Butcher crank. Safe or not?

[v8s_are_slow]

http://www.dsmtuners.com/forums/showthread.php?t=196880

Scroll about half way down and you'll see what I posted up (with pics). But to sum it up, I sent my crank to Buschur and they told me they'd take off 7 pounds but didn't. Sent them a picture of what i THOUGHT it would come close to looking like (http://www.ffwdconnection.com/butchercrank.shtml) and I was told that it'd be unsafe to run it like that. What do ya'll think? I've yet to hear anything about a Butcher crank falling to pieces. Anyone wanna give some input? Wisemen maybe? Thanks!

Scott

 

[Injected]

I'll repost it for you buddy. Hopefully they'll take good care of you. I'll throw in the pic of the fast forward butcher crank. Who told you that it was unsafe to run a certain crank?

Since I posted earlier about the crank I was getting knife edged and balanced by Bushur, I figured this would be a good place to post my update. I just received it over the weekend and to say the least, I'm not real happy right now...in a nice way of putting it. Even e-mailed them last night about it and was trying to write it in a nice way even though I'm really at the moment. Anyway, I'll let the pictures and the e-mail I sent speak for itself.

This is what I received....

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And here's the e-mail I sent to them in response (I'll post an update when/if I find out something from them)...

Hey Jarrod,
I just received my crankshaft over the weekend. And there's a BIG problem. When speaking to Nick on the phone I had asked him about getting it knife edged and balanced. I told him that I had looked at other places and they take about 7 pounds off the crank and that's what I wanted done. He told me that that's what you guys would do. Well, I got it back and all that was done was knife edging. Maybe a pound was taken off if that. My main reason for even wanting to get it done was because I wanted the weight taken off cause I'm trying to have my setup as light as possible and to get it to rev a lot quicker.

At the moment, I'm gonna have to halt my whole project until I find out something about getting my crank done. Was planning on taking it to my machinist tomorrow but that's not gonna happen now. I know you guys are some of the top guys in the business but the main reason why I've never bought from you guys before until now is because of the lack of pictures on your website and not really knowing what I'd be buying. But knowing what Buschur represents and the word of mouth on dsmtuners, I decided to buy anyway and figured the pricing was pretty decent. But at the moment I don't have my crank done like I had expected it to be done. You guys had the best price that I've found so far, and I've heard the saying, "you get what you pay for," but with your reputation I'm seriously hoping this isn't the case. Hoping you guys will do me right.

If I have to ship it back to you guys to get it redone, I'll reship it. But I don't wanna throw my engine together and halfass it because I have big plans for this build up. The original plan for the crank was to have it looking something like this....

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But went with you guys instead and have been planning to buy other parts from you guys for my project. Not sure if there was a miscommunication somewhere or what and don't know Nicks e-mail otherwise I'd deal with him directly. Just hoping this can be sorted out and hoping I won't be disappointed. Also don't wanna have to save up the money once again to send it out to anyone else to get it done like I'm needing. Please let me know something as soon as you possibly can. I'm hoping this can somehow be resolved as I'll be as patient as I can be if I'm done right by you guys.

Thank You,
Scott Laird

 

[v8s_are_slow]

I'm not trying to totally bash Buschur's name but Nick was the one who told me this. Now I just got off the phone with Cragger from Slowboy and he didn't really say it was unsafe. But what he did tell me was that most of the guys that run a crank that really have a lot of weight taken off usually are the one's who don't do much street driving on em. Told me that with the extra weight, it'll help with heat distribution which I didn't really think about. I asked him if the only reasons people were running them at the track was because of streetability issues such as stalling. He told me that yes that could be a factor unless I went with something such as a dsmlink, etc. to help it out with the idle.

"IF" it's unsafe to run with a lot of weight taken off that's fine and dandy. Just burns me up though cause I was told that 7 pounds would be taken off and it wasn't. And so that's what I expected but didn't get so that's what I'm mad about. Tell me upfront and it's a different story.

When i got it and before sending it off it was, 15.675 kg's or 34.56 pounds
After getting it knife edged and balanced it's 15.465 kg's or 34.10 pounds

Now I'm sure that ffwdconnection sells plenty of these cranks, especially being that they advertise it unlike most vendors. But I've never really heard much feedback on it. So wishing someone would chime in. Thanks!

P.S. Thanks for doing the work since I was too lazy

 

[Defiant]

Told me that with the extra weight, it'll help with heat distribution which I didn't really think about.

Ah, I know that principle. It's called Voodoo Horseshit.
What the hell does the mass of the crank have to do with "heat distribution"? Distributed to what, where?
You want some rotating mass, so the motor will carry itself to idle instead of just coasting down to a stop when the fuel's cut off.
Rotational dynamics inside an internal combustion engine are fairly convoluted. The Mitsubishi Silent Shafts were born to deal with some of the issues. Those big, honking counterbalances were put on the crank for normal use. Removal will make the motor harsher, and possibly a bit more peppy under certain running conditions. But I don't know what they'd have to do with heat.
As for the "unsafe" part of this mist-enshrouded tale, other than breakage from harmonic phases in the crank's revolutionary life, I don't see where removing them would make for much weakening of the crank webs, so long as the person doing the butchering had a basic grasp of strength in metals. Ears standing proud of the webs don't contribute to the actual strength of the crank, they just absorb twisting energy. Really long mathematical equations with quite odd symbols go into determining their design.

