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The 3.0 is slow for many reasons, one is that misengineered and very restrictive crossover, the other is the air intake. The biggest problem w/the 3.0 is that it can't breathe, it's congested! Let the engine breathe by getting rid of that restrictive x-over, put some headers on and modify your air intake and she runs pretty well! <img src="/forums/images/graemlins/kewl.gif" alt="" /> [/quote]
I do not agree here. The x-over pipe is a very common design on front drive V-6 engines (which was what this engine was designed for). It is still widely used wtih engines making a lot more power than the 3.0.
Personally I do not think that this engine was ever intended to go into this truck but Toyota needed more power to compete and this is what they had.
This was also Toyota's first V6. Typical 1 generation Japaneese stuff has its share of issues while they learn. In my opinion they did pretty well with only a minor head gasket problem and an engine that will easily run 200k plus miles. Shoot, GM and Ford can't do that today.
We like to complain about this engine but look at your other options for '89 - '95:
Ford Ranger: 160hp 4.0L
Chevy S-10: 175hp 4.3L
Nissan: 150hp 3.0L
Chevy 350: 205hp
Dodge 318: 180hp
and on and on and on.
We have come a long ways in the last 15 years as far as making power. Remember the '89 Mustang at 225hp, that thing was FAST at about 6.0 to 60. Today the Honda Accord makes more power and is faster.
How have we done this? Variable spark timing as a result of DIS is huge. This has allowed us to learn a lot about fuel maping, running richer and leaner while compensating spark to eliminate predetination. We have learned a lot about air flow and have improved heads significantly.
I think that EB may be on to something with the exhaust valve sizing. 2-valve engines are usually torque monsters but for some reason this engine is weak between 1,500 and 3,000 rpm. Then it dies out above 4,800.
If the exhaust was the limiting factor the header guys would be noticing huge power gains. They notice very little.
If the intake was the limiting factor the Camry V6 should be making a lot more power. It didn't. Or at least the guys who are porting the intakes should see it. They are not seeing huge gains.
Cams help but not like they should.
I think that I have seen every kind of intake box configuration imaginable with nobody noticing huge improvements either.
The cat? Plenty of you do not have cats. I took mine off and noticed nothing.
Exhaust? Nothing big here either.
What is left? The block, pistons, stoke, bore? Stroke and bore will have an effect on torqe or hp but they are not what will hold a 3.0 at less than 200 hp.
The fuel system? With the mileage that my truck gets I do not think that it is starving for fuel.
The heads are the answer. I have heard that someone is putting later model Camry 4 valve head on a truck motor. This may be it. Maybe EB could ship me a set of 3.0 heads with bigger valves? I am willing to pay. If there is room in there to get them in and still have a head that will be reliable.
