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General Information => General => Topic started by: jtanguay on December 07, 2008, 09:05:46 am

Title: Stud to replace the crank bolt?
Post by: jtanguay on December 07, 2008, 09:05:46 am: Just a thought... you could get wayyy more clamping force with less actual torque required that way. i guess the problem is finding a place that sells something that big?

thoughts?
Title: Stud to replace the crank bolt?
Post by: jtanguay on December 07, 2008, 06:22:22 pm: nobody??? virtually eliminate crank failures here!!! :lol: or is that just an absurd idea?
Title: Stud to replace the crank bolt?
Post by: truckinwagen on December 07, 2008, 06:58:44 pm: not an absurd idea at all, if you can find a stud that would fit.

go forth and find one!
Title: Stud to replace the crank bolt?
Post by: jtanguay on December 07, 2008, 09:17:43 pm: what about those guys getting head studs from fastener companies? they must be able to supply something to suit!!!

the main reason for my inquiry is because i'm assembling my motor (1.9 1Z TDI) and the crank bolt isn't that cheap (considering it has to be replaced everytime its taken off, as well as the substantially high torque required to properly tighten it.

just taking a guess here, but with a special moly lube, 70-80 ft/lbs should be good enough (and actually produce MORE clamping force than the stock bolt torqued at nearly double, if not more), and that is sooo easy to achieve (no fancy tools needed-just hook up the tranny and put it in gear)

my initial thoughts on problems with this idea are that removing the pulley(s) with the stud installed would be quite difficult... therefore a solution would be required; by cutting a slot into the end of the stud, or having a hex style nut shape ground in, so that a normal socket could fit on-space permitting of course. this 'extra' step of removing the stud shouldn't be that bad. a good few 'taps' would help loosen it up.

maybe the TDI crank fix wouldn't be necessary on a vehicle using a stud type fastener on the crank pulley??? :D

thanks
Title: Stud to replace the crank bolt?
Post by: jtanguay on December 08, 2008, 02:51:15 am: maybe even a stud to replace the camshaft pulley bolt too? virtually eliminate he possibility of it slipping, without over tightening? :wink:
Title: Stud to replace the crank bolt?
Post by: zukgod1 on December 08, 2008, 06:52:06 am: I like your thinking.

I would be willing to bet ARP has something already you could use. Give them a call with the dims/ thread pitch etc.
Title: Stud to replace the crank bolt?
Post by: AudiVWguy on December 08, 2008, 08:29:16 am: Why don't you call ARP?
Title: Stud to replace the crank bolt?
Post by: jtanguay on December 08, 2008, 12:35:15 pm: i'll contact them, but off chance does anyone have the proper dimensions/thread pitch for the crank bolt & camshaft pulley bolt??? if not i suppose i could go out and measure.

thanks
Title: Stud to replace the crank bolt?
Post by: lord_verminaard on December 08, 2008, 01:01:31 pm: It's an M14x1.5x47 I think. Very hard to find studs in that size. It just so happens that there are wheel studs made to screw in to VW hubs to replace the bolts that are M14x1.5x50, but they are double-ended. Might be worth a try though. I think they were grade 8.8.

Brendan
Title: Stud to replace the crank bolt?
Post by: cyrus #1 on December 08, 2008, 05:29:22 pm: You could probably also use a long set screw. It would then have the socket head.
Title: Stud to replace the crank bolt?
Post by: AudiVWguy on December 08, 2008, 09:00:15 pm: Check this out.

http://www.bildon.com/catalog/DetailsList.cfm?ID=M14.DE.Stud&Nav=10&SubNav=none

Imagine what kind of torque this baby can take! :shock:
Title: Stud to replace the crank bolt?
Post by: jtanguay on December 09, 2008, 01:11:37 am: Quote from: "AudiVWguy"
Check this out.

http://www.bildon.com/catalog/DetailsList.cfm?ID=M14.DE.Stud&Nav=10&SubNav=none

Imagine what kind of torque this baby can take! :shock:

hmmm very interesting!!! i was hoping to find a stud with a low thread pitch to increase the clamping force, but this seems like it would be perfect!
Title: Stud to replace the crank bolt?
Post by: truckinwagen on December 09, 2008, 08:51:22 am: good find!

so have we agreed that both bolts are 14x1.5?
I just want to make sure before I go and buy something.
Title: Stud to replace the crank bolt?
Post by: jtanguay on December 09, 2008, 12:45:23 pm: Quote from: "truckinwagen"
good find!

so have we agreed that both bolts are 14x1.5?
I just want to make sure before I go and buy something.

