Crank slip? maybe easy fix.

[Dano]

Lol I have 3 used crank bolts. One never saw the motor start and the other only saw 200 miles. FML.

If anybody wants them PM me


Tappin

[Tokay444]

Mic the length please @Dano;.

[Dano]

Can do

Should have sent them to Clint with dans timing tools. Oh well.


Tappin

[Chimmike]

This thread is all sorts of win. Thanks guys.

The big question now is: how would you remove a bolt torqued to 200 ft lbs? I needed a damn 725 ft lb impact to remove my last stock bolt!


Sent from my your mom's face on my junk

[Tokay444]

A higher flowing line to your impact would likely have made it easier.

[superskaterxes]

this one time i used a 1/2" impact on my crank bolt and it diddent slip, ever.

[timjs]

Originally Posted by superskaterxes this one time i used a 1/2" impact on my crank bolt and it diddent slip, ever.

One of our old techs used to do that with the DISI.

He ended up pulling two cylinder heads to send them out for valve replacements before he was let go.


Anywho, someone please explain something to me.
Why is everyone talking about HP limits on the bolts/torque specs?

The crank bolt doesn't give a shit if the engine is putting out a thousand ft/lbs... it drives the cams, engine accessories, and oil pump, and HPFP. Nothing else.
If anything, high boost actually LOWERS valve opening effort (more pressure above the valves, helping them open) therefore lowering the stress on the crank pulley.

I don't see how the crank sprocket is under any more stress in a 500HP application as it is in a stock application.

Maybe I'm missing some huge point, if so enlighten me.

[dturboman]

Originally Posted by superskaterxes this one time i used a 1/2" impact on my crank bolt and it diddent slip, ever.

on max tq? would love to know what number that gun put out , OEM or ARP?

Originally Posted by timjs One of our old techs used to do that with the DISI. He ended up pulling two cylinder heads to send them out for valve replacements before he was let go. Anywho, someone please explain something to me. Why is everyone talking about HP limits on the bolts/torque specs? The crank bolt doesn't give a shit if the engine is putting out a thousand ft/lbs... it drives the cams, engine accessories, and oil pump, and HPFP. Nothing else. If anything, high boost actually LOWERS valve opening effort (more pressure above the valves, helping them open) therefore lowering the stress on the crank pulley. I don't see how the crank sprocket is under any more stress in a 500HP application as it is in a stock application. Maybe I'm missing some huge point, if so enlighten me.

I think it comes down to the power delivery of the high HP/tq cars, the huge hit of power was enough to cause the crank to slip... yet my lower power tunes ( 470-500whp) it took it all day, so cars with huge power spikes and major shock, like high RPM launches on solid clutch setups (like I have) seem to have crank slip issues and when there is a massive power spike.

I can say first hand nothing causes slipping for me until my boost level/power levels were in the 40psi range and 600tq/hp

the way I see it =

More power= crank spins faster and abruptly = spins pulley and chain faster which can be too much stress and velocity for the OEM bolt and tq spec.

[Dano]

Originally Posted by Tokay444 Mic the length please @Dano;.

ok so I misplaced my original bolt with 55k+ miles on it and I can't be sure which of the other two bolts are which but I think we could make a guess.

#1 = 2.330"
#2 = 2.348"

#1 bolt was the one that only made it 75ft/lbs + ~40* before I broke everything...lol

but then again we don't know if all bolts are the exact same length to begin with and I def don't have orig measurements. So IMO this doesn't tell us anything conclusive.

These were measured on a 3" BluePoint mic.

[Tokay444]

Thanks @Dano;, and you're rite, without knowing what hey were prior, it's kind of redundant.

[06Speed6]

I have a 725'lb impact normally set to 100psi on a 1/2" line on a 40gal 14cfm@80psi compressor and I had to turn the pressure up to tank pressure to get my blown engines crank bolt off. I drained that tank at least twice before I turned the pressure up. Once the pressure was turned up it came off so fast that I didnt actually see it come off.

Edit: tank pressure is 145psi ish

[phate]

Alright guys, I have 3 new OE crank pulley bolts. I'm going to use 2 for testing and stretch measurements. I'll use the third as my permanent pulley bolt.

My question, to you guys wanting results, is about the crank washers. I have one set of new crank washers, and that's it. I am of the opinion that once they're torqued down, they cannot be reused. I really don't want to get 6 new washers because they wont be here by the weekend, and i really don't want to spend the money on them.

