, 2007 02:34 PM
Perhaps I am mis-interpreting what I have been told. But if the cranks cause the rod bearings to fail, that would be just as bad...correct? What exactly is causing the oiling problems?
I have heard of two "crank failures" (open to interpretation as the bikes did not belong to the person who witnessed the events). I also believe that Dan, Oldkawboy, mentioned that one of their strokers failed on them?
At any rate, just looking for the straight scoop.
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dougmeyer
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posted June 17, 2007 02:53 PM
The cranks don't fail. The rods don't fail. Even the bearings don't fail. But all these parts and usually the crankcase is lost when THE OPERATOR FAILS to take the necessary steps to keep the oil pump pumping oil.
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ninja12
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posted June 19, 2007 01:30 PM
I would call repeated rod bearing failures a crank or case failure.
I have seen 2 zx12 cranks that have broken in half ,
one had no journal damage, neither did case damage.
I would not put a stroker in 2000 cases!!!!!!!!!!!!!!!!!!
bad juju.
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psycho1122
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posted June 20, 2007 03:41 AM
Not this crap again.................
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entropy
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posted June 20, 2007 03:42 AM
quote:
I would not put a stroker in 2000 cases!!!!!!!!!!!!!!!!!!
bad juju.
But you prob would on the newer replacement cases for Y2K's, eh?? 
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Megabyte
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posted June 20, 2007 06:43 AM
quote:
Not this crap again.................
ditto. I've got an A1 w/20k + miles on the stroker, and still going strong. What's suppose to be wrong with the 2k cases, or am I missing something?
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Seth ZX12r UK
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posted June 20, 2007 06:46 AM
Megabyte did you modify the oil system at all?
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ninja12
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posted June 20, 2007 08:57 AM
Ok guys , I'm not knocking your all mighty 2000 zx12.
I'm one of the few zx12 racers in my area, and I have been inside more of these engines than most . I own a few blown 2000 motor, I bought them blown for parts. Interesting that
there are very few blown 2002+ engines to be had.
I blew several myself with the #3 rod every time,except the 1 center main.
every after replacing the cranks , and using differnet cases. Maybe pure coincidence.
It was not until I switched to 02 cases that my engines stay together.
If the 2000 engine was so good why did kaw change the cases in 2001 and again in 2002?
Why are the rods changed in 02? THEY MADE IMPROVEMENTS!!!!
I will say this again ALMOST EVER 2000 zx12 I know has had the engine replaced or rebuilt . I just counted 8 off the top of my head only 1 still running.
If I were on here asking for information, I would want to know this.
Sorry if I hurt your feelings.
G
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shane661
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posted June 20, 2007 09:33 AM
Thanks for the input Ninja12. My bike is an '02. I am trying to figure out if a stroker is the way to go, and I appreciate everyone's input.
I would like to know the cause of the oiling failures.
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entropy
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posted June 20, 2007 01:33 PM
quote:
Thanks for the input Ninja12. My bike is an '02. I am trying to figure out if a stroker is the way to go, and I appreciate everyone's input.
I would like to know the cause of the oiling failures.
oiling = uncovering pickup
when you decide to go stroker, i have a surplus, only slightly used but PRISTENE Y2K 4.6 crank; same as a 2002 but lighter.
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Megabyte
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posted June 20, 2007 03:30 PM
quote:
Megabyte did you modify the oil system at all?
We enlarged the oil feeder lines, that's all that I'm aware of ?
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shane661
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posted June 20, 2007 05:40 PM
Wolf Racing has replaced cranks twice, due to "oil starvation".
So, how do we combat this problem?? Obviously this is an issue with stroker's.
Is it simply due to increased acceleration? Or is their more to it?
Is a pan with a swivel pickup sufficient to cure the problem?
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ZXLNT
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posted June 21, 2007 02:43 AM
Is it a problem with the stroker cranks, or a problem of the bikes being ran the piss out of, which happens with hot rodded stroker cranked engine. Ya dont build a stroker motor for a grocery getter...
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entropy
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posted June 21, 2007 04:42 AM
ding-ding-ding!!!!
We have a winner!
(but i am still intruiged by Gerard's observation...)
quote:
Is it a problem with the stroker cranks, or a problem of the bikes being ran the piss out of, which happens with hot rodded stroker cranked engine. Ya dont build a stroker motor for a grocery getter...
And many of the stroker motors are being assembled by folks who really shouldn't be doing it;
in my experience THE MUZZY KITS ARE NOT PLUG & PLAY, you have to measure stuff....
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shane661
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posted June 21, 2007 05:02 AM
So, they are more susceptible to failure than a stock crank? I know that sounds like a stupid and obvious question. But I don't want have a ticking bomb on my hands!
I have put close to 200 drag runs on my stock engine, with 20k miles on it, since last
season. It has been down the Maxton mile about 15 times as well. Should I expect a
properly built stroker to hold up to that # of runs??