well if brendan is right... :wink:

considering that race guys torque their wheel nuts down to more than 150 ft/lbs, i think the crank pulley would be going NOWHERE if cranked down to that (especially with some moly lube)

actually i just opened etka and its saying M14X1,5X33 (1.6's at M14X1,5X33) so i think we're in business :twisted: just need someone crazy enough to try this!!! :lol: i think i might...
Title: Stud to replace the crank bolt?
Post by: truckinwagen on December 09, 2008, 01:28:26 pm: I will jump on this later today!

so both the crank and camshaft bolts are 14x1.5?
if so I will buy two and go for both!
Title: Stud to replace the crank bolt?
Post by: jtanguay on December 09, 2008, 02:44:25 pm: Quote from: "truckinwagen"
I will jump on this later today!

so both the crank and camshaft bolts are 14x1.5?
if so I will buy two and go for both!

the camshaft bolt is listed as M12X1,5X35SW18 not sure what the SW18 means though... it also says hexagon head bolt (combi)

now the camshaft bolt isn't as critical in this case, so the stock one should do... but the crankshaft stud idea is where its at 8)
Title: Stud to replace the crank bolt?
Post by: truckinwagen on December 09, 2008, 02:47:25 pm: just thinking, if they were the same I might as well do both, I like dealing with stud/nut way better than bolts anyway, especially when they locate the part like the crank and cam do.

I will go ahead and buy one of these studs then and shove it on the motor!

thank for the idea and the source!
Title: Stud to replace the crank bolt?
Post by: AudiVWguy on December 09, 2008, 09:10:38 pm: SO...........what kind of nut and washer are ya gonna use?
Title: Stud to replace the crank bolt?
Post by: jtanguay on December 10, 2008, 02:38:56 am: Quote from: "AudiVWguy"
SO...........what kind of nut and washer are ya gonna use?
\

yea we haven't fully decided on that.. yet.. but i do believe applying some moly lube might be a good idea to get some more torque applied.

can anyone comment on that? what is the max the nut should be torqued at??? what can a 14mm stud handle???

thanks
Title: Stud to replace the crank bolt?
Post by: lord_verminaard on December 10, 2008, 08:31:05 am: From what I've seen, most M14x1.5 wheel studs are AT LEAST 8.8, which calls for 90 ft-lbs of assembly torque. Most of the motorsport ones for VW are 10.9 or 12.9, although Bildon does not list the hardness on the ones they sell, I have seen similar ones at those hardness levels. Assembly torque for 10.9 is 133 ft-lbs, and 12.9 is 145 ft-lbs.

Brendan
Title: Stud to replace the crank bolt?
Post by: jtanguay on December 10, 2008, 10:16:16 am: does anyone know a formula to calculate the clamping force PSI using thread pitch, etc?
Title: Stud to replace the crank bolt?
Post by: cyrus #1 on December 10, 2008, 06:49:50 pm: I can find out a formula that will work... My brother is a mechanical engineering student. 8) We will need to know the tensile strength of the material though.
Title: Stud to replace the crank bolt?
Post by: clbanman on December 11, 2008, 03:08:44 am: http://www.engineersedge.com/calculators/torque_calc.htm
Title: Stud to replace the crank bolt?
Post by: jtanguay on December 11, 2008, 03:48:46 am: 14mm to inch = 0.551181102

Fastener Major Diameter (in.)
=0.55

Torque (in - lbs) Applied
=110.2

Axial "Clamp" Force (lbs)
=1000
Title: Re: Stud to replace the crank bolt?
Post by: vwt4 on December 17, 2008, 03:54:17 pm: Quote from: "jtanguay"
Just a thought... you could get wayyy more clamping force with less actual torque required that way. i guess the problem is finding a place that sells something that big?

thoughts?

This is a very, very GOOD idea :D

I am seriously thinking about adding it before bolting my new crank pulley back up (and repaired crank).

has anyone done it yet? pics!
Title: Stud to replace the crank bolt?
Post by: truckinwagen on December 17, 2008, 05:05:13 pm: well, I was going to do it, but as I was trying to figure out my fuel problem my timing slipped and I bent a few valves which means that all of my projects are on hold until after I get my head rebuild AGAIN.

it really sucks pouring this much money and time into something I haven't been able to drive in six months.

oh well, it gives me an excuse to port the head as it will have to come off anyway.
Title: Stud to replace the crank bolt?
Post by: jtanguay on December 17, 2008, 05:15:42 pm: i sent an e-mail to ARP but didn't get a response as of yet... i might try raceware as i'm sure they have 14mm studs out there with the right thread pitch on the one end, and the nice and low thread pitch (more clamping force) on the nut end.
Title: Stud to replace the crank bolt?
Post by: zukgod1 on December 18, 2008, 07:45:50 am: I had much better luck calling ARP, E mail can be ignored I think.