VHR Billet Block

Originally Posted by Elmo370z

Ahh that clears it up a lot more than google. I'm going to keep you in mind when I decide to rebuild my motor and do a dry sump set up to rev 9,000 rpms. As far as longevity what are your thoughts about it? Eventually I will track my car maybe once or twice a year and mostly driving it on the weekends.

Originally Posted by phunk

I would not do a wet-sleeved block with longevity in-mind.. I would do it for high power cars being used for drag racing, roll racing, standing mile, and other acceleration contest.

For road racing, I wouldnt do the wet sleeves... not to mention, I dont think the power of a road racing car is going to touch on the power where wet-sleeves would be in the discussion. Imagine trying to track a 1000rwhp 370z... that would make a great video but it would probably lose to 350rwhp all motor cars with good drivers.

I wouldnt put wet-sleeves on the discussion table unless we are talking about 800+ rwhp.

Originally Posted by phunk

Cosworth has HR/VHR headgaskets which I *believe* are manufactured by Cometic for Cosworth USA.

These are the gaskets I am going to try out on this build. My favorites have classically been HKS gaskets, but they only have DE style gaskets for the VQ.

What is very important is that you get proper head bolt or stud clamping force. This was the biggest problem for built DE's for a while, and cost the community a ton of money and gave VQ's a terrible name for high power. Everyone was using the standard ARP2000 head studs which had too low of a torque spec to hold up in the 500s and 600s, and head lift was a big problem. Nobody quite understood at first because it felt like the headstuds wouldnt be the issue after having just "upgraded" them. But it turned out it was the problem, and once people got the 1/2" studs done or L19 studs that could handle 90-100lb-ft of torque, the head lift issues and headgasket issues mostly subsided.

The VR engine uses a thread that is 1mm larger diameter than the VQ. Normally you couldnt machine a thread to just 1mm step-up because you wouldnt have removed the old threads yet. But I am pretty sure the PITCH is the same between the two, so very very carefully, it may be possible to oversize the threads up 1mm, but it would be a critical procedure and probably not recommended to bother. But I might try it, maybe. L19s havent been tearing out of the stock threads at high torque, but I would feel better with a larger thread in the block.