Aluminium Conrod Pros and Cons | GRP Connecting Rods [TECH TALK]
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- čas přidán 18. 02. 2018
- What makes an alloy rod more suited to drag racing than circuit and road use? Woody from GRP Connecting Rods runs Andre through the pros and cons of using aluminum over steel.
Also discussed are the considerations you need to take into account when calculating how long an alloy rod will last you, and surprisingly to some your power output isn't one of these. Why I beam construction is more popular than H beam from a manufacturers point of view is also touched on and Woody also dispels the myth of alloy rods 'stretching'.
Want to learn how to build a performance engine using components like this? Come along to our next free live engine building webinar to get a head start - www.hpacademy.com/free-engine... - Auta a dopravní prostředky
![3000HP, 150 PSI Of Boost | What Do YOU Know About Compound Turbo Systems | Shane T [TECH TALK]](http://i.ytimg.com/vi/1pV_tLbZY0A/mqdefault.jpg)
This guy is a great vendor. There's no BS about the product, and he's clearly knowledgeable about the tech.
I have been watching tons of HPA videos for educating myself about as much as I possibly can. So, I just want to say that Andre gives a legendary interview. It is hard to pull detail out of someone when both of you already know what it is. His way of wording the question to make the interviewee understand that Andre himself understands how the product works but, he wants them to explain it in more detail for the education of the viewer that doesn't know. I really appreciate that about these videos. I am just going through all the channel playlists now at this point.
Cheers for the kind words and glad you find Andres style effective. The goal is always to share something educational, but understandable.
There are some real gems hidden away in some of the older interviews. Anything with Shane T, Tony Palo or Collin Willshire I would recommend right off the bat as they are all very at ease on camera with Andre - Taz.
@@hpa101 I will definitely check all of those out then. Thank you very much for the recommendations.
Question: *Long, insightful, and detailed requiring an equally detailed answer*
Answer: "That's correct"
if you really listen to his questions, he answers the question he is asking. Leaving the only answer being "yes" . Watch his other interviews
@@ortan191 He does this but most of the time he words it like that to show that he knows the answer is yes but, he just wants them to elaborate on how or why it is yes for the education of us, the viewer.
DeuceTheGamer I agree that this style does save a lot of interviews time and also let a noob like me follow the conversation easily.
I really like your videos. You go so much more in depth about the specifics than other people you make it easy to learn quickly. Your name definitely fits I get educated with every video I watch. Keep up the good work! I know it's a little broad for many of your topics but personally I would really like a video on building torque in small displacement engines (think rally cars)
Thanks JT! The sole purpose of these is to help educate so we're stoked to hear they're hitting the mark with you. As always we're really lucky to have people like Woody who are happy to take a bit of time out of their own day to share some of their knowledge with us all too :) - Taz.
Definitely better than power automedia to explain and discuss specification
Hahaha. I love Andres videos and have met him before.Hes a lovely and extremely knowledgeable guy. Its people like him that make this industry a fun one. Its just funny that this guy looks like he didnt want to be interviewed haha. Maybe its just how he came up on camera.
Thanks and keep them coming.
Absolutely awesome interviews every time Andre. Credit to you mate. You ask all the the right questions and leave nothing left needing to ask 👍👍
Fantastic video, really interesting information!
I wish all interviewers were as knowledgeable about the subject in question and the interviewee also as knowledgeable and also as factual in their answers! Andre I really enjoy watching your videos, whether its just good preparation or actual knowledge of the subject you score a 100% + bonus marks!
Best interviews out there. Always informative and interesting.
Now that is the type of rep I want during my phone call.
100%, knowledgeable guy eh! - Taz.
Very good questions in depth covering all parameters.
Great questions answered of all my concerns
Andrea,you really are a outstanding teacher.Thanks
I work right across from Woody in the same motorsports building making a different part for race engines. Woody is big into Nostalgia drag racing and I’ve been meaning to hit him up at the track. He’s the one you talk to when ordering.
Excellent rep
Great vid as always
would love to find out more info on titanium rods andre. great vid!
Would be cool to see you guys interview someone for bearings. There's so many different kinds to choose from.
