Difficult Exhaust Stud Repair On Porsche Aluminum Heads - Top End Rebuild Pt. 5

[@GarageTimeAutoResto]

This car spent its early life on the east coast, USA. As a west coast guy this was the worst I've ever seen as far as stuck studs. The entire exhaust system was horrible.

[@jeffharrison5265]

Your patience is becoming legendary. Great job.

[@GarageTimeAutoResto]

Luckily, no heads were lost in the making of this video.

[@jamesenloe2791]

Not only am I impressed with your process of removing the broken stud, but that you didn’t immediately drop the “F-bomb” when it snapped. 😂

[@GarageTimeAutoResto]

The camera wasn't on the entire 8 hours 😀. I came back and tried again several times. Some of the video footage here I was expecting it to break off, so I could drill it anyway. This was really tough, right up there with sanding.

[@petem6291]

Tom I work in a machine shop and you did a class A job of removing those studs . The one thing that may help you in the future is when you drill your first hole you drill all the way through the fastener to ( 3/16) as you did. But on the second hole drill 3/4 of the way through the fastener( you are leaving a little step ) then drill to a size that close to the tap drill only 3/4 to the bottom. Now when you put the extract in it bits in to that little piece of fastener that is 3/16 and you can unscrew it like a spring because you are not pushing the fastener against the wall of the casting if you do it right the little bit in the hole( the step) goes concave when you hammer the extractor down into it and it unscrews . it works every time when every thing you drill is paper thin (but not touching the threads)

[@GarageTimeAutoResto]

Thank you, but isn't this what I did? I thought I showed this, no. Also are you a fan of the straight extractors or spiral ones ?

[@petem6291]

@@GarageTimeAutoResto you did a great job of explaining I was just throwing my 2cents in ( maybe I was not being helpful) and we have had the best luck with the straight extractors because if we break one they come out much easier . And we have had the best luck with Kroil and P/B Blaster we found they work well with heat .

[@GarageTimeAutoResto]

Awesome man. Thanks for the feedback and support!

[@carlmclelland7624]

YES, SIR! I've worn those shoes with the broken exhaust head studs. It's never easy. You had my sympathy, especially with the difficulty you encountered. My hats off to your patience and not damaging the heads before you succeeded.

[@GarageTimeAutoResto]

Thank you! My hands are tired. 👐👐

[@annoodannoo1032]

A lot of work indeed. Thank you documenting - I learn a lot.

[@dra911]

That looked quite painful, but I'm glad you got there in the end. My car came from England (salted roads took it's toll) - yet, I was fortunate enough to not suffer any broken head studs when removing the exhaust. I used one of those induction bolt heaters to loosen everything up and it worked quite well.

[@GarageTimeAutoResto]

Cool, I'd love to have one of those heaters myself! Were you able to use it on the exhaust studs too or just the exhaust nuts?

[@dra911]

I didn't try it, the studs were fine, I just cleaned them up (and the rest of the engine) and bolted up the new exhaust. So far, so good.

[@theshyfarmer]

I just gave my heads to a machine shop they blasted them drilled out every exhaust stud fitted new guides and recut the valve seats. Those heads are so valuable if you damage them. Also it's a must to change the exhaust head/barrel studs

[@GarageTimeAutoResto]

Well done! Can you reply how much the exhaust stud replacement was? Just curious. Did they put any kind of thread inserts in the heads?

[@theshyfarmer]

It was about 3 years ago and they charged about £750. They fitted inserts not sure what type but everything they did was proper. When they recut the valve seats It was a three angle cut. They also drilled the majority of the valve guides out before knocking the remainder out which is kinder on the heads. Also they checked if the heads needed skimming which they didn't. I will mention again if anyone in the UK is Interested I have all the tools and literature to assist a rebuild. A yoke to hold the motor to a stand, the spanner for the cam a wiesco piston ring compressor the cone type. A mount for the dial gauge and a little insert for calculating valve shims under the springs.

