Crank slip? maybe easy fix.

[dturboman]

So after some thinking and talking to ARP, I found a few things

1. ARP told me the bolt needs to be torqued to a MINIMUM of 150-175ft+ lbs for this platform
2. ARP also says for our bolt size 14mmx1.5 the minimum torque they recommend is 205ft lbs for a 220,000psi tensile strength bolt which is what our bolt is - anything under 184 is a bad idea according to them.
they have this chart up

ARP-bolts.com | ARP - World-leading Fastener Technology

Here is the paperwork that comes with the ARP bolt that fits our motor - one thing I was told to keep in mind was that TQ spec of 140Ft lbs was what they found to be best for a 1.8-2.0 duratec engine - Not highly modified.

Spec for bolt

http://arpinstructions.com/instructions/251-2501.pdf

[Boosted Beluga]

Good luck. Keep us updated.

[Darth_Nuruodo]

That's a really high torque number.... Also their recommendations to you over the phone are drastically above what they say in their paperwork, that's really surprising they underrate their minimums on paper even if it is for a drastically weaker motor.

[Nitr0EngiE]

well how many ft lb is 90lb + 90 degree turn

thats what i did on my bolt and then I even went a llittle further

[dturboman]

Originally Posted by Nitr0EngiE well how many ft lb is 90lb + 90 degree turn thats what i did on my bolt and then I even went a llittle further

if I had to guess I would say you're at 110 or so.

Originally Posted by Darth_Nuruodo That's a really high torque number.... Also their recommendations to you over the phone are drastically above what they say in their paperwork, that's really surprising they underrate their minimums on paper even if it is for a drastically weaker motor.

yeah its odd to see the Paperwork say 140 but their other documentation says 205, Only thing I could think of was they dont want to risk damage to the crank pulley pin for the 1.8/2.0 duratec that the bolt was originally built for.

we will see when I try it at 205.

140 is still much higher than what most of us have been doing

[Nitr0EngiE]

has to be more than 110, with a big jack pipe extending breaker bar it was very difficult to turn

[dturboman]

Originally Posted by Nitr0EngiE has to be more than 110, with a big jack pipe extending breaker bar it was very difficult to turn

I dont know guess we have no way to tell really, I read somewhere that extra 90* ended up with a Tq of around 110 and many people had a very hard time getting that extra 90*.

[Nitr0EngiE]

last time before this bolt i went to 160 ft lb on torque wrench and it was easier then this last time

160 previously was my guess as to what 90 + 90 turn would be

any more than 160 i would be afraid of breaking cams or the TDC bolt or slipping something.

i use a wrench on both cams and the cam plate and a bolt thru crank pulley and tdc bolt (not tdc tool a actual bolt)

to get to 205 i would be concerned. but makes me want to time motor as is and try to add some torque to it, but it might damage washers or my thread locker

this last time i torqued my buddy who weighs about 375 had to straddle motor sumo wrestler style to keep engine from moving it was that hard to turn(this was most recent when we did 90 lb + about 100-115 degree turn)

EDIT: Does ARP make factory bolt

[dturboman]

Originally Posted by Nitr0EngiE last time before this bolt i went to 160 ft lb on torque wrench and it was easier then this last time 160 previously was my guess as to what 90 + 90 turn would be any more than 160 i would be afraid of breaking cams or the TDC bolt or slipping something. i use a wrench on both cams and the cam plate and a bolt thru crank pulley and tdc bolt (not tdc tool a actal bolt) to get to 205 i would be concerned. but makes me want to time motor as is and try to add some torque to it, but it might damage washers or my thread locker this last time i torqued my buddy who weighs about 375 had to straddle motor sumo wrestler style to keep engine from moving it was that hard to turn(this was most recent when we did 90 lb + about 100-115 degree turn)

Do you have the ARP bolt? sounds like if you went that far past it and had that much trouble you might be close to the spec they call for for that bolt size.... maybe in the 160-180 range? getting past that is going to be hard.

