Resizing Rods for ARP Rod Bolts (Cap Screws) - Do you need to resize?
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- Опубліковано 15 тра 2021
- We use our ARP Stretch Gauge to work out if we need to resize the conrods on our V6 if we use ARP Bolts. What's the answer? Watch and find out.
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![How To Use A Rod Bolt Stretch Gauge | Performance Engine Building [FREE LESSON]](/img/n.gif)
You should have measured the bore with the factory bolts and checked for ovality as well and then check again after fitting the new ARP bolts. This would have been a true test
Clearance to rod bearing normal bolts std size bearings torqued to normal bolt torque
Vertical. : .0018
45 deg : .0025
Sideways : .0035
With ARP Rod Bolts Torqued to ARP spec
Vertical. : .0024
45 deg. : .0029
Sideways: .0041
Crazy .. great work love the tech-talk when backyard building motors thank you for doing all the hard work and getting all the right equipment I'm sure that was not cheap!!
As much as I like taking the piss out of you Scotty you explain things thoroughly and clearly and you get 10 points for that mate cheers
Learning this when the Crustida motor was being built was an eye opening experience. It's amazing how much the metal on rod bolts can contort and stretch from torquing it down. 😮👍
@@piffiiiiiiit I would assume so since it had to be undone to then redo it around the crankshaft. 👍
@@piffiiiiiiit yes they do
Definitely answered my questions. I'm happy to send it
But you still did not check the roundness of the rod bore! You only took one measure, you take at least 2, 90 degrees from each other.
Also you did not check if the measurement you took changed between the ARP and the stock bolt, that I assume does not torque to 55. Its not about the bolt you use that can change roundness, its the clamping force it can apply.
When you checked the clearances some where tighter, why is that? Shoddy grind of the crank or rods out of round? It could be crappy bearings it has happened but I would bet its rods out of round.
The stock bolts are TTY so its hard to compare them
@@STREETMACHINETV Torque the ARPs to stock torque.
@@mawe42 You can't torque an ARP to yield and expect it be rational . Stock bolts don't specify a torque number either. Otherwise, yes, he compared and measured incorrectly.
The main thing I didn’t see was multiple measurements at different angles to determine the roundness of the rod end, that was the whole point of this test I thought
Thanks Scotty, I appreciate your sharing of knowledge,i have an L67,is it more feasible to LS swap with all the bits than rebuild L67? It'll be pretty much stock for cruising, ta mate love your stuff
What about vs standard rod bolts? Also checking for ovality, common to check in three positions around the rod end.
The standard bolts are torque to yeild so it makes it hard to compare. Most people were concerned about the extra clamping force of torquing the bolts to stretch. There should be no difference between stock bolts or arp if they're both torqued to 55ft-lbs
@@STREETMACHINETV you are quite a bit wrong sorry to say. the reason arp say to resize on the instructions is the ovality not the nominal clearance. The torque method produces about the same stretch as the stretch method which is entire the point to get the right stretch without measuring the stretch with a special tool. The rod was honed round with factory cap screw with a certain preload caused by the torque to yield fastener. If you induce higher preload whether through torque or stretch method this makes it slightly out of round. Sometimes this slight out of round matters but usually it doesn’t at this level. The point is it’s out of round and awareness needs to be there as with high performance stuff it can cause problems
Or just plain ol reusing torque to yield bolts like normal and happy times.
Very interesting and informative Scotty.love this channel.
I'm not sure if anyone else pointed it out, but by the time you'd torqued that bolt once, it already has stretched, so backing it off then retorquing to measure is not accurate. You need to measure them before torquing, then once torqued to be accurate. And the other tip is to get rid of the extension on the torque wrench, that will cause a very minor error in your torque settings (assuming your torque wrench is calibrated properly). and don't ever have a hand flat on, or cradling, the top part of a torque wrench, as this will also throw your wrench settings out the smallest margin.
And then there's the real world
Scotty, much respect, but as others have pointed out, without a baseline measurement using the stock rod bolts (and roundness measurements), you haven't actually proved anything. Even if the stock bolts use the same torque as the ARPs, they're not the same stiffness as the ARP bolts, so you can't jump to the conclusion that the rod measurements would be the same.
The factory bolts are torque to yield, so we could get some but they'd be single use. But after the after reading some of the comments I'm just over the subject completely
I was taught by Tony from Toca Performace. He told me to always resize rods when using ARP rod bolts. When I built my V6 Precise Engine Builders on the Gold Coast said the same thing. Just send it anyway as im sure you are over it by now. I hope it lives mate keep doing what you do Scotty.