Well you are in luck. We spoke to King Bearings. Video coming soon. - Ben
High Performance Academy
Also interested
Roller bearings made out of M50nil carburized nitrided. Aluminin rods would not do good in 2 strokes espeaily
Really good pertinent questions even if some answers were a bit short! Interviewer eventually teased more detail out. Clear enough reasons why an alu rod will not suit my road race bike. Would have been interesting to know if an alu rod would have been acceptable in an older lower revving circuit bike (say under 7000 rpm) as opposed to the phenomenal high revs of many modern engines
@Andre I think you are as good of an interviewer as the original cast of Top Gear did car reviews
Awesome video as always, cheers Andre!
Excellent and wide parameters in coverage
Great information
Thanks!!!
You bet!
@@hpa101 do you know of anyone who used aluminum rods in a road race or time attack application??
Always a like and a comment for your work
Much appreciated Nigel!
any chance you guys could do a bit on titanium conrods?
Nice
You need a job on one of the top motorsport channels as an interviewer, fucking brilliant questions every video
How do alloy rods especially titanium ir something do in road cars, is the life much shorter?
He was a better interviewee than the Carrillo connecting rod representative, by far.
Oh yeah, carillo guy was not to bright
Very good Q&A session - the only thing I'd've liked to have been asked was the affect of temperature as, back in the day, it was believed that rev'ing the rods when cold was much more likely to cause failure than when the engine was warmed up. Don't know if that was an old wives' tale or fact, though, as there isn't a lot of warming up for top fuel engines... Maybe down to different alloys being developed?
They didn't get right into specifics but near the end cold and hot clearances are touched on. The word 'stretch' is the old wives tale, but the fact that aluminium expands more than steel and that it does need to be accounted for in your build is not ;) - Taz.
Thank you for the prompt reply.
I wasn't referring to "stretch" (although there will be some - Modulus of Elasticity - even with steel rods) but whether temperature was actually a factor on failure rates. Back in the day there were anecdotal reports of unexpected (brittle?) failures of rods on initial, cold running, often at relatively low rpm and little use - of course, the stories may not have been accurate.
Aluminium properties change with temperature and perhaps this also affects the fatigue life?
i have watched quite a few of your videos and you should be complimented on the questioning and insight you bring to them - definitely a big step up from most interviews and discussions :-)
would the rods be recommended for a daily running usage on a stroked engine?
It's best to get in touch with your supplier directly, tell them what your application and requirements are and then see what they recommend specifically for you. The pros and cons of this material are covered in the video so it's up to you to decide if the pros are sufficient enough to warrant dealing with the cons - Taz
Would be nice to hear facts on titanium rods
titanium is for extreme cases without a lot of hp, the material properties can be counter productive as you push things, which is generally why you don't see them used very often besides the tooling costs.
Also same as aluminium, no endurance limit. Steel does.😉
Chevy corvette had titanium rods on their LS7 427ci/7.0L it made 505hp and had a very long stroke of 4" inches and it also had a very high red line of 7,200rpm stock but was able to rev past 8k and make 700hp with a more aggressive cam and heads. Now also keep in mind that engine came in a Z06 which is intended for endurance racing and even won several 24 hour races like 24h of Dayton. Titanium has the strength of steel and weighs around the same as aluminum it is also very hard to machine and thus costs are very high to manufacture.
ls7 had dry sump oiling which helped in hi rpms
FYI, factory TI rods on LS7 are far from perfect or racing Ti rods. The main problem of Ti is that it cannot withstand friction unless coated or modified in some way. OE LS7 rods pre-09 type had coating delaminating on sides (they ride upon each other on rod pin) resulting in rods falling apart. GM had put them in to save expenses on oil. They should have introduced 10W-40 oil for LS7 engine because 5W-30 oil was breaking lose under piston skirt due to loads. So they had to opt to run Ti rods to save intertia in crank and rods, in order to make it work on standard 5W-30 oil.
With regards to aluminum rods, how suitable do you feel they would be in drifting, for example? Not quite drag racing and not quite a full road course.