They also say the TTY process of the oem bolt is not needed just a final TQ number as their directions state for this bolt.

the OEM bolt is not the same grade as the ARP bolt... maybe a 140kish tensile strengthen bolt (grade 8?) vs the 220k ARP

[Nitr0EngiE]

i never knew arp made a Crank bolt for us until recently, i have always used OEM

[Tokay444]

I hope the threads in crank nose have some seriously radiused roots.

Originally Posted by Nitr0EngiE i never knew arp made a Crank bolt for us until recently, i have always used OEM

Do not do this with the oem bolt.

[dturboman]

Originally Posted by Nitr0EngiE i never knew arp made a Crank bolt for us until recently, i have always used OEM

yeah, it was originally made for the duratec but it happens to fit our crank too.

ARP Balancer Bolt Kits 251-2501 - SummitRacing.com

[dturboman]

Originally Posted by Tokay444 I hope the threads in crank nose have some seriously radiused roots. Do not do this with the oem bolt.

yeah i thought you were using the ARP, Lucky that bolt did not snap... thats a lot of TQ on the OEM bolt

[Nitr0EngiE]

that oem bolt is massive i dont know how i could ever break it

wow i just read that ARP crank bolt is fucking chromolly I WANT

[dturboman]

Originally Posted by Nitr0EngiE that oem bolt is massive i dont know how i could ever break it

Everything can break, no idea what grade the OEM bolt is but I'm sure you can snap it

yeah the ARP bolt is a nice upgrade from OEM.

[06Speed6]

Originally Posted by dturboman So after some thinking and talking to ARP, I found a few things 1. ARP told me the bolt needs to be torqued to a MINIMUM of 150-175ft+ lbs for this platform 2. ARP also says for our bolt size 14mmx1.5 the minimum torque they recommend is 205ft lbs for a 220,000psi tensile strength bolt which is what our bolt is - anything under 184 is a bad idea according to them. they have this chart up ARP-bolts.com | ARP - World-leading Fastener Technology Here is the paperwork that comes with the ARP bolt that fits our motor - one thing I was told to keep in mind was that TQ spec of 140Ft lbs was what they found to be best for a 1.8-2.0 duratec engine - Not highly modified. Spec for bolt http://arpinstructions.com/instructions/251-2501.pdf I was not in the 150-175 range that's for sure, I'm going to try the ARP rating of 205 and see if that will hold, If I slip again so be it, atleast its a good test to see if we just need to torgue this bolt down much more.

Im glad I found that bolt, its seriously beefy compaired to the oem bolt. 200+'lb doesnt surprise me either, unfortunately my wrench stops at 180 lol

[silvapain]

Originally Posted by Tokay444 I hope the threads in crank nose have some seriously radiused roots.

That was my first thought too. It's not just the bolt you have to worry about; it's the threads inside the crank as well. Just because the bolt can handle 200+ ft-lbs doesn't mean it's a good idea.

[dturboman]

Originally Posted by silvapain That was my first thought too. It's not just the bolt you have to worry about; it's the threads inside the crank as well. Just because the bolt can handle 200+ ft-lbs doesn't mean it's a good idea.

True but ARP is telling me a min of 150-175 for this platform. That's a big jump over what many been doing. We will see how 180+ goes, I don't think it will be a issue if their telling me nothing under 150.

[Snyeed]

Would this bolt still be considered a one time use? Especially at those torque levels.

[dturboman]

Originally Posted by Snyeed World this bolt still be considered a one time use? Especially at those torque levels.

For the $30 I would just replace it to be safe.

[pinkcheese]

NO the ARP crank bolt is reusable, This from them directly. Also When I spoke to them I got something similar in response. 155ft/lbs min on the ARP bolt.

We have been using this bolt for quite some time now with great success. It's definitely held up on non keyed engines. Though This bolt does not solve the potential slipping of the crank design. IT is merely a band-aid but a damn good one.

Something I picked up on from someone else experience @formula Atlantic, when torquing these down. Don't do it on an engine stand. It should be done with the engine on the ground.

