Procharger crank pulley bolt ?

Hello, hoping someone can remember something from their install. I've got got the Stage 2 PC kit on my car and am installing a new crank pulley bolt. The kit came with a 120mm long new bolt and when I installed it originally I omitted the large flat washer that was installed on the bolt from the factory. The reason I'm now replacing the bolt is that it came loose and I was half guessing I should have had that thick washer installed to help with the bolt's stretch, don't know how valid that thought is, but it crossed my mind that it could have something to do with the bolt coming loose. Anyway, was in the process of installing it and see without the washer, looks to be just shy of 3/4" thread engagement into the crank. The flat washer measures 5/16" thick. So with the washer there is only going to be 7/16" of engagement which is less than the 12mm bolts diameter. From what I recall a bolt should have at least it's diameter of engagement?

Do any of you remember if you used the washer or not? I really don't want to end up without enough thread in my crank when I go to torque it down.

Thanks hopefully.

Bartly said:

Hello, hoping someone can remember something from their install. I've got got the Stage 2 PC kit on my car and am installing a new crank pulley bolt. The kit came with a 120mm long new bolt and when I installed it originally I omitted the large flat washer that was installed on the bolt from the factory. The reason I'm now replacing the bolt is that it came loose and I was half guessing I should have had that thick washer installed to help with the bolt's stretch, don't know how valid that thought is, but it crossed my mind that it could have something to do with the bolt coming loose. Anyway, was in the process of installing it and see without the washer, looks to be just shy of 3/4" thread engagement into the crank. The flat washer measures 5/16" thick. So with the washer there is only going to be 7/16" of engagement which is less than the 12mm bolts diameter. From what I recall a bolt should have at least it's diameter of engagement?

Do any of you remember if you used the washer or not? I really don't want to end up without enough thread in my crank when I go to torque it down.

Thanks hopefully.

Click to expand...

[MENTION=19360]Bartly[/MENTION] where did you ever end up on this at?

whatsup62 said:

@Bartly where did you ever end up on this at?

Click to expand...

Been a little while. My bolt came loose a couple of times, if I recall it was once without the large thick factory washer and once with it. I ended up buying a new bolt that was a little longer than the Procharger bolt and using the thick washer along with some blue loctite on the threads. I’ve checked it a few times since and it hasn’t loosened up once I used the loctite.


Edit looks like I didn't use that thick washer, but one from a local hardware store.

Any idea on what the length was and where you got it from?

Also is the one PC supplies the same length as the stock one?

Just looked though my receipts, I am thinking now I did not install a longer one than what came with the kit. Bought them at Fastenal. Looks like I bought a 120mm long one for the actual bolt and a 150mm one for installing the pulley (with stacking washers and a big spacer). The procharger one was also 120mm long which is longer than the stock one to accommodate the thickness of the supercharger pulley stacked onto the OEM pulley. Also, cant' quite be sure, but maybe I wanted a different bolt because the procharger bolt might have been grade 8.8 and I wanted 10.9. Anyway, fastenal p/n 11114712 for the 120mm and p/n 11113259 for the 150mm.



Not sure if me going to a 10.9 grade was the best of ideas, I did torque it to the value i found on line given it's size/grade so I'm thinking it stretched the right amount to hold in place, but the loctite also helped with that. I might have used low temp red.


edit. just went and looked at by engine and I didn't use the thick OEM washer. Now I remember visiting a few hardware stores around here and found a washer about half the thickness of the OEM one, but still thicker than just a standard washer. Sorry for the confusion.