any one in NZ make billet cranks for 3sgte /ge

[levinguy]

3sge/3sgte cranks are forged, 3sfe cranks are cast

what about 5s cranks?

[4agtepwr]

Stock 4age crank in mine that ive knife edged and lightend, not very much but a little and balanced but was very carefull when I balanced everything and stock front pulley as well, See's well over 9 grand pretty offten and no issues what so ever. Always run a harmonic balancer, there there for a reason. Alloy front pulleys destroy cranks/bearings/oil pumps. Im not so sure about 3s cranks but a good friend of mine runs a stock one in his celica which makes well over 500hp and the crank has never really been an issue, just the everything else haha

[iOnic]

Steve, are you suggesting that you've never seen bent cast rods?

[strx7]

3sge/3sgte cranks are forged, 3sfe cranks are cast

what about 5s cranks?

cast

[MAGN1T]

Steve, are you suggesting that you've never seen bent cast rods?

I've never even seen a cast conrod, they're all forged. Even in a 1955 ford V8.

Steve

[Celica RA45]

next you guys will saying i need to keep the altezza dual mass fly wheel .or the crank will break
and changing rod ratio will have no effect on the crank .it will only dwell at tdc longer same with bdc and it changes the piston speed down so i can rev it higher

[Grrrrrrr!]

next you guys will saying i need to keep the altezza dual mass fly wheel .or the crank will break
and changing rod ratio will have no effect on the crank .it will only dwell at tdc longer same with bdc and it changes the piston speed down so i can rev it higher

So you are saying that it spends longer at the top, longer at the bottom, and goes up and down slower... all while doing the same rpm? Thats seems illogical.

[Celica RA45]

we are talking milli seconds

[Grrrrrrr!]

we are talking milli seconds

You can talk femto seconds if you want, it doesn't change the fact that at X rpm you have Y time. If you are spending more of that time at the top and bottom you have to move faster on average in between to still complete the movements in the same amount of time.

[Celica RA45]

look at it this short rod piston speed maxes out about 8000 rpm longer rods changes piston speed so can rev higher im talking about piston dwelling at top d c longer thats it

[strx7]

look at it this short rod piston speed maxes out about 8000 rpm longer rods changes piston speed so can rev higher im talking about piston dwelling at top d c longer thats it

wouldn't spending longer at TDC and BDC mean acceleration and deceleration is faster which would put more stress on the crank?

[Celica RA45]

just found out that toyota australia use TTE cranks that are stronger and dont have problems ,like the std jap cranks ,seems like these are a problem if you rev these past 9 kay, say there you go
neil bates rod ratio is 148mm 10mm longer than std
its all to do with piston speed i have a 1.69 ratio std is a 1.6

[Akane]

WTF did I just read?

[MAGN1T]

Rod ratios is all bullshit, like lots of other things when it comes to cars, a compromise at best.
A longer rod puts less side loading on the cylinder walls, a shorter rod keeps the piston at TDC for less time supposedly reducing detonation or the effect of it.
It's just more money down the drain for no reason if you decide to change what you've got.

Steve

[Malcolm]

Actually having a greater rod ratio reduces your peak accelerations, not your speeds

Increasing the rod ratio reduces the force due to acceleration on the crank, conrod and piston, it also reduces the angular displacement that the conrod moves through during a cycle which reduces side loadings on the piston/cylinder walls. Unfortunately this does come at the expense of a longer/heavier conrod.

[Celica RA45]

thanks malcolm you got it it also lets it rev higher and the weight of the rod and piston works out to be the same as the std cast and beams rod ,as we use 20mm pins std is 22mm thinner rings 1.2 and 2.4 oil rings also grind crank down to use 4g62 mitso bearings on the big ends it all helps

[KinLoud]

Pulled a crank from a late model 5sfe - it was forged.

Ken

[Akane]

Pulled a crank from a late model 5sfe - it was forged.

Ken

How do you know that it's forged? Not doubting you just want to know how you can tell, besides no casting marks

[nzae86]

Here's one example of a forged crank

[Rookie]

How do you know that it's forged? Not doubting you just want to know how you can tell, besides no casting marks

This is a good how to: Cast Vs. Forged

Actually having a greater rod ratio reduces your peak accelerations, not your speeds

Increasing the rod ratio reduces the force due to acceleration on the crank, conrod and piston, it also reduces the angular displacement that the conrod moves through during a cycle which reduces side loadings on the piston/cylinder walls. Unfortunately this does come at the expense of a longer/heavier conrod.

This man, he knows.

Rod ratios is all bullshit, like lots of other things when it comes to cars, a compromise at best.
A longer rod puts less side loading on the cylinder walls, a shorter rod keeps the piston at TDC for less time supposedly reducing detonation or the effect of it.
It's just more money down the drain for no reason if you decide to change what you've got.

Steve

This man, he doesn't.

The only time you will find that having a large rod/stoke ratio doesn't help is on engines where the head can't keep up with the increased piston accelerations. A good example of this is smog era V8 engines, where the flow just couldn't keep up with the increased piston accelerations and would turn the flow turbulent, and as such you would lose lots of power.

I don't know why you would be trying to fix detonation with rod/stroke ratio, I personally would use tune, but hey. Having a longer dwell time at tdc also helps HP because at high revs it lets the flame front propagate fully, and means that you make the most of each explosion as opposed to the flame front chasing the piston down the bore.

so all in all, increasing the R/S ratio is a good thing for high performance cars.