Crusader 454's....Fuel Burn....Not so Good

Natchamp · Post by **Natchamp** » Mon Sep 24, 2012 11:18 am

Well Gents,

I've been enjoying my boat since getting it in the water but I think I have a major issue with the fuel burn. From doing a lot of reading and looking at RWS's fuel consumption before he went to yanmars I should be in the range of 22 GPH at @ 3k rpm.

Yesterday I went on a little fishing trip and observed the following results.

Boat 33' Express, 1/2 tank of fuel, great sea conditions, 4 people, flowscans.

At 3k RPM (highest I've taken it so far) I'm running @ 20 knots on plane which I think is pretty decent. Fuel burn for the strb engine is 18 GPH, fuel burn for the port is 13 GPH for a total of 31 GPH.

So, my question is should I install some Edelbrock 1409's or have my Qjet's professionally rebuild?

The cost is relatively the same. I do like the ability to change the rods and the supposedly easier tuning of the edelbrocks.

Any feedback on what route to take? Besides putting some diesels in cause that's what I really want to do but that's a whole nother thread.

todd brinkerhoff · Post by **todd brinkerhoff** » Mon Sep 24, 2012 11:44 am

You're running a very good speed for 3k. Are you able to reach 4400 rpm at full throttle?. If you have a clean bottom, which I know you do, and are able to reach the top rpm for those motors, i don't see being able to see a big change in fuel burn. Maybe a tune up, but i would think you would see an impact on speed and top rpm.

The only option sounds like diesels...lol. Let me know when you start. I want to follow that thread so I see how its done.

todd brinkerhoff · Post by **todd brinkerhoff** » Mon Sep 24, 2012 11:44 am

Stripermann2 · Post by **Stripermann2** » Mon Sep 24, 2012 12:02 pm

If all else, plugs, wires, fuel filters, timing, etc are on the money then swap out for the 1409s.

I replaced my Quads a couple months ago and wondered why I didn't do it sooner!!! Better fuel economy, better idling, easier starts...At about 3100 rpm, I am burning about 13 gallons, per side... whereas I was burning 17 port, and 15 starboard before the swap. Love these new carbs.

Just my opinion. Good luck.

Mike Kulp · Post by **Mike Kulp** » Mon Sep 24, 2012 12:32 pm

Hey Mark your speed at 3,000 rpm's is great I run that at about 3400 to 3500 rpm's and burn 30 to 33 gph depending on conditions I would check to see what rpms you get at WOT also I would check the advance weights in your distributors if you still have the old ones in, I rebuilt my Qjets probably 10 years ago but they are ready for replacement, the shafts get worn on the bottom.

prowlersfish · Post by **prowlersfish** » Mon Sep 24, 2012 1:03 pm

Your total fuel burn seems about right , as far as the difference , Have you calibrated the flow scans yet ? also check the tachs one reading higher or lower will make a difference .

Natchamp · Post by **Natchamp** » Mon Sep 24, 2012 1:08 pm

Thanks for all the info guys.

Paul, I haven't calibrated the flowscans, I will check out the instructions and see what it says but I can't imagine how/what you would calibrate since I wouldn't have a "known" to calibrate to? On a side note, am I assuming correctly that your F36 has a little more height in the engine bay (compared to me Express) to allow for the 6BTA's?

prowlersfish · Post by **prowlersfish** » Mon Sep 24, 2012 1:15 pm

I have about a inch of hight to spare for the Cummins

rossjo · Post by **rossjo** » Mon Sep 24, 2012 1:31 pm

Natchamp wrote:Thanks for all the info guys.

Paul, I haven't calibrated the flowscans, I will check out the instructions and see what it says but I can't imagine how/what you would calibrate since I wouldn't have a "known" to calibrate to? On a side note, am I assuming correctly that your F36 has a little more height in the engine bay (compared to me Express) to allow for the 6BTA's?

You have to fill the tanks, run over a know distance (longer the better) and then re-fill .... not an exact science, but you can calibrate them pretty close on along, steady speed trip.

rossjo · Post by **rossjo** » Mon Sep 24, 2012 1:32 pm

Natchamp wrote:Thanks for all the info guys.

Paul, I haven't calibrated the flowscans, I will check out the instructions and see what it says but I can't imagine how/what you would calibrate since I wouldn't have a "known" to calibrate to? On a side note, am I assuming correctly that your F36 has a little more height in the engine bay (compared to me Express) to allow for the 6BTA's?

You have to fill the tanks, run over a know distance (longer the better) and then re-fill to measure fuel volume .. then calculate .... not an exact science, but you can calibrate them pretty close on along, steady speed trip.

BarryL · Post by **BarryL** » Tue Sep 25, 2012 1:20 pm

Fill the TANKS? Who can afford that anymore...

Seriously though. 20 kts at 3,000 rpm sounds pretty fast. I am down in the 17kt range at that rpm and burning close to 34 gph combined but I run a lot of tab to keep the bow down and don't go very far on inland lakes so it's all about the slow cruise for me and having fun with family and friends. My wot is low at 4150 rpm and a top speed of 28kts.

1990 mid cabin with usually around a half of tank fuel both sides and half a tank of water.

Barry

RWS · Post by **RWS** » Tue Sep 25, 2012 11:37 pm

For the moment, let's set the numbers aside.

I want to hear your impressions regarding handling and ride first.

