Engine out, crank hub slip fix or no?

[1FastT2]

I'm in the middle of an engine build. The short block is complete and I'm finishing up the long block as I type. I'm still waiting for a few things to arrive. IE, VTT valve cover and a few misc items.

I keep reading horror stories of slipping crank hubs. I've already got $10k into this engine this winter and would rather not keep adding to this build if its unnecessary. Is this really a wide spread issue on higher powered vehicles?

I'm running a 6266 and will most likely not see above 800whp.

Is the install that difficult with the engine out?

What are everyone's thoughts?

 

[saskatchewan135]

Auto or mt car?

 

[1FastT2]

Auto or mt car?

MT.

 

[saskatchewan135]

I would install a solution while the engine is out. You wont be happy when saving 1k causes 10k in damage if it slips

 

[DCook]

Im in the same boat as you. Except 6466. And after hearing the vtt slip, which who knows if its the damper or not that caused it, max psi out of stock for theirs. Not much except a vtt bolt capture for good luck. My first stock motor bent a rod before anything else. Now im building one. May be ok with just a cbc. Or hold out until max is in stock. Ghassan makes a keyed but wont sell separately.

 

[1FastT2]

Im in the same boat as you. Except 6466. And after hearing the vtt slip, which who knows if its the damper or not that caused it, max psi out of stock for theirs. Not much except a vtt bolt capture for good luck. My first stock motor bent a rod before anything else. Now im building one. May be ok with just a cbc. Or hold out until max is in stock. Ghassan makes a keyed but wont sell separately.

I was a drives engineer for a major manufacturer of heavy machinery a few years ago and there is not one solution currently available that will work in the manner its intended to. Technically everything offered is nothing more then a band-aid. The only real solution to this problem is a keyed crankshaft and hub. Not a square key in a round hole. Unfortunately without completely removing the crankshaft these option will have to make due, now its just choosing the lesser of the evils.

The engine was never intended to run triple of the HP rating in which they are seeing on modified vehicles and to implement something that will completely eliminate the problem would mean a pretty serious overhaul impacting alot of different components.

 

[Torgus]

max psi solution has yet to slip right? I would go with that even if you have to wait a bit. Call em up and see when they will be back in stock.

 

[DCook]

max psi solution has yet to slip right? I would go with that even if you have to wait a bit. Call em up and see when they will be back in stock.

Nope, double dowel keyed iirc. And you can buy the install kit and diy.

 

[The Convert]

The max psi is the only one I’ve said will work since day one. It’s the only keyed hub/crank offering.

 

[GreyNBlueE92]

Weld (tack) it?

 

[Abacus38]

It’s as simple as do you have unprotected sex with hookers? The answer is no. Install the max psi crank hub fixed and send it.

 

[DCook]

It’s as simple as do you have unprotected sex with hookers? The answer is no. Install the max psi crank hub fixed and send it.

Some of us like living on the edge.....dont judge. Its like a box of chocolates, you never know what you're gonna get.

Hookers cost. Some of us cant afford them cause our cars fuck us then take our money by force. No lube either.

 

[fmorelli]

My way of thinking - I'll install the VTT capture for grins (cheap and easy) on my stock motor with upgraded twins. I won't be over 600whp and not drag racing. But that said, if I bend a rod or spin the hub, that will be my excuse to build a ported motor. And that said ... if I built a motor, I can't imagine not installing a hub slip solution.

I once built a stroked a bored BMW 2002 (the old car) which ran at 8k and everything was done from big valves and cam, porting, et al. This went into a complete restoration I spent 18 months on. 3 months after the car was on the road, blew the motor up due to something stupid. The cost was one thing, but the emotional let-down after all the effort and commitment had me stuff the car in the garage for a year with the cover. Didn't want to see it. The cost of the build is definitely a factor. But don't discount other costs - in my experience they may actually matter even more ...

For your amusement - I'm striping the '02 with House of Kolor paints ... pre-digital photography days, boys and girls ...