@@seanphilip8225 Benny knows his stuff mate and the amount of quality engines that have came out of that place when He talks I listen... asked the very same question about the very same rods and Benny will tell you to re size which he has done for me it’s cheap insurance.. no reason not too
@@lshouse9821 I have been using precise for years when Will and Graham were running the show before Benny took over. Nothing bur quality work come out of that shop.
@@STREETMACHINETV Can't blame you for being over it. You've essentially shown your flock of keyboard-warriors one small "test". If you were checking all the aspects of "resizing" and "roundness" (etc), you would have a much longer clip that would lose a lot of your viewers. Rock and a hard place...
And yet I saw another video on the same subject and the rods did have to be resized. On that video they checked the "roundness" by checking the diameter in several places, not just in line with the rod. It was quite a bit out of round. Could you have another go, just to be absolutely sure?
That was probably rod bolts and not cap screws
@@STREETMACHINETV tbh, I don't remember if it was bolts, or studs and nuts. Wasn't having a pop at you, btw. Keep up the good work, I do enjoy your videos.
What about the difference in the torque wrench’s
Could yours be off just a bit
When was then last time it was Calibrated
Super interesting.
So i want to know if 54ftlb is right for stretch because 55ftlb is a little to much or 54.5ftlb is correct for stretch . Can you test it ?
Great info, interesting stuff, I reckon that would have been spot on, without the lube on the thread, maybe that gave it it's slight extra reading on the torque, same as know grease, on wheel nuts when torqueing up.. really great info though..
Torque wise it makes sense that the setting the bolt stretch by torque results in over stretching the bolt. Under tight and they're insufficiently stretched to have maximum strength. Maximum tensile strength is reached beyond the elastic limit of the bolt which is why one time use bolts are a thing. Over stretched - so long as you haven't gone past yield point of the bolt - and it'll be a stronger joint and work.
In the absence of anything else you err on over tight not under tight. Counter intuitive to a lot of people but that's mostly cause people think over tight in the context of tightening fittings into say aluminium stuff where you strip off the threads from the walls before the bolt's reached maximum strength. In that case you're protecting the material you're screwing into and not going for maximum strength. When it comes to really tight things and where vibration would be an issue from being under-tight and you need all the strength you can muster from as small a fastener as you can get away with... then yep, over tight beats under tight.
Scotty mate use a engineer's scribing tool to mark the arp bolt head at what position they are at after you have toqued them down and how far you need to turn them back to get the stretch right on.:) Also maybe the same for the mains as well studs or nuts?
Hey Scotty love your shows can't wait to see the V6 Running keep up the good work mate.
the important thing to point out I suppose is to be sure you've stretched the rod bolts to spec otherwise you'll have the distortion?
I don't generally know diddly from squat, but I was taught to never "double click" when using a torque wrench. The race engineer who taught me always said "it's already torqued when it clicks, you're potentially over-tightening by clicking again." Everyone on YT does multiple clicks, and I can feel him ratting his wrench from beyond the grave when they do.
You're probably right, it's a habit I should get out of
@@STREETMACHINETV thats why there probably was that 0.5th too much stretch, also beebing torque wrench is more for "fine tuning", because you dont need to go so much over torque like with kliketiklik-wrench 🤔
Also the constant pull for torque reading, not a slow and not a fast yank.
Science with Scotty!!
Scotty the scientist !!!! Now just got taxi into the 10's !!! lol
Measuring bolt stretch is a far more accurate method of checking the clamping force. Just going by torque alone introduces variables - torque wrench calibration, operator on the torque wrench, bolt lube etc...Interesting to see how close the stretch is with the recommended torque however.
Scotty says “Lube”.....I could tell he had, “that’s what she said” on the tip of his tongue 👅 hahaha 🤣
He did seem to take a little too much plesure in saying lube, didn't he...
I've seen pictures on LS1Tech of an engine that was torn down after only a couple thousand miles after installing ARP rod bolts without re-sizing, every rod bearing had bad/abnormal wear, and would have likely failed before too much longer. Some people get lucky and they go a long time without re-sizing, but IMO, I'd rather spend the $80 to re-size my rods while I have the engine apart. It's not worth saving $80 to chance running a bunch or metal going through the engine and possibly ruining the crank, as well as having to spend the time to pull the engine back out.
