Crank slip? maybe easy fix.

[Alpha]

Originally Posted by 06Speed6 Anyone ever think that maybe our crank is flexing and loading the friction washers unevenly during high hp runs? I put alot of thought of thought into this since I am rebuilding my motor and I cant figure out how its possible for a properly assembled engine to slip timing.

Hmm... John was very adamant about running a crank girdle on my motor. Maybe he was onto this. I know Erich's not having any issues with his setup.

[jmhinkle]

Originally Posted by Alpha Hmm... John was very adamant about running HIS crank girdle on my motor. Maybe he was onto this. I know Erich's not having any issues with his setup.

Fixed your statement.

Many people aren't having issues with a proper build either without the need for hokus pokus BS. Ask @Realgib3; how far listening to john got him.

[Alpha]

Originally Posted by jmhinkle Fixed your statement. Many people aren't having issues with a proper build either without the need for hokus pokus BS. Ask @Realgib3; how far listening to john got him.

Hence the "Maybe."

Just tossing out the idea

[silvapain]

Originally Posted by Alpha Hmm... John was very adamant about running a crank girdle on my motor. Maybe he was onto this. I know Erich's not having any issues with his setup.

Like @jmhinkle; said, we already have a crank girdle stock. I believe PTP John just machines out pockets and adds metal plates to the OE aluminum girdle.

I have not heard of or seen any examples of the cranks walking on our engines.

[Tomas]

^ This.
They are called crank straps. You use longer main studs with metal plates under them on each bank for 2 studs each. Common on other engines with weak blocks. IMO not needed at all for us. And besides that, those crank straps aren't going to do anything as far as the crank pulley or the sprockets slipping.

I don't think crank flex is the problem.

Crank flex leads mostly to main and thrust bearing damage or the crank snapping in half. Not slipping of the crank pulley. Even if our crank where to flex you would have to have really massive amounts of it for the crank pulley to bend itself longitudinally to a degree where the pulley oscillates past the lip seal and rubs on the bore of the cover plate. That should be at least 4-5mm. IMO not possible. The crank would snap in half before it flexes that much. Oh and if the crank really were to flex to that point you should see the lip seal completely torn to shit and I don't think the people who have slipped timing have reported that. I don't think a bent or snapped crank has ever been seen here unless I am mistaken.

That drag team with the port injection MZR DISI block doing over 1000 hp does not alter the block or crank at all. I think it's safe to say the block and crank can handle much more than what anyone here is throwing at it. Forget block crete, straps or any other silly thing of that nature.

[phate]

More info about the ARP crank bolt - The most awaited build in MSF history

[08cosmic3]

I have crank pulley slip after replacing the chains, VVTA, guides and tensioner. I used all new washers and bolt. I even ordered another crank pulley bolt and washer and had a local shop torque to 73lbs + 90 degrees a 2nd time and I'm still slipping. My question is can I just add more torque or should I get all new washers and an ARP bolt and start over?

[Chimmike]

How much boost? What setup?


Sent from the depths

[guitarzan134]

Scott, Jeff told me about the ridiculous tension that the new Dayco belt put on the pulleys. Said the belt tensioner barely moved when he released it. With the constant movement of the pulleys while the engine is running paired with the large amount of tension created by the belt, it MIGHT have something to do with the issue you're seeing.

Did you ever discover the cause of your shredded belt?

I hate you're having these issues. I'd love to know the solution when you get there.

[06Speed6]

Check if there is a ridge on the two chain sprockets, I have two used ones with ridges where the washer sits on the sprocket and it probably isnt clamping them enough because the sprockets are hitting.

Edit: On my motor the 76'lb alone is enough to hold timing.

[08cosmic3]

Originally Posted by chimmike How much boost? What setup? Sent from the depths

21lbs 20% e-85 320/380 at the wheels. mods in sig.

Originally Posted by guitarzan134 Scott, Jeff told me about the ridiculous tension that the new Dayco belt put on the pulleys. Said the belt tensioner barely moved when he released it. With the constant movement of the pulleys while the engine is running paired with the large amount of tension created by the belt, it MIGHT have something to do with the issue you're seeing. Did you ever discover the cause of your shredded belt? I hate you're having these issues. I'd love to know the solution when you get there.

I got a new OEM belt and it's still slipping.

Originally Posted by 06Speed6 Check if there is a ridge on the two chain sprockets, I have two used ones with ridges where the washer sits on the sprocket and it probably isnt clamping them enough because the sprockets are hitting. Edit: On my motor the 76'lb alone is enough to hold timing.

Thanks, I'll look at the sprockets when and if I have to open it back up. Do you need new sprockets or can the ridges be filed off?

[06Speed6]

I filed mine off very carefully. There wasnt a ridge on the crank or damper pully so those must be a different metal.

[silvapain]

Originally Posted by 08cosmic3 I have crank pulley slip after replacing the chains, VVTA, guides and tensioner. I used all new washers and bolt. I even ordered another crank pulley bolt and washer and had a local shop torque to 73lbs + 90 degrees a 2nd time and I'm still slipping. My question is can I just add more torque or should I get all new washers and an ARP bolt and start over?

Did you make sure to clean every last bit of oil off the crank pulley, sprockets, and crank? Any oil on the washers will reduce their coefficient of friction. Make sure not to touch the flat surfaces of the washers at all.

[08cosmic3]

I guess I'm going to order new washers, ARP crank bolt, open it up and try again. I'll be very careful to clean everything and inspect the sprockets for ridges. Thanks for the info and if there is anything else I should look for or consider let me know.

[Tokay444]

methanol will help with removing any oil residue left on the sprockets, before reassembly.
are you not driving the car right now, or have you reset timing?

[SilverDemon]

One word...... Loctite.....

