Rods, Pistons And Other Things
The key components in the NORAD 3RZ engine are an object lesson in no-compromise engineering. The pistons, rods and crankshaft are essential components that must perform at 100 percent to allow the engine to realize its full potential. With this in mind, Norwood selected his components very carefully.
"I'm anal about what parts I put in a race engine," Norwood reveals. "I'd rather pay extra for a top-quality part than have to deal with the problems that arise when you start trying to save a few bucks. It's a matter of finding what works for your application and then sticking with it. I'm not saying that you shouldn't experiment or research your options carefully, but at the end of the day quality is the greatest consideration."
There's no question about the quality of the components in this engine. JE Pistons is an established manufacturer of racing pistons and the NORAD 3RZ features a set of 96mm custom slugs that are forged from 2618 aluminum alloy to give an 8.5:1 compression ratio.
The pistons are designed to withstand the extreme boost levels that this engine will see, but also, for weight-shaving purposes, to carry a minimum of material in non-load-bearing areas.
The wrist pins are JE 93-series high-strength tool steel items and the pins are located with JE Tru-Arc wire ring locks. LC Engineering installed its own Moly-Plasma dyke rings for best performance and then, finally, the pistons were sent to Calico coatings for treatment.
Calico coatings are the leading supplier of high-tech coatings to the performance engine industry and they offer several different coatings for different applications. The NORAD 3RZ uses Calico's CT1 Teflon-based coating on all of the bearings to assist with lubrication. Piston tops, chambers, exhaust ports and exhaust valves are coated with Calico's CT2 metallic ceramic coating to assist heat dispersion and help eliminate "hot spots".
The skirts of the JE pistons are also treated with Calico's CT3 matrix-flouropolymer high-stress lubricant coating and finally the rods and crank are coated with the CT5 flouropolymer oil-shedding coating to minimize drag.
The next component of the NORAD rotating assembly to be selected was the connecting rods. Rado's 2003 engines ran several different variations, but Norwood was specific about his choice for 2004.
"I really like Pauter Engineering's design," he says. "It's very strong. In fact, I ran Pauter rods for the entire season in Kenny Tran's Honda and we never had a single failure despite leaning on them pretty hard. (Understatement: Tran's 1.8-liter Honda is generating in excess of 1,000 hp.) Another thing I like about the design of the Pauter rods is that they have a very narrow profile and as a result we see minimal drag from them at high rpm."
Rado's 2004-spec engine's feature custom-billet 6AL4V titanium Pauter rods cut down significantly on the weight of the assembly (it's 33 percent lighter than forged steel) without affecting strength. Not inexpensive for sure, but Norwood is not interested in cutting any corners on this engine program.
The final component in the NORAD Toyota 3RZ is the crankshaft. As we found out earlier from Norwood, the stock Toyota forged-steel item is plenty strong, albeit a little on the porky side.
The answer comes in the form of LC Engineering's Pro-Lite version of the stock crank. This is a trick piece of equipment and it's a perfect example of careful development creating a part that is strong, light and reliable under extreme duress.
The stock crankshaft cores are tested and inspected for imperfections before LC begins working on them. Then the crankshaft is knife-edged to produce less crank windage and faster acceleration without sacrificing strength. Total weight reduction is around five pounds.
After the machining work is completed the crank is shot-peened and heat treated for extra strength. The journals are then micro-polished and finally the crank is dynamically balanced before it's Magnaflux inspected and treated with Calico's CT5 oil-shedding coating.
The main and big-end bearings are sourced directly from Calico and are pre-coated, and all the fasteners used in the assembly are top-of-the-line articles from ARP.
Norwood lastly comments, "The block and the rotating assembly are the heart of a race engine. If the job is done correctly, they'll take nearly anything you can throw at them. In an application such as this I prefer to hand over responsibility to a specialist like LC Engineering. We've shared ideas and I think the final result will be an absolute killer motor. LC proved last year it could build a bad-ass engine, but this year's motor will be a major step up in terms of outright horsepower."
The setup and dyno-tuning of the NORAD Toyota 3RZ will reveal lots about the potential of the combination, which we'll reveal in a future article. Next month, we'll look at the ancillary systems such as the dry-sump, charging and crankcase evacuation systems and examine the cam drive and camshaft design. Stay tuned.