No offense, but this is literally the most incorrect statement I have ever read on a forum. I'm a mechanical engineer and these kind of calculations are what I do for a living. I'm not arguing anyones experiences or stories, but just because you ran a 30hp engine on a 3/8 chain does not mean you USED 30hp (because of all the variables weve discussed). Id prefer to size everything so that if I do end up using the full power of the engine, it wont cause issues.
HP is a load at a speed - it DIRECTLY ties back to a tensile load which a chain is rated for. Consider a log chain (the kind you find in a tractor). Would you say the load it can carry depends on what kind of wood youre towing or what kind of ground it's dragging on? No. The chain gets rated for a load and all those factors determine how much of that rated load you actually use.
I know arguing on a forum is like peeing in the wind, but with all due respect, this is a subject I am confident in and your liberal use of "imo" and some of the incorrect statements ive seen are quite honestly scaring me. I'm only responding to try to educate and help prevent injury. Please dont take this as chest pounding.
If anyone cares, heres some reference material to keep you safe if using high power. This same information exists somewhere for .063 and smaller chain and thats what I was looking for but have not found. I know it's "worked" for some, but thats not what I was asking for - I want the actual data.
Check out page 22 for all technical data on 11, 16, and 18 harvester chain
http://en.oregonproducts.com/pdfs/Harvester_HandbookA106976af.pdf
Check page 7 for Stihls equivalent.
https://m.stihlusa.com/WebContent/C...nManuals/STIHL_Harvester_Saw_Chain_Manual.pdf