Filippo

 

[veer90]

FWIW when I had my motor built no crank hub fix existed. I wanted to do *something* to address it though. Looked into a bunch of things including stud conversion, torque specs, bolt material of construction, anything that would let me increase the clamping force on the hub. Talked to a bunch of techs also that told me some interesting things about the bolt.

Ended up doing all latest revision OEM parts / install except at the very end the crank bolt was overtorqued by 10* (spec is 100NM + 360*, I did 100NM + 370*).

Motor has about 30k miles on it now has survived 650+ whp for over 2 years, 100s of high boost highway pulls, dyno pulls, 2step/NLS, donuts, burnouts, etc. Saturday I was at a drift event and motor got bounced off the hard rev limiter a good 30-40 times. Drove it an hour to and from the event, too. So far no signs of letting up at all, fingers crossed.

My $0.02 on what's been working so far. YMMV

 

[1FastT2]

FWIW when I had my motor built no crank hub fix existed. I wanted to do *something* to address it though. Looked into a bunch of things including stud conversion, torque specs, bolt material of construction, anything that would let me increase the clamping force on the hub. Talked to a bunch of techs also that told me some interesting things about the bolt.

Ended up doing all latest revision OEM parts / install except at the very end the crank bolt was overtorqued by 10* (spec is 100NM + 360*, I did 100NM + 370*).

Motor has about 30k miles on it now has survived 650+ whp for over 2 years, 100s of high boost highway pulls, dyno pulls, 2step/NLS, donuts, burnouts, etc. Saturday I was at a drift event and motor got bounced off the hard rev limiter a good 30-40 times. Drove it an hour to and from the event, too. So far no signs of letting up at all, fingers crossed.

My $0.02 on what's been working so far. YMMV

Very interesting. I really appreciate you sharing this info!

 

[Rob09msport]

Do motors that have never been apart have same failure rate or is it more when the motor has been apart and put back together? Also please don't shoot but if it's a stock build what's to stop from a tack weld?
Last question why do high hp builds have more risk just cause revs change quicker? I could see if their was a super charger loading the hub and I get that cams would increase load but the only thing I can see is playing in higher revs alot more when not on stock snails.

 

[1FastT2]

Do motors that have never been apart have same failure rate or is it more when the motor has been apart and put back together? Also please don't shoot but if it's a stock build what's to stop from a tack weld?
Last question why do high hp builds have more risk just cause revs change quicker? I could see if their was a super charger loading the hub and I get that cams would increase load but the only thing I can see is playing in higher revs alot more when not on stock snails.

Its will be on a fully built engine. I'm sure a weld would work if the steel wasn't already tempered. Adding more extreme heat to the part may cause for a brittle condition.

Its only a theory however I would think it's spinning due to a higher shock load and less from the bolt losing its torque.

 

[Rob09msport]

I figured sonething like balance or harmonics would be issue forgot about tempering of the metal. So more of just more abrupt acceleration of crank due to higher cylinder pressure ? Similar to false knock on dmfw cars I guess correct

 

[veer90]

Its will be on a fully built engine. I'm sure a weld would work if the steel wasn't already tempered. Adding more extreme heat to the part may cause for a brittle condition.

Its only a theory however I would think it's spinning due to a higher shock load and less from the bolt losing its torque.

My working theory is rapid rpm transitions up and down cause it to spin.

My car spun hub on stock turbos FBO pump gas messing around with WOTbox. RPMs were bouncing like crazy from 3k to 4k in one of my logs, because WOTbox 2step is very basic and not smooth at all.

Motiv's shop e90 spun hub when Syvecs traction control kicked in - super aggressive torque management using timing reduction, also makes rpm bounce up and down very quickly.

That's 2 instances, one at ~400whp and one at ~900 whp. Common thread was bouncing rpm.

 

[veer90]

I figured sonething like balance or harmonics would be issue forgot about tempering of the metal. So more of just more abrupt acceleration of crank due to higher cylinder pressure ? Similar to false knock on dmfw cars I guess correct

On the dyno in 4th gear my car went from 50 to 140 in ~3.5 seconds under full boost. With full load, way faster than possible on the street and it didn't spin.

Plus if abrupt crankshaft acceleration is the issue everyone doing peels in 1st with TC off would have problems lol