1987 Barefoot Nautique fuel consumption

A lot. I had an 87 Supra with the 454. I never tried to measure fuel per hour but I know I spent money on gas. My current 351 is not fuel injected and still does considerably better fuel wise. I'm sure your BN is lighter than my supra was, but it will suck the fuel.

what is the price per litre in Germany Tom?
   Eric

at one point we hit $3.00 per gallon then they drop the price and you think your getting a deal, bait and switch

Hi,

Mojoman wrote: Unfortunately, big motor, more gas...

of course , but what exactly will be _more_... Will it be 5gal/h or 10 or 20???
When a$$uming something like towing a single wakeboarder at 20-22mph, having about 1000lbs on ballast and 3 people on board - what will it - roughly - take?

Mojoman wrote: if you have a chance at a CC,and are lucky enough to be able to afford gas period in Germany, then go for it and don't look back...

Running this boat (or any waterski-boat) on gas in germany would be a little heavy on the wallet, but with an lpg-conversion the fuel price drops to a third

Mojoman wrote: Happy boating

Thanks

Tom

Hi,

GottaSki wrote: you will pay for the ballast.

okay, sure.

GottaSki wrote: If you run gas, make sure the PV is NOT open at your typical boarding speed and load. Measure manifold vacuum and make certain the PV is indexed to a number LOWER then the measured vacuum. Optimal jetting and timing are critical to decent fuel consumtion. When its right, the difference between the engines fade, because energy in = work out becomes truer.

sorry, but i do not understand What is "PV"? "jetting" is the carburator adjustment and "timing" the ignition timing? Of course these have to be right for an engine to run efficiently.

Thanks,
Tom

the jets drive how much gas flows the power valve adds more under heavy loads. If you are converting to LPG then are you replacing the carb or using it in that application? If your using the carb I would think a jet change is a must to flow the right amount of LPG

I'm not an expert but here are my thoughts on the matter anyway.
The 454 will add a little bit more weight which will increase fuel consumption marginally. Otherwise, all things being equal, I don't think it will make that much difference. With a larger engine, you have the option of a reduction gear and different sized prop which would require the engine to turn fewer rpms for the same pull/speed. With a smaller engine you may need to run near wide open to get the results you are looking for. With an appropriate sized engine/tranny/prop, you may only need to turn 3000 rpm, which would mean less fuel consumption actually.
Like always, driving conditions are probably the biggest determinater of fuel economy. If you've got a heavy hand or if you run at wot, you're going to burn a lot of fuel, even with a V6. With the 454, you'll just be going faster or getting there quicker.

eric lavine wrote: one of these days your going to see diesel powered ski boats, I cant wait

Already there. Session (an offshootof Regal I believe) has been offering diesels in their boat for a year. Also, some guys in Australia have posted photos of a diesel (I thought it was a swedish motor) which they put in an 06 Super Air Nautique. Apparently Australia has pa$$ed a law that all commercial boats must be diesel. Since these guys run a ski/wakeboard school, they were required to install a diesel. BKH

Brian: If anyone had the scoop on that type of info, it would be you. You are a wealth of info on little known stuff.

New Mom doin' ok? Time is gettin' close!

john

our government wont allow volkswagon to import the tdi jetta because of poor emissions, but the car gets 50 miles per gallon at that mpg how can you produce emissions. we did many diesel re-powers and even built a 47 foot cougar with 3 3196 cat engines about 900hp each and we held and hold many endurance records with the boat.one is toledo ohio to buffalo new york, we buzzed accross lake erie in 3 hours 54 minutes in 4 to 6 foot waves we averaged 68 miles an hour with a top speed of 92 we were promoting off the shelf products that were available to the marine industry (no hi-perf stuff) but were just at the begining of diesel technology, they have that duramax diesel pumping 650 lb ft of torgue that is unbelievable, this is the kind of torque you need to spin props

Hi eric,

eric lavine wrote: straylight, what percentage of the cars in germany are diesel powered

i don't know about the overall percentage, but 70% of all newly registered cars are diesels.

eric lavine wrote: and what kind of fuel economy do you see from them??

Usually over here people need about 25% less fuel when running a diesel engine. I guess in the United States and the rather heavy speed limits the gain will be slightly more. I once drove from cologne to hamburg one way with a bmw 525 on gas and back with an audi a4 2.5 tdi on diesel and the mpg was about double with the audi...

eric lavine wrote: a diesel powered ski boat would be way to go.

I am not sure about that. Over here nearly all larger boats are running on volvo penta or mercruiser diesel engines and therefor these engines reach high enough production numbers to be sold rather cheap. Diesel engines capable of pulling wakeboarders and waterskiers do not reach these numbers and therefor are still way too expensive - see volkswagen marine. The pity is, as long as they are that expensive not a lot people will buy them and therefore those numbers will not rise...

eric lavine wrote: on the boat i ran (47 foot cougar) when spun those engines at 2650 we had step ups instead of reduction and you did not need a throttle man for over-rev, when we came out of the water the prop speed stayed the same because of the diesels. On one other re-power we did on a 1978 38ft Chris Craft, we pulled the big block chevys ans installed 3126 caterpillars(inline 6, 420 hp) the end result was 15 knots an hour more and cut the fuel consumption in half, plus you could run those things constantly with no fear of destruction unlike gas engines

Exactly this is why so many people over here with larger boats are running them on diesels. But this is usually a very low and steady rpm usage.

Ragards,
Tom

There was a post on Planet Nautique regarding diesel power in a wakeboard boat, I believe the same one Brian was referring too.

Pretty interesting.

Diesel Powered SAN

That's a pretty slick looking set up. Yanmar has some engines in the 300HP, 4L range with some pretty impressive torque curves. A Cummins or a Power Stroke or the Isuzu Chevy is using would be a beefy option (probably overkill). I'd stay away from any pre-Duramax Chevy.
I think Diesel is a natural marine choice if for no other reason than the safety. Don't have to worry so much about fuel vapors exploding.

I don't have any hard numbers, but I've got an '88 BFN and can give some anecdotal info. We put a 725# sack in the back and a 440# sack up front. My boat fills up w/about 24 gallons. When we go out we usually get at least four sets in (2 riders 2 sets each). I'd say on average I fill up when the tank is at 1/4 and that's about every third time out. So I'd say we use about a 1/4 of a tank each time out. Like I said, none of this is scientific, pretty much a gut feel. My advice is do it. You won't necessarily be happy about the gas $$$ you have to pay, but you won't regret it.