Will displacement remain at 1.8-liters?
Yes, we plan to keeps things as close to stock as possible.
The factory compression ratio is 11.5:1? What will the race engine run?
We are planning to run 9.0:1 compression in the race engine.
What is the factory combustion chamber size? Will it change?
It's 32cc; we will be leaving that alone, as well.
The pistons will be TRD spec...
The pistons will be TRD spec units from JE Pistons. The 83.5m bore slugs are 1.5mm over and feature custom placement of the wrist pin and ring set. Note the deep-dish treatment. Piston-to-valve clearance is key in this application, because if the VVTL-i system is retained (which the plans call for later) and lift is increased or timing aggressive is advanced, then interference can occur.
The TRD plan calls for deleting...
The TRD plan calls for deleting the VVTL-i system and running a heads-up set-up. A traditional adjustable cam gear will used for fine tuning in place of the VVTL-i's constantly tuned cam degree strategy.
Here we see the rocker arm...
Here we see the rocker arm off a 2ZZ. To delete the VVTL-i system, shims will be inserted at the tip to keep the system from engaging.
Is the combustion chamber an open or closed design?
Open design. It is almost like a hemispherical chamber, but it's got more of a wedge style to it because of the valves, which take up almost the entire combustion area. It has great valve angles. If you were to cut the head in half, it almost looks like a slice of pie with a spark plug hole in the center. Very efficient.
What kind of engine management system do you foresee controlling the 2ZZ?
We're running a PacTell stand-alone system. We run it on the SCORE off-road series and a couple other special applications.
Does it have datalogging capabilities?
Yes, and we definitely plan to use datalogging extensively for on-track tuning.
What about the turbo?
We're running a Turbonetics turbo, but I am not sure which one at this time, but I can ask them what they have in mind.
I'd sure ask them before they give you that horsepower target too. There could be a very rude awakening awaiting someone.
Currently, the plan calls for dyno testing a half dozen or so units until we find the right balance between spool-up and top-end flow.
The valvetrain will be running...
The valvetrain will be running Inconell exhaust valves and stainless-steel intake valves. The intake will remain at the stock 34mm diameter. The exhaust valve is 28mm from the factory and TRD will be using a 31mm with a 6mm stem. The thicker stem on the exhaust valve is for added durability.
Here we see some basic smoothing...
Here we see some basic smoothing on the exhaust side of the head.
ARP fasteners are to be used...
ARP fasteners are to be used exclusively in this build-up.