Articles, Blog

H Beam VS I Beam | How To Select A Connecting Rod [TECH TALK]

September 11, 2019

– When it comes to selecting a connecting
rod for your next build, one of the hot topics out there that’s
always been controversial is whether an H bean or an I beam design is
superior. Admittedly we’ve actually spent a lot
of effort trying to get to the bottom of this too and there’s just so many
conflicting stories, that we decided to get right to the heart of the topic and
we’re here with Richard from CP Carrillo. Carrillo are well known for producing some
of the industry’s best conrods, and we’re here to find out what the
exact answer to that question is. So Richard let’s get to the bottom
of it. H beam or I beam, is one superior or
does it just not matter? – It doesn’t really matter anymore,
you can design either to be as equally strong for the application you’re
designing it for. It all has to do with the cross sections
and how you design the connecting rod. – So it’s really about the material in
the rod and where abouts that material is located in the beam that makes
the rod strong or weak? – Correct, that is correct. – OK so one of the common myths that
I hear about this, or let’s assume that it’s a myth now that we’re talking about
these, is that when your’e designing an H beam rod, due to the layout of
the material, it by design must be heavier than an I beam conrod,
is there any truth in that? – That’s not always the case, you can
design the H beam rod to be just as light as an I beam rod, it’s how you
design it. – Now the other common myth that
we hear in the industry is that between the two designs, if we have to pick a
winner, and while admittedly a lot of the information suggests that the two
rods are very close anyway, that it comes down to the H beam rod
is a little bit stronger for engines that are producing high cylinder pressure
versus the I beam rod is potentially a little bit superior for very high RPM
engines where the rod weight is more critical. Again, is there any truth in those two
topics? – There’s benefits to both but you really
can design either one for either application if you design it correctly. – Alright so in Carrillo’s career or history
so far, you’ve really embraced the H beam rod, I think that’s probably what Carrillo
are best known for. But more recently we have seen you
bring out designs that are I beam design. So can you tell us why you’ve moved
into the I beam design as well? – We did some I beam stuff originally
for lower horsepower applications and then recently we started doing some
near net forged I beam rods for a little more power that, just less cost doing that
way when you’re doing near net. Other than that that’s really the only
reason. – Just for those that aren’t aware,
that near net that you’re talking about, can you explain that in a little bit more
detail, what’s that actually mean? – That means we actually forged the rod
very close to the final products. We do machine about 90% of it and
we leave the pocket of the eye section left as forged. – So that just reduces your machining time,
your machining costs and hence the cost of the finished rod? – That’s correct. Our bullet line which is our budget
line of rods that we do. – Now you’ve also got another rod that
you showed me off camera earlier which is kind of a combination of the
best of both worlds I guess. You’ve got an H beam design but you’ve
also taken some I beam design aspects into that as well, can you tell us why
you’ve done that and where the advantages are? – We did that, it’s an H beam with some
pockets underneath the pin and above the bearing and that helps disperse the
loads from the 6 o’clock and the 12 o’clock positions around the parts so that it’s not
getting the hot spots that you’re normally seeing. – So more consistent bearing wear over
time? – Yes correct. – Alright so now that we’ve dealt with the
H beam I beam and really what it sounds to me like is a lot of it out there in the
greater industry is really just marketing ploy as much as anything. But I also wanna talk about another
really hot topic which is how someone would select a rod for their particular
application. And I know that a lot of the rods that
Carrillo are now producing have a horsepower rating on them but when
it comes to selecting a rod it’s really not the horsepower that’s so critical so can
you talk to us about what you really need to know? – Inertia load and compressive loads are
important and that can be calculated using the bore stroke, RPM, piston
assembly weight and then combining that with the connecting rod length
and weight, we can determine if a rod is gonna be suitable for a given
application. That’s also the same information you
use for designing a connecting rod. We do use the horsepower number
but that’s to determine how much cylinder pressure there is. – So really what you’re more interested
in from a compressive aspect is the cylinder pressure. Now of course the cylinder pressure
is linked to the horsepower but it’s not a direct correlation there. So am I right in saying basically you’re
giving a horsepower number because it’s something that’s really simple for
people out on the street when they’re selecting parts to decide hey
look 800 horsepower, I know I’m gonna be under that, so I’m gonna be safe? – Yeah that’s correct. – But if someone was on the other hand,
designing something that’s outside of your realm of your off the shelf rods,
so let’s just say for example someone was building a Mitsubishi 4G63 and
they wanted to make let’s say 1600 horsepower and rev it to 11000 RPM,
probably beyond what your shelf stocked part will do, so are they best
to come to you and give you the design of their engine so you can
actually make something suited? – Yeah that’s exactly right,
that’s the best way for us to design something that will live in what you’re
trying to do. – Now we’ve talked about the compressive
loading and that obviously comes down to the horsepower but the other side
of the conrod strength which is really important is the tensile forces in the
rod, particularly at high RPM, this becomes a problem. So can you tell us how that affects
the design elements of the rod and what’s critical to holding that rod
together at high RPM? – At high RPM you have to select the
correct bolt so it can handle the inertia loads that are seen. Along with that is the design of the
rod as well to maximise the inertia load capabilities of the rod itself. But if you don’t have the right bolt,
it’s gonna fail under higher RPM conditions. – Look it’s been great to get some actual
insight into the design of a rod. Richard, appreciate you giving us that
feedback. If people wanna find out more about
Carrillo or maybe have Carrillo design a rod for their application, how are they
best to reach out? – You can go to our website at or call us at 9495679000. – OK great thanks a lot Richard. – You’re welcome. – If you liked that video,
make sure you give it a thumbs up and if you’re not already a subscriber,
make sure you’re subscribed. We release a new video every week. And if you like free stuff,
we’ve got a great deal for you. Click the link in the description to claim
your free spot to our next live lesson.


