Merc. Model 228 WOT RPM concerns

[LX Kid]

Have a good running '82 Merc./Chevy 305 in my Grady White with 3-blade SS Ballistic prop. Have good cooling and excellant oil pressure. Was wondering what kind of rpm's I could routinely run the engine for going long distances. Right now I hold the rpm's at 3500 and have a speed of 30mph. Is 4500 rpm's too much for long hauls?

 

[Bondo]

Re: Merc. Model 228 WOT RPM concerns

Have a good running '82 Merc./Chevy 305 in my Grady White with 3-blade SS Ballistic prop. Have good cooling and excellant oil pressure. Was wondering what kind of rpm's I could routinely run the engine for going long distances. Right now I hold the rpm's at 3500 and have a speed of 30mph. Is 4500 rpm's too much for long hauls?

Ayuh,... It'll wear out 25% faster...

 

[chrismurr1]

Re: Merc. Model 228 WOT RPM concerns

what is Merc's max RPM rating on those? my '84s have a max RPM of 4000-4400 so if your exceeding the max rated RPM your taking a big risk. you definately dont want to run WOT for long hauls. i would say your best fuel economy will be probably around 3700 RPM. it may only get ya a few more MPH but its better than risking the engine. i would say you can safely run it 700-800 rpm lower than your rated max.

 

[LX Kid]

Re: Merc. Model 228 WOT RPM concerns

I don't know what the WOT specs are for my '82 305.

 

[FreeBeeTony]

Re: Merc. Model 228 WOT RPM concerns

Are you sure your runnig 30MPH @ 3500 RPM's w/ that 305 Ron?

I am running 30MPH @ 3600 RPM's w/ a 350 w/ Vortec heads turning a 17" prop.....

How are you measuring your speed? Is your tach accurate? What pitch prop are you turning?

I have been looking forward to comparing numbers with you.....

 

[LX Kid]

Re: Merc. Model 228 WOT RPM concerns

Hi Tony. Long time no hear from you. I'm using both my speedo on the control panel and the speedo on my Lowrance GPS. They are both within 1mph of the other. I trust the Lowrance more. I'll have to go look at my prop but it's a SS Balistic 3-blade.

Update: The prop is 14 7/8 x 15 I'm using the new tach and did change the settings on the back after you thought I had the wrong selection on it. (Last Year)

 

[FreeBeeTony]

Re: Merc. Model 228 WOT RPM concerns

OK Ron......seems like you're numbers are better than mine...........your 305 is doing very well.

What is your WOT?

 

[LX Kid]

Re: Merc. Model 228 WOT RPM concerns

OK Ron......seems like you're numbers are better than mine...........your 305 is doing very well.

What is your WOT?

You've got a bigger engine pushing bigger prop = more gas.

Here's a crusing video, for you Tony, with my son at the wheel. http://www.youtube.com/watch?v=zw77HOpkJzg

 

[FreeBeeTony]

Re: Merc. Model 228 WOT RPM concerns

Looks like it is running great Ron..........

But what is your WOT?.......Just curious...........

 

[LX Kid]

Re: Merc. Model 228 WOT RPM concerns

Looks like it is running great Ron..........

But what is your WOT?.......Just curious...........

I ran it up to 4300 revs for a short period and did'nt want to go any further. That Edlbrock carb is sooooo sweeeeeet!

 

[FreeBeeTony]

Re: Merc. Model 228 WOT RPM concerns

Yes, that 1409 worked great right outa the box.....

What is your base timing? Do you have the Thunderbolt IV Ignition?

 

[LX Kid]

Re: Merc. Model 228 WOT RPM concerns

Yes, that 1409 worked great right outa the box.....

What is your base timing? Do you have the Thunderbolt IV Ignition?

8 Btdc with standard centrifigal advance distributor.