Does anyone make, or ever tryed to make a connecting rod out of 7075 aluminum, or perhaps some sort of titanium alloy. I know a stock one isn't extremely heavy but i can't help but wondering.
Aluminum connecting rod
- Thread starter BilletBlaster
- Start date
Aluminum rods are not made for longevity. They are a race only piece.
Aluminum fatigues when it's put through stress and them just snaps.
If you want to get crazy you can sand, knife-edge, and polish your stock rod to make it lighter and reduce windage.
Aluminum fatigues when it's put through stress and them just snaps.
If you want to get crazy you can sand, knife-edge, and polish your stock rod to make it lighter and reduce windage.
you could EDM holes in the length of connecting rod and retain its strength
to reduce mass ,aluminum isnt going to hold up especially under the rpessure and rpm of a drag motor
you must remember reliability is always very important no matter what
if you cant finish the race ...you cant win !
to reduce mass ,aluminum isnt going to hold up especially under the rpessure and rpm of a drag motor
you must remember reliability is always very important no matter what
if you cant finish the race ...you cant win !
hmmmm....
flotek, you ever EDM some holes in a rod or knife edge and polish one like paulie said? i would be interested to see if it net-ed any gains besides just throttle response.
flotek, you ever EDM some holes in a rod or knife edge and polish one like paulie said? i would be interested to see if it net-ed any gains besides just throttle response.
I have operated ram EDMs about every day for the last 12 years of my life ,i have not done this YET..although lately i have been wanting to try it .rotational mass is the best place to trim fat ,a ligther aluminum piston is noticable so imagine a lighter but yet tough steel rod ,it would surely in theory make more peak rpm and allow the crank to spool up quicker with less effort
yeah, makes sense. what percentage of the weight do you think you would be able to remove? i think i'd be worried about it breaking though....
what? holes and radii create concentrated stress points under axial loading...
your stress factor K would have to be less than one, which i don't believe it ever is. am i missing something?
your stress factor K would have to be less than one, which i don't believe it ever is. am i missing something?
not familar of the theory behind it but it can atleast be plenty strong for the application if its done right ,EDIT:I did some researching and it is a common misconception and one i belived could happen in theory ,hey guess i learned something ,but there is a possiblity it can be machined and wont be any weaker .the ram EDM process does not introduce the stress that other machining does ,internal stress is a huge factor in the longevity and strength of something in that environment. why dont you try it on your motor and report back if it held up or failed ? lol
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lol!! i DId it, worked great. i think everyone should drill holes and grind down there rods. and dont forget to shave the skirt for ultimate throttle response!
hahah i'm sure you got more motors layin around than i do, and i aint exactly got a, what, $12,000 edm in the garage haha
LOL, I think I'll stick to shaved flywheels to cut the rotating mass. As far as conn rod mods go, it would be stronger if you sanded and polished it. A porouse surface is more prone to stress breakage than a smooth surface. There would be some very mild weight saving in doing this as well. IDK about the aluminum not holding up though, there are drag cars out there with several thousand hp running aluminum rods. I would think they are not offered in the 2 strokes due to production costs, thinner steel rod affects intake charge less and also the aluminum offers a problem with the style of rod bearings used in 2 strokes.....discuss.....
would one hold up for a seson of constant changing rpms and conditions on a bike that doesnt get torn down after each run though.the temperature coefficient of aluminum and steel is different enough it would have ot be designed in such a way that bearing insert chase would expand at a thermal rate that would still work for the tolerances required, aluminum transfers alot of heat rod stretch could get tricky under high stress /rpm or possibly weaken it .
this is a very interesting topic. wildcard, i can see what you mean about smoothing it, all the pits are like little holes on the surface, which is a concentrated stress point. flotek, you have a good point about the bearings, and the aluminum's greater expansion rate and rod stretch would also have to be compensated for with squish band clearance.
but the facts still stand, we have aluminum jugs, aluminum pistons, and cases. my car has aluminum rods, and as wildcard said, many drag cars do fine with aluminum rods. granted, their not 2 strokes, but i think someone *coughflotekcough* should make an aluminum rod, possibly heat treat or shot pean it, put it thru a thorough testing, then post their findings for the world to see. who knows, maybe it'll make you a lot of money!
but the facts still stand, we have aluminum jugs, aluminum pistons, and cases. my car has aluminum rods, and as wildcard said, many drag cars do fine with aluminum rods. granted, their not 2 strokes, but i think someone *coughflotekcough* should make an aluminum rod, possibly heat treat or shot pean it, put it thru a thorough testing, then post their findings for the world to see. who knows, maybe it'll make you a lot of money!
i was trying to decide whether removing weight from the rod would yield more or less gains than removing the same amount of weight from the piston. my initial thought was that weight removed from the piston would be more beneficial b/c it has very sudden acceleration changes, even when the motor is spinning at a constant rpm, whereas the rod has a somewhat more circular motion. but then i thought again.
removing weight from a flywheel can be beneficial in certain applications, and although the bottom of the rod has a circular motion, the top moves just the same as the piston. so who knows, maybe removing weight from the rod will be more beneficial?
removing weight from a flywheel can be beneficial in certain applications, and although the bottom of the rod has a circular motion, the top moves just the same as the piston. so who knows, maybe removing weight from the rod will be more beneficial?
I see the point that it works in other applications and its a neat idea but when considering the potential gain for the average guy youd be way better off lightneing the flywheel and possibly removing the counterbalancer(drag application) if you wanted to cut down on rotational mass.for 99% of blaster owners I dont see it making a big enough difference with such a risk of catasphory,from a statisical standpoint : if it holds up theres a good percentage chance likelihood it helps increase throttle response and increases some peak rpms .. but if it fails and lets loose theres a 100% chance of expensive carnage and destruction