Do you guys think I should try to source a set of old washers, just so the setup is as close to normal as possible?

Right now, I'm leaning towards simply testing without the washers. I'm pretty sure it won't skew the results at all, and then we don't have to delay this any longer.

[timjs]

Originally Posted by phate Alright guys, I have 3 new OE crank pulley bolts. I'm going to use 2 for testing and stretch measurements. I'll use the third as my permanent pulley bolt. My question, to you guys wanting results, is about the crank washers. I have one set of new crank washers, and that's it. I am of the opinion that once they're torqued down, they cannot be reused. I really don't want to get 6 new washers because they wont be here by the weekend, and i really don't want to spend the money on them. Do you guys think I should try to source a set of old washers, just so the setup is as close to normal as possible? Right now, I'm leaning towards simply testing without the washers. I'm pretty sure it won't skew the results at all, and then we don't have to delay this any longer.

I have about 2343245 used washers if you need them.

[theschrum]

It would be best to test with old washers. I have extras as well (should have 6). I can try to find them if you need them. No use in spending $50 on some new ones.

[phate]

Originally Posted by timjs I have about 2343245 used washers if you need them.

Originally Posted by theschrum It would be best to test with old washers. I have extras as well (should have 6). I can try to find them if you need them. No use in spending $50 on some new ones.

Would either of you guys want to overnight them? I'm in Illinois, and would like to do the testing Saturday.

[theschrum]

I would also like to know how much torque the crank threads will hold. I bet the OE bolt would break before the threads gave. If somebody has a destroyed crank, we could test the ARP bolt at 235 ft lbs or so. If it holds at 235 or so, then 205 will be nothing to worry about.
I am not sure that we should even be concerned the threads.

Originally Posted by phate Would either of you guys want to overnight them? I'm in Illinois, and would like to do the testing Saturday.

Depending on what time I get off work tonight I might be able to.

[superskaterxes]

the gun wasent full bore but i would assume somewhere in the high 100 ft-lb range, maby 175-190.

this was an OEM bolt as well. the threads are an aggressive pitch and the bolt is huge, why wouldent it be able to take this kinda torque all day?

[timjs]

@phate;

I probably won't be able to send the washers off in the time frame you need them.
If you end up still needing some in the future let me know though.

I also have several new washers, although I'm not sure I want to let go of them honestly.

Anywho, here are some measurements I did today since I was doing a timing chain/vvt job anyways.
New bolt is approximately 2.401"
Used factory bolt is ~ 2.417"

Keep in mind these are approximate because the ends of the bolts are not perfectly flat therefore the spot you measure from affects the reading.

[superskaterxes]

make sure you mark the bolt before and after where you measured it to make sure its an accurate reading

[phate]

Originally Posted by timjs phate I probably won't be able to send the washers off in the time frame you need them. If you end up still needing some in the future let me know though. I also have several new washers, although I'm not sure I want to let go of them honestly. Anywho, here are some measurements I did today since I was doing a timing chain/vvt job anyways. New bolt is approximately 2.401" Used factory bolt is ~ 2.417" Keep in mind these are approximate because the ends of the bolts are not perfectly flat therefore the spot you measure from affects the reading.

No worries. I'm sitting at work wondering if I do, in fact, have some used crank washers. I kept just about everything from the last engine I tore down. I know I have the cam washers, so I think I would have kept the crank washers, as well. Silvapain says he might still have his, so I can drive up to his place if so.



Thanks for those measurements.

Originally Posted by superskaterxes make sure you mark the bolt before and after where you measured it to make sure its an accurate reading

Will do. There's a single rectangular notch on the thread end of one crank bolt I have. I'll use that as my reference if they all have it. If not, I'll mark it.

[dturboman]

Looks like what I will be doing is ARP to 200+ with some Locktite industrial thread locker.
and moving peak TQ further to the right. I will post the video on the dyno with the endurance stress testing when we get to that point.

Hopefully that will hold everything I can throw at it, as I dont feel like ripping into this motor.

I hope to find out in the next 3 weeks if it will hold.

