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Dusty1
Samba Member
Joined: April 16, 2004
Posts: 2160
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 Posted: Thu Aug 07, 2025 9:53 am Post subject: CB H beam rod question |
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After a lifetime of 311Bs I threw down on a couple sets of CB H beam rods. A few questions: Do the CB rods have built- in offset like the 311Bs? How do I know my CB rods are correctly oriented?
Bonus question: I got a set of pistons that don't have the little arrows on the crowns for orientation. I can figure it out if they're offset. If they're not offset and I (mostly) observe a 5000rpm redline, I'm o.k., right?
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67rustavenger
Samba Member
Joined: February 24, 2015
Posts: 11225
Location: Oregon
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| Posted: Thu Aug 07, 2025 10:23 am Post subject: Re: CB H beam rod question |
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"H" beam rods are not orientation specific. When I install them, I usually set the rods with the rod cap and rod ID numbers pointing up. It's just the way I install um.
If the pistons don't have any wristpin off set they too can be installed in any orientation as you please.
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Brian_e 
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Joined: July 28, 2009
Posts: 4058
Location: Rapid City, South Dakota
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| Posted: Thu Aug 07, 2025 10:37 am Post subject: Re: CB H beam rod question |
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Tits up, tangs down on the rods.
If you don't have tits on your rods, then go off the bearing tangs.
Brian
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Narrowed beams, Drop adjustable spring plates, Bus disk brake and IRS kits.
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Glenn
Mr. 010
Joined: December 25, 2001
Posts: 79698
Location: Sneaking up behind you
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| Posted: Thu Aug 07, 2025 12:35 pm Post subject: Re: CB H beam rod question |
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| Brian_e wrote: |
| Tits up, tangs down on the rods. |
^^^^^
THIS
Much easier to just be consistent.
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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
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modok
Samba Member
Joined: October 30, 2009
Posts: 27707
Location: Colorado Springs
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| Posted: Thu Aug 07, 2025 10:50 pm Post subject: Re: CB H beam rod question |
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H beam rod have no offset
They can be installed either direction, it does not matter which way they go.
Pistons with centered pins can go either direction also.
Pistons with centered pins are common in racing, you get a quarter percent more hp at the expense of more piston slap.
Being able to be installed wither way also simplifies cutting valve reliefs., all pistons the same instead of needing lefts and rights. |
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Dusty1
Samba Member
Joined: April 16, 2004
Posts: 2160
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| Posted: Sat Aug 09, 2025 11:30 am Post subject: Re: CB H beam rod question |
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| modok wrote: |
H beam rod have no offset
They can be installed either direction, it does not matter which way they go.
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I gotta say after all these years I'm dismayed that H beams don't have the correct offset.
I guess I'll just have to settle for galled pin keeper grooves and / teflon buttons like the good old days.
...or I'll call Carrillo, the originator of H beam rods. Carrillo has never been cheap. Near as I can tell they've always been right.
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daveblank
Samba Member
Joined: November 07, 2024
Posts: 167
Location: Dallas, TX
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| Posted: Sat Aug 09, 2025 1:36 pm Post subject: Re: CB H beam rod question |
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| modok wrote: |
H beam rod have no offset
They can be installed either direction, it does not matter which way they go.
Pistons with centered pins can go either direction also.
Pistons with centered pins are common in racing, you get a quarter percent more hp at the expense of more piston slap.
Being able to be installed wither way also simplifies cutting valve reliefs., all pistons the same instead of needing lefts and rights. |
I'm curious. Why does CB say to mount them with the tangs facing down? Is it simply so they all face the same direction...uniformity? are they just quoting out of habit? I'm not doubting you, I'm trying to learn. |
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Glenn
Mr. 010
Joined: December 25, 2001
Posts: 79698
Location: Sneaking up behind you
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| Posted: Sat Aug 09, 2025 1:42 pm Post subject: Re: CB H beam rod question |
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| daveblank wrote: |
| modok wrote: |
H beam rod have no offset
They can be installed either direction, it does not matter which way they go.
Pistons with centered pins can go either direction also.
Pistons with centered pins are common in racing, you get a quarter percent more hp at the expense of more piston slap.
Being able to be installed wither way also simplifies cutting valve reliefs., all pistons the same instead of needing lefts and rights. |
I'm curious. Why does CB say to mount them with the tangs facing down? Is it simply so they all face the same direction...uniformity? are they just quoting out of habit? I'm not doubting you, I'm trying to learn. |
Out of habit.
| Brian_e wrote: |
Tits up, tangs down on the rods.
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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
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daveblank
Samba Member
Joined: November 07, 2024
Posts: 167
Location: Dallas, TX
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| Posted: Sat Aug 09, 2025 1:46 pm Post subject: Re: CB H beam rod question |
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| Glenn wrote: |
| daveblank wrote: |
| modok wrote: |
H beam rod have no offset
They can be installed either direction, it does not matter which way they go.
