Home Depot LS1 Head Bolts? Dyno Kill Charts of ARP, OEM, L19 & More 

Find episode 2 here testing myths, used head bolts, and $$$ ARP 625 studs: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-0b2B6AUzYtw.html

I'm definitely curious about thread inserts (time-sert specifically considering they're advertised for engine repair).

RIP to all the indicators. Your service has not gone unnoticed.

This channel is quickly becoming the hardware test variant of Project Farm in the amount dedication and attention to detail, I love it. On behalf of all the subscribers, please Keep it up, and thank you. 👍 👍

Really cool test with off the shelf test equipment! At work (for a large diesel manufacturer), we've put in a lot of research to bolted joints and have some info that may be helpful here. The dial indicator was solid, in industry we grind the tops and bottoms of each bolt, and measure the stretch with an ultrasonic gauge (MC900), and correlate that to a tensile test to get actual preload. Bolt preload with a torque only torque procedure is typically accurate to +/- 30% using the same fastener design with the same threads and same coating... different coatings can influence the friction factor of the threads by typically 30-50% as well, which further compounds the error from a straight torque. different tensile diameters (like parts that have a waisted or turned down shank) will also vary the preload for the same thread size. In a straight torque joint, preload is directly proportional to the total friction coefficient times the torque applied, with the grip length (distance from the underhead surface of the bolt to the first engaged thread) being independent with no contribution. +/-30% is pretty excessive, so on more clamp load sensitive joints, we implement a torque+angle, non torque to yield (TTY). In these joints, about 1/3rd of the preload comes from the straight torque, with the resultant preload coming from the fixed displacement of the threads. This means that bolt friction only contributes to that 30% error to the first 1/3rd of preload. The difficult part of this though is that because it's a fixed displacement, the distance that displacement occurs over (the grip length) does matter. For the same angle of displacement, the shorter the grip length, the higher the preload in the bolt. This means that in this test, variation in the ram height, and moving from the thick block of aluminum to the thin block all affected the amount of stretch in the bolts when you used the torque+angle torque procedures called out by the manufacturers. If you need to control preload distribution tighter, that's where torque to yield (TTY) comes in. We can typically get to a +/-5% range with these fasteners, especially with yield sensing torque spindles. Again these torque+angle procedures are still sensitive to grip length, but because you're working in a different area of the stress/strain (or torque/angle) curve, they're a little less sensitive. Great work, and feel free to reach out with any bolt questions, especially as far as materials, coatings etc. go, and their effects on fastener absolute strength or fatigue strength... you've officially just scratched the surface!

I can't believe the amount of work that goes into this channel. Such a great service to us gear heads and tool fanatics!

Would love to see helicoil inserts tested! Use them all the time at work to fix stripped out threads in 6061-T6 aluminum in automation equipment and always wondered if they're equal, worse or better than the original threads. Great work as always!

I had a head gasket blow on an 1.6L ecotec and I was in a pinch so I went down to my local nut and bolt supply and bought 17 12.9 grade bolts and two nuts. Used the two nuts and the 17th bolt in a vice to "measure" how much torque it took to snap the bolt. I believe it was like 370 ft lb. Set the torque wrench to 300 and one by one removed the old bolts from the head and reinstalled the 12.9's at 300 ftlb. I don't care what anyone says. It worked, I went from being 120 PSI down in two of four of the cylinders to being 185 on all cylinders. The car hasn't seen a lot of miles since because catalytic converter stolen but suffice it to say hardware store can save your ass sometimes.

You missed the most important bolt... The 'sloppy mechanics' special. A stock head bolt that has been heat cycled and forged for 300k miles.

These "For Science" videos are fantastic

The ARP2000 bolts were suprizing. I've used them before being cheaper but not thought about using them on a really high powered job. Impressive

Factory head bolts get reused on a lot of budget builds. Would love to see the same test on a used OEM bolt.

Rivet nuts in varying sizes and materials would be interesting to see as well! As often as I use them to replace bolt and nut mounted equipment on bucket trucks, I have to say, they seem to hold up better when confronted by repeated operator errors 😂

Use a block that overhangs the hydraulic ram and set the indicator up on the underside of it. It will last much longer that way and still measure the bolt stretch.

It's wild that this video pops up in my feed this morning, as I just received a set of head studs for my engine build and was doing lots of research into ARP2000, L19, and aged 625

It looks like all the dial indicators were harmed in the making of this video. Thanks again for tickling the nerd bone

i am glad i brought ARP head stud kit for my turbo subaru !

