What do Studs do to your line bore??

We investigate whether or not studs distort the main bores
powellmachineinc.com

[@terryenyart5838]

It's amazing how torquing a fastener changes the clearance & roundness & types of fasteners can vary the dimensions. It may even be different on different blocks, like a BBC, Pontiac etc. Great information!

[@Tekjive]

After seeing you recorrect a cam lobe by the .001” with that hammer gun I can now understand how anything can effect everything, crazy

[@powellmachineinc]

Absolutely

[@chrisskaling4887]

It is not just the size that can change. It depend on how stable the block is also. I have seen thin casting blocks that the studs pulled the caps out of alignment as well as causing the hole to go out of around by .0006

[@woods-garage]

Interesting test to capitalize on the situation that came up. This verifies that the clearance changes, which should be good enough evidence to say you must use the fasteners that will be run when line honing. I see that people keep trying to make more experiment work for you, “what if you do this and then do that?”. Easy to say from a keyboard. Maybe they’d offer to pay your shop rate to get the answers. Thanks for posting.

[@powellmachineinc]

Absolutely

[@Mike62501]

What I found out the Root cause was lack of clamp load applied to the gasket. Reason was ARP used Paint to protect their fasteners from rust. Problem is your dial or clicker torque wrench says it is at the correct torque but they are readings the high friction between threads from Paint. I hade people wire brush the threads and it eliminated the problems use ing motor oil as lube like the engine guy has done for years. That’s when we told everyone to use ARP Moly lube which reduces friction 15-20% (I don’t remember this morning) but that’s the fix just use ARP lube @ the lower total torque. Hope this helps! M

[@HeadFlowInc]

Some shops will install ARP main studs but recommend factory torque specs unless you line hone the mains for the added clamp force of the higher torque ARP uses. Try testing this method

[@powellmachineinc]

The factory specs would put the Arp at a even Higher clamping load

[@Rezcue337llc]

Look up elastic limit. Torque causes rotation and tension creates elongation. Bolts twist more than studs when tightening. Staying just under the elastic limit on bolts will maximize clamping force.

[@ronlambright6056]

Guess that's why my machinist asked what i was using before he did it. He wanted it there at the shop.

[@vinmandich7756]

That's like a buddy of mine who was a customer as well put arp main studs in a old 383 I built for him this was back in early 2000s I told him I never tested the idea he said what if I torque till they start to move and stop there I told him it's up to you it's the higher torque and metallurgical difference in material in said stud that causes it to be better it's your engine but I would say better to do it right but your there he slapped one cap in torqued it as I kept checking it as soon as it grew he recorded torque set wrench and went on with it car ran fine never once hurt a main and has fallowed that rule since then I even tried it on a sbf of.my own it still running and seeing 7300 rpm on tye regular it's also possible to make over 600hp and closer to 1000 hp wit a factory 302 ford block if you know what to do to them as well as keep the tune on point

[@scotthatch4548]

Since the standard bolt goes to 75% proof load and the stud fastener is better material you can slightly adjust the torque value to see if the cap will go back round ... This still keeps you in the proof range of the bolt that goes up to like just past 85% of yeld strength of the bolt ... But your test is why it's always good to make sure it's torqued the same way and to same number as the hone and why it's good to mark the block with what you did

[@galenbrown3312]

Thank you for the information you share in your videos.

[@powellmachineinc]

My pleasure!

[@Mike62501]

Problem I found years ago working at FEL-PRO Gaskets. It was the same problem with people calling me up and saying we are having head gaskets slightly leaking. I had them send the gaskets in and

[@thisisyourcaptainspeaking2259]

Very interesting, it's valuable to know this!

[@roughwater3454]

At the end of the day its better to know for sure. This is good stuff...

[@turdferguson4124]

Interesting. It makes me curious to know if you were to line bore a block and caps with studs installed, and then replaced the fasteners with bolts, would the main bores be distorted in that situation too? With a bolt, the portion under the head is in torsion and tension all the way down into the block and imparts those torsional residual stresses into the block threads. With a stud, the stud is only in tension, so it transfers only those tensile loads into the block threads. So you are loading the structure differently before you start your machine work.

[@powellmachineinc]

We shall find out.

[@iancoachwerksllc]

I just now read this message after basically typing a similiar message.