Then when addressing the fuel burn data, consider the wetted surface area of this vessel, even though she's a 33' she has a massive beam and has the feel and space of a far larger vessel.

An advance timing light will veirify the correct total advance.

The Quadrajets are SUPPOSED to have a particular metering rod.

If they have been through a backyard rebuilder or certain "production" shops, they may be set up incorrectly.

There are exhaust "diverters" that can be machined out of the cast iron factory units

Extended trim tabs with factory "drop fins" will also imporove her running attitude for better performance

I got as high as .81 NMPG on mine but was just not satisfied.

Now back to the performance of the boat.......

Then you can run some numbers for upgrades and then run long term operating costs and then finally factor in the DIFFERENCE of how much more this boat will be worth when it's time to sell.

If you factor in a 10 year life cycle of ownership, the numbers WILL change.

My 10 meter has had two owners, the original owner owned her for 18 years, me, a mere 11 years

The numbers will look different over time.

then factor in all the intangibiles.

Now about the handling and that ride.....

RS

Natchamp · Post by **Natchamp** » Thu Sep 27, 2012 12:09 pm

Well, it's probably not very fair to give my opinions about ride because this is my first boat and so I don't have any previous boat to compare to. I have ridden in other boats but not actually driven very many. Having said that, I will share my observations which should be taken for what they are worth!

Since I have put my boat in the water I have taken it very easy with the throttles because I'm still learning the boat and developing confidence in the motors and everything else. Also, there have only been a few days when I've taken it out where the conditions were good. The last trip I took was without a doubt the best conditions and the highest speed I've taken it.

It was a nice calm day and we headed out at 8am to do some local fishing. The seas very calm with small swells @ 10 seconds apart. At about 2,500 rpm the boat planes well and everything smoothens out. The steering becomes less "mushy" and feels much more responsive to inputs. If I remember correctly this was something @ 17 knots.

So then I took it to 3,000 rpms and this was @ 20 knots. Wow!, it really improved and felt like a completely different boat. Smooth as silk, excellent steering feel, and simply consumed any swell/wave with ease like a knife through butta. I loved this, I mean really loved this. To me, at this point it really felt like smaller much nimbler boat but with the added benefit of slicing through the swells as if they weren't even there.

So, as you can tell I really think this boat responds well to getting her ass out of the water and being on plane as much as possible.

I currently plan on putting some new carbs on it to hopefully get some better economy, better cold starts, and smoother running. What I would really like to do is put some diesels in her and I've been doing a lot of research on that subject. The financials for diesels is a hard one to justify as everyone knows. I do love the boat but there is one thing I would "like" to have and that's a salon which would be enjoyable for when I'm just relaxing on the boat in the marina. So, I am still up-in-the-air on what to do long term. I could put diesels in my Express, or buy another boat with diesels and a salon. It's not a straight forward or easy decision because of all the pros/cons for each scenario. Until I can figure that out I'll keep fine tuning what I have and enjoying her, and that doesn't exactly suck! I swear, there isn't a person that walks by my boat on the dock that doesn't say "wow, that's a nice looking boat" which of course makes me feel good after all the work I've put into it.

aaronbocknek · Post by **aaronbocknek** » Thu Sep 27, 2012 6:38 pm

mark, i'm so glad that you are enjoying your vessel. the one thing that i noticed when i went out for a ride with mike and kathy on their 10m mid cabin was the amazing ride in chop, wind and swells. it was my first time riding on in a delta conic boat and i was really impressed at how she handled the water. like mike has said any number of times....''this boat lives for water like this !!!" i also noticed how it flattens out the water behind her too.... in fact, there were several vessels trailing behind us taking advantage of the 'flatter water'. but, i can also see how you would feel a bit closed in when sitting in the cabin. i was sitting in my salon this afternoon, all 4 cabin windows wide open, steady refreshing breeze blowing through. i looked up from the sofa where i was reading and i just looked around and said,''wow, this is really open and airy''. perhaps, once you've had a chance to enjoy the fruits of your labor, you might consider a sedan version of the international.... the 10.8 meter sedan might be just the ticket for you. open and airy salon but the advantage of a fly bridge and a salon.
just a thought. you've put so much work into your vessel, just take some time to enjoy her.
aaron

this one is in san diego and she's got diesels (yanmars) !!

http://www.yachtworld.com/boats/1985/Tr ... ted-States

BobCT · Post by **BobCT** » Fri Sep 28, 2012 8:48 am

Mark,

I would strongly suggest rebuidling the Quadra-Jets, they're great carbs when setup correctly. I rebuilt mine and then sent them to a Q-Jet specialist who bench tested them and made final adjustments (Cliff Ruggles).

I literally haven't touched the carbs in over two years. They start right up even after sitting for a week or more and I'm ready to leave the dock after a couple of minute warm up. I have the idle set at 600 in neutral which shows how well they're tuned.

I'm burning about 24-25 GPH between 15-16 knots. This winter I'm going to change the linkage so the secondaries open a bit later so I can pick up some speed. I've done extensive testing and under no scenario is it worth gaining the add'l 2-3 knots compared to the fuel burn.

My Crusaders are almost 25 years old now and I've added 1/2 quart on one engine over about 75 hours. I've thought through the diesel scenario too but I'd be throwing away perfectly good engines so it's kind of hard to justify. If you have any doubts about the layout, don't drop diesels in just yet because you'll never get the money back. You could sell you're boat in 5 minutes if you wanted to as is...

Bob