Not even remotely. There are plenty of ways to make enough power for any kind of drift car you can imagine without aluminum rods. The whole idea is to take advantage of aluminum's ability to absorb shock on the bearings and crankshaft, AT THE COST of longevity. That's not what you want in a drift car. There are a plethora of options to build a motor with steel rods that is capable of more power than you'll ever need drifting. You don't see 3000hp+ drift cars for a reason. Road course would actually be very similar to drifting in this regard, I don't quite know what your trying to achieve with an aluminum rod drift car engine lol
Are you running as a 2 stroke?www.4btswaps.com/attachments/2cyclesbc-jpg.6839/. I assume you made a poppet u-loop scavenged 2 stroke.
Good vid, as usual... It's interesting though, you see quiet a few guys in the States running alloy rods in 1200 - 1400hp 2JZ's that are running on the street. It's scary hearing rods rated in "runs". I want alloy rods like these guys use in their 2JZ's for my RB30. The only question I think wasn't answered well was- at what point should I start to think about using alloy rods in my engine. Going to sign up for the listen in, was a little disappointed when I signed up for one of your tuning listen in's and it was live to air in the bloody middle of the day. Dude, most people are at work on the eastern seaboard during the day- and these are the people with the finances to be able to pay for one of your actual courses. It's these people you want to show a little teaser to in the form of a listen in. What's the point in putting it on at a time convenient for dole bludgers and children? Most workshops (like mine) close at 5p.m.
Hey Daniel,
From my personal take on the discussion, the answer to your first question is covered at the start. If you're running your car on the street, you're probably not going to want to use alloy rods unless you're happy to deal with the increased maintenance and associated costs that they will bring. As Woody mentions you're really best to give someone like him a call, give them all the details they need, and then they will tell you what's going to be best for you and your personal application.
As for the webinar times, it's a shame that didn't line up for you but to be fair there is more than just the East Coast in the world Daniel 🌎We change the time and day every webinar to target different areas and countries. We also email out a recorded version just in case you miss it or the time doesn't suit and you don't want to wait until the next one. Hope that helps! - Taz.
Why not a hybrid crank mainly aluminum and steel where need be?
The steel is where the roller needle bearings ride on because steel is much harder than aluminum.
Wont aftermarket rods not influence the lubrication of the cylinder walls? Original GM rods had oil thrower tabs on the outer side (crank side of the bearing pocket) most aftermarket rods have nothing? Will I need to modify the rods with oil channels or the crank before use?
If this is a concern that your rod supplier hasn't addressed in a way you are happy with either grab the aftermarket rods that do, or keep the stock ones and their limitations.
It's not something we have specifically had concerns about or any issues with, but that's just our experience and decision making - Taz.
Very little power gain to be had with alloy or titanium rods; that’s why alloy rod manufacturers rarely give specifications in that context.
As the guy says, it’s really just the alloy rod’s malleability that suits them for such a high powered environment. However, the greatest load on a conrod is directly after the exhaust stroke, as then their ductility is strained, and alloy rods have far less ductility than steel conrods.
So, alloy rods (and to some extent Titanium) rods give very little HP benefit for drag racing applications as the engines don’t rev into very high numbers like F1 engines do.
Another way to say it is; for almost all (including some performance/racing) applications (and within reason) the overall static (translational) weight of the crankshaft and con-rods don't matter much.
This applies to alloy con-rods as well as the majority of their measured (translational) weight actually becomes rotational energy/weight when the engine is running.
This means that very little of those sections of the lighter conrods that actually made them slightly lighter than the other steel conrods will be near the piston’s wrist pin; and since those conrod sections (near the wrist pin) do not constitute and/or meaningfully contribute to rotational mass/energy even when the engine is running (as they are translational mass) there really is very little real (translational) weight saving.
And, it is translational weight saving that matters the most with these components.
Put simply the majority of the mass of a conrod is always at the big end section - so a translational weight saving of a few grams across the whole conrod (when it is not in motion when the engine is running) may not mean so much in rotational mass/energy terms.
Great post. So unless my engine goes above 10k rpm, just go steel con-rods or maybe even whole steel rotating assembly? ... Any point in Alu pistons and crank then?
Remember, Top Fuel dragsters are getting pulled down all the time; so con-rod reliability isn’t such a big thing - but crankshaft reliability is, and alloy con-rods (due to how they stretch and compress) save crankshafts.
