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Head Development
Page 1 | Page 2 As part of our continuing cylinder head development, Raby's Aircooled Technology, in part with our 3.0 litre (2980cc) Type 4 build-up, has been working on new and improved type 1 style head for the VW Type 4 and Porsche 914. Current plans call for a fully CNC billet head, with ports designed and tested by Jake Raby and Len Hoffman, with CNC programming and machining by LN Engineering. Based on preliminary estimates, the improvement is staggering, especially in comparison to the "Conventional" Type IV cylinder head. What's important here isn't necessarily the output, but the huge change in output and smoothness of the torque and Horsepower delivery through all the entire rev range.
The above picture is an estimation of what our 3 litre would produce if paired with modified 2L "Conventional" Type IV heads. The valve sizes and port work done to these heads have reached the maximum potential of the stock Type IV cylinder head design. The test engine has been designed to realistically give both types of cylinder heads an "Equal" playing field. We have chosen a camshaft that does not benefit either cylinder head specifically, simply to prove the added efficiency of the higher flow rates and design of the "MassIVe heads". Keep in mind, the software used for this analysis is not any Desktop Dyno, but rather a full blown engine analysis package used by the pros!- Like us.
Both the intake and exhaust flow figures are shown here for the MassIVe heads, intake on the left and exhaust on the right, respectively. Mind you that these figures are actual flow bench data taken an 28 inches of water. Len Hoffman has worked very hard to build his own flow bench with data acquisition accurate to one tenth of one CFM tested consistently! Len decided to build this new bench because no other VW flow bench had the capability to flow these monstrous amounts of airflow accurately. The intake, in it's initial form, without much work, flows 280 CFM! Remarkably even the first prototype head has an I/E ratio of 76%! An I/E ratio of 80% is considered to be literally perfect for proper flow efficiency. That's significantly more than most Type 1 Performance heads. With 3 litres of displacement, we're going to make sure to use this flow to it's full potential, I wouldn't have it any other way, envelopes were designed to be pushed!!
Shown here is the estimated output of our 3 litre Type 4 fitted with our heads. These figures are based in whole from REAL flow bench data shown above. The 270 HP plots should not be a problem, as we're planning on exceeding the HP/litre produced by modern Porsche engines, such as the Boxster S, which only produces 260 HP with an additional 200ccs and 4 valves per cylinder! As with everything mechanical some outside forces enter the equation, so real time testing will definately be the key to showing the potential of this cylinder head and engine. Streetability and Longevity are our primary concerns with this engine, as it will be fit with our very own DTM cooling system and the largest LN Engineering Nickies cylinders ever made custom for us at 105.07mm! If we can't do it, we'll darn sure try! Currently we plan on doing four configurations of this engine before it is ever permanently installed into my vehicle. During this time it will see numerous back to back tests with the different cylinder heads, two different engine management systems, Vs. carburetors and even a roller cam design. The final configuration will find our cylinder heads installed, custom JE pistons made from NASCAR forgings, numerous coating procedures, full cryogenic enhancement and last but not least our roller camshaft and lifters. In final form my goal is to surpass 300 HP. And the answer is Yes, this is a 100% street car, driveable daily, either on the freeway or in town, and even utilizing air conditioning! The engine will be cooled with our DTM cooling system pictured below, and will prove that this cooling system can cool even the largest of large engines, as well as the lesser powerful counterparts that most average enthusiasts desire. This engine has used 100% of my development network and I would like to Thank every member of that network that has dedicated their time, ideas and thoughts into this remarkable project, with what I am sure will be exceptional results!
Cooler cylinders and heads keep the engines efficiency higher and increase engine life and even increase fuel economy! Fuel economy is a benefit of higher efficiency! So is HORSEPOWER!!! Jake Raby Copyright 1997-2008 Raby’s Aircooled Technology. |
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