Best VH for NA build?

[WBY]

Hey guys, just a quick question. I'm planning on lightly building a VH to put into my 300z. All I'm really hoping to do is cams, ECU, valve springs if necessary, nothing major. I know that there are some differences (minus the chaing guides) between the 90-93 VH and the 94-96 VH. The biggest difference that I know of is the intake manifold, and I've read many posts on this forum that the eariler VH (90-93) has more power or at least feels stronger than the 94-96? I figure that the difference can't be too much, just curious if one is actually better than the other for building NA or if the difference is just too minimal to bother with. I currently have a very nice VH from a '94 Q45 and now I have a chance to pick up another VH from a '92 that appears to have low miles. Just wondering if its actually worth bothering with. Any input would be appreciated, thanks!

Mark

[elwesso]

I think most of the differences come from the ECU.. Its proven that a 90 Q45 stock ECU is slightly more agressive than the 94s.. Also, the 90-93 Qs were slightly lighter than the 94s so that would make a difference, not to mention the different 1st gear in the slushbox..

I think if you set a 94 VH45 and 90 VH45 on an engine dyno on the same ECU that they would be basically the same.

[Mettler]

The VH45DE is the only VH engine that exists

[WBY]

Thanks for the input guys! I know that the VH45DE is the only VH out there, its just that the 90-93 has a slightly different intake manifold than the 94-96 and I was just wondering if that would actually make any difference in the performance. I guess for now I'll just stick with the '94 engine that I have unless this '92 sells really cheap Thanks!

Mark

[Mettler]

Thanks for the input guys! I know that the VH45DE is the only VH out there, its just that the 90-93 has a slightly different intake manifold than the 94-96 and I was just wondering if that would actually make any difference in the performance. I guess for now I'll just stick with the '94 engine that I have unless this '92 sells really cheap Thanks!

Mark

Sorry, I was taking a sarcastic jab at Elwesso :p The jap spec VH41DE is actually the best base motor due to its superior dual row timing chain setup & a few other differences, but this is less useful to you being in the USA and all.

[elwesso]

im not taking it as a sarcastic stab, im taking it you FINALLY came to your senses!

[Mettler]

How so ? The jap spec engine is still better, it's just less common in the states. I'd always recommend it before a 45 though! But if I had to choose a VH45DE, it'd be the 1994 version. Oval ports + metal backed timing chain guides ftw

[Q45denver]

How so ? The jap spec engine is still better, it's just less common in the states. I'd always recommend it before a 45 though! But if I had to choose a VH45DE, it'd be the 1994 version. Oval ports + metal backed timing chain guides ftw

What's the advantage of oval ports?

[Mettler]

Oval ports achieve better feng shui on the engine, increasing harmony and prosperity.

Also, they reportedly flow a bit better, but this has yet to be thoroughly compared between a dual port & single port motor. Oval port is my preference because it ultimately lends itself to higher airflow capability, but in stock form, I believe people are noticing very little difference.

[Q45denver]

Ok, thanks. So probably a wash with sodium filled valves on earlier engines. My 1990 sure feels alot stronger vs. my 1995. Both are running NICO ecus which I have interchanged on occasion so I'm pretty sure it does not have anything to do with the ecu. The 1990 does not have the precats in headers but I'm told this does not have much effect on performance. So the only thing I can think of that might account for the difference is the slightly lower transmission ratios and weight and possibly the changes in the intake and the injectors.