  • Reply goldenvtr March 22, 2019 at 8:47 pm

    this guy didn't interview or represent carillo well, good job andré keeping the conversation going

  • Reply BoostHit March 22, 2019 at 8:51 pm

    "that's correct"😂

  • Reply BaSeL March 22, 2019 at 8:55 pm

    ANDRE interviewing himself

  • Reply MafiaboysWorld March 22, 2019 at 9:27 pm

    Carrillo are so good that they can have the worst representative available talking to Andre and still sell their entire stock.

  • Reply High Performance Academy March 22, 2019 at 9:44 pm

    Not everyone is very relaxed in front of the HPA camera but Richard gives some solid information particularly towards the end and we always appreciate the time people take out for us at busy events like PRI =)
    If you want to stand out in the crowd at the next event you go to, grab your own HPA t-shirt here: – Taz.

  • Reply Blue fire S1KRR March 22, 2019 at 10:09 pm

    Was Andre interviewing the janitor? I love the closed answers to open ended questions.

  • Reply Global Garage March 22, 2019 at 10:38 pm

    He answered the same for every question….”we can design for that” This guy didn’t represent the brand well at all. Sacked.

  • Reply thhonyy tone March 22, 2019 at 10:44 pm

    i remember the day i mounted the carillo's connecting rods on my car….it's such a piece of the art…like a moment when you touch something very special for your engine and not the crapy diesel you are working on all the week.

  • Reply FamilyMan Racing March 22, 2019 at 10:49 pm

    3 mins in so far, and all of it wasted. Unique experience on this channel.

  • Reply Hammerhaus Kennel March 22, 2019 at 11:09 pm

    Great content as usual, thanks!!

  • Reply TyreMulisha March 23, 2019 at 12:24 am

    Love the no bullshit , straight questions, great vid 🍻👍

  • Reply Kristian Keppel March 23, 2019 at 12:30 am

    Pulling a tooth is easier than getting info out of this guy.

  • Reply Robbin Milatz March 23, 2019 at 1:10 am

    This guy is asking the right questions with even better posture.

  • Reply kayzrx8 March 23, 2019 at 2:49 am

    Same answer for every question 😂

  • Reply cncaliguy09 March 23, 2019 at 3:10 am

    Dry and too the point interview. Love that force half smile.

