Hey guys, I am rebuilding again, and this time I am going with Juke head bolts. For anyone that is using them, what method did you use, did you bottom tap the block or did you use washers? I have a bottom tap but it seems to start cutting as soon as I start threading, I cleaned the threads as best possible and still seems to catch right after a couple of turns, it has resistance. The tap is the correct thread and pitch. So I am thinking about just going with the washer route.

 

I’m curious, what’s the rationale behind using Juke headbolts?

 

The same for using HR head bolts. HR head bolts seem to have lost their good quality so the Juke bolts are a replacement/stepup.

 

its normal for a fresh tap to cut a little in old threads. the original threads were probably formed or cut with a slightly smaller or possibly worn tap. if its cutting the correct size threads it is fine as long as you get good thread engagement.

 

But that to me means that its making the existing threads thinner by taking material away as you thread in the tap. Which will therefore make it more prone to strip and have a failure. At least thats my thought pattern for this

 

The tap is probably only cutting at the very tip of the threads, because the stock threads are probably rolled or formed and not as sharp.

While you are right, and a rolled/formed thread is stronger... you are not going to strip out the threads when you have that much thread engagement and are only tightening to what is probably around 80-100lb ft.

 

It makes sense, I am a bit paranoid on removing any material at all from the existing threads. My other concern is, having washers, how would that affect the torque specs if the Juke bolts are designed for no washers?

 

The juke head bolts should have washers already on them.. You are just adding another so they don't thread as deep... Which I figured you were trying to avoid by tapping deeper, no?

 

Could you not just shorten the juke bolts?

 

I just tapped a spare block, and I am def not doing this to the good block, you can easily tell that the threads are much shorter and the tips are getting trimmed. I have a set of DE used bolts, I wonder if I can use the washers from those (cutting the bolts in half). I am going to call JWT and ask them what they do about washers.

I wouldnt want to mess with the juke bolts by cutting them.

 

they will tell you to use your DE washers or to use SR20 washers which are free from the bolt, or to use ARP washers. Either or wouldnt make a difference.

The tap you are using is probably fine, but taps also come in several different thread classifications and maybe you ordered an over-sized one.. or could order an under-sized one.