Pistons with centered pins can go either direction also.
Pistons with centered pins are common in racing, you get a quarter percent more hp at the expense of more piston slap.
Being able to be installed wither way also simplifies cutting valve reliefs., all pistons the same instead of needing lefts and rights. |
I'm curious. Why does CB say to mount them with the tangs facing down? Is it simply so they all face the same direction...uniformity? are they just quoting out of habit? I'm not doubting you, I'm trying to learn. |
Out of habit.
| Brian_e wrote: |
Tits up, tangs down on the rods.
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Cool |
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modok
Samba Member
Joined: October 30, 2009
Posts: 27707
Location: Colorado Springs
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| Posted: Sat Aug 09, 2025 1:57 pm Post subject: Re: CB H beam rod question |
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| daveblank wrote: |
| modok wrote: |
H beam rod have no offset
They can be installed either direction, it does not matter which way they go.
Pistons with centered pins can go either direction also.
Pistons with centered pins are common in racing, you get a quarter percent more hp at the expense of more piston slap.
Being able to be installed wither way also simplifies cutting valve reliefs., all pistons the same instead of needing lefts and rights. |
I'm curious. Why does CB say to mount them with the tangs facing down? Is it simply so they all face the same direction...uniformity? are they just quoting out of habit? I'm not doubting you, I'm trying to learn. |
it's an easy answer to install them the same way as OE
Rods and pistons usually need to be installed a specific direction.
Same with LS engines and late cummins 5.9. it doesen't actually matter, but it's still best to put them back together the same way the factory did, because otherwise people question it. That's proven! LOL
But if it didn't matter then why DID the factory put them a specific direction?
I'm sure it's just human nature.
and it's kinda convoluted really
I mean, it's well known wisdom that if you make a part that can be installed wrong, it will be installed wrong. So, always design it so it can't be installed wrong.
All the time we get around here.....oh, the deflector under the generator stand, or the carburetor venturis, or 44idf carb boosters put in wrong. those could have been prevented by deign tweaks.
But cylinders are round, pistons need to be light weight, rings...... there is no easy design tweak to prevent incorrect assembly of these parts, so you have to know which way they go and take care to put them right.
Except wouldn't the ultimate fix be......if both ways would work? yeah, but then people freak out when they encounter that and put them a specific way anyhow.
People get confused about it all the time and always will.
Last edited by modok on Sat Aug 09, 2025 2:23 pm; edited 1 time in total |
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daveblank
Samba Member
Joined: November 07, 2024
Posts: 167
Location: Dallas, TX
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| Posted: Sat Aug 09, 2025 2:16 pm Post subject: Re: CB H beam rod question |
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| modok wrote: |
| daveblank wrote: |
| modok wrote: |
H beam rod have no offset
They can be installed either direction, it does not matter which way they go.
Pistons with centered pins can go either direction also.
Pistons with centered pins are common in racing, you get a quarter percent more hp at the expense of more piston slap.
Being able to be installed wither way also simplifies cutting valve reliefs., all pistons the same instead of needing lefts and rights. |
I'm curious. Why does CB say to mount them with the tangs facing down? Is it simply so they all face the same direction...uniformity? are they just quoting out of habit? I'm not doubting you, I'm trying to learn. |
Makes sense
it's an easy answer to install them the same way as OE
Rods and pistons usually need to be installed a specific direction.
Same with LS engines and late cummins 5.9. it doesen't actually matter, but it's still best to put them back together the same way the factory did, because otherwise people question it. That's proven! LOL
But if it didn't matter then why DID the factory put them a specific direction?
I'm sure it's just human nature. |
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Dusty1
Samba Member
Joined: April 16, 2004
Posts: 2160
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| Posted: Sat Aug 09, 2025 3:05 pm Post subject: Re: CB H beam rod question |
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| modok wrote: |
...if it didn't matter then why DID the factory put them a specific direction?
I'm sure it's just human nature. |
I say,
"Never question Porsche."
Doctor Ferdinand Porsche that is. Had Dr. Porsche's marching orders been,
"Build me a sure thing Grand Prix winner!" we could have had a four valve per cylinder DOHC Volkswagen or Porsche (pick one) motor in 1939. The bastard back alley offspring of Porsche and Offenhauser, DOHC each side, four valves per cylinder.
On a different time line in a different universe Kdf Bugs could have been powered by one liter motors making their power at the 100hp/liter level.
If piston slap was my thing I'd drive a worn out Subaru. 
