Thread: VH45DE Pistons in VE

It would def be cool to see that's for sure.. Are you going to use that big crank aswell?

No, just a stock crank with this motor.

The strain is on the rod bearings, pin, skirts and bore. That extra weight is over exponential.

The lower sides of the skirts have more weight against the bore, the small end bearing starts to cop more and more stress. The VH piston doesnt have cooling feed channels and it certainly doesnt have any skirt coatings. Its at a higher chance of cracking from higher RPM use.

There are many variables here that will make this unreliable. Not because im a "naysayer" but from an engineering perspective. The whole project is dangerous for reliability - but hey - go for it right?

meh. go with a 1.6 crank to solve those issues. well, most anyway

And 25psi of boost on a 9:1CR DET isn't exponential force compared to a stock DET? I don't see people blowing up motors there

I think what Autech is saying is that the heavier weight of the pistons and the extra side-load they are going to put on the cylinders. Also keep in mind that rpm is an exponential force acting upon a much heavier piston. So the higher you rev, that heavy piston is going to show extra wear.

But the stock DE comes with 17mm rod bearings and the GTiR comes with 19mm. Yet real-world examples show the DE sized bearings holding the same amount of power without any issues.

I guess we just have to look at the tensile stresses going on, not just the compressive.

There are many ways to measure reliability.

People build motors to fit needs. Some build motors around the thought of keeping it for 30,000mi+ while others build them to the limits, race them and move on less than 10,000 miles later. It seems as though people on here look at all builds to fit their "daily" and last them forever.

I will continue to try new things, learn and have fun with these motors. I know what I want out of this motor, that's all that matters.

^^^Thas what I'm talkin about!!!

Sure i know what your saying.

Im not talking about daily driver miles. Im talking about race situation - maximum loads and stresses.


Coheed: 1.6 crank puts higher stress on the roads and bearings. More than a 2.0 crank does. With a longer sweep and shorter rod the stress is trasnferred throughout the crank rotation - using the 1.6 crank puts higher spikes of stress on the bottom end.

Definitely need to see if this works.