fuel / Range Question?? 2800 SCR

[Mothers Day]

Hey Guys:
I am seeing a ton of 2800 SCR's at the marina, haven't been able to ask any of those owners yet.
What's the fuel range? I know it depends on rpm, but just the basics around 3,000 - 3400 which should give me approx 25 mph. (ocean)

Local destination of Catalina Island off the West Coast is only 28 miles, and I don't trust guages much.
If I can keep from filling up at 8.00 per gallon I'd like to keep from spending money foolishly.

[Baby Blue]

We've had our '98 2800 one season now.. love it!
7.4L carbed.
I store by boat 45 miles from our dock in a indoor heated building.
Leave the dock at full tank and made the run twice now. once to bring home and once to store, same location.
cruised 3400 which is about 26 mph for us with 2 people.
Started at full tank and was at 7/8 full when I got there so you will be fine. Same held true for both trips. just top off tank prior to the trip if you plan on doing some cruising around.
When purchased our fuel sender was bad. easy to replace and I upgraded gauges so I'm pretty sure it's accurate.
I'd guess you'd have a 200 mile range on a full tank...just my best guess though. you should be able to trust the guage though.
If you at 1/4 tank and fill up how many gallons does it take?
your boat should be 102 gallon capacity.
hope this helps.
BB

[Mothers Day]

Shoot. I should have been clearer. My 2800 has twin 4.3 liter motors.
But thank you for all the info
Ps. Are you fresh or salt water?

[Baby Blue]

we are in fresh water (lake erie).
not sure on the twin 4.3's. I know a few guys have them here.
maybe try posting on general discussion. I think that gets more views.
BB

[mmwjr]

The 4.3's should burn about 8 gph each at that rpm therefore you will burn about 20 gallons each way.

[Mothers Day]

thanks guys, appreciate the help. I like using the 1/3 - 1/3 rule and at 20 gallons I should be real safe.
Thanks again,

[shrew]

Originally Posted by Mothers Day

Hey Guys:

What's the fuel range? I know it depends on rpm, but just the basics around 3,000 - 3400 which should give me approx 25 mph. (ocean)

I have a 97 2800 with a single 8.1. It came with a 7.4.

Most came with single big blocks, though I've heard of a few with twins. The 2900 which replaced this model came exclusively with twins.

Gal per hour is really the number, which will be relative to RPM. Range and speed are going to be relative to wind, tide, current, sea state, hull condition.

When running at 3600-3800 rpm, I'm burning around 20+ gallons per hour I estimate. I doubt you'll be able to cruise 25 mph @ 3000 rpm. I 'd expect you to be around 18-20 and running very inefficiently. I'd expect to see yourself falling off plane and worked the throttle get back up on plane, and throttle back to 3k, and eventually dropping off again. That is unless you had drive out all the way, tabs in all the way and a glass day.

[Mothers Day]

No. I'm seeing about 22-23 at 3300.
Slightly lower rpm with following sea. My boat has almost no additional weight added since I haven't really outfitted her yet.
I'm being told 4 blade props really help too. Sea conditions have consistently been 4-6 foot and rough so I've never held WOT for more then 30 seconds. And don't like to push motors anyway
Thx for the input and info

[mmwjr]

How long have you had the boat? Have you calculated the GPH yet at your cruising speed?

[Mothers Day]

Just a few months and spending all my time on Upholstry and minor mechanical issues like water in the oil.
I'll calculate once I'm ready for a long trip simple math. Just trying to get a feel for what others are seeing similarly equipped.

[mmwjr]

I use boat tests in magazines of similar boats ton weight, beam, and length.

From what I have seen the 4.3 is around 8 GPH in most applications. Since you have 2 double that plus add some margine.

A single big block typically is 15 GPH.

Even using the big block GPH for twins you should have enough fuel to make the trip and back.

[Lawnman]

I have a 98 2800 scr with twin 4.3's i usually get 2mpg at 3200-3300 rpms.

[mmwjr]

Originally Posted by Lawnman

I have a 98 2800 scr with twin 4.3's i usually get 2mpg at 3200-3300 rpms.

Is that per engine or the composite of both?

[shrew]

Originally Posted by Mothers Day

around 3,000 - 3400 which should give me approx 25 mph. (ocean)

3000 - 3400 is actually a big range because it spans the tipping point where the boat wants to jump on, or fall off of plane.
The approx. speed at 3000 is going to much different than at 3400.
My point was that 25 mph at 3k is not reasonable.

Originally Posted by Mothers Day

No. I'm seeing about 22-23 at 3300.
Slightly lower rpm with following sea. My boat has almost no additional weight added since I haven't really outfitted her yet.

Here you're actually getting 22-23 at 3300. It will be lower than the target 25 when you drop down to 3000. In fact, you haven't loaded the boat yet. My numbers are real-world numbers with water, fuel, gear, clothes, food, coolers, dinghy, portable generator, dinghy outboard, beer (yes, I feel 3-5 30 packs warrant its own weight calculation thank you very much for not judging our lifestyle).

I fact, I think I estimated 18-20 at 3k which these numbers are closer to corroborating than refuting.

Get the boat loaded up and your projected numbers are going to go down.

[shrew]

What size, blad and pitch props are on the boat now? I went to a 4 blade FWD, 3 blade AFT @ 22.5 pitch and it made a huge difference. The 3blad 24p on the boat made the boat a dog. 24P is NOT the stock prop pitch.