WOT question

[Justin Larsen]

Hey all,

Getting more comfortable with my vessel now and had a picture perfect glass river to play on yesterday morning so I decided to see what wide open throttle looked like on my 94 220 OV. I was only able to rev to just under 4200 and achieve 38 MPH. That seems low and I was wondering if anyone had any experience to confirm or discredit that though. The set-up: mercruiser 5.7 with aplha 1 gen 2 prop is an aluminum quicksilver 1916p19, not sure what the gearing is on the drive (anyone know how to find this out?)

Thanks all.

 

[sbw1]

Hey all,

Getting more comfortable with my vessel now and had a picture perfect glass river to play on yesterday morning so I decided to see what wide open throttle looked like on my 94 220 OV. I was only able to rev to just under 4200 and achieve 38 MPH. That seems low and I was wondering if anyone had any experience to confirm or discredit that though. The set-up: mercruiser 5.7 with aplha 1 gen 2 prop is an aluminum quicksilver 1916p19, not sure what the gearing is on the drive (anyone know how to find this out?)

Thanks all.

Google 5.7 WOT spec and you will find lots of info. It depends on year and gear ratio of your particular set up.

 

[MrHappy]

Besides the open bow we have the same set up. I haven’t put her at WOT in a long time. When I first bought her she had 290 hours. I did open her up. Got what is expected, 4600 RPM and 46 MPH.

I have a Stainless Steel 3 bladed prop, 14.5 X 19.

While on vacation in Michigan last week I took her up to 4,000 RPM and was doing 41 MPH.

I like to cruise at 3,100 RPM. Seems like I get the best gas mileage(per hour) at that RPM.

 

[sbw1]

Besides the open bow we have the same set up. I haven’t put her at WOT in a long time. When I first bought her she had 290 hours. I did open her up. Got what is expected, 4600 RPM and 46 MPH.

I have a Stainless Steel 3 bladed prop, 14.5 X 19.

While on vacation in Michigan last week I took her up to 4,000 RPM and was doing 41 MPH.

I like to cruise at 3,100 RPM. Seems like I get the best gas mileage(per hour) at that RPM.

A 5.7 will last forever if you cruise 3,000-3150 RPMs and keep up with the maintenance. Our 260 Express was new in 1979 and we sold it in 1986 with 3,800 hours on it. The 5.7 still ran very strong, had the same wot as when new, and used no oil. Very durable engine if properly cared for.

 

[MrHappy]

View attachment 90351
A 5.7 will last forever if you cruise 3,000-3150 RPMs and keep up with the maintenance. Our 260 Express was new in 1979 and we sold it in 1986 with 3,800 hours on it. The 5.7 still ran very strong, had the same wot as when new, and used no oil. Very durable engine if properly cared for.

 

[MrHappy]

I was just talking with someone that knows engines. We were looking at my 1997 Suburban. 5.7 liter and the same engine as my boat. He said the same thing you did. The 5.7 is a very reliable and long lasting engine.

 

[Thornton69]

The '97 carbureted 5.7 in our boat was originally in front of an Alpha gen 2. Specs on the cover say 42-4600 wot. It is in front of a Bravo 2 now with a bit better than a 1000 hrs on it. It still tickles the 40 mph mark at 4450 in our heavy 245. Tough engines but this one is starting to show some oil deposits on the #7 and 8 plugs by the end of the season. Getting close to refresh time.
edit. I guess in '94, merc wasn't into the roller cams yet. Yours may have a different rpm rating.

 

[Chris-380]

We have 16 boats on our dock, I bet 4 or 5 have 5.7 that went between 4-500 hours. I always thought they were bullet proof, but seems like the 1999-2002 era had an issue with head gasket Between The 3/5 or 4/6 cylinders. Both merc and VP

View attachment 90351
A 5.7 will last forever if you cruise 3,000-3150 RPMs and keep up with the maintenance. Our 260 Express was new in 1979 and we sold it in 1986 with 3,800 hours on it. The 5.7 still ran very strong, had the same wot as when new, and used no oil. Very durable engine if properly cared for.

 

[Chip S]

Hey all,

Getting more comfortable with my vessel now and had a picture perfect glass river to play on yesterday morning so I decided to see what wide open throttle looked like on my 94 220 OV. I was only able to rev to just under 4200 and achieve 38 MPH. That seems low and I was wondering if anyone had any experience to confirm or discredit that though. The set-up: mercruiser 5.7 with aplha 1 gen 2 prop is an aluminum quicksilver 1916p19, not sure what the gearing is on the drive (anyone know how to find this out?)

The Sea Ray propeller chart for your boat is at https://owners-resources.searayweb..../1994 Sport Boat Sport Cruiser Prop Chart.pdf . The gear ratio is 1.50:1. The OEM prop was 14 x 19 with a WOT of 4600 rpm. Your Quicksilver 1916p19 prop is 14.5 x 19 so it should be fine. Not sure why you are ~ 400 rpm low for WOT, although the extra 0.5 inches of diameter may reduce WOT slightly.