We are all aware of the many recent advancements in performance part engineering for a traditional Pontiac engine. These range from new cylinder-head technology to a myriad of valvetrain and rotating assembly parts, along with ignition and fuel system evolution. With this in mind, HPP is embarking on a long-term strategy to build a test stroker 455 of our own.
The entire purpose of this engine is to become what is known in Detroit as a mule. In engineering parlance, a mule engine is one that is exposed to different parts, theories, and conditions to accurately determine the best combination of components for an intended use.
Our Pontiac mule will be dedicated to finding the best combination of street/strip parts with accurate and progressive testing. The mule will be confined to dyno duty only. As time goes on, it will be exposed to different cylinder heads, camshafts, valvetrains, intake manifolds, fuels, and carburetors, along with anything else we can think of. It will appear with a good deal of regularity but will not be in every issue.
[1] Before beginning the align-boring...
[1] Before beginning the align-boring procedure, all measurements were taken and the block was cleaned. The main caps were removed by Craig Wise to allow fixturing of the mandrel.
Once again, HPP will be working with RaceKrafters Automotive Machine in Lancaster, Pennsylvania. Bob and Craig Wise are well versed in Pontiac engine building, and have an excellent facility with the latest in engine building and test equipment. The shop boasts a Stuska engine dyno with the newest Depac data acquisition and control system, a Super Flow 1020 test bench for cylinder head and intake manifold development, an Audie Technology Cam Pro Plus for camshaft inspection, a Serdi cylinder head shop to precisely cut the valve-seat angles, and a Sunnen SV-10 programmable cylinder hone.
The Sunnen hone will be able to create and control the cylinder wall finish in a way that Pontiac engineers could have never imagined when our 455 block was cast in the ’70s. This is important since major advancements in piston and ring design require a special crosshatch finish. This will allow us to bring the cylinder wall into the 21st century with the newest technology.
[2] With the block secured...
[2] With the block secured in the align bore, the mandrel that holds the cutting tool is carefully located in the proper place.
Though the main purpose of this exercise is to test traditional Pontiac engine parts, there is a very important aside to it. HPP recognizes that the Pontiac community involves more than just older engines. There are many hobbyists who are enjoying the virtues of newer Pontiacs with a corporate powerplant. For this reason, the information that will be covered in the machining and assembly installments of the mule program will apply to any engine.
The basics of machining are the same regardless of the year of engine. Thus, we will provide a technical over view of how each procedure is executed and its need, along with the synergy that is established with other processes. The author’s goal is to educate the HPP reader on advanced machining theory. This is not an attempt to make you a machinist, but to establish how and why certain steps are required when reworking an engine.
[3] The cutting tool is located...
[3] The cutting tool is located using a dial indicator.
A common mistake that is made during an engine rebuild is to short-change the procedures. How many times have you heard a ring and bearing job identified as a rebuild? That is not a rebuild—it’s just a ring and bearing job.
For accurate test results, we will need to rebuild our 455-based mule. That means a complete disassembly and machining of all critical areas to bring it back to as new tolerances. Everything that is being done to our test engine is what will be required for a proper rebuild of any Pontiac engine, not one that will only live its life on the dyno.
When it comes to engine work, you need to take an all or nothing approach. Either do the job right or live with the mill as it is. From the author’s experience any time someone tries to scrimp on machine work, the engine is never right and usually has a multitude of issues, such as poor oil control, excessive noise, or a premature failure.
[4] Here the cutting bit that...
[4] Here the cutting bit that will size the cap and saddle is clearly seen.
[5] The cutting tool starts...
[5] The cutting tool starts on one end of the block and walks through all of the main caps. Though the align bore procedure is mechanized, it’s controlled by Craig with a watchful eye.
[6] Here is the mandrel and...
[6] Here is the mandrel and cutting stones for the align-hone procedure.