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Alstrup
Samba Member
Joined: July 12, 2007
Posts: 7864
Location: Videbaek Denmark
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| Posted: Sat Aug 09, 2025 3:34 pm Post subject: Re: CB H beam rod question |
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| modok wrote: |
| daveblank wrote: |
| modok wrote: |
H beam rod have no offset
They can be installed either direction, it does not matter which way they go.
Pistons with centered pins can go either direction also.
Pistons with centered pins are common in racing, you get a quarter percent more hp at the expense of more piston slap.
Being able to be installed wither way also simplifies cutting valve reliefs., all pistons the same instead of needing lefts and rights. |
I'm curious. Why does CB say to mount them with the tangs facing down? Is it simply so they all face the same direction...uniformity? are they just quoting out of habit? I'm not doubting you, I'm trying to learn. |
it's an easy answer to install them the same way as OE
Rods and pistons usually need to be installed a specific direction.
Same with LS engines and late cummins 5.9. it doesen't actually matter, but it's still best to put them back together the same way the factory did, because otherwise people question it. That's proven! LOL
But if it didn't matter then why DID the factory put them a specific direction?
I'm sure it's just human nature.
and it's kinda convoluted really
I mean, it's well known wisdom that if you make a part that can be installed wrong, it will be installed wrong. So, always design it so it can't be installed wrong.
All the time we get around here.....oh, the deflector under the generator stand, or the carburetor venturis, or 44idf carb boosters put in wrong. those could have been prevented by deign tweaks.
But cylinders are round, pistons need to be light weight, rings...... there is no easy design tweak to prevent incorrect assembly of these parts, so you have to know which way they go and take care to put them right.
Except wouldn't the ultimate fix be......if both ways would work? yeah, but then people freak out when they encounter that and put them a specific way anyhow.
People get confused about it all the time and always will. |
Tang orientation matters. Just look at the newer BMW B series engines as well as the M57´s (?) My BMW knowledge is limited. The younger generation of engineers thought it didnt matter... Hmm. Why do we see so many rod & bearing faliures on these engines then????
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993 |
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modok
Samba Member
Joined: October 30, 2009
Posts: 27707
Location: Colorado Springs
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| Posted: Sat Aug 09, 2025 3:47 pm Post subject: Re: CB H beam rod question |
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This is not a vw specific problem
it's way bigger than that
Tho far as the VW specific part, we don't know who offset the rod journals when designing the 1300/1600 engine
I doubt it was porsche, and I doubt it was karl rabe
but whoever it was, thank goodness they did
IMO the biological love of symmetry is a hindrance to mechanical design, because there is really no proof in symmetry is desirable in machine design whatsoever.
So get over it.
The pin bushing does not need to be perfectly centered in the cylinder.
Harmonics destroy crankshafts and what tends to resonate with maximally strong strong harmonic peaks....well, something that is perfectly symmetrical.
Symmetry is desirable for biological organisms because it is a sign our genes are working right. Engines don't have genes.
You gotta get past it, in fact REAL beauty is just slightly asymmetrical.
If you had a car where one headlight was bigger than the other, people wouldn't like that instinctively.
They both used the same bulb in the old days, that's a good reason, but not anymore. You can't take the left headlight housing out of a subaru and put it on the right. And if you get a right hand drive subaru and drive it here then the headlights are backwards, blinding everybody on the other side of the road. So now a subaru has four specific headlights, not one. Oh well. And if you have pistons with an offset pin AND specific valve reliefs, then you end up with two or four different pistons. |
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Glenn
Mr. 010
Joined: December 25, 2001
Posts: 79698
Location: Sneaking up behind you
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| Posted: Sat Aug 09, 2025 8:18 pm Post subject: Re: CB H beam rod question |
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| modok wrote: |
| If you had a car where one headlight was bigger than the other, people wouldn't like that instinctively. |
Yes, it sux when the left side of a person's body is smaller than the right.
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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
Member #1009
#BlueSquare
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Dusty1
Samba Member
Joined: April 16, 2004
Posts: 2160
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| Posted: Sun Aug 10, 2025 6:50 am Post subject: Re: CB H beam rod question |
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| modok wrote: |
| IMO the biological love of symmetry is a hindrance to mechanical design, because there is really no proof in symmetry is desirable in machine design whatsoever. |
Ah- HA! I knew you're a groovy and cool metaphysical kinda guy. 
Both my parents were artists. I was totally hung up on symmetry as a youngster. Hung up on a lotta things.
On the metaphysical end of things, the Birkenstock crowd can groove on the "vibes". Engine builders actually know and understand the "vibes", the way parts react and inter- act in actual reality. Thus, "tuning" an engine. It's not that different from tuning a guitar or a piano or a xylophone for that matter. Guitar not tuned = sounds like shit. Motor not tuned = runs like shit.
