anyone with an engine building/racing background discuss here

[pen15]

ok all this is what i have been thinking about for the past week i suggested it to my boss and he laughed but here it goes titanium gudgeon pins now i know you can get tooled steel but making a 20mm solid pin from good old titanium i would think be a great idea getting rid of useless reciprocating mass and could lighten up a bottomend a fair amount

so my question is to you sam and you toxin and others out there what do you think, it was just a thought but it might be something worth looking into or even trying on a shit stock motor that you don't mind killing

sorry if you mods think its in the wrong section if it is can you move it to a more suitable section

cheers
mat

[Sam-Q]

ok firstly you have to know I talk big and know random bits of theory here and there but I am really far from an expert. The little I know is that they are prone to galling however they are available off the shelf. Also there are pins that are still steel but of a much lighter design also available off the shelf. Losing weight in this area is an excellent idea. Frak and Assassin would be the real experts on here I would think

[Slimer86]

Food for thought, pauter make an optional titanium rod available in their range. 4ag rods are in the range, specify titanium and hand over a lot of money.

[fantapants]

also, and i dont know if this is relevant, but titanium is a VERY soft and stretchy metal. Its surface is VERY tuff, but the metal itself is very flexible and soft. this may be a reason its not a great idea? Ive heard of hollowed steel being used to great effect though....

[assassin10000]

Depends on the alloy.

Sure titanium is light, and stronger on a weight to strength basis. But it can also fail a lot quicker with repetitive stresses. It also galls/siezes. IIRC. I don't remember how it responds to fatigue though.


A good lightweight chromoly pin & titanium alloy rods would be the way to go.

Andrew

[KENut]

I wouldnt bother making your own... As assassin said get chromoly pins.

Theoretically a solid pin would expand more, putting more friction and heat into the surface. Hollow will transfer heat more effectively. < just thoughts.


Before worrying about pins I'd chose the best and lightest crank I could, good pistons and rings with a anti friction coating etc, then decent rods. Usually more to be gained here

[sam2306]

while we are on topic of thing's like this, has anyone ever used anodized rocker arm's ?

[pen15]

Food for thought, pauter make an optional titanium rod available in their range. 4ag rods are in the range, specify titanium and hand over a lot of money.

yes i know of pauter's rods the x beam design is very intriguing and yeah i have email'd them and for $2500 im not sure i would front the cash id rather a set of alloy rods for around the $800 mark


ok firstly you have to know I talk big and know random bits of theory here and there but I am really far from an expert. The little I know is that they are prone to galling however they are available off the shelf. Also there are pins that are still steel but of a much lighter design also available off the shelf. Losing weight in this area is an excellent idea. Frak and Assassin would be the real experts on here I would think

do you know the company who makes them i do know wiseco make a lightened pin and its very cheap but i thought id look around


also, and i dont know if this is relevant, but titanium is a VERY soft and stretchy metal. Its surface is VERY tuff, but the metal itself is very flexible and soft. this may be a reason its not a great idea? Ive heard of hollowed steel being used to great effect though....

yeah i have heard of this but imo if you can make a con rod from titanium why not a pin?


Depends on the alloy.

Sure titanium is light, and stronger on a weight to strength basis. But it can also fail a lot quicker with repetitive stresses. It also galls/siezes. IIRC. I don't remember how it responds to fatigue though.


A good lightweight chromoly pin & titanium alloy rods would be the way to go.

Andrew


my little amount of research has found that titanium fatigues from contaminated oil and such as titanium rods are coated in something to stop that contamination i cant remember the coating but i can find it out

really would like to know of company's who make light pins anyone know of any??

cheers
mat

[pen15]

while we are on topic of thing's like this, has anyone ever used anodized rocker arm's ?

this is way off topic but i use them at work all the time many different brands and ratios seem to all work well but this isn't the thread for that

[KENut]

yeah i have heard of this but imo if you can make a con rod from titanium why not a pin?

rods and pins have different material requirements. Pins have greater surface temps for one. Not saying you ccant use titanium for pins. Do you have specs on the titanium you want to use?


On the subject of anodized rocker arms (sorry for continuing ot) are we talking rollers? If so I've seen heaps of failed ones, they usually have a big roller bearing but little material around it.

[ke_70]

what about the wear of the pins. steel vs titanium? if its anything like ally then if you get one little dag or shit it it then the titanium will "ball up" (think snowball rolling down hill) and destroy the pins in seconds.

isn't it very brittle? there for prone to fatigue?

[Sam-Q]

apparently titanium rods also suffer from fatigue, I saw on Billsherwoods site a custom set that where gold coated by memory.

Now a lightened crank doesn't have the biggest advantage of a lightened pin. With a lightened pin the inertia stresses of the whole recipricating assembly is reduced, crank is rotating mass only. Also it can pay to purposely leave some mass in the roating mass.

[assassin10000]

really would like to know of company's who make light pins anyone know of any??

cheers
mat

Original largeport pressed 18mm, or largeport/smallport/20v floating 20mm ones?

Dan/Oldeskewltoy went to several manufacturers to track down some press fit ones for his engine build.
http://forums.club4ag.com/zerothread?id=26593&page=3



Titanium wrist pins have to be COATED to prevent galling. That coating can wear off and lead to problems. They use ti pins in motox bikes, but when doing a top end job they replace the pistons & pins every so often. If racing them, sometimes anywhere from 1-3 races.

Andrew

[Frak]

My motorbike is factory fitted with titanium rods, they used these rods in the bike to homologate them for World superbike, the rods were lighter than equivalent steel items and during WSBK there is no record of a failure, most bikes went for years with the same rods, infact in the race prep manuals it makes mention of lifing pistons etc but not the rods. The rods are coated on the big end and gudeon pin to stop galling.

[fantapants]

frak would that longevity have much to do with the length of the rods in a motorbike? i might be wrong, but they are a way bit shorter arnt they?

and ti is anything but brittle.

[Skylar]

Fatigue will only set in if you exceed the fatigue stress. Those bike rods were probably designed with the fatigue stress above the maximum stress seen in the engine while operating within the specified parameters.

A fatigue failure will only occur when you exceed the fatigue stress a number of times and the life of the comonent decreases the further you exceed the fatigue stress. They say a component has 'infinite life' (of so many million cycles, can't remember the exact number) as long as the stresses applied to the component is less than the fatigue stress.

[sundee]

Random suggestion, but thought of 7075 alloy, used alot in aircraft strutual components. Super light and super strong

[Sam-Q]

aluminium as a whole has no minimum fatigue limit, so while the 7xxx grades are tough as they won't work for rods, well unless you put an hour meter on them