For chainsaw enthusiasts looking to maximize the performance of their equipment, modifying and tuning their saws can unlock significant power gains. Within the realm of chainsaw modification, porting Pioneer Chainsaws, particularly within the P-series, has emerged as a popular and effective method. This article delves into the experiences of seasoned users who have explored the potential of porting these robust machines.
One experienced user shared insights into enhancing the performance of several Pioneer P-series chainsaws, including the P62, P41, P52, P42, and P45 models. Their approach centers around carefully adjusting key engine parameters to optimize power output. A foundational technique involves modifying the squish band and base of the cylinder. Initial modifications often include reducing the squish and base height, which can significantly impact compression. For instance, targeting a compression range of 180-200 psi on a P62 model is considered a worthwhile starting point for performance enhancement.
Exploring specific models further reveals tailored approaches. A 655BP model, closely related to the P-series, was mentioned as having stock porting with measured compression of 95 and 119 psi and a squish of approximately .024 inches. While minimal case matching and exhaust port polishing were performed, the internal porting remained untouched, demonstrating that even without extensive porting, these saws offer a strong baseline performance.
The P52 model showcased the impact of squish adjustment. With a tighter squish of .020 inches and the exhaust port divider removed, this saw reportedly rivals the 655 in performance when cutting a 20-inch log. Interestingly, the user noted that a previous iteration with a pop-up piston was actually outperformed by the current setup, highlighting that optimal performance isn’t solely reliant on a single modification but rather a combination of factors.
For smaller saws like the P42, even minor porting adjustments can yield noticeable improvements. A P42 with a .027-inch squish (without a gasket) and ported to 97.5 and 118 saw significant gains in responsiveness and cutting ability, described as “pretty snotty” despite minimal changes to port size and shape.
Currently, the focus is on rebuilding a P45 model. The user is aiming for compression figures of 96.5 and 119 psi, with a target squish of .019 inches, reduced from the initial .025 inches (without a gasket). Challenges in base cutting due to machine shop setup costs are noted, indicating that achieving precise squish measurements can sometimes require overcoming practical limitations.
While specific compression numbers are mentioned, the user emphasizes that the actual psi at their altitude isn’t a primary concern. The focus remains on achieving optimal performance through a combination of porting techniques and squish adjustments, based on experience and observed results.
In conclusion, porting Pioneer chainsaws, particularly the P-series, offers a pathway to significantly enhance their power and cutting performance. Techniques like squish band and base modifications, along with careful consideration of exhaust porting, are key to unlocking the full potential of these robust machines. The experiences shared provide valuable insights for those looking to delve into chainsaw modification and optimize their Pioneer saws for demanding tasks.