Stay with steel rods for street and race applications.
Correction; in my first post I meant to say alloy rods have far more ductility than steel. Apologies.
Jim; ex AMG (Mercedes Benz) Powertrain (control systems) Engineer.
Jim Stanley but the main question is will they fit my Honda ?
Yes, but only on the proviso that you can afford the cost of having them bespoke made.
They will not be cheap.
And, the fact of the matter is that you will get no (meaningful) extra power with alloy rods; the cost of them could (if diverted into something else) probably add another 50% of power/torque to the Honda.
You didn't mention how the rods do in street applications I would like to see how they would do in a high performance street engine
Have another listen Dylan, the longevity is discussed in relation to street use right from the start. A 'road car' or 'road application' is the same as a street car :) - Taz.
How do I claim my spot?
Hit this link: www.hpacademy.com/free-engine-building-lesson/ - Taz.
Wow maybe titanium rods will be best of both worlds?
That guy knows his shit, lol
the biggest load on a rod is during hydro-lock in a fuel car and under detonation in any engine ;)
Design everything below endurance limit of the steel 😉
R these rods all felons
6:10, heavier viscosity oil than tightening up clearance.
High viscosity oil and large clearances are old drag car engine building techniques that need to die in a fire. Oil has changed a lot from the 1950s and 60s. There's no reason why you should be running a 20w-50 oil in a modern strip/track car. Guys still do it anyway, and they are just wearing out their engines quicker running loose clearances.
Im on amsoild dominator synthetic 2 stroke oil in my rotary. Its SAE 30w like BRP XD-100 and little cheaper. Im gonna try some motule 800 2T but its sae40w like silkolene pro 2 sx. Igot my 8v92 on a shell rolettla/BRP Xd-100 combo and it works great. My small block v8 2 stroke in on the BRP-XD-100 oil.
That added "5th" syllable drives me nuts!
0.1% of the content on the internet is in a New Zealand accent but we manage to persevere and struggle through daily. I believe in you =) - Taz.
Aluminum, Aluminium, Condominium and this guy is the Ted Cruz of motorheads.
why not make titanium conrods?
They already exist. World of Outlaws used to run them in their Sprints, not sure if they still do as I have been out of that form of racing since the 80's.
ummmm....$$$$$$ for one.
Honda NSX came with Titanium rods in the 90's...
Me "i love aluminum and i could totally make these at home for a way cheaper price than buying steel rods, should inform myself about that shit"
Dude: totally roasts aluminium rods on road cars
Now sad me but thanks for the info dude
Hey at least you know before you've fitted any - Taz.
Are these running in 2 stroke road race poppet valved u-loop scavenged conversions like this VW 2 stroke diesel:czcams.com/video/kot9GYBeCJ8/video.html
If you do not exceed its yield strength, steel has a virtually infinite service life. That is why they are so great for cranks and rods. Aluminum does not. In many cases it can be over built so it has an extremely long life, like and aluminum rocker arm. But for the extreme duty that a con rod sees they are great for a sprint but not for a marathon.
Aluminium is double the expansion of steel. i.e. steel = 12x10/6 aluminium = 24 x10/6.
To a rough approximation, the peak force on a connecting rod will be during the intake stroke, and consists of the force needed to accelerate the piston downwards, and the force needed to pull the piston down against the vacuum at the intake manifold.
f_peak = (piston mass)*(stroke_length/2)*(2*pi*RPM/60) + (vacuum)*(pi*(bore/2)^2)
The actual force calculation is a lot more complicated due to the non-sinusoidal motion of the piston and friction forces. Be sure to use consistent units (Use SI units and everything will work out).
What happens when there is boost? And some other guy further up in the comments said max ConRod force is right after exhausts stroke. I don't know who is correct, never thought about it really.
You have several forces added together in the connecting rod.
1. The force required to accelerate the mass of the piston, wrist-pin, rings, and connecting rod itself in a cyclical motion. The piston's acceleration is greatest when the piston is changing direction near top-dead-center. The acceleration at bottom-dead-center is also high, but it is less than the acceleration at TDC. This is due to deviation from sinusoidal motion of the piston because of the crankshaft geometry. The force contribution from acceleration is just F=ma. This acceleration depends on the engine RPM.
