Are those titanium rods in your pants or are you just happy to see them.

[MNGSX]

Eagle has (last june) released some titanium connecting rods for Hondas and SBC's that are quite affordable and they say they have new applications in the works. The honda rods list at $1200 but I have seen them for a bit over $1000... At $1200 that is 300 per rod. That is $200 less than what the lowest price once was. I think we all need to start riding eagle products ass to make ti 4g63 rods available. Yes I know there are GRP and groden aluminum rods but ever see all those nick nacks made out of used pro racing aluminum rods? So spend $1200 instead of $600 and not have to do it again unless you really blow the thing.

A 4g63 ti rod would weight about 375gr as opposed to about 576gr for the std eagle rod. A guessbased on the difference between the two honda rods but close.

That is a pretty big weight savings. All engines are different based on rod length and journal size but around 25% of a rods weight is reciprocating weight. So you go from 144gr of reciprocating rod weight to 93.75gr. You go from 432gr of rotating mass to 281gr.

Multiplied by 4 that is 200gr of weight that does'nt have to go up and down per rotation and 604gr that does'nt have to spin.

So 7.05 oz or .44 lbs of reciprocating weight is cut as well is 21 oz or 1.33lbs rotating weight. All the lightened cranks do help but each ounce cut from what goes up and down (reciprocating weight) is like cutting a pound from what goes around and around.

 

[GRNDSM]

Do you have any idea if they are looking at making them for 4g63? I guess they would be a nice option for some high revving motors, but someone building such expensive motor is probably not going to use Eagle rods, as they are not known for highest quality.

Another point, I remember Curt B. saying how he is using “heavy” pistons and he saw of the best hp numbers at highest RPMs of any 4G63 (especially if you consider that he was using small turbos).

Also, from personal experience, getting lightened FW didn’t translate into any noticeable improvement that could be measured in the ¼ mile.

So, theory aside, just how important is it to reduce the weight of that rotating assembly?

 

[MNGSX]

Do you have any idea if they are looking at making them for 4g63? I guess they would be a nice option for some high revving motors, but someone building such expensive motor is probably not going to use Eagle rods, as they are not known for highest quality.?

Yes they are one of the engines in consideration. I have seen Eagle rods used by some shops in some high end stuff. Pruven had them in a USCC car, it had other issues but Roys USCC car dynod 650 AWHP and climbing with them. You get get crowers for about $470 a rod and ti Pauters for around $6-700 a rod... Since I have seen the regular eagles hold up to alot with good tuning IMHO why bother when a Ti rod is stronger. If you built it to handle the same stresses as the forged 4340 rod it will actually be stronger since it weights less and the lower reciprocating weight of the rod places less stress on it at the same identical power level and RPM. IMHO I'd run Ti eagles with the lightest weight HQ forged piston I could find... It's kind of like how some people kill ACT street disks running 12's and someone else runs into the 8's on the same street disk. Beat on anything and it will break.. Bad tune, bad knock, bang a rod goes bad.... Do something that bad if you don't take out a rod you kill a piston instead.

Another point, I remember Curt B. saying how he is using “heavy” pistons and he saw of the best hp numbers at highest RPMs of any 4G63 (especially if you consider that he was using small turbos).

That is a factor of tuning. Heavy or light reciprocating or rotating assembly the airflow at any given RPM is all in the induction system. You will make more power with the same airflow with a lighter assembly. Lightening the reciprocating assembly with all things being equal would make a good bit more power. Lighting the rotating assembly will make some gains but not as much.

Also, from personal experience, getting lightened FW didn’t translate into any noticeable improvement that could be measured in the ¼ mile.

That may be your experience but you will find a lightened crankshaft, light flywheel and very light aluminum rods in the fastest AWD DSM. I don't think those parts selections were made by accident.

I gained throttle response (a TON) by going to a 4.75lb SSG flywheel and it is noticably faster. Rev matching is easy...

