Lets get back to the head transfer from the camary.

I have no Idea what i would take to change the SOHC to the DOHC, but It could be cool to try if they would fit on them. How would a person find out about it?

 

Dunno if it would work at all I think it would take a lot of modding the 3vz to fit the DOHC.

The timing would have to be changed to accomodate the DOHC
the VVT requires different computer, might need to change the fuel tank and pump might need to be different.

mebbe some of you might be interested in doing a project like that, but it may or may not work quite like you want. I dont know of anybody thats done such a thing...or even tried, but its pretty risky and costly....

I for one have no money for such a project, and even if I did, I would probably just prefer to go with a 5vz, which in my opinion would be an easier project especially for the money required, and so far as Ive heard it turns out pretty nice. Plus the TRD supercharger is floating around a reasonable prices, which I would definitely opt for if I had the 5vz.

IF someone decides to try making the 3vz into a Dohc ITs definitely a project you should put up here on the messageboard and tell us all how it goes.


If you got the time and money go for it.



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I would also like to mention that engine size doesnt mean that its weak or not. take for instance the subaru WRX. It has a 2.0 L 4 cyl boxer engine that produces 227 horsepower. or the Isuzu engine currently used in the rodeos and rodeo sports, 3.2 L v6 produces 205 HP. Its not the size, rather the design of the engine and what its been tuned for.

I personally think that the 3vz was poorly designed and that toyota should have stuck the the 22RET. I would love to find an 86-87 4runner or truck with the turbo, which produced more power than the 3vz. The 3vz has been plagued with head gasket problems. That aside the 3vz is not all that bad my 94 has 241,000 miles so far, but It has had a rebuild. As long as the head gasket doesnt blow its pretty good, and if fuel economy is a problem, just be glad you dont drive an H2.
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Was it the Acura Legend or the Acura NSX?

 

The 3.0 that is in new cars is the 1MZFE and it is quite the power house, it has become quite the all purpose motor being in everything from the sienna to the solora. This motor replaced the 3VZFE which is DOHC. For some odd reason they decided to put the SOHC version, the 3VZ-E, in the four runner. The 3VZ was way before VVT, and quite a lot of 1MZFE's are available with out VVT seeing as it is a fairly new technology. The swap from SOHC to DOHC should be fairly straight forward since it is pretty much the same engine. Same block different head. Shoudln't be too much hard then swapping heads on a honda. If any of you could talk to a mechanic who specializes in toyotas and find out what hard ware would be needed that'd be awesome. On first thoughts all you would need would be the heads, new head gasket, and probably some timing accesories(timing chain and such).

Oh yeah, check out my mad researchin' skillz boi!

 

NSX. But the Legend powerplant was decent too, just not VTEC powered.

 

Output of toyota engines

According to this, turning the 3vz-e to a 3vz-fe would boost hp by 50 and ft/lb buy 20! This would give more hp than a stock 5vzfe, but less torque. I still looking into the possibilty of this.

 

Hi everyone, I'm new here and just found this board. Actually I was referred here from another bulletin board. Anyway, I have a 1988 runner 5sp and I have been disappointed with my gas mileage too. What is the intake tube mod that I have heard about? I did a search for it and didn't really come up with much. Also, does a less restrictive exhaust do much to help with power or gas mileage? I am basically looking for the best bang-for-buck mods that I can do to increase my gas mileage.

Thanks,

Scott Stanley

 

Have you guys ever driven a heavy vehicle with high HP and little torque? Yeah, it doesnt go anywhere at low RPM's. By all means, go for the swap, but when all is said and done, you are going to really need more torque.

My old 95 Civic SI with 4 people in it comes to mind. It was around 160HP with about 110ft-lbs of TQ...at 6K RPM! Yeah, city driving was really fun.

Let's be realistic here guys. We still have to match up the head design, oil passages, coolant passages, etc. Someone needs to get a headgasket from each engine and compare.