500+ hp with almost 500 lb ft of torque, no slippage

[silvapain]

Originally Posted by SilverDemon One word...... Loctite..... 500+ hp with almost 500 lb ft of torque, no slippage

Are you saying you applied Loctite to the crank bolt threads, or to the surfaces of the friction washers?

[Tokay444]

both i think
scott had some face loctite with a very high shear strength for the sprockets.
not sure how he'll get them apart if needed.

[Realgib3]

680 I believe. Its a retaining compound, not a thread locker, so its used on the faces of everything. Something like 4000psi shear strength. You need a torch for removal I think, but hopefully removal is just never necessary.

[StayBroke]

I also used loctite retaining compound lol.

sent to you from me

We use a bearing puller at work to break thw stuff loose. I dont no if that would work on thw car tho.

sent to you from me

[SilverDemon]

Originally Posted by silvapain Are you saying you applied Loctite to the crank bolt threads, or to the surfaces of the friction washers?

No, not the threads, that would be suicide...hahaha!!

I de-greased the washers and all the mating surfaces. Then applied the primer and finally the loctite 680 to faces of all mating parts. I assembled everything with the motor in time with just the old crank bolt putting pressure against the assembly. Let it set up overnight, removed the old crank bolt, installed the timing cover then installed a new bolt and torqued it to the service manual specs. All along checking that the motor is still in time.

Yes, a torch (small map gas) will be needed to remove the assembly if I have to take it apart.

[Realgib3]

Originally Posted by SilverDemon No, not the threads, that would be suicide...hahaha!! I de-greased the washers and all the mating surfaces. Then applied the primer and finally the loctite 680 to faces of all mating parts. I assembled everything with the motor in time with just the old crank bolt putting pressure against the assembly. Let it set up overnight, removed the old crank bolt, installed the timing cover then installed a new bolt and torqued it to the service manual specs. All along checking that the motor is still in time. Yes, a torch (small map gas) will be needed to remove the assembly if I have to take it apart.

This is exactly what I just did over the weekend...

And on another note, I just looked down to thank your post and saw Silvapain, but at a glance it looked like SilverDemon...and I thought you thanked your own post. Wow that was trippy. Maybe I needed to sleep more this weekend. wow.

[Tomas]

Originally Posted by 08cosmic3 I guess I'm going to order new washers, ARP crank bolt, open it up and try again. I'll be very careful to clean everything and inspect the sprockets for ridges. Thanks for the info and if there is anything else I should look for or consider let me know.

You need to make sure the sprockets for the oil pump and timing chain are correct. They are NOT the same. One is thinner than the other. When you install the crank pulley with all the sprockets and friction washers it should protrude from the crank snout quite a bit. Almost a full 1mm I would say. If it doesn't you will clamp the shoulder of the crank snout with the washer of the bolt instead of the shoulder of the pulley and that will cause it to slip.

Not to sound like captain obvious but also make sure the friction washers on the cams are between the sprockets/ VVT and the cam shoulder. Not under the bolt.

[Nitr0EngiE]

Fwiw using an arp bolt I just torqued 85 ft lb on crank pulley then 90 and another 45. I don't know how much torque that is but I never want to slip

I did basically the same thing two years ago with oem bolt and never had the crank slip and I ran the shit out of my car before turbo took A shit

[Tokay444]

I wouldn't advise that at all.

[timjs]

Originally Posted by Nitr0EngiE Fwiw using an arp bolt I just torqued 85 ft lb on crank pulley then 90 and another 45. I don't know how much torque that is but I never want to slip I did basically the same thing two years ago with oem bolt and never had the crank slip and I ran the shit out of my car before turbo took A shit

What made you do it that way? I don't see how the bolt could be stable anymore.

Not to mention the threads in the crankshaft.

[Nitr0EngiE]

That's how I did it before and it worked very well

I am just sharing what I did for information purposes. I am not un doing it I will run it like that. There is no real proof of the perfect way to do it other than key the crank which is what I will do next time I take it apart. I'm not looking for approval, simply sharing info and there are other people here who says they did it to 300 ft lb and no body says anything negative like everyone is saying to me now.

Take note of what I did for comparison or pretend like I'm a moron and have but done it previously which every it does not matter to me

[Tokay444]

Who torqued to 300lbs?

[Erich]

We simply made sure everything was clean and torqued to shop manual specs. It is also important to make sure motion is maintained through both the initial to the torque spec (forget what the actual spec is) and the 90 degree (think it is 90 degree, but again not sure as it has been a while) follow up.

[Tokay444]

Anyone every slipped timing on a factory motor?

[timjs]

Originally Posted by Tokay444 Anyone every slipped timing on a factory motor?

I'm interested in this answer as well.

Of all the disi engines I've replaced, (shoot, any of mazdas non-keyed engines for that matter) none slipped timing on their own.
All of the head jobs I've done where the timing was off and bent valves, an outside shop had recently did a timing chain replacement.

Basically, the factory procedure is very good when done properly.. Personally I don't see the need for changing a thing unless you increases loads on the chain. Springs and cams mainly. Although even an upgraded HPFP or thicker oil are indeed a higher load on the chain but negligible I'm sure.

[Celestspeed3]

On that topic, I recently ordered a Cosworth dry sump kit, and I needed to make some modifications to the oil pump gear. They told me they no longer key the cranks, that was only done at the beginning when they weren't sure if they could trust the friction washers. There billet cranks I believe are keyed because that's how they were designed.

[Realgib3]

I've yet to see proof the crank needs keyed. What I have seen is that the factory setup leave VERY little room for error and if you do mess up even the slightest bit, it will mean the difference between holding timing at 700+whp and holding 50whp.

That means keying the crank can eliminate the assembly error which means you'll never slip no matter what. Basically it looks like it's not a necessity but is good for piece of mind.