[@DoubleRRestorations]

Nice work getting those studs out Tom. Lots of patience there.

[@GarageTimeAutoResto]

Hi Russ, good to hear from you.

[@DoubleRRestorations]

@GarageTimeAutoResto Thanks Tom, Good to be able to catch one of your vids. Been super busy lately. Going to try to get my Camaro Project restarted this week. I finally got the Mustang moved over out of my work bay. That project took way longer than I expected.

[@GarageTimeAutoResto]

Good for you! Nobody ever gets a car project done ahead of schedule, ha ha

[@ChuckJ1944]

That was really marvelous.I've Never gotten into the engine that deep. Someday maybe you could tell us the difference between compression and leak down.

[@GarageTimeAutoResto]

Duly noted. I'm sure I could talk for hours on this, ha ha.

[@miniprousa]

That happened to me. Worse feeling when the snap but best feeling when you take them all out.

[@GarageTimeAutoResto]

Indeed, I'm just glad to be able to continue and finish this engine

[@richvandervoort2950]

A carbide drill can be used to remove a broken off extractor or taps. I have even used cheap carbide cement drills.

[@pyrogenusa]

My least favorite thing are broken studs, the collet removers are the best, left hand drills also good to drill out flush breaks. I also have a 3/8” extension with a “Parker taper” and a T handle, to apply torque and use a pneumatic hammer to pound the stud. Congratulations on not killing a head in the process.

[@GarageTimeAutoResto]

Hi John, this is such a tedious process. I tried left hand drills too. They did nothing for me. Also tapped vertically many times with a regular hammer. A few of these studs would only come out one thread at a time. This was the worst I've ever seen. Not originally a California car!

[@billgaytes6845]

Ive been here, the solution I found is before you break off both studs is to make yourself a drill jig with the correct spacing. bolt it down with the remaining stud and drill out the other one. Fit new stud and then repeat.

[@GarageTimeAutoResto]

Very good advice. In fact Stomski racing makes a tool that does this. I found drilling a pilot hole and adjusting it with a carbide burr was enough to get the hole centered, but a drill fixture is a must if doing this more than once.

[@garagechronicles9008]

I paid a shop... shame. I hope you go over piston height in the cylinder and the clearance. I have to do my 3.0 with new cylinders and JE's. Haven't done them before with the talle piston. Nice job so far, sir.

[@GarageTimeAutoResto]

Ok, I'll do my best. This is a stock engine, so it is less likely to find any tight or potential interference spots.

[@doctorcountersteer6580]

Easy peezy with left handed drill bits

[@GarageTimeAutoResto]

I tried that to no avail.

[@rocoporco6216]

Always love how you show the details. Patience was definitely practiced in large dose. Just wondering if you would have secured the heads, then tried removing the studs would have helped?

[@GarageTimeAutoResto]

Thanks! My thought process on the impact wrench and unrestrained head was to send vibration waves through the metal. The wrench is plenty strong enough to break the stud, so I kept it on the lowest setting and let it vibrate. It worked on some but not all.

[@rocoporco6216]

Yes, figured... my thought process is that by securing the head, you'd have deeper penetration of energy from the impact. Starting at the lowest setting as you did. Honestly, enjoy the authenticity and patience. Keep up the good work.

[@cramiro71]

Hi Tom, another great video. Which in your opinion is a good workshop manual for an European targa 3.2 from 85? I bought a cheap Haynes to start with but it is too basic

[@GarageTimeAutoResto]

Get the Bentley manual or the factory manual is best. Also the Wayne Dempsey book on engines.

[@IUnknownIDispatch]

My first thought would've been to remove the studs prior to sending them out for machining. Why? I worry about the heat from welding nuts onto the studs affecting valve seals...etc. Thoughts?

[@GarageTimeAutoResto]

Yes, it would have been better to remove the studs first. The heads get much hotter than this while driving though.