 

Stanley:

First we need to know what engine you are running. The 4 cylinder, or V6.

as far as gas milage goes, It will never be great, but there are a few things you can do to get it better.
1) Tune up
2) Intake silencer removal mod. ISR mod
3) modify your driving style. In other words, The truck will only go so fast, mashing the throttle will just use more gas.
4) Free flowing exhaust.

on the front page of the website, there are a bunch of stuff if you scroll down, and a page dedicated to mods, check them out, they are great.
front page


Now back to the DOHC mod. This is something that we need to follow up on. I am going to talk to some toyota mechanics here, and see if I can get a head from a salvage yard cheap to compare.
If anyone has info, let us all know.

 

The 3.0L is a great engine...if you're living in Japan. I found this out when I went there last year. The Toyota engineers and managers are Japanese and grew up in Japan, they've never driven here in America. Their speed limit is 50mph, they have no hills like our rockies or sierras, and they don't tow anything. They have no concept of what we have to deal with here and are way too conservative to take risks by making bigger engines, they're going to stick with what they know and that's making small, relatively fuel efficient engines vehicles. Only now are they figuring out that americans want power and that's why the tundra is such a big hit. Nissan will likely find that out too with their fullsize truck.

 

HI All

I’m new to this forum as my son (fooddude) owns a 94 4runner. I’m not a Toyota engine expert, but I do know a little in general about engines. In general, SOHC have better torque at the lower RPM range than the DOHC. I can see the DOHC work for everything except 4 wheelers who enjoy crawling through mud and over big rocks at lower RPMs. With that said, I enjoy mods like head swaps and making them work. So I’m not discouraging the idea, just giving some light to why the 4runner might be a SOHC.

Beary

 

Seeing as I am not much of a 4 wheeler and my runner is just my transportation I am seriously lookign at this for a little more oomph and better mileage. Now if only I could get a job....

It's rough here in fort worth.

 

I agree with your theory - generally speaking. But explain to me why the D16Z6 (1.6 SOHC VTEC, 106lb-ft TQ ) has less torque than the B16A (1.6 DOHC VTEC, 111lb-ft TQ) then?

I dont think the SOHC/DOHC comparison is a rule of thumb.

 

Ok, I've heard a lot about different engines, and bad gas mileage from the 3.0 L V-6. I know that those numbers don't mean much when looking at them in general, but I'm asking what, in the engineering, caused the Toyota 3.0 L V-6 to be crap. Along with the, dare I say, Ford 3.0 L V-6? Is it fuel injectors, a low compression ratio, or even just the valve lift? I still love my engine, I just want to know WHY it's the way it is.

 

>>I agree with your theory - generally speaking. But explain to me why the D16Z6 (1.6 SOHC VTEC, 106lb-ft TQ ) has less torque than the B16A (1.6 DOHC VTEC, 111lb-ft TQ) then?<<

Hi 96

At what RPM are your numbers. Torque and horsepower change as a function of RPM. Other things are a factor also, but as a general rule, all things being equal, DOHC torque curve is lower at low RPMs but raise faster because of larger volume or air being pulled through from two sets of valves. That is also why dragsters prefer super chargers over turbos. Super chargers pump more air at low RPMs raising the hp and torque at the low end. Turbos generally kick in at the higher RPMs.

>>I dont think the SOHC/DOHC comparison is a rule of thumb.<<

NO it's not a hard firm rule, but it is a good rule of thumb. I don't knw why the 4runner 3.0 is a SOHC. I was just speculating that 4 wheelers in general need more power at lower RPMs.

Have great day

Beary

 

D16Z6 (SOHC) 106lb-ft TQ @ 5200RPM

B16A1 (DOHC) 111lb-ft TQ @ 7000RPM

 

You guys make me hate my '94 TOYOTA PICK-UP 3.0 L V6 ever more than what I hate it now.

 

well I happen to LIKE my 3.slow...

 

King...
I can't stand to see you unhappy. I'll give you $500 for yours and you can go get that new 3.4 in a Taco.

 

I'm going to refer back to my previous post. I love my engine, it gets me where I want to go, and does good off road. I'm not bad mouthing this one bit, but I do want to know what causes it to be so bad. I know that it can't be just because it has a SOHC.