VRX460 Magnum

[raydhd]

192 reminds me of the built in cooling shroud of the VC 625 block.

[Calleberg]

Those and the twins where never of great interest to me for go kart use, too big and possibly a nightmare for the clutches (and frame?) Also My VC460 seem healty enough to match some of the 125cc two strokes. The 625 where not around for long was it?

[raydhd]

It is still for sale from zongshen us.It seems they were VERY sensitive to any less than perfect mounting angle for oiling and the billet rod was not available soon enough. A youtuber had one torn down and the whole short block was incredibly well built. I think VC with the EPA issues on the 460 just wanted to sell an approved engine that they were the sole provider of. Unlike the 460 where there was a whole lot of engine development with the 390 clones in racing the 625 had nothing. And that soon showed up. Now VC is really just pushing the 670 engine swaps. Somewhere Geoff stated he wanted out of the engine business. MAYBE speed equipment BUT not complete engines. Harbor freight is supposed to start selling 460's here. I think ECcarbs wildcat 460 was the start of 460's back in the USA but they are out of stock. As the old saying goes Stay Tuned. I asked Geoff on his site IF the long rod and piston production would be restarted and got no answer.

[Calleberg]

Those Chinese blocks I posted pictures of earlier does seem to match the ECcarbs Wildcat block, maybe this is the way forward after all, the rest of the china engine looks slightly different with the old school type valve cover compared to the wildcats weird 4 bolter

[raydhd]

I noticed some of the 460 inverter generators also use the 4 bolt valve cover like the wildcat. Really curious what the rocker arm set up is like in them. That and the extra block shrouding and fan housing makes a lot of sense for the quieter inverter units.My all power america 460 generator the oil filler is a much larger diameter and the valves themselves use automotive style keepers. I converted it over to champion rocker arms and moly push rods and everything bolted in.

[Calleberg]

Maybe I need to correct myself, it appears 92mm stroker pistons have evolved since 2017. What VC used to supply was a heavyish cast piston with 2mm top and second rings, basically 1980'ies tech.

Today NR racing supplies a 92 mm equivalent to the Honda GX390 tier 3 piston which is a lighter low friction more modern design with a 1,2mm ring pack.
The real kicker is that the comp height is 1mm taller than the original VC piston, which makes the long ARC rod and newer style piston closer to the 4.51 VC rod and piston combo. Fun fact; NR racing and some off the other suppliers still show a picture of the original VC style piston in their webshop.
Oh, the lightweight piston is missing its piston pin locks, so in reality it is somewhat heavier, the actual pin is lighter than the VC pin due to a 0.9mm larger id.

[raydhd]

Now you got the seeds of doubt in my mind as to which piston is in my Omega? It came from NR. Being I bought last winter it is probably the earlier VC unit which was actually the dished clone piston with the top milled down. Are there any top markings to identify which is which ? It is great the 460 92mm engine goes on even without VC's support.

[Calleberg]

Not sure what you mean, they both look identical on top, flat tops with a small cast in arrow. It does seem though that the newer style piston has a thicker crown, with the extra thickness being very close to the increase in compression height.

[raydhd]

I am guessing by that I have the old style as there very little material above the top ring. Shepard had me do some measurements to ascertain what could be eyebrowed for the hemi valves. We concluded that was not a candidate. He was going to you the Ross forged unit from NR.

[Calleberg]

Well the new style piston does have roughly one more milimeter of chinesium in the crown and the racing type piston skirt style is possibly placing a tiny bit more meat close to where the itty bitty valve relief cuts would be.

This 90 mm Hemi piston seem to be a very similar casting
https://www.nrracing.com/product-p/4...onkit-hemi.htm