  • Reply Dean Crawford March 23, 2019 at 5:06 am

    Good grief , this guy isn't forthcoming on information . He didn't even mention anything about the forging process and metallurgy , how they test the rods in cycles vs time vs load pressure etc ……..🤔

  • Reply Dane Prostamo-Brown March 23, 2019 at 7:51 am

    What a flog

  • Reply Dave A March 23, 2019 at 7:51 am

    the rep should be a politician… didn't really give any answers… still dont know whether a i beam or h beam is better… saying that it depends on the design, doent help.. big can of worms, but was hoping he would of gone into more details when you asked him about the 4g… eg. a h beam of a i beam because….

  • Reply Craig Tripney March 23, 2019 at 8:10 am

    Some useful info but this guy is like getting blood out of a stone ……….

  • Reply Matt Bradley March 23, 2019 at 8:44 am

    It bizarre how i'm literally on the cusp of buying some 156mm Carillo H beam rods for my 4g63, 2.2L destroker build and you release this video. Love HPA. Andre's the man.

  • Reply Alyn Penners March 23, 2019 at 12:56 pm

    How about cross beam rods?

  • Reply YZFoFittie March 23, 2019 at 8:00 pm

    Ahhhhhh, gotta love good engineers, they never have any people skills… lol

  • Reply shonuffgl53 March 24, 2019 at 12:33 am

    Saw you walking around TX2K man and interviewing Titan Motorsports wanted to say what's up and thanks for the great content you put out but didn't want to ruin the interview. Keep the content coming. As an engineer, I love it!

  • Reply Petr Blazek March 24, 2019 at 1:05 am

    My tuner from Poland told me Manley on 4G63 the H rods do brake, the I rod is stronger. Ad he tunes rally cars. Tuned my evo9 on H rods. Not what I wanted to hear from my tuner, lol.

  • Reply Doug Caine March 24, 2019 at 3:41 am

    torque is essentially proportional to cylinder pressure not hp…

  • Reply mr323i March 24, 2019 at 4:40 am

    Most can't afford aftermarket conrods because some stock rods can handle well over the stock limits. Most stock rod can handle about 400 to 500 depending on the engine

  • Reply Litch March 24, 2019 at 6:23 am

    So this is the bloke they sent to showcase CP products… Something tells me he got the shorts straw and would rather be somewhere else.

  • Reply lockjawjak March 24, 2019 at 6:19 pm

    I started pissing myself laughing at around 2 minutes, this guy is so dry fuck me hahah. Stout work by Andre as usual

  • Reply Kyle March 25, 2019 at 1:40 am

    a lot of non-answers

  • Reply MrSupermasi March 25, 2019 at 11:05 am

    cylinderpressure is linked to torque not directly horsepower…

  • Reply MasterRothman March 26, 2019 at 7:34 am

    It still leaves the audience with no clear answer on H-beam vs I-Beam. IE clearly rates the rods based on the HP and RPM. On this interview you can't get a clear picture on what rod to use.

  • Reply Warren Walker March 27, 2019 at 9:16 am

    Nice Docile reference there.

  • Reply 90s Hero March 28, 2019 at 2:08 pm

    Not so much on the tuning side of things, but I enjoy these info videos and have been watching for a while. Andre is a smart guy for sure

  • Reply Scott H March 29, 2019 at 8:56 pm

    Do have to use aluminum for hp over 3000 hp can a H Beam rod

  • Reply nickacelvn March 30, 2019 at 7:48 am

    I heard a tale once long long ago (actually i saw it in fst4s and rotaries) of a certain SR20 that was circuit dirt racing over here in godzone that kept bending carrillo rods and opted to use a nizmo rod instead (with 0 faliures) Do you remember the car? What was up with that then?

  • Reply Felix Gonzalez March 30, 2019 at 4:38 pm

    What about X-beam conrod :D?

  • Reply Kurt Betton April 2, 2019 at 1:43 am

    This guy's responses are drier than a cotton ball in the middle of a desert sandstorm.

  • Reply sajsed2 April 2, 2019 at 3:12 am

    Great video, Richard gave very bland and generic answers thanks for translating it for us regular folks. 👍🏿

  • Reply Bryce Corbin April 4, 2019 at 3:23 pm

    Given the dimensional constraints of your typical V8 crankcase, which sort of force connecting rod beams into the cross-sectional dimensions we are accustomed to, an H-beam is usually slightly superior. While an I-beam's strength around its primary axis (parallel to the crankshaft) is higher than an H-beam of comparable weight, the H-beam is more "square" in its strength; i.e. it's strength around its secondary axis (perpendicular to the crankshaft) is usually identical to its primary axis number. Given that connecting rods primarily fail due to buckling, and not stretching, they will fail in the direction of their lowest strength. The H-beam's weakest axis is stronger than the I-beam's weakest axis.