[dturboman]

Originally Posted by pinkcheese NO the ARP crank bolt is reusable, This from them directly. Also When I spoke to them I got something similar in response. 155ft/lbs min on the ARP bolt. We have been using this bolt for quite some time now with great success. It's definitely held up on non keyed engines. Though This bolt does not solve the potential slipping of the crank design. IT is merely a band-aid but a damn good one. Something I picked up on from someone else experience @formula Atlantic, when torquing these down. Don't do it on an engine stand. It should be done with the engine on the ground.

I agree that it does not make up for the keyless design but with the ARP set to 155+ it greatly reduces the chances of it slipping and will be plenty reliable for most modded speeds.

I was not even close to being at 155+ and it took a lot for my crank to slip, so I'm going to run the same tune that caused it to slip but with with 180+... It will be a good little test.

And yes you're right the bolt can be reused as its not a TTY

[Mizzle]

Why aren't we just keying the crank?

[dturboman]

Originally Posted by Mizzle Why aren't we just keying the crank?

Might as well key the cams too if going to keying and for many who have built motors on the Oem bolt keying would require a full disassembly, would be a PIA when the ARP provides the insurance many want.

Or you you can go arp bolt @180 and give the crank pulley a little weld , lol cheap and it will hold.

[pinkcheese]

Originally Posted by Mizzle Why aren't we just keying the crank?

It isn't just that simple, because keying the crankshaft requires some specific tools. for one the crank pulley or in the disi's case, pulley's machining grooves in them for a key cannot be done easily sense it is a hardened steel. The other major issue is timing the sprocket and crankshaft properly for the key. Once they make the cut its done and you are locked in. This can have a huge impact on how you time the engine crank sensor to piston TDC. Granted this can be tuned out with the positioning of the CPS but only so much. Still have to be within a small window of accuracy when making the two cuts. The sprocket cut if done can be made anywhere sense the cam's can be positioned to offset it.

For the engines I have built we have used pre-cut crank sprockets just to make it easier on the machinist. used two separate companies for these, Cosworth and a European company SBD. Raceline also makes them but I have not used their product's before though the formula Atlantic guys do with success. There is a difference in sprockets for us not in the teeth count but in the design the disi is two piece while the mzr is 1 piece. I believe superskates took dimensions of both of these and they were very similar.

[Tokay444]

Anneal sprocket.
Cut key way.
Re harden.
Figure the FUCK how you goin to time engine.
...?
Profit.

[dturboman]

Originally Posted by Tokay444 Anneal sprocket. Cut key way. Re harden. Figure the FUCK how you goin to time engine. ...? Profit.

Sounds like all sorts of fun.

[CosmicArkie]

@Dano;

You in on this?

[doubleflusher]

I have a bolt if anyone needs it.

[Dano]

why does everyone ASSUME the additional 90* angle doesn't add up to a shit ton of TQ?

I think @phate; is gonna use his TQ wrench on his head studs and measure what the additional angle comes out to be. ARP ft/lbs spec vs OEM angle spec. Maybe he would be willing to do the same on his pulley bolt? I seriously considered using the OEM spec on my ARP head studs as it SOUNDS like more torque than 60ft/lbs.

I went with the 75 + 90* on my crank, but what is the max guys are using with the OEM bolt SUCCESSFULLY?

I am not afraid to add some more angle if its commonly done but I don't have a high HP motor by any means and would suspect this is all un-necessary unless you change valve springs and or are attempting to rev out past 7K.

interesting subject and I was not aware there was a huge problem with crank slipping as long as the proper procedures are followed.

[Tokay444]

I need it.
You can't use oem torque specs on anything but own studs/bolts, and vice versa. Different materials are different.

[phate]

Originally Posted by Dano why does everyone ASSUME the additional 90* angle doesn't add up to a shit tone of TQ? I think phate is gonna use his TQ wrench on his head studs and measure what the additional angle comes out to be. ARP ft/lbs spec vs OEM angle spec. Maybe he would be willing to do the same on his pulley bolt? I seriously considered using the OEM spec on my ARP head studs as it SOUNDS like more torque than 60ft/lbs. I went with the 75 + 90* on my crank, but what is the max guys are using with the OEM bolt SUCCESSFULLY? I am not afraid to add some more angle if its commonly done but I don't have a high HP motor by any means and would suspect this is all un-necessary unless you change valve springs and or are attempting to rev out past 7K. interesting subject and I was not aware there was a huge problem with crank slipping as long as the proper procedures are followed.

