Doesn't seem right ...

rjrose · **Posted:** Thu Jul 11, 2013 8:08 pm

My buddy has a '95 sea ray with "big block" motors (7.4L?). We were cruising together the other day. I was running @ 3900 and just barely keeping up with him. He told me he was running @ 3200. I have the 6.2 Mercs. I know there are a ton of variables involved but I was surprised at the difference in rpms and speed.

Open for discussion.

TX H210SS · **Joined:** Thu May 27, 2010 9:10 am **Posts:** 1488

Do you know what the prop setup is on both boats? That's where the rubber meets the road.

taz42169 · **Posted:** Fri Jul 12, 2013 5:31 am

I think TX really, really, really, really wants to know what size prop he's running! :twisted:

acguy · **Posted:** Fri Jul 12, 2013 5:47 am

Need more info, are both boats stern drives or are you running inboards in that boat

rjrose · **Posted:** Fri Jul 12, 2013 6:59 am

Don't know what size props he has. Both boats are inboards. As I mentioned, probably too many variables to come to any solid conclusion. I have smaller engines, more weight, etc.

wkearney99 · **Posted:** Fri Jul 12, 2013 7:58 am

There's an old saying "there's no replacement for displacement". Larger engines certainly make a difference, especially for constant duty cycle activity like running at cruise speed. They're just making more power. Combine that with lesser weight and, well, you've seen the outcome. Props can certainly make a difference too.

But meanwhile also pay attention to the condition of the bottom of the boat. Any amount of growth on it will absolutely make for slower running speeds. I know ours is a pig when a cleaning is needed, like a 10mph hit on the top end.

rjrose · **Posted:** Fri Jul 12, 2013 7:28 pm

Thanx for your comments, Bill. Long time since we chatted.

Bottom condition is not a factor as least not the way it is/can be with you guys in salt water. Since I moved to "coastal Georgia" I have been horrified by what I see growing on boat bottoms. One of the many reasons I did not take my boat down there.

I will find out about his props but in the big scheme he just has more power.

ric · **Posted:** Sat Jul 13, 2013 12:22 am

You can't compare small block to big block.

billcruise · **Posted:** Sat Jul 13, 2013 7:43 am

ric wrote:

You can't compare small block to big block.

Agree completely... Buddy's 328 with big blocks happily cruises at 3200 while my old 328 with 5.7s happily cruised at 3800

www.iFourWinns.com

Doesn't seem right ...

Who is online