testing props for 23 DVCC with F250XCA 4.2L

[captmatt]

I have been testing props to find a good choice for my 2013 23 DVCC with F250XCA (4.2 L). I am interested to hear your experiences.

So far, the best prop I have tested is a Mercury Mirage Plus in 15 pitch. It gives good fuel economy at mid and upper cruise rpm and feels "right". I may go with this prop. I am looking for lower speed planing though, so I am going to try a couple of four blades.

I also tested a three blade black painted Yamaha prop in 17 pitch original to the boat, and a 15 pitch Powertech OFX4. The OFX4 gives great stern lift but is not enough pitch. The painted stainless is a good choice as well but does not provide much stern lift or low speed planing.

I have looked at the other prop threads. My motor is a 4.2L with a 1.75 gear ratio so props that work well on the 3.3L motor will be too much pitch for a 4.2L. I am not going to install a permatrim.

Does anyone have experience with an OFS4 in 16 pitch? How about a Mercury Mercury Enertia ECO in 17 pitch? A Mercury Rev4 XP in 16.5 pitch?

Mercury Mirage Plus in 15 pitch

rpm	mph	mpg	inches per min	pred. MPH	slip
11	4	3.2	9428.571429	8.9	55.20%
33	23	3.4	28285.71429	26.8	14.13%
35	24	2.8	30000	28.4	15.52%
36	25	2.9	30857.14286	29.2	14.44%
36	26	3.3	30857.14286	29.2	11.02%
37	27	3.1	31714.28571	30.0	10.10%
38	27	3	32571.42857	30.8	12.46%
40	28	2.7	34285.71429	32.5	13.76%
43	32	2.7	36857.14286	34.9	8.32%
45	33	2.5	38571.42857	36.5	9.65%
46	35	2.3	39428.57143	37.3	6.26%
48	36	2.4	41142.85714	39.0	7.60%

black stainless 3 blade 17 pitch

rpm	mph	mpg	inches per min	pred. MPH	slip
9	5	5	8742.857143	8.3	39.61%
11	6	4.8	10685.71429	10.1	40.71%
13	7	4.3	12628.57143	12.0	41.47%
32	23	3.4	31085.71429	29.4	21.87%
35	26	3.4	34000	32.2	19.25%
37	28	3.2	35942.85714	34.0	17.74%
39	31	2.9	37885.71429	35.9	13.59%
41	33	2.8	39828.57143	37.7	12.51%
44	36	2.6	42742.85714	40.5	11.06%
45	37	2.6	43714.28571	41.4	10.62%

 

[GoodChance]

What is you max rpm with the 15" Mirage Plus? I would think it's greater than 4800 rpm. Give me a call if you want to talk about it

 

[captmatt]

Those numbers are just what I was able to record. (The conditions varied a bit as well - rougher when I tested the Mirage Plus.) I was not able to take the boat above 5400 with the Mirage Plus because of conditions, but there was more throttle left. The three blade black stainless has a max rpm of about 5600 and 50 mph.

 

[GoodChance]

Get some more numbers including WOT and graph in Excel.

I would think that your boat with an F250 4.2l would easily be able to spin a 17" Mirage Plus prop to 5800 RPM.

Given the cost of new props, and overall performance, the Mirage Plus is hard to beat. Yes, there are other props that will/might give you slightly better performance but will cost you $600-800 for marginal increases in fuel economy. And you don't run that far in a typical trip to warrant such expenses