[@jeffhammond8969]

Great presentation! Did you consider using an inductive heater on the studs?

[@GarageTimeAutoResto]

That is a great tool, but I don't have one. I'm not sure it would fit on the stud close to the fins? I used my tig torch to heat the side of the stud and a few would still not back out even after it cooled.

[@jeffhammond8969]

@@GarageTimeAutoResto makes sense. Imo, unless they would come out easy, based on what I've heard and you're experience, it would probably be worth the expense to have someone extract them.

[@tomthompson7400]

never use an impact gun on seized studs ,, all they do is ring things off ... double nut and weld when the stud is still there is a mighty good start ,,, but its heat and reheat that does good , with a full to cold space inbetween ,,, lots of patience also the lube of choice at the moment is Wurth Injectorex , it works well where others dont seem to.

[@GarageTimeAutoResto]

Never say never because this is the only thing that worked after doing what you suggest. These were cycled up and down in temperature over several days.

[@tomthompson7400]

@@GarageTimeAutoResto ah ,,, no ,,, the trick is to heat the stud / nut combo as hot as you can , nearly white hot , then leave it ,,, repeat as needed , Ive been doing this sort of job for a long long time , and every time the rattly gun comes out things snap ,, its the thermal expansion difference that does the work , so heating it all up together does not get a big enough difference fast enough to crush the rust , then as you know a heated and constrained lump of metal shrinks back to being smaller due to the restriction , granted its better on steel than alloy , but same idea , when its cold the lube will work , but it takes time ,

[@GarageTimeAutoResto]

I heated the stud several times near the head with my tig welder three times and soaked it overnight in Kroil. Yes, white hot. Sometimes drilling is necessary. How many times are you heating and cooling a stud? The aluminum expansion in the oven and the vibration from the impact gun set on low was the most effective for me. And the ones that broke were drilled.

[@Cevan42]

Curious as to why you had the heads rebuilt and then removed the exhaust studs. Also, is it somewhat rare to have Alusil cylinders on a 3.2 Carrera?

[@GarageTimeAutoResto]

I thought the shop would remove the studs as part of the rebuild, but then I found out it was $700. All the 87-89 cars had Alusil I think.

[@Cevan42]

Gotcha. Rebuilt my ‘86 last year and had Nikasil cylinders.

[@akokarski]

Those studs that broke were all next to fins? That’s a really tricky stud not a lot of room and thin shoulder. I would have cut the stud just long enough to put the nut on. Put a rod between the head and nut so there is a little gap weld the nut, put beeswax instead of kroil. Turn the nut in a bit then out. Either way you got it out without breaking taps or extractors

[@GarageTimeAutoResto]

I tried bees wax too with no luck. That was the first thing I tried.

[@theshyfarmer]

I've got all the specific tools manuals to rebuild an 87 911 if anyone is interested

[@Andrew1849]

Can new studs be stainless steel? Love your videos

[@GarageTimeAutoResto]

Thanks for watching. I know titanium and stainless studs are available and both won't corrode. The only problem with stainless steel is the threads gall up. I'm going to go with yellow zinc plated steel and stay out of rain puddles😀

[@ShainAndrews]

Quality stainless cold welds instantly (this is what you guys call galling). It is not the panacea many believe. Accept the fate that is aluminum. The one advantage is the exposed thread area will last longer, but expect the same fight when it comes time to remove the studs.

[@GarageTimeAutoResto]

If it's not one problem it's another. Cold welding for me is for bad welds with too little amperage, ha ha.

[@Kris-82]

@@GarageTimeAutoResto I think ot's rather galvanic corrosion issue and going woth stainless steel bolts is way worse solution than zinc plated. Apart from that I didn't get the point what is best methodology to remove broken studs. Using the biggest drill as possible - sure if you are able to not go off center which for some cases can be really, really hard

[@GarageTimeAutoResto]

What's ot's?