Fuel burn curve for mideighties 454350 Crusader

"Did Crusader ever print or po

"Did Crusader ever print or post a basic fuel burn/rpm curve for their mid-eighties 454/350 engine? If so does anyone have the information to share? If not, can anyone offer/share information on typical burn at 1850 - 2250 - 2450 - 2750 - 2900, etc. I would appreciate the help. Thanks"

10 to 12

12 to 15

15 to

10 to 12

12 to 15

15 to better own some Exxon stock!

Jeff

"Does anyone have good numbers

"Does anyone have good numbers for the burn of a mid-eighties 454 cu. inch, 350 hp Crusader at 2000 RPMs, 2500 RPMs and 3000 RPMs? Thank you."

"That's it, Jerry. I wasn&

"That's it, Jerry. I wasn't kidding.

Jeff

PS: Those numbers are GPH per engine."

"My 88' model 38' Luhr

"My 88' model 38' Luhrs w/twin 454's burn about what Jeff indicated- over 3000 rpm's she burns at least 15 gph p/engine. A 200 mile trip out and back for offshore fishing out of Charleston, SC runs about $1100.00 for the day. It just ain't as much fun as it used to be! :>)
Mike Austin
"HATTERASER""

89 luhrs 400 --454s flowscan

89 luhrs 400 --454s flowscan 9000 installed the best gas mileage i can get is running around 2450 RPMs --11 knotts SOG burn 6.5 gallons per engine...If i run over 3000 RPMs gallons per hour hits the roof around 15 gallons per engine

this is taken from the user gu

this is taken from the user guide of 1984 monte carlo offshorer 30 with 2 454 - total fuel burn for the 2 engines.

3000 rpm - 108 liters per hour
4400 rpm - 230 liters per hour

I can email you a picture of the guide if you want.
p.

I have a 47ft Harbormaster wit

I have a 47ft Harbormaster with twin 350 Crusaders. I have been tracking the fuel for 10 years. At 2000 RPM I average between 8 and 9 GPH.

At 3600 RPM it jumps to about 14 GPH.

If I take it easy I can run about 20 hours on a tank of gas which btw is now $4.69/gal in my area.

I operate on the other end of

I operate on the other end of the curve. I have a Gibson 50 foot with two 454 CIDs. I run on the Tennessee River at 1100 RPM at 7 MPH burning 3.3 gallons per hour per engine by tank measurement. At 1800 RPM I run at 10 MPH and burn 5.5 gallons per hour per engine. I have a hard time putting fuel in at $5 per gallon.

Chuck Hanson

I learned long ago that when you step on the boat you are boating no matter how fast or slow you go. When I was on the Mississippi River I could go all day at 1000 RPM and make 10 MPH with the current. Upstream is yet another matter.

"1988 model 350,s, 34 Hattera

"1988 model 350,s, 34 Hatteras. 3000 burning about 24 gph. I believe starboard engine using 15-20% more than port so when that problem is fixed I hope to reduce this number. Never run over 3200 unless testing the motors. Think at 1650 and 7kts I am using about 4-6gph. Never hooked flow scan to the gps and we have analog meters."

"1988 454 model 350's fuel

"1988 454 model 350's fuel consumption:
idle (650) Port 3 Star 1.5
1500 Port 6 Star 4
2500 Port 12 Star 8
3000 Port 18 Star 12
I have only pushed WOT once and she never got to full speed but she pegged the 36 gph meters. They always surge when you apply throttle then settle. I was going to wait to see where they settled at, I backed off instead. (that most likely cost me $20 in 45 seconds)

Chuck I'm with you. At 1100 I she goes about 6-7 knots and this year the boating has been short trips to anchor up and swim instead of running 20 miles out to fish. I refuse to boat less, I will just not go as far and keep the rpm's down. Picked up an 8 foot achilles to bomb around in also."

"jerry: I've got a pair of

"jerry: I've got a pair of Q-Jet topped crusader 454 FWC - 1986. When I contacted crusader ~ 1990, I asked the same Q. The answer was NO published numbers Because the load placed on the engine varies with the application (hull, loading, prop,gear ratio, etc). The tech indicated they (Q-Jets) were jetted 'for worst case', which I interpreted as rich, at least for my application.

You can calculate what the 'ideal' fuel consumption would be based on your desired air:fuel ratio. This gets discounted for volumetric efficiency. Bottom line is I checked the plugs to ensure there was not a lean condition wheen I rejetted. That was 1990-92, it took that long to find the time to tweak. Went from 16GPH down to 12. I'd be inclined to do it much faster with today's fuel prices"

"Be REEEEAL careful leaning ou

"Be REEEEAL careful leaning out a carb unless you know exactly what you're doing, and take regular plug readings. Blown pistons cost a hellova lot more than gallons of gas!

Jeff"

""Q jet worst case", I

""Q jet worst case", I believe it. Follows is what I'm now getting with out of the box 600cfm carters, a low rpm edlebroc manifold, and a high energy ignition system, using twin digital flowscans, gps speed on a two way course, and a two engine average:

1000rpm-1.9gph
1500 - 3.7
2000 - 5.6
2500 - 7.5
3000 - 10
3250 - 11.4
3500 - 12.3
4000 - 18.5
4250 - 21.3
4500 - 24.0
4600 wot - even more, but not recorded.