So, theory aside, just how important is it to reduce the weight of that rotating assembly?

Reciprocating weight accelerates to a stop then changes direction. Rotating weight moves in a single direction. Loosely speaking, removing one ounce of reciprocating weight is more beneficial to longevity and efficiency than removing a pound of rotating weight. In other words, don’t waste time grinding the crank counterweights. Concentrate first on the rods, pistons, and pins

http://www.hotrod.com/techarticles/82378/index1.html

I'm working with Engine Analyzer pro and will run various component weights in a 4G63. It can calculate parasitic losses and much more.. Aluminum or Ti rods combined with light pistons are good for alot of HP. I'll have very accurate numbers soon...

 

[pianoman]

have you gotten any numbers yet?

 

[2-0turbo]

Since I have seen the regular eagles hold up to alot with good tuning IMHO why bother when a Ti rod is stronger. If you built it to handle the same stresses as the forged 4340 rod it will actually be stronger since it weights less and the lower reciprocating weight of the rod places less stress on it at the same identical power level and RPM. ..

The Ti rod is not going to be stronger. Let's throw that word stronger out--it's bogus. 4340 will have higher tensiles than the Ti rod. No alloy of Titanium I'm aware of can beat 4340--that stuff is simply amazing. Titanium has a higher strength to weight ratio (quite strong at 50% density of steel, no endurance limit like Aluminum). So, they can make it actually bigger (beefier--think beam section) than the Eagle 4340 rods and still be lighter. Specific strength is where it's at.

 

[MNGSX]

The Ti rod is not going to be stronger. Let's throw that word stronger out--it's bogus. 4340 will have higher tensiles than the Ti rod. No alloy of Titanium I'm aware of can beat 4340--that stuff is simply amazing. Titanium has a higher strength to weight ratio (quite strong at 50% density of steel, no endurance limit like Aluminum). So, they can make it actually bigger (beefier--think beam section) than the Eagle 4340 rods and still be lighter. Specific strength is where it's at.

I agree but I meant stronger in application... The same size and shape between the materials will still have strength difference. Pushed beyond their respective limits I'd expect the 4340 to come apart on the exhaust upswing at a lower rpm than the Ti rod and the Ti rod to give on the combustion stroke at a lower power level than the 4340 or at a lower level of knock... Since neither rod is obviously crappy going passed the limit for either is'nt easy..



If the part is lighter there is less stress on the rod due to the reciprocating weight reduction... Peak g forces at TDC at 8000 rpm are 4000g's so multiply the reciprocating weight by 4000... Reducing the reciprocating weight by 50grs means that you have reduced the amount of stress at TDC by alot.


Right now I'm looking at 4340 rods because a custom length rod charge coupled with the Ti price makes me think I'm taking a rod somewhere else..

 

[MNGSX]

have you gotten any numbers yet?

I can get it to spit out numbers for friction differences between 2.0 and 2.4 (quite large) and some other interesting data... Nothing accurate on reciprocating weight to HP that goes into moving it...

 

[2-0turbo]

If the part is lighter there is less stress on the rod due to the reciprocating weight reduction... Peak g forces at TDC at 8000 rpm are 4000g's so multiply the reciprocating weight by 4000... Reducing the reciprocating weight by 50grs means that you have reduced the amount of stress at TDC by alot.
..

Agreed.

 

[blue1]

Titanium is possible one of the toughest metals per weight known but i have been in the aircraft industry for the last 18 years in engine overhaul, why dont they use titanium in anywhere but the cold sections of the engine???? i will leave it there!

 

[hostile]

Why does honda use ti rods in the NSX?

And why did GM decied to use titanium rods, valves and push rods in their new vette?

It is going to get cheaper the more people use it, and eventually these parts are going to become more common place in oem and aftermarket applications.

Titanium has a melting point somewhere around 3000 degrees. So if your engine internals are getting that hot there is going to be big problems anyways.