[@wisconsintractorpullingforum]

Great lil video! Thank you

[@philipmazzuca2269]

Run the bar back through it and watch the shadowing……….. that’s how I learned. Definitely distorts

[@puppygadget3189]

Interesting

[@StefanNistor-v5w]

The stud doesn’t stretch like designed fasteners, so it’s getting over torque and another thing thing it’s changing the load points on tread in a block (pull’s in different spot’s not like soft bolt equal load) and it’s definitely going to change after getting it to operating temperature and back. And ls block expends a lot it’s dose not have extra material that’s probably why it got that design of bolts. I think it’s needs to be tested with getting block to working temperature.

[@siliconvalleyengineer5875]

You could explain the benifits of installing main "studs" over using OEM bolts for a weekend pampered muscle car. Thank you sir.

[@powellmachineinc]

It's just more clamping load for higher hp stuff

[@wheelieking71]

Not nit-picking, definitely not insulting or stirring the pot. But: You only showed measuring one direction. And said it "added bearing clearance". In order for that vertical clearance to get loose, something had to get tight. No way the bores are still round. I think if you are gonna feed info like this to the masses, more info, better explanation is necessary. Obviously the "lesson" here is torque the caps for line boring with the fasteners that will be used during final assembly. Love the videos, great stuff!

[@baby-sharkgto4902]

I think he might have assumed everyone would have come to that obvious conclusion

[@miketaylor7487]

It would have been really easy to do a couple of extra measurements.

[@4speed3pedals]

I have something else for you to check. Honing plates for SBC use the same length bolts to fasten it to a block for boring. SBC heads use 2 different length bolts to clamp the head to the deck. I think you will find a similar situation with a honing plate. Thing is, I do not know of one that uses both longer and shorter bolts. I wonder if studs would also influence this vs bolts. Could a solid spacer be added to a honing plate that uses one height bolt and then hone round? Be an interesting test. Honing plates were originally steel and now aluminum has taken over for the most part. It would be interesting to see the results of different combinations to see which is actually the best for cylinder resizing. NASCAR probably has gone through all this with some of it's engine builders but who would you contact that would tell you?

[@powellmachineinc]

Bolt length isn't as much a issue as thread engagement

[@megasharkz1r]

You have to remember when the engine is at operating temperature or a bit hot all that will change, a little extra clearance can be a good thing.

[@bobwhite4344]

interesting test and results.

[@mikediamond1522]

What would you get by just backing the bolts up and pulling them back down? On torque, especially heads. Torque them to specs, then back each one off slightly to free up under head friction and pull back down. I guarantee they will move another flat (1/6 turn). Sometimes; a third pass is needed. Mike

[@Anthony-nw5zv]

Thanks for sharing .

[@powellmachineinc]

Thanks for watching!

[@hot355clubby]

Very interesting 👌🏻 but what did it do to the horizontal clearances?

[@powellmachineinc]

It pinched in about. 0005"

[@xxkingslayemxxgamer5553]

You would not think it would change it but I guess it did

[@powellmachineinc]

Definitely surprised me

[@MarkRopel]

That's good to know, thanks..

[@myfastcars]

I really enjoy your channel and on this same note, What does changing from GM LS engine Torque to Yield one time use bolts to ARP Head studs do to the cylinder bore? I have started using ARP Head studs vise the TTY OEM Bolts. What is your opinion? Does it effect any critical measurements?

[@powellmachineinc]

We have a video on that

[@marks2254]

Wow, that’s.001 all the way around or just in the direction shown in the video? Don’t you think it would return the zero if you went back to bolts?

[@BrokenPortriats]

Ok.... hard to argue with a Sunnen dial indicator. A whole .001" ? - but how? Studding added that much strength to the fasteners that it distorted the main caps? Or was it the block that moved? Or both? Would not believe it - but there it is.

[@earlbrown]

That's interesting. I've done that same test a few times over the years and there was no movement. Years ago, I swapped in some ARP studs on my Turbo Buick V6 engine. I hand lapped the caps to dead-nuts minimum clearance, and the studs didn't move the vertical clearance any. Last year I was finishing up a 351W and when I was going to final torque, one of my stock main bolts went limp and wouldn't reach final torque. Stuck in a set of ARP studs and, same thing, no movement. Then just for funs, I put a set of ARP WaveLoc bolt in my resized rods. No movement there either. I wonder if the 6 bolt main caps had anything to do with your movement? Or did you use a feeling gauge on the cap grinder when you surfaced the caps? On my examples, I had hand lapped the caps flat beforehand.

