NA builds. How far to go?

[jondee86]

I guess what I was trying to say in my previous post (but didn't spell
out) is that your power goal is not out of reach with a bigport engine.
Both engines have the same bore and stroke. The smallport has more
compression from stock and the port sizes on the heads are different.

Many people consider that the bigport head is better for high power
applications, and it is not difficult to bump the compression up with a
set of pistons. A good porting job will allow more air into the engine
and a decent set of headers will help get the exhaust out.

Cams with the emphasis on lift rather than duration will make more
torque and power while keeping peak power within your rev range. And
of course a fresh bore and hone with new pistons and rings will always
work better than an engine pulled from a wreckers yard.

The compromise you have to consider is the balance between power
and torque. This will be influenced by throttle size and manifold design.
A smaller ITB (say 42mm) will give better throttle control and better
low end torque, but a larger ITB (say 45mm) will be better for top end
power. The overall length of the intake from trumpet mouth to valve
head is also a key factor in getting a good result from ITB's.

So yeah... plan it out on paper. Talk to people who have been down the
same path and had good results. No sense in reinventing the wheel with
a high power 4AGE... it has already been done 1000 times by others

Cheers... jondee86

PS: Here is a link to something worth reading...
https://motoiq.com/extreme-engine-tech-t...oyota-4ag/