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entropy
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posted June 21, 2007 06:06 AM
 Edited By: entropy on 21 Jun 2007 07:12
Shane
you are missing the point completely; do you seriously expect a built motor to last as long as stock???
Your stock motor is just exactly that: a stock motor which has been highly engineered to give good performance and longevity, AND it has been manufactured by professionals.
The 12 motor is already a very high performance motor; I remember my 1980 CBX had an astounding 101hp at 1050?cc. The 12 has 175hp w/pipe!!!!!
Want more hp? You are going into "interesting" territory.
Changing the OEM set up to stroker crank & aftermarket pistons changes the equation completely. Just like shooting significant N2O or turbo.
1. The stroker is making more hp than the motor was engineered to have. OBVIOUSLY this puts various parts out of their design specification. Will this out of spec motor live as long as the OEM??? NO, absolutely not. Will it live a long time? Maybe.
2. How long the motor lives will depend upon at least 4 things:
- How extreme is the build?
The more hp over stock, the less the life (more or less)
- How well was it built?
The person who puts the stroker motor together has to be very careful with set up. Experienced builders know what to check, what tolerances should be. An improperly assembled motor will fail early, sometimes immediately.
- what application?
Use it on the street and it may live a long time. Race it, "not so much"
- how you use/abuse it?
Run it into the limiter all time? Rev the piss out of it NOT under load? Race or dyno a cold motor??
Shane, there is no magic bullet to give you significantly more hp than stock AND keep OEM reliability.
My advice?? Don't even consider having yr motor built. Stick with a small dry shot.
[entropy gets off his soapbox and goes back to work...]
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buddy
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posted June 21, 2007 06:47 AM
My advice?? Don't even consider having yr motor built. Stick with a small dry shot.
Excellent advice. But if you still want to stroke, here's my 2 cents worth.
I had a 1427 that a rod (stock) broke in. Took out cylinder # 4 and everything else. No harm to the crank.
Re-used the crank in a 1375cc (Apprx.). wrist pin on #3 was gone after about 50 runs, destroying that motor. No harm to the crank.
Built another 1375 reuseing the same crank. Wrist pin missing on # 2 wasting that motor. No damage to crank.
No oiling problems, no absolutely known problems. I think weak wrist pins for so much nitrous applied for so long (1 mile), as the wrist pins were only 75% as substantial as stock pins. It was fun for 7 runs tho.
I'm not trying to come across as an engine builder, only relaying observations which may or may not be valid.
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Megabyte
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posted June 21, 2007 08:02 AM
Edited By: Megabyte on 21 Jun 2007 12:00
Well, the add doesn't say "reliable." Maybe Doug could give us his expert knowledge and experience on the subject ?
Maybe he already gave us his expert opinion:
"The cranks don't fail. The rods don't fail. Even the bearings don't fail. But all these parts and usually the crankcase is lost when THE OPERATOR FAILS to take the necessary steps to keep the oil pump pumping oil."
Muzzys has improved the 1361 kit for the ZX-12 owner who just can't get enough! This kit is now a 1375 and includes everything you need to turn your ZX-12R into a 210 horsepower monster. Like wheelies? Over 120 lbs. ft. of torque at 7500 rpm ought to provide all you need. Want low end power for those "tough" situations? How about 100 hp at 5000 rpm? It's a straight shot from there to 210 hp at 10,000 until you hit the rev limiter! This is street-able, controllable horsepower that creates a well mannered monster out of your ZX-12R. This kit contains everything you need. It is a true bolt in; no machine work is required. The forged pistons provide a 13.5:1 compression ratio. The kit contains a crankshaft with a stroke increase of 4.6 mm, special base spacer and gasket, 2.4mm oversize pistons, rings, clips,
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Seth ZX12r UK
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posted June 21, 2007 12:43 PM
So an accumulator would be a good thing on a stroker that is going to be LSR'd or 1/4 miled or more proffesionally a dry sump.?
How difficult would it be to fit an auxillary oil cooler, so as to get additional volume of oil into a stroker?
Pro's cons?
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TRNorBRN6001
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posted June 21, 2007 01:31 PM
Billet strokers sure cost a lot if they get damaged. My two cents, just drop in a big bore kit and leave the bottom alone. If you just have to have a stroker then get an expert builder who has had experience with stroker 12s.
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Megabyte
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posted June 21, 2007 01:52 PM
quote:
If you just have to have a stroker then get an expert builder who has had experience with stroker 12s.
That's exactly what I did, and I've been giving the same advise. Mike Velasco built my stroker on the same bench he used to build race engines for Ducati.
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dougmeyer
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posted June 21, 2007 03:40 PM
Edited By: dougmeyer on 21 Jun 2007 16:44
Exactly. In fact I did write that blurb.
