There have been a lot of questions lately re: prop pitch, shaft diameters, transmission ratios, etc. (they seem to come in waves!) so I decided to dig out my spreadsheet from IP Engineering circa 2009 with all of that information for the various models. I used this spreadsheet to code a new table for the IP Comparisons page (LINK). Select 'Engine & Prop' in the Compare: drop-down menu to view this new resource.
There's no data at this time for four models (IP26 Mk I, IP26 Mk II, IP360, and IP520) but I'll reach out to the fine folks in Largo to see if I can fill in some of the blanks.
Some models had more than one complement of engine/trans/prop listed in the spreadsheet (whether due to factory options or year-over-year changes). In these cases I added separate lines to the table to reflect the possible configurations.
Just about anything (engine, transmission, prop, etc.) might have been changed by previous owners in the years since your boat left the factory as part of an upgrade or repair effort.
It's always possible that the factory may have made temporary substitutions with equivalent or better parts due to product availability issues with their vendor (i.e. Yanmar) that aren't reflected in this table.
For these reasons there is no substitute for physically verifying what is actually installed on your boat before ordering replacement parts, service kits, manuals, etc.
If you have any questions or comments please let me know ...
____________________ Stuart Williams
Webmaster, IP Home Port
The Original Website For Island Packet Yacht Owners Since 1998
Stuart. To help round out a blank spot in your data, my IP38 came with a Prowell 19x12. Still running it and it works great. Repitched it a few years ago to around a 10 inch pitch which gives me a better top end, around 3400 RPM. Used to be around 3100.
Use caution when selecting a prop based on the original IP prop choice. I have found that several IP models were over-proper by the factory. Running at high speed with too much prop will reductive life of your engine. The problem will show up in excess wear/failure of the bearings on the crankshaft and/or the connecting rods. If your IP will not reach the Yanmar specified max RPM at full throttle, your boat is over-proped.
____________________ Art Richard IP32-34 St. Petersburg, FL
Believe it was factory installed. Boat did not have a spare fixed pitched prop when I got her 10 years ago so I'm thinking the Prowell was original. And it was overpropped as mentioned by Art. Should have been 10 inches vs 12.