Honda GX160 Crankshaft Questions??

[Colemanman]

Ok so I have a Honda GX160, stage 1, governor removed, 2 degree timing advance, total timing is 30 degrees and a light weight flywheel with stock valve springs and pvl flywheel. Does this have the forged crank like the gx200 does? Are they alot stronger than the cast predator and clone cranks? What can the crank safely rev too?

 

[65ShelbyClone]

All the genuine Honda GX160 and GX200 cranks are forged. Many, if not most of the Chinese variants do too. They are all designed to rev no higher than about 4000rpm, so there's nothing inherently "safe" about going beyond that. Breakage most often happens above 7500 or 8000.

 

[Colemanman]

Cool cool

 

[itsid]

Nah the crank is a secondray failure
you can rev it to the moon and back w/o any problem,

it needs a shock to fail, and a particularly heavy one at that.
it takes some beating,
but the inertia of a fast travelling piston and or flywheel is significant enough to break absolutely everything
above a certain threshold (8000'ish doesn't sound too far off)
the reason race kart 2strokes rev twice as high easily is not a "better material" crankshaft.
while it's more carefully balanced it the rest that makes most of the difference!

There is no better crankshaft than the stock one!
different lift perhaps, better balanced (you can balance your crankshaft yorself if you like)
but not stronger material.


'sid

 

[65ShelbyClone]

And usually the engines that spin 8000+ are built to make a lot of power anyway, so it's not simply a matter of RPM that causes the crank to fail.

There are also no-name aftermarket cranks that are solid and don't have a cross hole through the rod journal. I want to get one for my nitro hemi GX140, but I imagine it would need some serious balancing. I don't recall exactly, but want to say that 160/200/212/etc cranks usually need mass added to the counterweights.

 

[Colemanman]

Right on guys thanks got information. Its helpings me learn alot

How come they drill the jorunals? I noticed that before on a few of my cranks during governor removal

 

[65ShelbyClone]

It's a lot faster and cheaper in mass production than adding weight to the other side of the crank.

 

[Colemanman]

Oh ok its a balancing method. Good to know.

 

[JTSpeedDemon]

Generally as long as you keep it topped up with good oil and make sure all the internal clearances are in check (Mainly the rod journal and wrist pin), it's pretty hard to break a crank, there's hardly any examples of that happening here on the forum. Most of it comes down to mindless assembly on the bottom end.