An internal combustion engine is just a big air pump. You want to get the air into the combustion chamber and out of the combustion chamber as efficiently as possible with just the right amount of fuel and spark to make the maximum horsepower. Up until this point we have shown you what it takes to build the internal parts of a 400+ naturally aspirated K Series engine and in this part of the series we will deal with all those bolt on parts needed to support the work inside the engine that we have already done. There are a lot of options on the market for bolt on K series engine parts. Knowing your goals and working with the right people go a long way to get the correct parts on your engine the first time around.
Let’s first discuss how to get the air into the engine. We have been long time proponents of the intake manifold and single throttle body setup on the naturally aspirated K Series engines and up until recently that is what we ran. This time around with all new fresh parts, a larger displacement engine and the potential to flow more air we decided to use an Individual Throttle Body setup from Kinsler. The 70mm individual throttle bodies are huge. These will flow more than enough air to support 400+ naturally aspirated horsepower. We are still convinced the horsepower can be made and supported with an intake manifold and single throttle body but we are at the point where the R&D had to be kicked into high gear with that setup and with R&D comes time and cost. Using the proven Kinsler ITB setup just got us further ahead in a quicker time frame.
To get the air out we worked with Myers Competition Manifolds. You just don’t open a website and order a header for an engine build like this, you consult an expert. Very few people have built as many and learned as much about what K Series engines want for header design than Jack Myers. With his data and knowledge learned from hundreds of headers built he is able to take the information you supply as far as engine size, internal parts being used, horsepower goal and engine use and build you a header that will meet your needs the first go around. No trial and error, no comparison testing needed, just the right header ready to be bolted onto your cylinder head.
The air is flowing in and out of the combustion chamber and now we focus on the fuel needed to create the horsepower. Fuel Injector Clinic has continued to grow into a top supplier of fuel injectors for a large variety of applications. From your basic bolt on street engine to 2000hp fire shooting monsters they have the injectors for your application. It is important to keep in mind the type of fuel you are using for proper sizing and functionality of the injectors and with Methanol and the desired horsepower the Fuel Injector Clinic 1650cc would not only support the current goals but give us room in the future to make even more power.
The new generations of large flow injectors are not a hindrance to idle characteristics or partial throttle drivability anymore either, another great development in the world of high performance modern day engines. Fuel flow to the injectors is handled by a Weldon 2035 fuel pump with a Weldon Racing Teflon Diaphragm Fuel Pressure Regulator. Again going with a tried and true brand Weldon Racing builds fuel pumps for airplanes. The aviation industry has the most stringent requirements for parts being used on airplanes, especially military planes which is where Weldon Racing fuel pumps got their start. All of this knowledge has trickled down to their high performance fuel pumps for race cars. They are pricey compared to other options on the market but this is truly a situation where you get what you pay for. Weldon Racing fuel pumps can go thousands of hours before needing any service and the ability to rebuild the fuel pumps at a very low cost make what you purchase today a fuel pump you can use for the long haul. This engine is being built for drag race use only so it will see limited run time.
With that in mind we only need a small radiator to do the job of cooling the engine and with the CRX chassis engine bay space is at a premium. What we are using actually started as a full width Griffin Radiator for the CRX chassis. We had a local fabricator cut the unit down to the size we needed to fit in the engine bay. It then got an electric fan and a Meziere Electric Water Pump to flow the water through the engine. Turn the engine on, turn the water pump on and let the cooling happen. Electric water pumps are a great way to free up some horsepower as they take the power robbing drive belt off of the engine.
Another advantage of the electric water pump is to be able to run it while the engine is not running if needed to cool the engine down even quicker in the pits. 16v batteries are a great option for race cars as they eliminate another power robbing drive belt from the engine but in our case we have decided to stick with an OEM Honda alternator with a Braille lightweight 12v battery. 16v batteries can be temperamental in our experience. At the track you have to ensure that you always have power to charge them between rounds and even still they randomly do just go bad. I can recall 2 specific experiences in the last 5 years on another car that left us scrambling for a 16v battery around race day as we realized the one we have been using failed.
The factory Honda alternator leads back to a Keep It Simple Stupid mentality and that worked for us with racing. To round out the parts being used on the engine spark is being controlled by NGK coil packs with Denso Iridium Spark Plugs in the cylinder head and we run a catch can system off of the crankcase and a scavenging system off of the valve cover to rid the engine from as much crankcase pressure as possible.
That wraps up the external accessories in the engine bay. The next and last installment of this series will review the setup of the engine management and chassis to put those 400+ horsepower to the track. This engine is being built for the World Cup Finals Imports vs Domestics All Motor Class Oct 31st – Nov 4th, 2018 at Maryland International Raceway. [gallery link="file" columns="4"]