H-Beam Vs I-Beam conrods...

[brett_celicacoupe]

it would be interesting if you could compare a H beam and I beam with the same cross sectional area. same material as well.

although probly not possible

[kingmick]

If your guys really want to know why not just email or ring people like John sydney{race engine builder for supercars} or Cosworth even Hendrick motorsport, much easyer and you find out why they use certain Rods.
V8 supercar have been using Oliver{very very expensive} I-beams for a few years now because they have a low rev limit and they can handle 1000km's before being thrown in the bin. They use the I-beams to lower rotating mass as thats all they can do with there rev limit, they make everything lighter{rotating mass} to help spinup to point that matches the strength needed with some saftey margin to get the 1000kms or so till the $30k+ freshen up.
Dosnt matter which is better its more a cost thing to most people, i cant see many people on here{myself included on my own engines} spending $4000+ on a set of top quality I-beam rods!

Email some of the big engine builders, im sure one of them will tell you there reasons.

One for Stew, i have somewere and ill find it of were there developing the rods using the fracture line of the steel for the big End join, to get more strength.

[ed]

PM me the emails of these engine builders mick

cheers mate
ed

[kingmick]

look them up or ill have a look for them tommorro slacko

[ed]

lol - you have em already - just PM me - ive got bags to pack! going to churmanny

[kingmick]

http://www.hendrickmotorsports.com/default.asp
http://www.cosworth.com/contactus.php

Sydney John Racing
Flag no.1
19 Treforest Drv Clayton VIC 3168
ph: (03) 9543 5064 Motor Engineers & Repairers

[oldcorollas]

Email some of the big engine builders, im sure one of them will tell you there reasons.

One for Stew, i have somewere and ill find it of were there developing the rods using the fracture line of the steel for the big End join, to get more strength.

surely they won't say... for the same reason you won't... because it cost your workshop a lot of money developing the engines....

umm.. can you rephrase that in clear english, i am not sure what you mean.


for kicks, here is a formula 1 conrod. cos, you know.. it's really crap and all that..
methinks if F1 are using I beam... then they MUST be ok for high rpm (if designed properly )
now compare it to your normal rod... what do you see? much much better for resisting bending load from the turning crank/mid rod inertia....

and here is a link to a PF thread on same, with some good links from it.
http://www.performanceforums.com/for...hp?p=839558691

[ed]

all mechanical logic in my head points to I beam

[oldcorollas]

all mechanical logic in my head points to I beam

aye. a given cross sectional area, as long as the wall thickness is not "too thin" will be similar in compression.. with the I-beam at advatage to reduce buckling from thin walls (the outside of the I supports the inside from buckling... H beam, you have flimsy wall thickness on either side...)
in bending... not hard to see the I-beam has an advantage there....

H-beam look like they are better, cos they are a prettier shape and appear to have more meat in the plane of bending.... but in reality?? most aftermarket rods are much better than stock rods, regardless of the design

[kingmick]

surely they won't say... for the same reason you won't... because it cost your workshop a lot of money developing the engines....

umm.. can you rephrase that in clear english, i am not sure what you mean.


for kicks, here is a formula 1 conrod. cos, you know.. it's really crap and all that..
methinks if F1 are using I beam... then they MUST be ok for high rpm (if designed properly )
now compare it to your normal rod... what do you see? much much better for resisting bending load from the turning crank/mid rod inertia....

and here is a link to a PF thread on same, with some good links from it.
http://www.performanceforums.com/for...hp?p=839558691

In english " Another key element of the evaluation project was looking at the benefits of switching to fracture split steels,which allow the ‘big-end’ of a conrod to be separated into rod and end-cap,along a pre-determined fracture line.This subsequently ensures a perfect fit between the two halves."

Yes but what are the F1 rods made out of and what are they trying to achieve? less rotational mass with just the right amount of strength to make the distance. F1 also loads the rod diffrently from a road car or PushRod V8 nascar etc.
I would imagine one F1 rod would cost the same as a big HP 4ag engine!

[kingmick]

yep that bloody carrillo that has been making the H-beam rods for most forms of racing for many years have no idea: Even TRD make them for the race engines. It all comes down to application and cost

[ed]

but how much side/side bending does a rod see...?

most of the load i imagine would be tension/compression along the I beam ends...

[The Witzl]

Well i still dont care, i'm happy with my rods so you can all eat a p00!

[ed]

my rods p0wn5 your rods

[whatthe?]

Well i still dont care, i'm happy with my rods so you can all eat a p00!

I concur. My eagle H beams are much prettier than the pooey standard 7M I beams