 

[MNGSX]

yep...

Just dont use Ti valves unless you do many valve jobs a year.

They dont hold a grind.

 

[hostile]

yep...

Just dont use Ti valves unless you do many valve jobs a year.

They dont hold a grind.

Where did you hear this?

 

[kalla]

It is good to hear that more and more fabricators are starting to employ titanium. I say this because the reason titanium is so expensive is that it's ridiculously hard (read: expensive) to refine it from raw ore. Way harder that it is to make aluminum. The price of titanium is coming way down, and will keep going down the more it gets used in regular consumer goods.

What is this about titantium not "holding a grind"? It is probably hard to grind them effectively as it's such a hard metal. As far as titanium not being used in "hot parts" of aircraft engines .. it probably has thermal properties (expansion?) that is less desirable at high temperatures in that application than say a nickel-alloy steel. I am no metallurgist though.

 

[hostile]

Titanium is possible one of the toughest metals per weight known but i have been in the aircraft industry for the last 18 years in engine overhaul, why dont they use titanium in anywhere but the cold sections of the engine???? i will leave it there!

Don't they use titanium in jet turbines?

 

[Eagle 5]

depends. in a jet engine they can get away with some stuff since they only run at full power for a very short period of time. Where as in gas turbines powering generators, they run at full power for HOURS continuously. so some of the materials we use are cobalt, inconel based. inconel is some strong stuff. cobalt based metals are VERY strong and beat steel. also some of these materials can handle very high temps without many problems but also guys, some of the metal in gas turbines does not see temps above 1400-1800. and higher temps are very shrot periods. though the flame temps are closer to 2700-4000 degrees. its all about cooling and many of the ways they cool the metal and keep heat from it.

 

[blue1]

Eagle 5 i bet you work at GE! Titanium is only used in the Cold areas of the jet engines and the only time they get hot is during heatsoak when the engine is shut down, but the amount of stress on these parts are astronomical (fan blades pressures are measured at the roots in a lot of tons per square inch' If i am not wrong all the blades down to the High pressure turbine areas are titanium and then they change to more exotic metals (inconels, rene's and a heap of other names and codes i have forgotten which have a very high nickel content for the heat!
Titanium should be machined, and or welded in an enert gas to keep its properties viable that why it is very expensive to make things out of tit' properly.

 

[hose101772]

Heres a crank for you're mile high winding 2.0.

Here

 

[IAMCLP1]

Heres a crank for you're mile high winding 2.0.

Here

Wow look that the price... I will take a dozen!

 

[Eagle 5]

Eagle 5 i bet you work at GE! Titanium is only used in the Cold areas of the jet engines and the only time they get hot is during heatsoak when the engine is shut down, but the amount of stress on these parts are astronomical (fan blades pressures are measured at the roots in a lot of tons per square inch' If i am not wrong all the blades down to the High pressure turbine areas are titanium and then they change to more exotic metals (inconels, rene's and a heap of other names and codes i have forgotten which have a very high nickel content for the heat!
Titanium should be machined, and or welded in an enert gas to keep its properties viable that why it is very expensive to make things out of tit' properly.

haha, indeed I do work at GE. Down in Advanced Combustion Engineering. So we deal with the HOTTEST stuff..literally. Though turbine blades have to deal with heat straight on.

theres also HS188, Inco xxx, Hast X, MarM (tbc coating maybe)

Another reason why titanium is hard to machine is because of its atomic structure. Steel is not normally pure iron but made up of different metal or alloys. Well because of how the carbon atoms in steel are arranged it is easy to machine steel. Sure SS is hard but you can still do it. Titaniums structure is different from steel and makes it harder to machine it. Basically steel can shear easier than titanium. I forget the exact structures of both but steel an range from a few different ones and I think titanium has one type of structure but its one of the best.

