Cut crank vs Uncut crank

[boostjnkee]

Hey everyone. I've looked and looked, talked to many different people, and i've gotten a mixture of answers. Is it true that a cut crank with eat up bearings? I have a crank for my build but it will need machined for oversized bearings and i've been told go for it, it's all a myth. But then i've also been told to not run a cut crank due to the (nitrate?) coating or something like that. I just realllyyy don't want to spend all this money getting my car together and tuned then have to rip it apart after little driving due to my crank eating bearings like the cookie monster. ALL INPUT GREATLY APPRECIATED! thanks dsmtuners!

 

[simple jake]

I had my crank cut .25mm 10,000 miles ago and it was doing fine before I lost oil pressure and spun a rod bearing. I would be fine with cutting another crank but I don't think I would ever go past .25mm.

 

[TSimage]

Its a myth more so. I have ran a cut crank in the past and I will be running a DOUBLE cut crank on my high comp motor within the next couple of seasons. If it is done right and you have a shop that stands by their work then you have nothing to worry about.

 

[bryanwheat]

If it is cut right than it will be perfectly fine. Remember that the crank should never actually touch the bearings. If you do have a crank it is crucial that you have it straightened beforehand (it is is bent) so that everything comes out straight. It is also a good idea to have the damaged journals checked or cracks by magnifluxing them.

 

[ed1380]

At what point do you pay big $$ to get a crank cut or straightened, when you can get a good used crank for under $200 shipped?

 

[307dsm]

My crank is cut, recently built the engine it only has 500 miles on it so its a myth ..... so like my machinist if u take it to the right place to get it cut with the right machinery then u wont have nothing to worry about and that the builder knowa how to inspect that everything is to spec then u should be good...
just make sure the cut it right and balance it.

 

[TSimage]

At what point do you pay big $$ to get a crank cut or straightened, when you can get a good used crank for under $200 shipped?

I've had cranks that were in the $1200+ range (Magnus cranks) Also my current one is an FFWD Butchered crank-

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Why get rid of a perfectly good custom crank?

 

[bryanwheat]

At what point do you pay big $$ to get a crank cut or straightened, when you can get a good used crank for under $200 shipped?

It cost's 80 dollars to have the main and rod journals cut, 30 to have it straightened, and 30 to magnaflux it. 140 dollars for a crank that you KNOW is straight and in spec versus sending money to someone who THINKS their crank is in spec.

 

[ed1380]

I've had cranks that were in the $1200+ range (Magnus cranks) Also my current one is an FFWD Butchered crank-

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Why get rid of a perfectly good custom crank?

You know what I meant A stock crank is good enough for 95% of us

It cost's 80 dollars to have the main and rod journals cut, 30 to have it straightened, and 30 to magnaflux it. 140 dollars for a crank that you KNOW is straight and in spec versus sending money to someone who THINKS their crank is in spec.

Where were you when I asked this?
http://www.dsmtuners.com/forums/cylinder-head-short-block/412131-what-do-crank.html

 

[BogusSVO]

And always..ALWAYS clean the crank before you instal it, no mater if it just came the machine shop and "They cleaned it"

Make sure to gun brush and clean the oil galleys in the crank!!!!

 

[agentorange313]

I've had cranks that were in the $1200+ range (Magnus cranks) Also my current one is an FFWD Butchered crank-


Why get rid of a perfectly good custom crank?

TSimage, I have heard great things about FFWD butcher crank, but I have also heard there are issue with idle with using these cranks? Are you also using a lighten flywheel? thanks

 

[boostjnkee]

And always..ALWAYS clean the crank before you instal it, no mater if it just came the machine shop and "They cleaned it"

Make sure to gun brush and clean the oil galleys in the crank!!!!

yeah, i usually make it a point to clean stuff again, even after the machine shop "cleaned" them. Thanks so much for the imput guys! guys ill take my crank to the machine shop and have it cut and all that good stuff.

 

[biglady112]

We run machined mitsubishi cranks over 200mph on a regular basis. And run over 130mph in the quarter mile on a turned crank as well. I would run a machined crank any day over a stock crank. I 100% trust the work we have done to them and have one of the best places in the country right here in Denver that does a fantastic job.

 

[simple jake]

Biglady do you have any videos of these 200mph runs? I'd like to see them! I'm not trying to sound like a dick I really wanna see a DSM going 200mph!

 

[TSimage]

TSimage, I have heard great things about FFWD butcher crank, but I have also heard there are issue with idle with using these cranks? Are you also using a lighten flywheel? thanks

Never had an issue then again I'm Auto so I wouldn't know if it as an issue related to the worthless 5spds .

 

[nitrouskris]

Biglady do you have any videos of these 200mph runs? I'd like to see them! I'm not trying to sound like a dick I really wanna see a DSM going 200mph!

check youtube. they was guy running a 2gen "7 bolt cut crank "doing the standing mile. dont remember the class he was in but he did hold a record at 202.

 

[WES_393]

We run machined mitsubishi cranks over 200mph on a regular basis. And run over 130mph in the quarter mile on a turned crank as well. I would run a machined crank any day over a stock crank. I 100% trust the work we have done to them and have one of the best places in the country right here in Denver that does a fantastic job.

What is this place in Denver you're reffering to? I need a new machine shop.

I'm also running a cut crank, no issues yet.

 

[goodbuds]

dsm's are making the same power with cut and uncut cranks. it's like having a really nice set of underwear. only the owner knows what he's wearing.

 

[Shadow21]

I run a cut crank in my 4g64 and have been for the past 3 years and one year of that ive been turbo'd. I beat the snot out of the engine and its still going strong.

 

[92AWDHX40]

I run one throw it in and dont worry about it, lots of people run cut cranks in all kinds of cars i know pleny of old school mechanics, itll be fine.

 

[biglady112]

Onl 2G that has done any LSR event was Doug Elfman at Loring. He went 206 or 208 and did not set any record. And as far as we know, no other 2G land speed races nor holds any records. We don't even hold any and we have been 213mph.

 

[red1993gsallmt]

Brian Portilla of dogbox racing was 9.0 at 160mph on a .020 cut crank, he ran that car alot and never had an issue but the 4g63/4 cranks are amonia hardend to about .020 so dont cut more then that away