    Why did the automotive industry almost exclusively choose the I-beam then? Because it can be forged in a single stroke. The H-beam is more complicated to forge. Simple economics masquerading as superior design.

  • Reply Phone User April 4, 2019 at 4:01 pm

    Love this guys answers, short and accurate. This guy knows his shit.

  • Reply Snipeuout69 April 5, 2019 at 2:34 am

    Did the math .. Total words spoken
    Andre 85,347
    Richard 12

  • Reply John Saum April 5, 2019 at 3:17 am

    All i know is I've seen more broken i beam rods than h beams

  • Reply John Klem April 6, 2019 at 12:14 am

    So i "guess" H for boost, I for RPM.
    Depending on application of coarse, jeez guy, fucking spit it out.

  • Reply Nunya Business April 7, 2019 at 3:00 am

    Fuck me that was like pulling teeth!

  • Reply oldstyle analog April 7, 2019 at 11:50 am

    I got a mazda rotary.No rods needed.

  • Reply Mikael Gaiason April 11, 2019 at 3:56 am

    Are cracked rods still a thing?

  • Reply ISSA OOF April 12, 2019 at 8:19 am

    What’s best for an RB in high rpm and HP?

  • Reply themikeshow April 15, 2019 at 7:19 pm

    I will give Richard the benefit of the doubt and guess that it's camera shyness, since Carillo did choose him as their rep. Might be a great guy, just wasn't tested in front of a camera. Another possibility is that he is blazingly jealous of Andre's hair 🙂

  • Reply 7173mach1 April 17, 2019 at 4:45 am

    Andre you are the best interviewer in the business. I learn a so much from every vid. Thank you!

  • Reply Skippy April 20, 2019 at 2:03 pm

    Something I came across a while ago, closing piston to head clearance when you have a stronger conrod and/or a lighter piston. Any thoughts on that?

  • Reply Sho Yu Weeni April 20, 2019 at 4:49 pm

    Doesn't really matter since most of the force on a rod is tension due to deceleration in the stroke. Maybe under high boost applications H beam is stronger at a lighter weight, due to basic mechanics, supposing there's a torque on the rod during the compression stroke. Whether or not you need the extra strength under compression is a whole different question. I don't know at what cylinder pressure you're getting more force than deceleration. I guess it would depend on your target rpm as well.

  • Reply Phos9 May 7, 2019 at 5:09 am

    H beam focused rod manufacturer says H beam rods are just as good.

    Basically an infomercial, the I beam is a superior structure. Take cast rods for example, where the choice of structure causes a negligible difference in cost, have you ever seen a cast H beam?

    No, what’s actually happened is that metallurgy has reached a point where a forged H beam is lighter than a cast I beam for a given stiffness.

  • Reply 0jodele0 May 24, 2019 at 5:55 am

    He is a typical salesman…it's like asking a wolf to guard the chickens when asking him which is better, H-Beam or I-Beam. Carrillo were the first ones to sell the H-Beam design. And that is correct what he said, "for lower HP applications." If you use identical material for the same loads the I-Beam design will be lighter.

  • Reply griplimit May 26, 2019 at 12:21 am

    "What's better H or I beam rods?"
    "Doesny matter, it's all about design."
    "What style is your highest hp rods?"
    "H beam…"

  • Reply ISSA OOF June 25, 2019 at 8:57 am

    Which is best for an RB26? Or any stroker kits for the RB in general? RB28-RB30/3.2

  • Reply Sam taylor July 4, 2019 at 4:08 am

    Whats stronger in compression. a universal beam or a universal column?

  • Reply Joshua Szeto July 30, 2019 at 7:58 pm

    they should keep that guy at the factory and bring someone else to represent the company at these trade shows. so pointless

  • Reply gazon Charles August 2, 2019 at 11:31 pm

    This is crazy i am more confused than before sounds like a cross examination waiting to here him say i plead the fifth

  • Leave a Reply