Scotty that wasn't the real topic of discussion. The discussion was around whether the rods needed to be resized if you changed from standard cap head bolts to ARP bolts. Which of course the answer is no. All you did was test the difference in checking tightening methods. Which could easily be out by you double clicking with the torque wrench. You can add a little more tension to the rod bolt / nut tightening a second time by virtue of how those torque wrenches work, you should only ever click them once, slowly and evenly. If anything your demonstration illustrated that paying a whole lot of money to test stretch is a wank if you do it up with a good tension wrench in the first place.
Can't say I disagree with any of that, but yeah I'll get out of the habit of double clicking the torque wrench.
Yeah, not one to throw a spanner in the works and I’m not saying anyone or Scotty is wrong, but, When I was building engines I would measure the big ends straight up and down, across the bore and diagonally. I called it the pizza method because if you could imagine a pizza with its 8 slices, you would measure the bore on those cut lines like a pizza. This was to make sure you have a perfect circle under the correct torque applied. However all machining was done under the same torque conditions. Just saying, thats how I was taught.
Scotty good work! Just send it. At the end of the day, the shows not called Carnage for shits and giggles.😂😂
I wish you would have checked the roundness of the big end after using only the torque spec since most people go by that. Especially since you found the stretch was off when you torqued it. Interesting video though. Thanks.
Years ago had an ARP tech rep try and tell me to use 135ftlbs on the headstuds on a Rover/Buick V8. Yeah, that would work, and yes I did remind him it was an alloy block. Became very defensive he did.
RIP block
Some of the Toque numbers, they lose before it ever gets that tight.
@@wobblysauce They would reach zero, as the studs pulled out!
What a great video. I didn't realise I'd be so interested in half a thou so much. Put a stamp on it and send it!
Geez I'm early today!
Front row seat ))
Yes
Awesome video today guys thanks.👍
What about a 2002 5.3 LS engine for a LS swap?
Lucky for me that’s the same engine I’m working on
I’m just a nobody in regards to all of this but once a stretch bolt has been torqued up doesn’t that render that bolt useless, never to be used again?
I’m only asking cause I’m sure there has only been 1 set of bolts & they’ve been done quite a few times....
ARP bolts can be reused several times
That is the theory, but loads of people reuse them also and you have failures in both camps if something else is wrong with the engine.
More of a what you feel comfortable with.
I may have missed it but did you check multiple angles with the dial bore gauge to determine out of round? If you only check one point it could be oval and you would have no reference to be able to tell.
Good point but that is a whole different test though. The original discussion was around some people saying that changing the stock cap head bolts to ARP bolt would mean the rods would need to be resized, which is absolute garbage because the new bolts just screw in, the distortion comes from bending the actual rod while aggressively pound the old bolts out with a hammer / press and fitting new ones. 10 lbft either side of manufactures specs is not going to distort a rod out of shape because you are pulling the two clamping faces together. What Scotty should test while the rods are out, is for out of round in several spots like you say.
He also took torque away so they are really not torqued to 55 ft lbs. I seen other test done and they do need resizing
We're happy to send it too...... lol
Probably that difference in stretch vs. your torque is result that you have uncalibrated torquewrench. With just calibrated wrench the stretch could be correct 7thousands.
Should do the ford style pressed rod bolt for comparison
Pretty interesting, nice one Scotty.
Great stuff buddy keep up the good work
Regards from Bill
Your t-shirt is not as concerned with pesky tolerances! I see what you did there! 🤣#carnage+
hang on..
'that's what she said'
Well there ya go eh? Nice result.
Be interesting to check the figures against a stock Rod bolt to illustrate why ARP is better, I mean we know ARP is better but to show how MUCH better.
Coz Leg out of bed kinda ruins a blokes day.
Nice haircut too
ARP uses higher strength bolts which take more force to stretch. That causes more clamp force on the connecting rods. Stock bolts will fail in high performance engines or high RPM. They are already stretchy out and have less clamping force to keep engines together
Wow
SEND IT YA DAAWWWWWWG!
Great to see you at it again this week bro. Just stated watching the original stuff you started with, do you ever sit back and reflect on them days too where you are now? For say the blue bird?
What about main studs ?
Different situation, generally you would get an align hone, but it depends. I've put together a few engines without honing and they've been fine but in a fresh build I'd probably do it.
Tighten them to the torque spec rather than loosen them to spec
Does it matter?
