Thread: "True HP"
View Single Post
Old 03-21-2013, 12:29 PM
TRBenj TRBenj is offline
MC Devotee
Join Date: Dec 2005
Boat: 1990 Ski Nautique
Location: NWCT
Posts: 1,205
Originally Posted by FourFourty View Post
(Which is the same way that PCM makes the 6.0HO...... They just use a different long block assy.)
I do not believe that is true. The ZR-450 uses a cam made specifically for PCM, per the engineer I spoke with at length. The cam, intake and different A/F curve (which makes use of 93 ocatane) are the things that separate a 409 and a 450.

Im not disagreeing on the different hp rating conventions. Ilmore does seem to be the only one quoting the CARB numbers, for whatever reason. I dont doubt the different marinizers put out comparable hp levels when comparing similar engines. It is convenient that all of the Indmar and PCM numbers are low, though. Who actually conducted the CARB testing? Do all marinizers go through this (and only Ilmore chooses to publish those numbers) or did Ilmore take the initiative to have the competitors tested to the same standard they chose? The numbers on the 350 based PCM sure look way out of bed with the way those boats perform (277hp vs. 330-343 stated). I saw the same chart posted at the MC booth at the boat show, I took it for marketing spin. Its not like automotive headers on a dyno will give you real world hp numbers anyways. Like I said, the proof is in the pudding (the way the boats perform).

Originally Posted by EJ OJPROP View Post
Tthe 13 X 14.5 spins 3750 RPM or so at 36. Lower RPM at that speed than say another brand of boat with another brand of propeller. The 13 X 14.5 is well suited to do it's slalom thing with the Ilmore and 1.26:1 trans.
Eric, does that mean the 13x14.5 is the (common) stock prop on the 197's these days? Even 6.0L's? Im guessing youre referring to the SN200/Acme1868 (12.5x14.25) running very high RPM, which was the stock prop on the Excal (350) boats... though now Ive heard CC is going to the slightly larger 654 (12.5x15). Its been my experience that OJ's run slightly lower RPM vs. Acmes of the same dimensions for whatever reason. A prop with 14.5" pitch sure seems short for a 6.0L though... one would think it would need a larger wheel to keep from bouncing off the rev limiter at WOT. Ive seen 6.0L 196's run right up to the 5600 limit with 12.5x15.5 Acmes. Not sure where Ilmore puts the limiter, but assume it would be similar.

PT, I sure would think the 197/6.0L would be good for 44-45 even with a big guy like you on the end of the line. You can hold off on that Sanger for now- you know where to go if you need a 60+mph Barefoot Boat! No outboard necessary.
Reply With Quote