 

[ISUJakey]

Have someone draw the crank up in ProE, Solidworks, or some other CAD software and run an FEA analysis on it. Granted you are going to have to know the exact composition of the crank along with as accurately as possible, a model of the forces acting upon it to receive decent results. At least you'll have a theoretical model as to whether the crank will fail or not.

 

[lewroe59]

I hope they do you right, because customer service is VERY important.

 

[v8s_are_slow]

Just wanna clear up a typo I noticed I made. Sorry...didn't mean heat distribution, I meant heat dissipation. Hope that clears things up.

As for the crank, I'm needing to get this thing built and I just don't have the time that it takes to send the crank off all over again to get it done the way I'm wanting it and to spend even MORE money. This is very unfortunate for me. So I'm getting the short block built with the crank the way it is but the stage 3 head I had planned on buying from them isn't gonna happen after this. Going with another vendor because if they couldn't do a simple job as the crank right and as they told me they'd do it, nor do they post many pictures of their products on their website which makes purchasing a 50/50 chance on what you'll get, I'm not gonna take the chance of spending over $1000 with them on something more important the 2nd time around.

Of course I'd still like to hear some input about this because I've never heard of any safety issues with using one of these cranks.

 

[1990EclipseGSX]

I have a butcher crank in my FFWD longblock. Can't say I have had any problems whatsoever with it...


Chris

 

[bjones18]

1. Heat disipation is needed close to your combustion chamber... hence Rutan cooling only the head for long distance flight (less weight). The mass of your crank & block will not have temperature spikes as long as you have coolant & oil flow.

2. FEA? Has anyone here correlated FEA to actual life? it ain't a push-button operation. What are the forces, under what conditions? Modal input considering viscous film, gaps, & friction? Yeesh!

 

[ISUJakey]

2. FEA? Has anyone here correlated FEA to actual life?

FEA provides a theoretical model and is used on a daily basis across the globe. I do realize that it is not perfect, which I have experienced first hand but if it is 100% worthless, why it is so popular?

Key phrase:

theoretical model

it ain't a push-button operation. What are the forces, under what conditions? Modal input considering viscous film, gaps, & friction? Yeesh!

I realize that FEA is not a push-button operation hence why I explicitly said,

Granted you are going to have to know the exact composition of the crank along with as accurately as possible, a model of the forces acting upon it to receive decent results.

I would personally love to sit down and run every FEA software package on the market: ProE Mechanica, Comsol Multiphysics, CosmosWorks, etc. however it is simply not realistic for me. I gave a suggestion of trying FEA which you seen to not agree with so what do you recommend? Do you suggest any professional society papers on crankshaft analysis?

 

[TSIfreek]

Scott If you wanted the crank that FFWD posted on there site you should have sent your crank to them but it may have been more expensive. I would only run a crank that had that much material taken off as the FFWDs is if they croyed it after to strengthen it and thats why I think Buschur only knife edged it. Its not a good Idea to run a super light crank on the street because you will be losing that rotating mass to keep the engine going at lower RPMs. I would be happy with what I have if I were you just get it balanced and journals polished and you are ready to go.

 

[Defiant]

Just wanna clear up a typo I noticed I made. Sorry...didn't mean heat distribution, I meant heat dissipation. Hope that clears things up.

Not in the slightest. What heat is going into the crank that it's going to be dissipating?

 

[bjones18]

FEA provides a theoretical ...if it is 100% worthless, why it is so popular?

....you seen to not agree with so what do you recommend? Do you suggest any professional society papers on crankshaft analysis?

1. didn't say worthless. 2. done the 15 page MSME Diff EQ's for 2D FEA 3. FEA is an outstanding tool. 4. check my history, I quoted an excellent paper (on line) on crankshaft strain-gaging for vibrational loads.

A hammer is a great tool... it is not my only tool. I have run FEA, CFD, and ADAMs, check and you'll find two of my SAE papers... brake cooling and vehicle roll control. I find experimental results most beneficial, and use CAE to explain deeper why my experimental results are the way they are.

Experience is key. I will trust the FEA results from someone who has been modeling crankshaft physics on a daily basis for 3+ years. But, automesh some CAD & "fake in" boundary conditions... I'll pass and find someone to talk with who has built engines for many years.

 

[TSIfreek]

I have one word for you guys REALITY

 

[v8s_are_slow]

Scott If you wanted the crank that FFWD posted on there site you should have sent your crank to them but it may have been more expensive. I would only run a crank that had that much material taken off as the FFWDs is if they croyed it after to strengthen it and thats why I think Buschur only knife edged it. Its not a good Idea to run a super light crank on the street because you will be losing that rotating mass to keep the engine going at lower RPMs. I would be happy with what I have if I were you just get it balanced and journals polished and you are ready to go.