I think if you build a 1361 and ride on the street or even drag race it WITH A STREET TIRE, it's quite unlikely you will fail a bearing. If you go to the strip with a wide tire and or ESPECIALLY a long arm, you might very well fry one sooner rather than later. Why, because the tire and the arm allow you to create aft G loads that you cannot reach with a std arm and street tire. If you ride long wheelies with the engine screaming along at 10K, you will fry one as well. This is NOT an engine failure. This is people not thinking through the whole package.
Seth, the aux cooler will not "cure" anything except hot oil (which is not a problem anyway).
The problem is unporting the pickup due to high aft G due to hard launches possibly with a low level coupled with high rpm and slow drainback. It doesn't matter how much oil you have socked away somewhere in a cooler if you unport the pickup.
Look- you guys are aware of your engines, your buddies engines, and through hearsay, your buddies buddies engines. I have a different perspective.
Bulletin: there are a LOT of ZX-12 racers and owners who are not in this forum. When at Muzzys, I was obvously aware of the HUNDREDS + of stroker cranks going out the door all over the world every year. I know how few calls we got about problems- single digit %'s for sure. Properly assembled and taken care of they are as reliable as a stock crank.
This bullshit started with the infamous #3 rod failures on ZX-11's. Even the magazine guys believed it. Through real testing we PROVED that that was a drainback problem and had nothing to do with the crank, bearings or pump.
I experienced it first hand. In 1998 I was doing testing on the dyno and found that running a quart or so low gained about 3 hp. So later that year at Bonneville I ran my ZX-11 in that form. I was concerned though, so after every run I would carefully measure the oil in the catch bottle and replace the ounce or two that I had lost to make sure I didn't get low. But I guess I got behind on my counting because on what was my last run of the year, tucked in at 197mph I sawed the cases in half (literally in half) with a broken rod (the result of an oil starved bearing). Needless to say it was exciting getting stopped. there was 300V everywhere from the engine to the taillight. That was the only bearing I ever failed on a ZX10/11 in 10 years at Bonneville, El Mirage, and the dragstrip. Including The injected nitro ZX-11 engine in the EZ Hook liner.
Later when we were selling a lot of engines to car guys we developed an external drainback system so the engines wouldn't blow in left turns (which trapped the oil in the head). Before atht everybody was howling about "the dreaded #3 rod failures". Funny how a couple dash ten hoses from the head to teh pan cured the bearing problem. Again 100's of engines.
JEEZE Give it a rest. Please listen to those of us who have been doing this awhile ( Me, Y2, Entropy, Psycho, Mega, etc). There is no need to re-learn our lessons. We're trying to help you here.
Doug
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Seth ZX12r UK
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posted June 22, 2007 03:48 AM
Edited By: Seth ZX12r UK on 22 Jun 2007 04:52
quote:
Exactly. In fact I did write that blurb.
I think if you build a 1361 and ride on the street or even drag race it WITH A STREET TIRE, it's quite unlikely you will fail a bearing. If you go to the strip with a wide tire and or ESPECIALLY a long arm, you might very well fry one sooner rather than later. Why, because the tire and the arm allow you to create aft G loads that you cannot reach with a std arm and street tire. If you ride long wheelies with the engine screaming along at 10K, you will fry one as well. This is NOT an engine failure. This is people not thinking through the whole package.
Seth, the aux cooler will not "cure" anything except hot oil (which is not a problem anyway).
The problem is unporting the pickup due to high aft G due to hard launches possibly with a low level coupled with high rpm and slow drainback. It doesn't matter how much oil you have socked away somewhere in a cooler if you unport the pickup.
Look- you guys are aware of your engines, your buddies engines, and through hearsay, your buddies buddies engines. I have a different perspective.
Bulletin: there are a LOT of ZX-12 racers and owners who are not in this forum. When at Muzzys, I was obvously aware of the HUNDREDS + of stroker cranks going out the door all over the world every year. I know how few calls we got about problems- single digit %'s for sure. Properly assembled and taken care of they are as reliable as a stock crank.
This bullshit started with the infamous #3 rod failures on ZX-11's. Even the magazine guys believed it. Through real testing we PROVED that that was a drainback problem and had nothing to do with the crank, bearings or pump.
JEEZE Give it a rest. Please listen to those of us who have been doing this awhile ( Me, Y2, Entropy, Psycho, Mega, etc). There is no need to re-learn our lessons. We're trying to help you here.
Doug
Some good points and advice there Doug.
Speaking for myself, the oil cooler idea was to try and get some extra oil in the engine to prevent unporting of the pick up.
Unporting is the ONLY concern I have with the stroker. How do I prevent it.? (other than not wheelying or running a long arm)
What is the fix other than the billet/coby oil pan with a sidewinder.
In other words is there a fix and forget for LSR/Street/1/4's stroker do it all 12r ?
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