I worked at a construction company and they changed the nut and bolt supplier. I was using 1/4 -20 bolts and I snapped 3 out of 12 off, and I was just snugging them up. They held the cutting wheel on a asphalt cutting that would be mounted on the front backhoe bucket. I said something to the other mechanics and they hadn't had any issues yet. I drilled out the brokens and the boss went to replace them. He thought I was over tightening them. Well he snapped 2 of them off and only had one hand on the ratchet and was just over what we considered snug. They were marked grade 8 however they were not even close to the older bolts that we found in the back of the bin. All in all it was good that it was cought before they started being used to bolt on fifth wheels on the trucks or for suspension work. Someone got to go through all of the NC and NF stuff and pick out all the new style nuts and bolts. I'm not sure how things ended up after they confronted the place about it.

To save the dial-indicator you could rotate it 180c, and measure how much it's moving upwards. And ofc something which sticks out on the "cylinder head" to measure against. Then upon breaking, it would hopefully jump upwards away from the dial-indicator.

I think that this is a great advertisement for the $60 Chinesium PQY Racing Studs, especially targeted at those guys that attempt to re-use their OEM Head Bolts. Obviously not a replacement or even competitor for anything ARP, but priced and strength proven to be better than OEM. Great Info.

I design and test head bolts like this for all of the major OEs. Uniformity of clamp load is by far the most important factor when attempting to seal a head gasket surface like this. Max clamp load sound sexy but that's not what generates long term reliable performance. TTY is your friend.

You should 3D print ( or soft aluminium) a small flat bracket for the indicators, with a break away notch. You can use a screw in the rod with a 4-48 screw, and offset the indicator out of the "kill zone"

As a racing engine builder, the decision you talked about in the beginning of the video is a daily thing for me. I appreciate the work yall put into your videos!

This video was right up my alley. I used to have all this in a class at school years ago, some mechanics also were explaining this to me, bo now seeing this video all became crystal clear. Next video I will watch is yours about bolt grades.

Your channel is pure gold! This was the most fascinating one yet. Nice to see where my money went when I used ARP on my last engine build. I'm super impressed!

Thanks for making a video I suggested! I appreciate all your hard work!

Xotics are being used now in some LB7 Duramax racing applications, but many are still unsure about them. I would love to see them go head to head....pun intended

Really enjoy this. Something new, educational, and putting brands to their claims. 👍👍

To save yourself on dial indicators, make a simple little one-to-one ratio pivot with a light spring pulling down on one side, put the sprung end on the top of the cylinder head, and then put the tip of the dial indicator on the other end so that the dial indicator is always reading down and then when there is failure the dial indicator will not receive an impact. And since the pivot is one to one it will still give you an accurate reading.

We had a customer use generic aftermarket studs in a mustang 5.0 coyote. We had it on the engine stand and literally shot a stud past my head 30 minutes after it was torqued down. It went up to the second level and through the back of a cabinet. We found it in the cabinet. Scary as hell. I can see easily when you calculate the estimated 100mph or faster flying passed your head.

You could do an extractor episode with all those broken bolts ya have now also.

Very informative!!! Great test!! That answers alot of questions for us car guys/engine abusers who wonder if saving a couple bucks at build time is really worth it in the long run!! Keep the content coming! GREAT JOB!!!!

Some starving child in africa could have eaten that dial indicator!!!11!!!!!!1!!!!

Really fantastic tests guys. Loved this. Yes please on thread inserts.

What's most impressive to me is the fact that the cheapo amazon ones are actually pretty competent for someone going for ultra low budget upgrades. The only unknown would be the consistency of manufacturing.

Great idea for a video!! You guys deserve WAYYYYY more subs than you have currently!! Thanks for all the info you've given us

This is the answers to the questions I never had but should of asked, thank you sir for this awesome video

I've done bolt tensile/stretch failure studies utilizing a jig and an instrumented press, the sound from even the small ones would make everyone in the area jump, wish I could have watched you guys running this in person

Here's a good test for you, the LS crank bolt is debated as to whether it needs to be replaced after being used once, the manual shows it's a tty bolt but many people reuse it, would be really cool if you tested the stretch the stock bolt makes after being installed at the manuals torque specs 👍 great video

Very good and educational video all the tests that I try to measure in my head now tested with accuracy. Appreciate your work and I’m very grateful for it.