2. Gas pressure on the piston face. The force is equal to the relative pressure (assumed uniform across the cylinder) times the cylinder crosssection area (piston face area on a flat topped piston). Relative pressure should be used, because the pressure inside the crankcase is generally only a little more than atmospheric pressure. F=p*A.
3. Friction forces of piston rings on the cylinder wall (usually negledgeable compared with other forces present.).
If you have boost, on the intake stroke, the forces due to gas pressure (pushing down on the piston) will help accelerate the piston downward and will require less force from the connecting rod to accomplish the same acceleration.
On the compression stroke, the compression of the gas will help to decelerate the piston, also reducing force on the connecting rod.
On the power stroke, the downward force on the piston will be much greater due to more air/fuel having been burned in the cylinder. My guess is the very start of the power-stroke is where you will see the highest force on the connecting rod.
On the exhaust stroke, since the exhaust valve is open, the force on the connecting rod is mostly due to acceleration of the piston, and the cylinder pressure drops rapidly once the exhaust valve is opened.
With a 2 stroke is constant down force.
American - Aluminum
Everyone else - Aluminime
*Aluminium ;)
It was a scientists fault for not being consistent for word rather than just the US just deciding to pronounce it different - Taz.
From your words will be good in two strokes aplication😀dirt bike 😈
GRP Conrods?
Glass Reinforced Plastic???
'Prolly run longer then the aluminium rods..
@steelmesh yeah, but plastic conrods though?
as @Godfrey Poon pointed out GRP (Glass Reinforced Plastic) conrods..
Giononni racing products
Wow we own a 350 Chevrolet engine in drag car and we've been using the same aluminum rods for 30 years I'm not talkin about the same brand I'm talking about the same rods so you telling me they won't last oh and don't say making horsepowerI'm moving a 3000 pound car with a 98 hundreds second 60 foot so I believe they are going to hold up on the Street and also the deceleration stuff they run aluminum rods and sprint cars and late models just don't hang a 900-pound piston on the other end of it
The reason why aluminium rods are not advised for a street application are fairly stated here. From there it's up to you if you want to believe the science and experience of many other companies, engineers and engines out there or of your own use case, granted it is a drag application too and not a street application either way - Taz.
Are you running it as a 2 stroke like this 2 stroke cheavy conversion:www.4btswaps.com/attachments/2cyclesbc-jpg.6839/. Do run an oil injection system into the intake?
*Aluminum* conrods. Alloy ≠ Aluminum.
Cheers Tumdeaux. When alloy is used in this industry in relation to conrods it is referring to Aluminum unless specifically stated otherwise as a rule ;) - Taz.
I know HPA. But the industry is wrong.
Language is constantly changing and evolving, as Joshua has also subtly pointed out hilariously =D. You're going to have a very sore forehead and a slightly secondhand wall if you worry about it too much Tumdeaux. That said cheers for keeping us on our toes :) - Taz
Spin fast, bend easy. Yeah, no. Wouldn't touch them unless you are building a naturally aspirated race engine, and are stuck in that engine category. Great for building 10,000+ RPM engines, terrible material for cylinder pressures exceeding what you can achieve with Compression ratio and atmospheric air pressure. I'll take a set of chrome moly alloy, cast fracture split steel rods, over forged aluminum rods any day of the week.
I would to as they hold up better in 2 stroke conversions as well like this v8:www.4btswaps.com/attachments/2cyclesbc-jpg.6839/
TL;DR, Alloy rods are good for drag racing, Steel rods are better for street and track cars :)
Someone please say,Dwell
Say CONNECTING ROD. I dare you
Unless it's a double dog dare we're not interested sorry - Taz.
Aluminium rods can run into the block not a cam..
It depends on the engine... In a small Chevy getting the rod to clear the cam can sometimes be much more difficult than getting it to clear the block.
It's pronounced aluminum bud!
Except when it's not 🤓 - Taz.
I feel like they said the same thing over and over:...
And yet everyone is like “what about a street car? What about my dirt bike?”
In a dead race world you just throw everything away after a few minutes of engine time
Only what you have to - Taz.