Titanium is not stronger than steel. but it has a much higher strength to weight ratio making it nice to use on some things.

oh and compressor blade tips on some engines have enormous forces put on them. insane when you look at a decent weight tip rotating at 10,000 rpms for hours on end and the blade being about 20" or so away from centerline.... nice forces going on

 

[Nanan]

Titanium is not stronger than steel. but it has a much higher strength to weight ratio making it nice to use on some things.

Ti has the highest Strensity ratio of any known metal. So yea its "stronger" then steel when you compair to pieces of equal volume.

Sadly Ti fatigues quickly when its heated which is why the compressor blades in jet engines are not Ti. The upside is that the pistons would have long sence melted before these temps were hit.

Ti rods would reduce rotational mass which will free up Hp but in the costower ratio it really doesnt make a fesable material for a car engine in the use of a daily driver.

If you want a good rod which can handle alot of stress without failure untill you have gone into extream ranges then as said before 4340 is about the best option out there.

As far as I know there would be no real issues with Ti valves, infact there is alot of R&D going on wrt to TiN coated Ti valves for race engines which get a heck of alot hotter and run a heck of alot higher rpm ranges.

 

[blue1]

Compressor blades i know for a fact in GE engines are Ti, High pressure turbine and back in the hot areas aren't. sorry just a fact of 19years building the suckers!!

 

[Nanan]

Depending on design the Forward most intake Compressor turbines can be made of Ti as they will not see much of a change in temp. But the rear most compressor turbines will see alot of temp change due to heat soak in both long duration opperation and after the engine is shut off.

 

[Eagle 5]

that, and when you have 2500 - 4000 degres fahrenheit of gas moving across the blades, metal will tend to melt and wear out VERY quickly, but thats why we have cooling on the first couple stages of turbine blades. And long durating... were talking running the engines at full power for HOURS, days on end. a jet engine may only be at full power for 60 secs during take off and run a hotter temp out the combustor, but since its a shorter period they can. Gas turbines for power generation run lower temps out the combustor but have to last at those temps for way longer than any jet engine does. some of these thins get run continuously for days, others run for a few hours, get shut off, run for a few hours, shut off etc.

some info on steel, titanium, and carbon epoxy

4140 carbon steel
Sut 1770 MPa ultimate strength
SE 740 MPa endurance limit
E 200 GPa elastic modulus
unit weight 76.5 KN/m^3 duh

titanium grade 29
Sut 825 MPa
Se 300 MPa
E 114 GPa
unit weight 43.949 kN/m^3

Carbon epoxy
Sut 456.6 MPa
Se 274 MPa
E 110.4 GPa
unit wieght 16.287 kN/m^3

so, take a rod you need to design, you have forces acting on it. you want to make it to be the lightest you can. which do you use between steel and titanium? guess what, steel will be lighter for the part. BECAUSE it does not need to be very big in order to handle the forces, where as the titanium will have to be bigger becuase its strengths are much lower than steel. the pieces may weigh possibly close to the same, but one is much bigger than the other.

We had a design project for making a shaft for a wind turbine. we did analysis between the 3 above and the steel would be lighter than the titanium. YES, steel would be lighter. The titanium needed to be at least .7 m in diameter to handle the forces on the shaft, the steel was only like .5 something. Titanium is good where there are not large forces and you want to be very light etc, but ultimately steel is where you generally want to be.

Now valve springs can be made of titanium to save weight because they are not u nder large forces. And the fact that the springs will be the same size regardless of what they are made of, the titanium will be lighter for that volume. Connecting rods will be different as there are large forces on them, so you could use titanium, but your rods will need to be much bigger to handle the same loads as steel which would be smaller.

Hopefully that makes some sense to people.

Now there are many many types of steels, titianum etc etc. these are just a couple and that steel is pretty damn hard. but also, for those higher strengths, the steel will become more brittle.

 

[DJpHGotBanned]

what's the story on the carbon epoxy?

 

[Vanish70]

Groden Aluminum rods might be a good compromise...
456 grams each