Brilliant, absolutely superb! This is such an important issue especially when assembling critical components, engine parts, or essential support fasteners. Thank you for this excellent presentation, on behalf of most apprentice and professional engineers, Ciao, L

Would love to see this retested with bolts heated to simulate operating temperature of engine

You guys are just crushing it with the great content, never stop.

That was amazing, thank you!! And I'll just add the anecdotal information that I have the Cina grade Gen4 studs in a couple of my LSes and they're working great. Torqued with exact ARP instructions, making sure to have the bottom side of the washer and adjacent head surface very clean.

Great work gents, I have some input about the dial indicators, if you would have a washer larger then the slug of cast iron or like you ran the test on the shorter bolts, you could have run the indicator upside down and compressed it and read the measurements on the way out and not ruined all those dial indicators! Bolts really are for accountants and studs are for engineers...

Can you do a test where you torque the bolts to spec and then wait 24 hours and torque again to see if they move further (like they relaxed and loosened)? I saw a video one time where a guy would consistently get ~1/8th turn next day.

Dang TTC! Just when I think this channel is running out of material you guys hit a home run! I'm really into it. I'm definitely with the above comments about time-sert, I'd like to see how those perform. Great job as always and I'd like to see some more merch come out for your channel. The t-shirts are awesome ;) (hat's wound be awesome!)

For all but the most extreme Applications the Felpro seems like a very good bet as had lowest extension just prior to yield, the OEM bolt had nearly double the exentsion at the same tensile load, but would need to see at least a full set of each tested to see if there really is a consistent difference.

12:14 - Quick note. There is "detonation" and there is "pre-ignition" which are both distinct, different phenomenon in a gasoline internal combustion engine with distinct failure modes and solutions. But there is no "pre-detonation". Unless you were trying to cover both terms with one. Pre-ignition is when the air/fuel mixture is ignited BEFORE the spark plug fires, often due to a (sharp) hot-spot in the cylinder, or an over-all high temperature due to a dynamic compression ratio that's too high. It only takes one or a few of these events to completely destroy an engine, create holes in the block, etc. as all of the mixture is ignited at the wrong time, and the cylinder is still rising. The solution for this is to avoid sharp spots in the combustion chamber, use adequate octane fuel, and adequate temperature spark plugs (so the electrode doesn't become a source of pre-ignition). Detonation is when the air/fuel mixture has already been set alight by the spark plug and the flame front is propagating, increasing the dynamic compression on the unburned air/fuel mixture remaining in the combustion chamber. Eventually the remainder of the unburned fuel ignites all at once instead of in a controlled burn, spiking cylinder pressures and damaging (pitting) piston heads, cylinder walls, and poppet valves. An engine can survive many, many detonation (AKA knock) events compared to pre-ignition before any major damage is done to the engine and failure modes are much more gradual. This is because only a small amount of the mixture is ignited at the wrong time and the cylinder is almost always traveling back downward at this time. The solution for this is to ignite the mixture appropriately late in the cycle, use adequate octane fuel, avoid octane reducing PCV systems if possible, and be aware of static and dynamic cylinder pressures.

Thread inserts would be an interesting video. My dad would always use HeliCoils and I never thought they could hold up to a good tapped thread, but in a pinch they always seemed to work, after that I was wondering about the theoretical max load of rivnuts.

Best video I've ever seen on cyl. head hardware. Bravo, full marks!

Good video, thanks for doing it. You really helped me out about me selecting the bolts I'm going to use.

Very interesting. Just to let you know, I believe you made a small mistake in the strength calculations, that resulted in strength numbers a bit lower than they should be. The mistake is in calculating the tensile stress area of the bolt/stud. This should be done based on the average of the minor diameter and the pitch diameter. For an M11x1.5 that results in a tensile area of 72.3 mm^2 (0.112 in^2). That means the OEM 10.9 studs for example have a strength of 163 ksi rather than your figure of 145. Likewise, the ARP2000 is 226+ vs 201+, the L9 at 236+ vs 230+ and the PQY at 188 vs 167. Likewise for the rest. Not a big deal, but it puts the results more in line with the specifications.

Great info man. I coulda sent you 6 different styles of those honda studs.

Thanks for the video! I know you put a lot of effort into it. I have used all types of cylinder head bolts from ARP to knock off brands. I always wondered about the strength difference you guys helped answer that question. One note to others, it's very important on how you prepare your bolt. When adding lube, or Teflon sealer it can really change the pressure when torquing the bolt making it stretch beyond the desired limit. So, be sure to install your bolts as dry as possible and with clean threads. If you have to use Teflon sealer use it sparingly. Also ARP lube is the most consistent over regular oil, or other forms of grease. Thanks again!