[@philipmazzuca2269]

Earl- not that I’ve done many……. But the two I have done caused distortion. 2 SBCs

[@earlbrown]

@@philipmazzuca2269 Curious. Where your caps ground or lapped flat before you swapped fasteners? Or did you just swap over without any kind of machining?

[@iancoachwerksllc]

Too me, the torque just applies in a different way than a bolt. When torquing a bolt, it has to pull against the threads down low, while friction is building while grabbing at the threads. On a stud, the threads are at the top and applying force in a different location, it is just pulling the stud while not turning the stud or creating the same friction. A bolt may almost have a wander to it depending on how tight the shoulder is against the rod cap hole. I am curious, how exactly straight is the at hole in relation to bearing cap surface. Could just be going at an angle a couple thou off.

[@powellmachineinc]

Yep, and what we see sometimes is expected and sometimes it's the opposite

[@kevin2960]

I have put studs in a few times and they still measure correct but you should align bore or hone. at least check them

[@xlr8r3VA]

Very interesting! It looks like you are checking a studded LS block which appears to be aluminum. Do you get the same results in a cast iron block?

[@davescheidt4533]

Did it go back to zero when the bolts were reinstalled? Just curious

[@richardwhitingjr5069]

You also never want to torque plate hone an engine after it's been final honed without a torque plate. You'll wind up with an out of round bore and have to rebore it to make it round again. And I'm not telling you what I've heard, I'm telling you what I've seen on my own motors.

[@BEANS-O-MATICtransmissions]

Worse than the added clearance is, the reduced clamping force on the OD of the bearing. IMO

[@danr7025]

While watching the video i noticed you were not holding the Sunnen at 90 degrees to the block. Will that add a thousandth too the measurement? No longer the shortest distance between two points?

[@powellmachineinc]

We rock it to find the smallest measurement which is the size

[@timmer2896]

So it added .001 voc , so did it pull in the cap at the parting line. ?

[@powellmachineinc]

Not really, about. 0002"

[@timmer2896]

@@powellmachineinc , I have never checked , but always wondered . I never get a warm fuzzy feeling using the factory squishy bolts , as customers don’t want to pay for studs and installation , now I can give them evidence , thanks .

[@michaelfarrell6448]

Did you remove and retourque a regular bolt and measure

[@davidsnyder2000]

Changing out the fasteners, if I’m understanding correctly, I would think it would alter the dimensions a tiny bit. Just because you’re using different hardware. Why I think that, I couldn’t tell you. I just think once you have everything bored with set hardware, don’t mess with changing anything 🤷 Seems risky. By the way, I hope the customer has to pay a little extra for changing things up after the job was already done 😐🤷 Causing everything to have to be reworked all over again…..

[@davidsnyder2000]

By the way I liked and subscribed 🙂👍 Super interesting fact learning this.

[@powellmachineinc]

@David Snyder yes definitely gonna have to pay for 2 line hone job's

[@shanerorko8076]

I would be charging the customer for the extra labour.

[@gtgarage]

Good demo, but you have 5 bearing caps so the issue has potential to actually 5 times worse. I have to laugh at these guys who disassemble their engines, order up some ARP hardware and just install it without the machine work. I'll call it 50/50 whether or not there's gonna be a problem, but over the space of 5 caps there's potential for size differences bigger or smaller AND having the alignment of the bore shift a bit. I've seen it, it makes for a damn tight crankshaft. Using ARP or similar hardware is a crap shoot without the proper machine work. The clamping forces for premium (ARP) head bolts/studs and bearing caps is quite a bit higher than stock = distortion.

[@powellmachineinc]

I believe all blocks should be line honed, but we have done several back to back tests on Ls blocks and it doesn't affect it.

[@powellmachineinc]

kzbin.info/www/bejne/q4HRe3aPfpZjprs

[@James-fs4rn]

👍 do the studs and the bolts have the same thread pitch?

[@bucksnortbumblefuk6872]

How about switching from a stock main bolt to a arp main bolt?

[@powellmachineinc]

I have never seen a aftermarket main bolt?

[@powellmachineinc]

​@Big Bore Racing yes, but not a LS

[@bucksnortbumblefuk6872]

@Powell Machine Inc forgive me, I was implying on a sbc.. lol. Nothing whatsoever to do with a LS. My bad. Long day....

[@powellmachineinc]

@@bucksnortbumblefuk6872 gotcha