Comparison between VH45, US VH41, and JDM VH41 heads... many pics!

[Mettler]

Why are these guys with highly modified VHs swapping out the ignition coils+fuel injection setup for a distributor and a carb?

They're not as highly modified as you think. Many VH superstock engines run stock rods & factory HLAs etc... with just decompression pistons and porting + cams being the only power mods. Oh, and of course the intake and exhaust mods.

The distributor and carb setup is to make the engines meet the regulations.

Superstock racing has been around for years, from the days when everyone used a SBC or a Ford, and now that the japanese V8 motors are prevalently being used, they have to be running the same kind of configuration to keep it 'fair' and competitive. (lol, as if significantly increased curtain area due to multivalve engines is fair :p VH engines dominate now)

Rules across the board also necessitate throttle restrictor plates, max of 12.7mm valvelift, 10.0:1 max compression, etc.

[T45]

Your 92 has the sodium filled exhaust valves. My 92 had the sticker on it.

[tmorgan4]

The guy that sold me the engine sold me some crap for what I paid, and the engine was completely disassembled. With as many Q parts as it sounds like he has, I wouldn't be surprised if they came from a different engine. I can't remember seeing that sticker, but it DID have the siamese intake ports.

On another note, the shop that rebuilt the heads had to replace one valve for me. Now that I think about it, I never thought to ask if it was an exhaust or intake valve. If it was an exhaust valve I'm sure the new one ISN'T sodium filled. What difference it will make having one non-sodium filled valve if that's the case...I have no idea.

[T45]

If the lower runners are siamesed as well then your valves are more than likely sodium valves. If the lower runners are oval port then it's a newer engine.

Whether or not your replacement one is... who knows. If they bought it from infiniti it is, assuming it's for a 92.