I have arp2000 on mine, it's a 14 mil 12-point socket. I have 24 of them holding my head on and my turbos produce around 100 PSI at the manifold with wide open throttle

As a machinist this pains me to see indicators being launched into low orbit lmao, great video guys as always.

This must be the best "bolt" porn on the net! Seriously I have once again learned a lot more and think back of times we re done heads only to see them fail again. No proper engine tuner could look past this channel! Perhaps give them dials a good grave yard.

Why this channel doesn't have more member is way beyond me. Always good, scientifically accurate content. I'd take Torque Test Channel's opinion on a tool WAY before any review. Thank you for taking your time and money to answer questions a lot of us always wondered!

Absolutely great information. The methodology of your testing seems to be a very real analog for real-world use

My dad told me about an old racer's trick a while ago when we were building the engine for my truck and I would be curious if there is any merit to it. Basically you torque the head bolt down, then hit it with a hammer to "shock" it and take the twist out of it, then torque it again and you get more toque out of it.

I assume you may be a car guy haha, I would love to see this test in 1/2 inch to see how much advantage they actually offer over stock size

Omfg thank you I searched for a video like this a few months back and got mad no one had made a video yet but there’s been 100,000+ engines built with upgraded bolts and studs.

Torque to yield was to remove the compression under the cap to shaft region. A Cap screw is compressed to form the head. Therefore the grains are compressed too. Studs were produced to counter the compressing factor in cap screws. Long linear grains undisturbed are much stronger. Still the preferred method for ultimate available strength.

Thanks for a great video as always! It would be interesting to see a similar test with lug nuts. I think in some countries as well as the NHRA, the studs need one widths amount of length sticking out from the lug nut. Does that really make a difference? Do open or capped lugs hold better? Do steel wheels hang on better than aluminum wheels? Also, so lug nuts hold better than lug studs?

Be careful drawing conclusions from this testing. There are so many factors that go into the design of threaded connections. Thermal expansion, head material and thickness, head gasket material and thickness, block material, lubrication, anti-rotation features and more all effect the clamping load and the bolt stretch. You have shown that stronger bolts break at higher loads, this was already known. I would caution against saying that stronger bolts = less head lift, they are likely correlated but it is not always the case.

TIME-SERTS kick ass . Saved me during a rebuild. Didn’t discover I had stripped head bolt threads until I went to torque down the heads , very inconvenient. But they work people ! Worth the money

I think a similar test of connecting rod bolts would be interesting. There are lots of opinions out there about what are the best. My theory is the difference is not necessarily material, it is that some bolt manufacturers use alternate thread profiles, e.g. UNJ instead of UNF. Would be cool to see real data. It was interesting to see all failures occurred within the treads, just where they should!

I have no life

Glad to see always useful content here.👍

Another note worthy plus of studs over bolts is they put the tension on the nut instead of the threads in the block. Which in an aluminum block, the steel nut will handle much more than cast aluminum threads

very cool thanks ttc and yes thread inserts would be wicked cool

Rather than destroying indicators, do a hinge which will run the indicator in a negative Motion rather than pushing INTO the indicator.

Yes, thread inserts please! And also do them in aluminum heads. And also compare them to welding the hole closed in an aluminum head and re tapping

Love it that you are car people. We are a special kind of breed.

Use a large washer/ring and put it somewhere on the setup, then measure from under the washer with the dial indicator. When it breaks, all the flying parts go AWAY from your dial indicator...Basically you preload the indicator then unload it as the bolt stretches. You could also do a lever thingy, with a 1:1 ratio, and measure on the other side of the lever (one side touching the bolt, other side meant for the indicator). In this case you measure from above as you did in this video, but since you are not measuring the bolt but the other side of the lever, it again goes AWAY from the indicator. Hope this helps or comes in handy for future tests ;) Kind regards, M

Always informative AND entertaining!

would LOVE to see various TTY headbolts Nissan Juke, Volvo, Audi/Volkwagon, and others. Or even TTY bolts in general. Many are used in european car suspension

You did a great job with this. You may want to consider torquing to a given bolt stretch. Coatings, lubricants and variations in manufacture can have a significant effect on preload vs applied torque. Joint failure actually occurs once preload is exceeded at that point you basically have zero preload on the gasket. Normally these fasteners in this application would be fatigue tested with cyclic load applied to a preloaded Joint. Basically your higher strength bolts are installed at a higher preload to prevent Joint separation. Again good job it gets people thinking about what they are paying for.

