I know nearly everyone here hates the 3VZ and loves the 5VZ (3.0 and 3.4 respectively), but when you look at the math, they aren't actually all that different.

150HP/3.0L = 50HP/L
180lb-ft/3.0L = 60lb-ft/L

190HP/3.4L = 55HP/L
220lb-ft/3.4L = 64.7lb-ft/L

The 3.4 isn't actually that much better, displacement-to-power wise. Yes, I have driven both, and yes, I acknowledge that it is a night and day difference. I'm simply talking math here.

Here's where my crazy idea comes out, feel free to laugh at me.

Hypothetical situation (truly): someone with a 3VZ-E powered Truck or 4Runner has the bottom end go out. They don't want to go through the trouble of a full 3.4 swap. Would the 3VZ heads bolt to the 5VZ block? Essentially, you'd wind up with a 5VZ-E. Especially if you are living in California, this would greatly simplify smog checks, since all the original intake/heads/emissions stuff would bolt on (maybe?). I don't kid myself that you'd get as many gains as a DOHC 3.4, but an SOHC 3.4 should yield some nice results, I'd think.

I know this isn't the case, but assuming the HP/L numbers stayed the same, you'd wind up with 170HP and 204lb-ft.

Something to think about anyway.

won't work, waste of time and yes, the 3.4 IS significantly better, despite your math musings. <img src="/forums/images/graemlins/smile.gif" alt="" /> I've owned a number of both, and I actually like the 3.0, but it really doesn't compare to the 3.4.

If I did my reading correctly, the intake/exhaust stuff is on opposite sides, or at least the bolt-on stuff is. I'll hafta do a little digging.

Imho the 5cz is actually pretty torquey if it can move my T100 pretty well. Also think of it this way, its a very efficient engine in terms of power. Dodges 3.9L only makes 175hp and 220tq and it has a half a liter more. Fords 4.9L has over a liter more in displacement yet only makes 160hp/260tq and chevy's 4.3 makes 190/250.

This make sense to ya? They all have bigger engines yet only produce marginally more power.

And that is why good analysis does not rely on one arithmetic illustration....

There is no comparison between the engines. The difference is the sum of many small refinements adding up in the best possible way.

Well, this is about the response I predicted <img src="/forums/images/graemlins/lol.gif" alt="" />



I still maintain the 3VZ is a decent motor, and agree the 5VZ is awesome, but not quite as awesome as most people make it out to be. IMHO.


My main reason for posting this is to address the 5VZ shortblock idea.

Does the .4L come from bore, stroke, or both? If the shortblock wouldn't work, would the 5VZ crank in the 3VZ block fit/help any? Now that I'm not at school anymore, I need these wild and crazy ideas to occupy my mind during the day <img src="/forums/images/graemlins/drunk.gif" alt="" />


That and I plan to stay here in Kali and any way I can keep things smog legal more easily is always good to know.

You would have some missing headbolts.

There was a guy on another board claiming to have 3.4 heads on a 3.0 and after going out to the shop and looking I thought to myself BS. After staring at this crap and thinking maybe there was a year change I called in the Toyota gurus.

Tim at DOA racing said noway because of headbolts and valve timing, John at LCE said the samething, and Ted at enginebldr sent me a very colorfull and detailed email confirming what the other guys had said.

That would take away all the great attributes of the 3.4... teh heads! That is what is making the extra power, the .4L of displacement maybe gives it 5 hp, the heads are where power is made!...

As far as displacement-to-power ratio goes, you are correct.
However, there is a flaw in your general logic, in that this ratio is not terribly important if you want a powerful/fun truck... it really matters more for fuel economy etc.
For example - how'd you like an engine that gets gets 65 hp per liter? Better, right? Well, take one out of a Mazda Protege (or any othe small car). It gets a whopping 130 hp with only 2.0L.
But I bet you wouldn't enjoy that motor very much, eh?

Now, how about a nice big 5.0 or something? Think that wouldn't be a powerful motor, since it only yeilds 50-55 hp/L?
Hell no. The thing is, what matters in the end for your truck is the total power, not the relative power. It's not like you can actively adjust how much of the CCs you use in order to make the most of that ratio anyway. What's you're talkin gabout is power efficiency... a totally different animal from what *I think* you're looking for here.

Honestly, I think that teh amount of work involved in hibrid-izing a 3.0 and 3.4 is greater than just doing a full swap, and dealing with the smog ramifications directly.
Not bein gfrom CA... I'mnot familiar w/ thsi issue. Is it not legal to change the motor? Or, do you just have to have all teh matching equip for the donor vehicle?

Just can the 3vz and get a 5vz. I am THIS far from yanking my 3.0 out in favor of a 5vz. I am getting spoiled by my 97.