Maybe that's why they did it, but that's NOT what they told me they were gonna do before I sent them my crank, and not what I was wanting to pay for. But it's being used regardless. Just know who I just marked off my list of vendors I'll use now though.

 

[bjones18]

I have one word for you guys REALITY

Not sure what your point is.

In the early 1900's there was a competition between the "brain-iacs" & the "metal benders." Which group could win the technological race? Nobody knew the answer.

In case you are wondering, scientists (brainiacs) won... Physics is REALITY

 

[gSx_r1der]

So any negatives torunning a ffwd butcher crank. Besides drivabilty, cause that is my last worry with the fucing 272's in there ruining all drivability whatesoever.?? Somone chime in here and let us know....

 

[RoasT BeeF]

Regardless of what Buschur, or anyone on this site says as the reason for them only knife edging the crank is irrelevant. He wanted a service that he was told he would get and he did not. Bottom line.

Keep us updated on whether they choose to correct this problem for you.

 

[MarsaGSX]

Sory to bring this thread back..used Search button and don´t wanna start new thread..

How about use Eagle Crank?for 700-800usd..you get new forged,tested crank.I think the safest crank....
or butchered old crank.. pay for process 550usd +balancing?+ shipping and still...you got stock crank..(I got in mind your old crank should be not grinded...)
I know some "lower" HP aplication don´t need eagle crank,but if you spend like 600usd in butchering,Isn´t worth get new Eagle???
What ya think
Venca

 

[paper_clip_boy]

Although I think the Eagle Crank is a tad bit lighter, To some people, a lighter crank that will make the engine rev easier and spool up a turbo quicker is what they want. Im sure you can buy the Eagle Crank and send it off to FFWD to have it Butchered but then your looking at around $1500, Thats a hefty price for most people when they could use $200 of that and get a stock 100mm Crank and use the other $1300 to get a nice fat turbo.

Personally, Im still contemplating getting my Crank butchered. Because I live In Canada, The prices do skyrocket for me slightly as I have to Pay for some quite expensive shipping over the Border and Back. Also I have to deal with exchange rate.

In My build I am using things that will make the engine a Normal 2.3L but with a twist.

We all know that 2.3L are great in the Low end but are risky up high. Im not worried about that "Ovaling Out" the cylinder bullshit, because its not like im going to be doing that every week. 8.5K redline will be ok and imagine how easily it will reach that with an Aluminum Flywheel, Butchered Crank, Possibly Aluminum rods (Expansion Isuues), and Possibly an Aluminum Driveshaft.

Go as light as you can, and get good engine management. Everything will be fine.

 

[AshTsi]

I'm so i finely completed piecing together all the parts to do the 2.3L... I've been looking at FFWD's crank butcher process, I've been doing my research about it, seeing that people think and how it works in there cars. They are mentioned in and out of a few threads but not much about actual peoples experiences with them.
All i've really gathered is that NO it does not effect heat distribution, Yes they are safe (or else why would ffwd do it), And it makes the car hard to drive as far as daily drivers are concerned.

What im trying to clarify is Why does it make it an unfit daily driver??? Is it just because they are trimming off so much weight that there isn't enough rotating mass to keep it rotating smoothly at idle? Is that the only reason? or is there something I'm missing?
Can we get some input from people that actually have them and drive them ritually? Is it hard to deal with? or is there a way to get past the idle problem by adjustment?

Thanks guys
~Ash

 

[GVR4592]

My cousin has it in his car, I built the engine and tuned it, honestly I didn't notice anything negative or positive. I'm sure less reciprocating weight is good, but I didn't notice any quicker revs or stalling because of the weight loss.

 

[AshTsi]

Well it is a known fact that the less rotating mass the less power it takes to turn it so in theory you would be gaining power because of the lighter weight crank.. but how light is too light? thats where everyone saying that it's not a good daily driver is coming from i guess, just its to light unless your constantly revving it such as in racing. But i want to hear from someone with actual experience, and too see how it worked out for them and if they had any problems or not, and if they did how they over came them if at all...

 

[GVR4592]

Did you even read my post?

My cousin has it in his car, I built the engine and tuned it, honestly I didn't notice anything negative or positive.

Translation: I have actual experience with this part, there are no negative side effects. I didn't notice that the engine revved any quicker like some people have said it does.



I'm sure less reciprocating weight is good, but I didn't notice any quicker revs or stalling because of the weight loss.

Translation: I know that a lighter crankshaft will accelerate faster with the same forces acting on it as a heavier crankshaft. Some people claim they can tell if an engine has a lighter crankshaft, I couldn't tell. I didn't notice any difference from a stock weight crankshaft. There were no negative side effects. It idles like stock, it doesn't stall, it doesn't have any excess vibration. Anybody that says it's not good for a daily driver obviously hasn't used it.

 

[AshTsi]

Sheash... Sorry i wasn't trying to offend you or anything, you don't have to treat me like im dumb though, i just typed before i thought about it i guess.
Just looking for more than one response thats all. it seems like every other person has a different experience as far as it was alright vs tough daily driver. By the way, what setup is your cousin running?