Originally Posted by superskaterxes the gun wasent full bore but i would assume somewhere in the high 100 ft-lb range, maby 175-190. this was an OEM bolt as well. the threads are an aggressive pitch and the bolt is huge, why wouldent it be able to take this kinda torque all day?

pretty high tq... I think we need to worry about breaking the crank lock pin too. The Impact gun might not break it as easy a torgue wrench would with the constant pressure... I know my engine builder had to hold the pin with a prybar to stop it from breaking when setting to 200lbs.

[Dano]

Originally Posted by timjs @phate; I probably won't be able to send the washers off in the time frame you need them. If you end up still needing some in the future let me know though. I also have several new washers, although I'm not sure I want to let go of them honestly. Anywho, here are some measurements I did today since I was doing a timing chain/vvt job anyways. New bolt is approximately 2.401" Used factory bolt is ~ 2.417" Keep in mind these are approximate because the ends of the bolts are not perfectly flat therefore the spot you measure from affects the reading.

FWIW

the measurements I gave you were with a mic taken at the center of each end of the bolt...both ends are depressed in the center.

[phate]

I just use a bolt instead of that little crank lock pin, lol.

[bcmurphy87]

yea i got a grade 10 bolt to replace the pin once i found TDC

[silvapain]

Originally Posted by dturboman Looks like what I will be doing is ARP to 200+ with some Locktite industrial thread locker. and moving peak TQ further to the right. I will post the video on the dyno with the endurance stress testing when we get to that point. Hopefully that will hold everything I can throw at it, as I dont feel like ripping into this motor. I hope to find out in the next 3 weeks if it will hold. pretty high tq... I think we need to worry about breaking the crank lock pin too. The Impact gun might not break it as easy a torgue wrench would with the constant pressure... I know my engine builder had to hold the pin with a prybar to stop it from breaking when setting to 200lbs.

When torquing the crank bolt to spec the flywheel should be installed on the other end, and you should use a pry bar on the flywheel teeth to hold the crank in position.


Tapadatass

[superskaterxes]

Originally Posted by dturboman Looks like what I will be doing is ARP to 200+ with some Locktite industrial thread locker. and moving peak TQ further to the right. I will post the video on the dyno with the endurance stress testing when we get to that point. Hopefully that will hold everything I can throw at it, as I dont feel like ripping into this motor. I hope to find out in the next 3 weeks if it will hold. pretty high tq... I think we need to worry about breaking the crank lock pin too. The Impact gun might not break it as easy a torgue wrench would with the constant pressure... I know my engine builder had to hold the pin with a prybar to stop it from breaking when setting to 200lbs.

please use a paint stick on the bolt/pulley/timing cover so if it does slip you can see if the bolt loosened or the pulley slipped under the bolt

Originally Posted by silvapain When torquing the crank bolt to spec the flywheel should be installed on the other end, and you should use a pry bar on the flywheel teeth to hold the crank in position. Tapadatass

theres an SST to hold the FW teeth to one of the trans housing bolt holes

[TWOptSL0W]

so this is great that we have a sort of option for the crank bolt, but what about the cam bolts? if this crank bolt is a good fix, i think the cam bolts would be the next weak link (if they arent already)

seeing as how i slipped and fucked my motor in a bad way, i need to slap bandaids on it everywhere so it doesnt happen again

[phate]

Originally Posted by TWOptSL0W so this is great that we have a sort of option for the crank bolt, but what about the cam bolts? if this crank bolt is a good fix, i think the cam bolts would be the next weak link (if they arent already) seeing as how i slipped and fucked my motor in a bad way, i need to slap bandaids on it everywhere so it doesnt happen again

Did you slip on the cam or crank?

[dturboman]

Originally Posted by TWOptSL0W so this is great that we have a sort of option for the crank bolt, but what about the cam bolts? if this crank bolt is a good fix, i think the cam bolts would be the next weak link (if they arent already) seeing as how i slipped and fucked my motor in a bad way, i need to slap bandaids on it everywhere so it doesnt happen again

if we can get the specs on that bolt maybe we can find a high strength alternative with a higher torgue yield.

anyone know the cam bolt specs?

[TWOptSL0W]

Originally Posted by phate Did you slip on the cam or crank?

dont know, but if the crank slipped and then we make that stronger, the next thing to go is the cams...i dont want to ruin a 3rd motor

[phate]

The cam bolts aren't TTY, and the manual doesn't call for replacement. Cam and bolt are steel....I wonder if we can get away with a higher torque on those, too.

