Building the EVO II 4G63T

[dvscoupe]

After having an over heating issue I've decided it's time to build this baby

A quick brief is that I want to build a forged 2 litre with 272 degree cams running 1.5 bar boost from a TD06-20G.

It will get all the trimmings as time goes by but to start I'm looking at the bottom end.

Which of the following would be best suited for my car?

1/ Wiseco Forged Pistons & Eagle Rods

2/ Wiseco Forged Pistons & Manley H-Beam Rods

3/ CP Forged Pistons & Manley H-Beam Rods

4/ JE Forged Pistons w/ Eagle Rods

5/ CP Pistons w/ Manley Turbo Tuff I Beam Rods Combo

6/ Wiseco Forged Pistons & Manley Turbo Tuff I-Beam Rods

7/ JE Pistons & Brian Crower H-Beam Rods

Which is the best pick from the above?? They are all similar in cost.

 

[CLuTZ]

Eagle and J.E have been proven time and time again!

 

[BYBY5L]

^ 2nd that

 

[dvscoupe]

cheers guys

is there any difference between the H beam rods and I beam rods apart from the shape?

 

[BYBY5L]

h beams are apparently stronger while bein less tolerant of detonation, an like to snap, where as i beams are more likly to bend, think i beams have a lower side to side weight loading, sum1 plz correct me if im wrong tho

 

[dvscoupe]

Some info I found on another site

The subject of H-beam versus I-beam connecting rods comes up every once in awhile, and it’s a fun topic for bench racing. But one thing I’ve noticed is that many enthusiasts have the mistaken impression that cylinder pressure loads, such as from superchargers or turbochargers, is what fails connecting rods. This tends to be reinforced by many connecting rod companies that rate connecting rods by horsepower. All connecting rods are designed to withstand incredibly high compressive loads. This is not what typically will cause a rod to fail. What tends to damage or fail a connecting rod is the change in direction, especially at bottom dead center (BDC) when the rod is subjected to tension and the rod bolts are strained to prevent the cap from pulling apart from the rod. This makes engine speed, rpm, the real connecting rod killer. Weight is another big factor, which is usually a bedfellow to strength. But the reality is that a lighter rod is most often better in an rpm application since the lighter rod presents less of a g-force load on the cap and rod bolts. This also makes the selection of a connecting rod bolt as important as the rod itself. Another point worth considering is that the big end of an H-beam rod tends to take up more space than an I-beam, which makes clearance an issue when it comes to stroker cranks. All this places the selection of I-beam versus H-beam far down on the list of important selection criteria.

 

[lozza]

Rods will fail by both compressive (by buckling) or tensile (fracture) depending on where they are in the cycle and the loads applied.

Failure occurs at TDC and BDC because this is where the greatest acceleration and therefore moment of inertia occurs (just before and after it is vertically stationary at the top and bottom of each stroke). This is why light pistons with light rods are more advantageous when piston speeds and rpm are high.

In tension (which occurs at TDC) rod bolts stretch occurs and the rod can fail by fracture (tensile crack across the rod at its weakest point).

In compression (which occurs at BDC) the rod will buckle (bend like a banana) and this is a function of moment of inertia (weight and acceleration) and compressive load. So in this case torque limits its strength (this is where horepower ratings come from).

Another type of failure is from shock loading from uncontrolled detonation which is additive to other failure modes.

I-beams are generally stronger than H-beams . Have a look at F1 conrods and you will see what I mean - It all comes down to largest second moment of area in the axis most likely to fail.

In regards to pistons you haven't considered the alloy:

2618 alum alloy = stronger, heavier, larger PTW clearance (wiseco)

4032 alum alloy = weaker, lighter, smaller PTW clearance (JE)

 

[EVO-00X]

^3 times JE pistons + Eagles rods (Im running this combination too)

I've also built a 4G63T engine with Wiseco pistons/Eagle Rods and was very impressed with their quality. Really depends on what compression ratio you want to run as well as most of the JE and Wiseco pistons selling in kits on the market will be a 8.3:1 or 8.5:1 ratio. You'll usually find CP and Arias Pistons on the 8.7:1, 9.0:1 or more side. Each piston composition serves a purpose as far as low/high silicate content goes as well. Do some research.

Eagle rods are great for the price and will handle as much power as you'd want to throw at them on a high performance street car. I remember Rob Barac had 900hp with Eagle rods too at one stage. Why pay more??? Like all new parts in the block you need to get them checked and balanced by the machine shop before engine assembly.

 

[Liberoz]

This is my set up 8.5:1

Like all new parts in the block you need to get them checked and balanced by the machine shop before engine assembly.

Solid advise above

 

[JC evo1]

After having an over heating issue I've decided it's time to build this baby

A quick brief is that I want to build a forged 2 litre with 272 degree cams running 1.5 bar boost from a TD06-20G.



Which of the following would be best suited for my car?

Which is the best pick from the above?? They are all similar in cost.

I wouldnt hesitate to use any of the parts you've listed, whats more important is the engine builder and tuner. I have the eagle/wiseco combo because i wanted 9:1 comp and the lightest weight - less stress on bearings at high rpm.

 

[lozza]

whats more important is the engine builder and tuner.

couldn't agree more - forged set-up won't last long if it's not put together and tuned right.

 

[GSRPSI]

Eagle and J.E have been proven time and time again!

ill back that one up, when i was starting to build my motor i ask a few engine builders and most of em recommended J.E pistons and Egale rods

 

[JAP63]

Good to see another tech answer champ..You a Mech Engineer?

In tension (which occurs at TDC) rod bolts stretch occurs and the rod can fail by fracture (tensile crack across the rod at its weakest point).

Wouldnt TDC bring about compression on the rod...as it is compressing gas and the valves are shut...or are you reffering to the exhaust cyle here? where it returns up to push gas out, and is therefore unloaded...?

In compression (which occurs at BDC) the rod will buckle (bend like a banana) and this is a function of moment of inertia (weight and acceleration) and compressive load. So in this case torque limits its strength (this is where horepower ratings come from).

Do you know if the compression on the rod is greater as it compresses gas going upward, or when its blown down by igniton, ive always wondered this......never been given a straight answer...I agree with you though, that first sweep around the crank on the way back up for the exhaust cycle would be one of the worst time for the rod bolts...as would the return down, or any change in direction for that matter as you said..That and people over revving engines on decel!!:fuuuuu: (could this be why My Evo III only lasted 3 months after I sold It <_<..)

It all comes down to largest second moment of area in the axis most likely to fail.

Agreed, though youre not really loading the rod up too much 90 degrees to the direction of the sweep, and if you do..it wont last long!:lol:.....I cant see it happening too much though...unless your crank was floating axially maybe.. (crankwalk)
From what I see in them pics All them H and I beam rods follow the same principle, their second moments are greatest all in the same planes..So basically, the one with the greates area at the greatest distance from the centre will be the strongest rod...there are other factors, yet in basic, which looks the thickest is genearlly the strongest...Bare in mind, this only stops it bending..it can still snap, which is a completely different principle

There are so many different forces at different times happening on the rods.....If you really wanted to know the best rod to buy, you need to know shitloads, probably info they wouldnt release to you..such as material specs, tensile and compreesion test data, If you were really concerned, go for the rod that is the closest to a box shape of the lot, and is physically the biggest..this may limit your RPM though.

Like Dre said, time and time again, certain makes take the punishment, let that be the best evidence I say.

 

[howc]

i think he meant that the rod bolt is under tension and the rod is under compression at TDC which would sound logical to me.

As the rod is pulling the crank up, the rod bolt undergoes tension.