Like a guitarist tweaking their tuning in the middle of a song, an engine builder lnows when something isn't quite right.
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BFB
Samba Member
Joined: November 03, 2014
Posts: 2752
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| Posted: Sun Aug 10, 2025 9:08 am Post subject: Re: CB H beam rod question |
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| modok wrote: |
| daveblank wrote: |
| modok wrote: |
H beam rod have no offset
They can be installed either direction, it does not matter which way they go.
Pistons with centered pins can go either direction also.
Pistons with centered pins are common in racing, you get a quarter percent more hp at the expense of more piston slap.
Being able to be installed wither way also simplifies cutting valve reliefs., all pistons the same instead of needing lefts and rights. |
I'm curious. Why does CB say to mount them with the tangs facing down? Is it simply so they all face the same direction...uniformity? are they just quoting out of habit? I'm not doubting you, I'm trying to learn. |
it's an easy answer to install them the same way as OE
Rods and pistons usually need to be installed a specific direction.
Same with LS engines and late cummins 5.9. it doesen't actually matter, but it's still best to put them back together the same way the factory did, because otherwise people question it. That's proven! LOL
But if it didn't matter then why DID the factory put them a specific direction?
I'm sure it's just human nature.
and it's kinda convoluted really
I mean, it's well known wisdom that if you make a part that can be installed wrong, it will be installed wrong. So, always design it so it can't be installed wrong.
All the time we get around here.....oh, the deflector under the generator stand, or the carburetor venturis, or 44idf carb boosters put in wrong. those could have been prevented by deign tweaks.
But cylinders are round, pistons need to be light weight, rings...... there is no easy design tweak to prevent incorrect assembly of these parts, so you have to know which way they go and take care to put them right.
Except wouldn't the ultimate fix be......if both ways would work? yeah, but then people freak out when they encounter that and put them a specific way anyhow.
People get confused about it all the time and always will. |
For all the times ive busted your balls about something you said, i gotta play fair and give credit where credit is due , that was well said.
Far as ppl liking symmetry, thats only an illusion, we THINK we like symmetry but we actually dont. Ive read books and studies done on this and all say that we are subconsciously attracted to asymmetry. Thats why the focal point of most pictures is above center, a vehicle in a photo or at a car show is more interesting if the front wheels are slightly turned. ALL of us have one side larger than the other, have ya’ll ever seen a picture of a face where they mirrored one side? It looks weird. Somehow you know something isnt right with it.
I studied this partly for doing custom paint work, like everyone thinks they want their flames mirrored from one side to the other but it’s more interesting if it’s not.
I really like asymmetrical things, my wife gives me shit about it all the time.
Also plan to build an engine with different size P&C in 1&3 than 2&4, if you want to call that asymmetrical, i dunno?
Definitely agree with your point on ppl holding to symmetry unnecessarily
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chrisflstf
Samba Member
Joined: February 10, 2004
Posts: 4108
Location: San Diego
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| Posted: Sun Aug 10, 2025 9:18 am Post subject: Re: CB H beam rod question |
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I like symmetrical boobs (.)(.)  |
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SGKent
Samba Member
Joined: October 30, 2007
Posts: 42755
Location: at the beach
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| Posted: Sun Aug 10, 2025 10:35 am Post subject: Re: CB H beam rod question |
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| Dusty1 wrote: |
| modok wrote: |
H beam rod have no offset
They can be installed either direction, it does not matter which way they go.
|
I gotta say after all these years I'm dismayed that H beams don't have the correct offset.
I guess I'll just have to settle for galled pin keeper grooves and / teflon buttons like the good old days.
...or I'll call Carrillo, the originator of H beam rods. Carrillo has never been cheap. Near as I can tell they've always been right.
.
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we've had teflon buttons fail
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modok
Samba Member
Joined: October 30, 2009
Posts: 27707
Location: Colorado Springs
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| Posted: Sun Aug 10, 2025 3:09 pm Post subject: Re: CB H beam rod question |
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I have never had a piston pin drift out of anything I built.
Just have to follow the known guidelines of how to blueprint engines.
Get your clearances right, rod bearing clearance, rod side clearance, pin bushing clearance, pin side play in the piston, ends of pin square and correct shape, rods straight, decks straight.
H-beam rods are FAR stronger against bending, so I guess them being 1mm off center is fine, or MORE ok than with an I beam rod.
You have to understand the material and heat treating and manufacturing process to understand why H-beams work, just strictly speaking the shape is kinda stupid, but the thin sections heat treat very well, putting the core in tension and edges in compression, and is easy to make custom lengths.
I too would prefer to have a NICE forged I-beam aftermarket rod, but most of them are really goofy and cheap, too thin here, too thick there, huge bolts, not offset right, so, oh well. |
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