It was my understanding that bolting down a cylinder head is analogous to using great big springs to hold the head to the block, and you want the bolts to stretch. Utilizing the yield point is a means of achieving more consistent clamping force, as you can turn the bolt an extra 1/8 turn and/or get significantly different torque readings and achieve a similar amount of clamping from one bolt to the other. The friction factor varies much too much at high clamping loads to use twisting torque as a means of measuring how much clamping force the bolt is exerting. However, the bolts can be manufactured consistently enough to where they all yield at very similar clamping loads. Anyone who has done enough head jobs can attest to how some bolts take massive amounts of force to achieve that final 1/4 turn while others achieve that 1/4 turn much easier. If you used a torque wrench to do this, just imagine how much clamping force variation you would have. But if you turn the fastener 1/4 turn, it is going to stretch the same and clamp the same.

Have to admit, didn't expect quite such results, well done and those dials may be at peace with their mission well done!

this was pretty awesome and honestly I use ARP bolts when building either stock or mild engines when I built my 12.5:1 compression Honda g23 I used arp studs and they were expensive and that was 5 years ago I can't imagine what they cost now but my 350 horsepower Ford 302 has ARP bolts and I've re-torqued them three times, three different sets of heads no problems whatsoever

I've not read 'all' the comments, so forgive me if it's a repeated suggestion, but you may be able to save a few pennies on indicators if you invert the indicator and indicate off of a tab that's affixed to the head of the fastener. Then when it lets go, it just takes off and the proboscis of the indicator just extends to its functional limit unharmed. How you affix the tab to the head of the screw is TBD . . . Quick epoxy, super glue, hot glue? I know to test oem button caps and dials we often "glue" tabs or shafts to them to get linear displacement numbers. Love the channel.

Never seen thread-lock on a head bolt. Great video thanks.

They're entirely correct. No dial INDICTORS were harmed. However, the dial INDICATORS are another story.

This is no doubt one of the best and most useful videos I’ve ever seen regarding hardware. Great job fellas

You can run a Honda for a long time on grade 8…. Also you take your stretched turbo head studs out and they work fine for ever on NA applications……

OK...if you don't want to kill as many indicators the next time, build a small hinged lever to indicate off of (essentially a see saw). Make the ratio of the sides 1:1 or some other factor if you like. But when the load side breaks free and up, it drives the opposite (indicated) side of the lever down and away from the piston on the dial. Speaking for a friend....

Time-serts, Keen-serts, Helicoils.... Spirals, thin-walls, thick-walls. I've used the thin-wall Time-serts with great success for repairs to engine block threads for brackets and the likes.

I love these kinds of scientific testing of products!

The dial indicators all getting broke is admirable but also extremely hilarious.lol great video

Love it! Pleasure as always !

As the gauges get hammered, I’m hearing the Hindenburg news guy saying… “oh the humanity of it all!?”

Oh that intro... thank you. I was expecting something along the lines of "the following is exceptionally dangerous, do not attempt".

Interesting on the slow motion how the indicator tip accelerates faster than the fastener pushing it up. As fun as it was to watch you murder a bunch of indicators, next time you might want to rig up a 1:1 "teeter totter" lever with one end on the fastener moving up and the indicator tip on the other end of the lever, moving down. This way when the fastener fails, the indicator tip is extending and the indicator is out of the killing zone. Interesting info and video, thanks.

This is the type of thing that you'd get the see once every ten years in a popular mechanics back in the day. . . But now, in today's internet world with youtube and individual creators, we (as a collective buying audience) can be SO MUCH more informed as per how all of the items on any individual market will fare given their respective use cases. Basically, today's world really makes it possible to be a FAR more informed buyer. Pretty neat. And kudos to you guys for the scientific approach to all of these things.... couldn't ask for better.

Informative as always 👍👍 Hell yeah I'd be interested in seeing the Thread Inserts on a up coming video!

So I *finally* understand torque to yield thanks to this video lol. Going to school for engineering and it's just math, nothing practical. Between this video and some calculus I now know how to properly size head bolts lol.

as you kept increasing the pressure. i found myself scooting back into my seat. Safety squints activated.

Would be interesting to see 625+ arp studs as well. In the crazy stuff we upgrade to custom 14mm arp studs. The bigger diameter gives more thread surface to allow more torque without pulling the threads out of the block.