Run on a very deep V sportfish, sea level, hot/humid, about 9000# boat, otherwise empty. You can see WOT is pretty high at 4600rpm. I've now put >700 hours on each engine since the carb replacement, which got me some 20% fuel usage improvement. There has been no detonation, or other unusual piston damage, and I've looked. The stb engine spun a big end bearing 8 years ago, and the port engine broke a ring a few years back. Note that these engines were original, 1975 engines, with original internal parts.
Some simple financials:
If you figure nominal cruise at 3200rpm, that's about 24 gph and about $100/hour in fuel for a twin engine boat. At 1000 hours, that's $100K. Yes, you can afford to lean out, you actually can't afford not to."

"I am getting something VERY c

"I am getting something VERY close to what Diver Dave has with our Silverton 34C with ALMOST the same set up. The Carter carbs were rebuilt by me last season and still perform flawlessly (so far).

I believe we need a bit more prop as I can surpass the 4400 mark with ease BUT...Until that new photo tach shows up, I really have no idea what thos old tachs are telling me. I am still on the hunt for the 4 blade ones"

"diver dave and Al, Would you

"diver dave and Al, Would you be willing to share your set-up? May attack the thing this winter lay-up (Minnesota),
BRegards,"

"Glenn,

If you mean engines

"Glenn,

If you mean engines: twin 454 with Carter AFB carbs, Delco EST distributors, MR43T AC spark Plugs, New valve jobs this May 2008 both with all new cooling system parts. Exhausts are 4" with 3" adapters to the mufflers and out to the transom. Props are 18 x 21 with #3 cup.

If you mean fuel management: Garmin 4212 with the GFS 10 fuel sensors via NMEA network an extremely simple installation. Monday ran 62 miles round trip and used about 68 gallons of fuel. Clean bottom, flat ocean."

"Glenn:

The gear ratio play

"Glenn:

The gear ratio plays a big part in the load the engine sees.

Another thing that helped me out a whole lot was proper sizing of the exhausts. Mine came with 3" hoses to the wye pipe, then 4" thru the muffler and out the transom. When we switched manifolds, go the 4" to 3" reducers because they were cheaper than new hose. Following spring, changed the hoses to 4" from risers to the wye pipe then 5" thru the mufflers & out the transom.

The ironic thing is that the mufflers were 5" parts - only had to remove the thick reducing donuts."

"I did the following steps to

"I did the following steps to lean out my engines:
1) a Jacobs Omni-pac went on, still using MR43T's but gapped to .045.
2) replaced the stock iron manifold with Edlebrock dual plane AL, I had them irridited.
3) had to source an aluminum 12 deg carb wedge.
4) one engine has a carter AFB, the other an edlebrock, both marine, both 600/650 cfm; they are almost identical. You will NOT need a 750 cfm for rpms below 5000!
5) the formed steel fuel line won't fit, I went with a stainless over-braided hose, with AN6 fittings.
6) I bought a AFB strip kit, did not have to use it, after doing the mandatory spark plug high speed color check. Carbs were fine out of the box.
7) I have the older, Prestolite distributors, breakerless, stock mech. advance.
8) Note that I am using square bore carbs on a spread bore intake; the 12 deg wedge worked OK as an accidental adapter; I had no vacuum leaks.
9) My throttle cable bracket worked, even though the carbs have different cable positions. Later engines may require more heroics here.
10) The new carbs have electric choke, which I like. Run the 12v choke wire to a sw 12volt circuit (i think i used the alt. power wire), it has a seperate regulator.
11) the Q jet flame arrestors fit fine.

I think that's it. Be carefull with coolant, in that you now have aluminum in the system. It's not as forgiving. I'm currently using no anti-freeze (no freeze threat here), but only tap water and 1 qt. of DD2000 additive. I saw a fair amount of internal passage corrosion with water and just water wetter.
12) 4" single exhaust muffler systems.
13) set advance to 30 deg at 3000rpm.

other notes: I don't know if the Jacobs system did anything for fuel consumption or not. Mostly bought them to eliminate the coil, and to insure a virtually non-foulable spark. Very happy with the carbs, no surging, flat spots, etc. I do have one that will have a stuck choke every once in a while (sticks open). My cold engines will not start with an open choke, even in 90 deg weather."

"Thank you guys, This is grea

"Thank you guys, This is great stuff."

"Dave,

Did you intentionall

"Dave,

Did you intentionally opt for the aluminum 12 Degree wedge? I am sure you know Crusader does have the black composite one available.

When rebuildng my Carter Carbs, I used the manuals from the Edelbrock 1409...I do not have my electric chokes wired in. I keep the levers zip tied back to keep the butterfly open all the time. Have never really needed the chokes and we do get some cool November / December mornings here (NJ)"

"Interesting Al. I have twin 3

"Interesting Al. I have twin 350's with Carter carbs. I too decided to wire the chokes open. Never had a problem, always starts and runs great.

I recommend it!"

"I'm not sure why the port

"I'm not sure why the port engine always needs choke to start. My buddies marine 454 with Q jet also has its choke zip tied open. Last month, I did a bottom end job to fix its broke ring/scored wall issue. Maybe it behaves different now at startup."