If you guys want the crank bolt angle vs torque tested, now is the time. I'll be finishing up my engine next week My torque wrench was calibrated prior to my build and it is good for 250lb-ft.


I missed out on doing the head studs, we weren't talking about this stuff yet (like the day after we were, lol). @Tomas is going to do the head bolt and stud testing.

[dturboman]

Originally Posted by phate If you guys want the crank bolt angle vs torque tested, now is the time. I'll be finishing up my engine next week My torque wrench was calibrated prior to my build and it is good for 250lb-ft. I missed out on doing the head studs, we weren't talking about this stuff yet (like the day after we were, lol). @Tomas is going to do the head bolt and stud testing.

Do it ! Then we have real data not just guesstimates.

I just spoke to someone who did a crank bolt to 85 and 90*, total tq was 145ish, so I assume if we do 75 plus 90* we will end up around 120-125. Still way off from the 155 minimum ARP says to use for this platform - I think for the ARP to really improve over the oem it needs to be 184-205 like their bolt guide says.

[Monotonous ONE]

Moar like gheystimates.




Mirite?

[06Speed6]

Keep in mind the oem spec isnt using moly lube so its even lower than that.

[dturboman]

Originally Posted by Dano why does everyone ASSUME the additional 90* angle doesn't add up to a shit tone of TQ? I think @phate; is gonna use his TQ wrench on his head studs and measure what the additional angle comes out to be. ARP ft/lbs spec vs OEM angle spec. Maybe he would be willing to do the same on his pulley bolt? I seriously considered using the OEM spec on my ARP head studs as it SOUNDS like more torque than 60ft/lbs. I went with the 75 + 90* on my crank, but what is the max guys are using with the OEM bolt SUCCESSFULLY? I am not afraid to add some more angle if its commonly done but I don't have a high HP motor by any means and would suspect this is all un-necessary unless you change valve springs and or are attempting to rev out past 7K. interesting subject and I was not aware there was a huge problem with crank slipping as long as the proper procedures are followed.

A few have had the slippage issue, mine happened 2x both times as peak tq hit....600lbs of tq just seemed to cause too much stress, the ARP held a little Better than the OEM but let go on a 44 psi dyno run. The ARP was tighten to the factory spec not the range ARP gave me over the phone just the other day, so I don't it was near its true clamping potential.

Originally Posted by 06Speed6 Keep in mind the oem spec isnt using moly lube so its even lower than that.

Didn't even think of that, I think Moly lube can lower tq needed by 10-15%

[06Speed6]

Yeah under torquing is as bad as over torquing

[phate]

Originally Posted by 06Speed6 Keep in mind the oem spec isnt using moly lube so its even lower than that.

True, I use ARP UltraTorq on just about everything with a torque spec. [Love that stuff.] I suppose if I had a crank pulley bolt to sacrifice, I could check it both ways if we want that info.

I used UltraTorq on the crank pulley bolt (new OE) for the gray 6, and @silvapain used it on his new OE bolt as well. My thought was the initial 75lbs could be thrown off not using it. We would really need to measure the bolts after tightening to see what is going on.

Even if I don't do some of this testing on my engine, I could do it on an extra crank I have. Wouldn't be a big deal.

@doubleflusher - is that bolt new and how much do you want for it?

[06Speed6]

A used crank bolt should be fine, its clamp would be less but the torque should be the same

[dturboman]

Originally Posted by 06Speed6 Yeah under torquing is as bad as over torquing

Yeah, I'm willing to bet when this bolt is set at 184 -205 like their guide says it will hold a ton of stress... More than enough for prob 99% of the MZRs

I' m excited to see if it will hold the 44psi, 46 psi tune and the track abuse

Everyone says just key it but not every can or will do that.