Great stuff checking this Scotty. Fact of life is that you'll still get the odd naysayer no matter what method you go with
It does matter about resize if the rods to put them back to perfection in roundness for a reliable long lasting engine that will be serviced correctly and driven correctly you may get 250,000klms out of it without a problem but when you build an engine that’s going to put out more than double the factory output and more it pays to tear the bloody thing down every 20 or so passes to check the bearings and internals or if street driven at least every 10000klms to see if all is wearing as it’s supposed to be so it does and doesn’t matter
I like ur shows but what u should of done was use the standard bolts torqued to holden specs then changed over to the ARP bolts torqued to holden spec then to ARP's recommended torque specs. That is the only way u could tell if it distorts the rod.
The holden bolts are single use, torque to yeild so we'd have to buy some
@@STREETMACHINETV aw damn. Maybe just torque the ARP bolts to holdens specifications then to full stretch and see if there is any distortion? I know youse aren't building the engine to last but it would be good to see if it does distort due to extra clamping force.
The amount of engines I've sent like crappy 4g15's with L19 bolts cranked to the shit and the big ends were never the problem are vast haha if you're building it at home that's basically already enough to say you're sending it anyways so to everyone with an opinion on the interwebs, thanks but no thanks 🤙
IMO, this is inconclusive. You need to measure the brand new bolts then torque them. Then repeat with your used ones. You then need to do it with the stock ones to see if it does distort the bearings in anyway. Would also be good to confirm if the stock ones are TTY. Great info regardless and good to see people putting it out there.
LS engines have cracked big end parting lines so they lock back together better than a traditionally machined conrod so you can't resize them even if there wrong 😊
I hope in the 2 years that has past since this comment you have learned that it is wrong...
@@jcanfixall1585while he is wrong about not being able to resize them. He is correct that with the cracked capped design that they are stronger/have a less probability of needing to be resized with the use of arp rod bolts.
@@chrisfrizzell1050 hopefully you will learn too!!!
@@jcanfixall1585 hopefully you will. Do some research clown
You'll bend an L67 rod before you break a factory bolt. Seen engines all torn up and the big end still on the crank journal, bolts still in place. The rest of the rod smash to oblivion lol.
Good to finally see a video basically myth busting the debate, in this particular application.
Excellent work.
Myth wasn’t busted. Roundness wasn’t even checked.
Bit of Monday morning Scotty. I swear I saw Telfo at Highball on Sunday morning but couldn't work out if it was him
You guys must be some kind of voodoo snake charming fortune tellers or something..been pondering this very question for days =D
I remember the first supermang start up video, was so excited thinking the next week it was gonna go down the strip, the next video comes and it's just "we broke supermang"
Yep, shit happens
And why wouldn't a set of outside micrometers, or even a vernier caliper, measure the rod bolt stretch just as accurately as that $$ ARP gauge? Aslo, when was the last time that torque wrench was calibrated, if ever? Accuracy is only as good as the instrument used to measure it. No test for roundness before you swapped bolts gives a scewed conclusion.
HI SCOTTY
So its length no size that MATTERS LOL thx buddy
Just Send It, that’s what she said
I think it’s just to save their own ass incase something comes back on them so that’s why ARP just say to resize rods
The ocd machinists will be freaking out over 1 micron that makes no difference lol.
Im thinking you should have measured it before the 1st torq, then after, then use fresh bolts and do the stretch again. 🤷♂️
Why it returned to same length untorqued, it doesn't stay stretched
@@STREETMACHINETV you could have found out for sure.. im just thinking out aloud so to speak, not hanging shit scotty. Another q could be do they stretch more the second torque.
Now I’m wondering if Scotty’s torque wrench is inaccurate by 0.5 - 1 ft-lb.
Yeah i stretch mine :)
With all the keyboard claims that they're out of round still I'm happy to sit back & see how quickly this engine runs the bearings.
Going by all of the "experts" this engine should be dead very quickly.
Only one way to stop this argument would be to involve a big engine building shop that people "might" respect.
Otherwise keep up the awesome content team. Ps I have no opinion on this as I'm no engine builder.
This test is so incomplete in various ways ..
If it measures ok, no.
Lube and Moist are the 2 greatest words in the English dictionary .
Don’t forget flange. Another beauty.
Fresh Carnage on a Monday - what a neat surprise 👌
But not so many “that’s what she said “ jokes 👎😂
Chinese measuring tools 😂
Uncle Rodney has extended his family to stretching point she said
Your test is flawed, you didn’t measure for ovality
Rods screws caps lube are you guys doing car videos or exploring pawn Avenues your titles and the things you just say can really be misinterpreted by a blind mind hahaha not saying you are a bunch of wankers but lol
Scott, according to the majority of the keyboard warriors, you didn't measure the angle of the dangle, dry or lubed ;) Worse than getting kitty litter in your Vaseline...