Does anybody know if the vr38 crank fits into the vq35hr block.

 

Not directly.

The HR has a 57mm big end housing bore, and the VR has a 59mm. VR rods are also .894" wide at both ends, compared to .818" of the HR. So basically you would need custom rods made to handle the task. Then again, you were probably thinking custom rods anyway.

Another obstacle to overcome... the VR crankshaft does not have the oil pump drive on it that a VQ crankshaft has. Where the oil pump drive goes, the VR crank is lathed down to match the inside diameter of the timing sprocket.. and the VR timing sprocket is just like the VQ except it has a second set of sprocket teeth further back that goes in area of the oil pump drive. The second sprocket is for running for the VR 2-stage oil pump which is down in the oil pan.

These are the differences that *i am aware of*. I am otherwise under the impression that the VR crank does fit the HR block as far as sitting in the mains, and the front and rear seals. So, I believe that if you used custom made rods, and machined a sleeve to slide down the crank, before the timing sprocket, and drive the oil pump, you could possibly run it. But I might not be correct, never tried it... only listed what I know is different.

 

Thanks for that info the oil pump drive is not a prob as we run a dry sump and the pump is removed. The next thing is the deck hight if it was the same i might be able to run gtr rods.

 

VR rods are 13.26mm longer than HR rods... between that and the stroke of the VR crank, that would put your pistons about 16.76mm deep into the cylinder heads at TDC. Better use a REAL thick headgasket

BTW use the timing gear sprocket from a VR. It will have the extra teeth for the oil pump you dont need, but it lines up the offset of the timing chain teeth in the same spot as a VQ crank.

 

Which dry sump do you have? Custom or Dailey?

 

I built a custom billet sump and a weaver pump for this motor looks like rod ratios would be all wrong with that set up might just put a 37 crank in.
I have photos of the motor on one of my threads.