Stripped Engine Block Threads

[Domo_K]

Hi All,

I am pretty new to car stuff and made the mistake of trying to install my own ARP Head studs.. I got my 27Won FMIC in myself and got overconfident.

So it is the thread for stud #2. It kept feeling weird to twist it down there and I kept having to back it out and then lo and behold, the whole thread came out. It was a dumb move and I am accepting the expensive consequences of this. Luckily I have some connections and can possibly get away with not paying as much as the average person hopefully...

I am considering Helicoil or Time-serts for all of these threads for an experiment for the sake seeing what it does. Is this feasible? Which brand do you prefer and why? For reference, I am also having them still install the ARP's because I might as well have them do those as I will be replacing the gasket and machining the head. Will this also make the head a little more bulletproof?


Thanks guys.

 

[jtlctr]

Yikes! I would consult a machine shop with engine building experience about repairing this.

 

[Domo_K]

All good! I already have a place in mind and I have a close friend who knows someone that has been in the game 40 years. He should know a thing or two.

 

[NeRO_CTR]

Ouch!!! I’d definitely a timesert it.

 

[Domo_K]

Okay cool. If I can't afford to do all of the threads, I will at least do the number 2 stud.

 

[AZCWTypeR]

Check the wall thicknesses surrounding the stripped hole. Helicoils have the smallest outside diameter. But if you plan multiple disassembles, beware Helicoils can back out as bolts unthread.

 

[Domo_K]

Thank you for letting me know.. I will see if they can find a time-sert for the thread pitch and size. I wonder if anyone else has done this before. if not, I will be the first one to time-sert a 1.5 block. Of course through my own mistakes.

 

[Domo_K]

Alright, so I got my engine in a engine builder's shop. They tried to charge me 12k for a new motor in a regular mechanic shop cause they did not want to deal with it. I did not know to go to an aftermarket shop. Much more reasonable. Also, from what I have been told by the tuner shop is that Helicoils are optimal for aluminum blocks and time-serts are a big no-no. Stay tuned. I will update with my results in the future. They can't really get to my car until about end of month so I will have my nice little Volvo until then.

 

[AZCWTypeR]

Helicoils are easy to install. They sell kits with everything needed in every thread size, including left hand. If doing it yourself, McMaster.com and eBay are go-to's for such things.

 

[CTR]

Care to elaborate on why you were installing head studs into an otherwise stock car?

 

[Domo_K]

Care to elaborate on why you were installing head studs into an otherwise stock car?

I installed a FMIC and ran a tune. This was for reassurance on the head lifting

 

[Domo_K]

Helicoils are easy to install. They sell kits with everything needed in every thread size, including left hand. If doing it yourself, McMaster.com and eBay are go-to's for such things.

Yeah, maybe I should have done it myself but at the same time, I don't want to mess anything else up. The other installs in the future I will be able to do myself but head studs may be out of my wheel house. I didn't realize how soft the threads were. Barely, and I mean barely any type of resistance and you have to back it out and clean the thread holes and try again. I thought I was being gentle and well, not gentle enough. Lesson learned.

 

[matt23fe1]

How were you tightening them?? Did you use a ratchet on the stud itself? They’re only supposed to be threaded in by hand, then you torque the nut.

 

[Domo_K]

How were you tightening them?? Did you use a ratchet on the stud itself? They’re only supposed to be threaded in by hand, then you torque the nut.

I threaded in by hand and then used a split-beam torque wrench. I was also told that sometimes the aluminum blocks just have shit threads. From what I felt and saw, it was a thin slinky made out of aluminum. Helicoils are much stronger than what they install from factory. I felt a little resistance on the second one and I should have backed it out and the clean it again. Cleaned it wirh brake cleaner and everything, just kept getting resistance.

I will say that I definitely know how gentle you have to be with those aluminum block threads now. Never making the same mistake again.

 

[Domo_K]

I am back. The install was difficult as the tap was only 3.6 inches. No one told me this and well, that was all I could get out of the drilled hole. Any extensions were too large to fit. I had to do all the work myself and I documented most things. I am posting pictures so you guys could see. Time will tell if the studs hold. The new one sits about a 1/4 inch higher than the rest but I did get full thread en

gagement with a much larger Helicoil (30mm). I think that is the saving grace here for me. I talked to many people about this and there is not many people who are willing to help and I got disregarded.

I went into this project with zero guarantees I would make it out of the other side and it still remains to be seen but, the car is running fine. Zero coolant leaks besides the valve cover leak when I didn't seal correctly and the thermostat housing leak (Replaced).

If this lasts and is successful, if anyone ever needs help on this since not many people were willing to help me. Just DM me. I don't know much about cars and I somehow succeeded in fixing this, temporarily at the very least. It has, however made it through many heat cycles already.

I also installed a fresh new head gasket as well. I checked with all feelers and all was well below spec since I never overheated the engine.