Topic: Exhaust Stud Helicoil pulled out?

[LiveeviL81]

Hey Guys!
Bad news to start Easter weekend... When tightening my exhaust studs down, my 4th cylinder upper stud pulled out. I "unscrewed" the helicoil the P/O must've installed but I don't see much threads left to throw another helicoil in. I'm pretty upset as I was only at 8ish ftlbs and had not fully squished the copper down.
Thoughts? Hoping I can salvage it with a new helicoil tomorrow, if not... I guess I'll upsize the stud to M10 and see what happen.

Kaleb

[CycleRanger]

You could go up a size and use a step stud.

[grcamna2]

You could go up a size and use a step stud.

   I've seen those in certain hdwe. stores a while back;excellent product.

[HondaMan]

Maybe also look at Keenserts: I've used them in both exhaust port situations like yours and in the upper engine cases when the long studs got too corroded in the case and the threads ripped out when the studs were removed, requiring a larger hole to fix it. Keenserts will require a 10mm tapped hole for the 8mm stud size, and come in all the threads needed. They mount flush or non-flush, depending on the ones you choose.

[Tracksnblades1]

Helicoils have always been a disappointment when using more than once…😩

These work better in aluminum especially when the bolt has to be used. 😁
Requires a bigger hole than a helicoil though..

https://www.amazon.com/Z-400-4-CR-Threaded-Stainless-Internal/dp/B002WC8TSE/ref=asc_df_B002WC8TSE/?tag=hyprod-20&linkCode=df0&hvadid=244072168312&hvpos=&hvnetw=g&hvrand=16366027770143355828&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9057590&hvtargid=pla-552790806404&mcid=31db6a952f423d9a83664e27a38b2d82&gclid=EAIaIQobChMI8ouhx8uYhQMVxUtHAR17Tw8PEAQYASABEgK8IfD_BwE&th=1

[LiveeviL81]

I purchased these reducers https://www.amazon.com/gp/product/B0BZV1DR71/ref=ox_sc_act_title_1?smid=A15ZZE9TVIJLI0&psc=1 incase I do have to tap to M10.  I'll also look for the step studs. Didn't know they existed.

[grcamna2]

Maybe also look at Keenserts: I've used them in both exhaust port situations like yours and in the upper engine cases when the long studs got too corroded in the case and the threads ripped out when the studs were removed, requiring a larger hole to fix it. Keenserts will require a 10mm tapped hole for the 8mm stud size, and come in all the threads needed. They mount flush or non-flush, depending on the ones you choose.

I just watched an installation tutorial on these and they look good.
Do they come as a complete kit?(6mm,8mm,10mm,etc. with necessary installation bits/tools) and how do they compare to TimeSerts, price,etc. ?

[CycleRanger]

I purchased these reducers https://www.amazon.com/gp/product/B0BZV1DR71/ref=ox_sc_act_title_1?smid=A15ZZE9TVIJLI0&psc=1 incase I do have to tap to M10.  I'll also look for the step studs. Didn't know they existed.

I got the step studs from https://belmetric.com/.
I used one of them on my XS650 a couple of years ago.

[bryanj]

Keenserts dont have instalation kits, they use standard taps, maybe with an odd pitch, then just screw in and tap down pegs.
They do need quite a bit of metal round the hole, 6mm thread uses 10mm tap so 8 probably 12

[grcamna2]

Keenserts dont have instalation kits, they use standard taps, maybe with an odd pitch, then just screw in and tap down pegs.
They do need quite a bit of metal round the hole, 6mm thread uses 10mm tap so 8 probably 12

I was waiting for Mark's answer as he presented what looked like a good product;seems I would have been waiting for a long time.

bryanj,Thank you for this information.
How have these Keenserts held-up in use,if you might know?