Who wants to pull the threads out of one?

[dturboman]

Originally Posted by TWOptSL0W dont know, but if the crank slipped and then we make that stronger, the next thing to go is the cams...i dont want to ruin a 3rd motor

ARP crank bolt with industrial thread locker


Tack weld cams at north, east, south, west...and threadlocker = win!. lol

Originally Posted by phate The cam bolts aren't TTY, and the manual doesn't call for replacement. Cam and bolt are steel....I wonder if we can get away with a higher torque on those, too. Who wants to pull the threads out of one?

we can atleast get away with a 20-25% increase.... I say we we try 50% and see how they react.

[phate]

I'll be running stock valve train, so upper end of torque spec is fine for me, haha. By all means, I hope someone will try this out. I don't have spare cams, lol.

[dturboman]

Originally Posted by phate I'll be running stock valve train, so upper end of torque spec is fine for me, haha. By all means, I hope someone will try this out. I don't have spare cams, lol.

on my stock cams I was still gaining power past 6500 and into 7k.... if I was going for 500's I'm not sure I would risk the heavy springs and aggressive profiles.

I will give the higher torgue a test on the cam bolts... might as well throw it into the mix with the crank bolt test.

[TWOptSL0W]

Originally Posted by dturboman ARP crank bolt with industrial thread locker Tack weld cams at north, east, south, west...and threadlocker = win!. lol we can atleast get away with a 20-25% increase.... I say we we try 50% and see how they react.

if i could tack anything, i would have already had them all keyed. the cams need to be adjusted in the motor to be timed correctly. i dont really think they crank will be as much of an issue as teh cams because i think we can find solutions for the crank. cams are another story though

[dturboman]

Originally Posted by TWOptSL0W if i could tack anything, i would have already had them all keyed. the cams need to be adjusted in the motor to be timed correctly. i dont really think they crank will be as much of an issue as teh cams because i think we can find solutions for the crank. cams are another story though

time motor, figure out way to tack weld cams to pulley.

[phate]

Bolt testing is blowing my mind right now. Hope my torque wrench is man enough to handle this.

[phate]

I didn't get as far as I wanted. I did the dry thread test and started backing off the pulley bolt. I was foolish to leave the pulley lock bolt in place and it sheared it off in the timing cover. I need an easy out, and I'll do the UltraTorq testing tomorrow.

Anyway, testing and results:

Starting length: 2.399"/2.401" <--measured 90° from each other, but very close

To start, I set the bolt at 25lb-ft, so I could measure total rotation and total torque from this point.

Step 1) 25lb-ft to 76lb-ft: 21.5° Movement
Step 2) Let cool, double check after 25 minutes, no further movement
Step 3) Increments of 10lb-ft, measuring rotation at each step

Data:


And the chart of data:

^^The graph should note that it is only 55.5° @ 250lb-ft, rather than the 54lb-ft.

I took the bolt all the way up to 250lb-ft and it was only 55.5° of rotation. I DID NOT finish the rotation. You can see in the 'projected' portion, I foresee it taking around 360lb-ft to get this thing to 90° without lube on the threads. I'm anxious to see what happens with the UltraTorque.

Length at 55.5° rotation/250lb-ft: 2.401/2.401" <--measured 90° from each other

No change in length But the bolt is still good

What's that tell us? Don't go by torque on the OE bolt, lol. I'd bet even the rotation from 25-75lb-ft will be greater with the ultra torque.

[SilverDemon]

So, am I reading this correctly? 77° after the initial torque is 250 ftlbs on a dry bolt?

[phate]

Originally Posted by SilverDemon So, am I reading this correctly? 77° after the initial torque is 250 ftlbs on a dry bolt?

No, the engine rebuild manual has you torque to 75lb-ft, then an additional 90°. I wanted to measure the initial rotation, so I started at 25lb-ft, then went to 76lb-ft and checked the rotation - 21.5°.

So the total rotation from 25lb-ft is 77°. But what we're really after is the rotation after 75lb-ft - only 55.5°.


I edited my above post because I have 54° in places where I should have said 55.5°. I'll make a note about the graph as well.

250lb-ft (total), from 75lb-ft was only 55.5°.

Edi: PS - My torque wrench only goes in 2lb increments in even numbers. So I've been using 75 and 76 interchangeably, lol.