[newday777]

Helicoils have always been a disappointment when using more than once…😩

These work better in aluminum especially when the bolt has to be used. 😁
Requires a bigger hole than a helicoil though..

https://www.amazon.com/Z-400-4-CR-Threaded-Stainless-Internal/dp/B002WC8TSE/ref=asc_df_B002WC8TSE/?tag=hyprod-20&linkCode=df0&hvadid=244072168312&hvpos=&hvnetw=g&hvrand=16366027770143355828&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9057590&hvtargid=pla-552790806404&mcid=31db6a952f423d9a83664e27a38b2d82&gclid=EAIaIQobChMI8ouhx8uYhQMVxUtHAR17Tw8PEAQYASABEgK8IfD_BwE&th=1

The description says those are for hardwood

[newday777]

Maybe also look at Keenserts: I've used them in both exhaust port situations like yours and in the upper engine cases when the long studs got too corroded in the case and the threads ripped out when the studs were removed, requiring a larger hole to fix it. Keenserts will require a 10mm tapped hole for the 8mm stud size, and come in all the threads needed. They mount flush or non-flush, depending on the ones you choose.

Definitely far better than helicoils.

How to install Keenserts

[HondaMan]

Maybe also look at Keenserts: I've used them in both exhaust port situations like yours and in the upper engine cases when the long studs got too corroded in the case and the threads ripped out when the studs were removed, requiring a larger hole to fix it. Keenserts will require a 10mm tapped hole for the 8mm stud size, and come in all the threads needed. They mount flush or non-flush, depending on the ones you choose.

I just watched an installation tutorial on these and they look good.
Do they come as a complete kit?(6mm,8mm,10mm,etc. with necessary installation bits/tools) and how do they compare to TimeSerts, price,etc. ?

Depends on where you get them: I've installed many of them so I have their tools. I bought the first toolset at Grainger's, about half a century ago...

[bryanj]

First keenserts i saw was in 75 being fitted into the studs/bolts for cam tower holding, never pulled out but did let a bit of oil down as nobody at the time was aware of the "blind" hole problem, thats how i know the 6mm inner has the 10mm tap but of the "odd" pitch that is not used much

[bryanj]

Nice video on fitting/removing, never seen a proper tool, just screwed in and tapped tangs down, i seem to remember the smaller ones only having 2 tangs, but that was a very long time ago

[HondaMan]

Nice video on fitting/removing, never seen a proper tool, just screwed in and tapped tangs down, i seem to remember the smaller ones only having 2 tangs, but that was a very long time ago

Yep 2 tangs on the 6mm. That's what I remember, too.
I've used a lot more of the 8mm, with the 4.

[grcamna2]

Nice video on fitting/removing, never seen a proper tool, just screwed in and tapped tangs down, i seem to remember the smaller ones only having 2 tangs, but that was a very long time ago

I watched the video.

[LiveeviL81]

Appreciate all the help guys! Got the stud installed the other night and after waiting for all the locktite to set all weekend was able to get the exhaust on last night. My only worry will be if the stud unscrews when I go to loosen the exhaust in the future after the heat breaks down the Locktite. But unscrewing is a lot better than pulling threads out!

Kaleb

[grcamna2]

Which one did you decide to go-with Kaleb ?

[LiveeviL81]

Which one did you decide to go-with Kaleb ?

Ended up putting in a 10mm helicoil and then purchased these https://www.amazon.com/dp/B0BZV1DR71?psc=1&ref=ppx_yo2ov_dt_b_product_details 10mm male to 8mm female inserts. Got both locktite-d in then installed the original 8mm studd with locktite as well. Was able to torque all of them to the same space (12ftlbs) and nothing else pulled out. If I did it again, I would probably bore all of the studs out to 10mm, helicoil and then get the 10mm-8mm step studs. Make it overkill so I could really torque stuff down.

[rotortiller]

ended up putting in a 10mm helicoil and then purchased these

That should work fine and is much more than likely stronger than the original. A little anti-seize on the stud should prevent the inserts from screwing out during removal. That is kind of like a twinsert install. SS is way stronger than aluminum inserts and you now have a large thread surface in the base cylinder head metal. Nice to see you taking things in hand and thinking on your own.