Lavey help

[Dewey]

Hi all,
I am new to this board, but I can already see it is leaps and bounds above the rest as far as performance boats. I have been into boats all my life and have had jets, v-drives, and outboards. I am hooked on the outboards for now. My last ride was a 19' Daytona, kevlar, with a modified 2.4 carb. motor. It ran about 90 mph.


I recently purchased a 1992 Lavey Craft 20.8 Sebring with a 260hp 2.5 efi. It's spinning a 24 pitch cleaver at 7400 rpm at about 72-74 mph. It has hydraulic steering and about 12" of setback not including the Land & Sea Jack plate. I ordered a 26 pitch Mazco RE3 and hopefully it will be delivered to day. With the cleaver it won't carry the bow and porpoises at WOT.

Is this rig capable of 80 mph without modifying the motor? Any suggestions on the best setup?

[WillyT]

I see you found your way over here, Dewey. Glad you could join us. I'm sure some of the guys (and/or gals) can help you with the setup of your Lavey. Like I said on the other board, I think the round ear you ordered will be better than that cleaver on your boat. Your setback sounds about right, so I think the prop is the main thing. The other thing that comes to mind is that your engine probably has the CLE nose cone (correct)? You may pick up some speed if you get that converted to a Bob's cone (or a JC cone). The CLE continually shows to be rather slow on bigger boats compared to a Bobs/JC. Even the newer Sport Master gear case is typically slower than a Bobs/JC on bigger boats. That's why some people have gotten rid of their Sport Master and switched to the Torque Master (which has no pointed bullet). Try the prop first. I think you will like it, especially since your hydraulic steering will keep the inevitable torque from being a big issue. Make sure that your trailing edges on your hull are sharp and not rounded. Good luck!

[Dewey]

Thanks WillyT. Glad to be here. I have the sportmaster gear case, not the CLE. That would have been one of my first things. I don't want to weld and fair the sportmaster because I like the clean polished look it has now. We'll have to wait and see what the prop does. Hopefully LaveyT may have some additional insight.

[sosmerc]

Completed my 1988 Laveycraft 20ft. tunnel project about a month ago....still waiting for correct conditions for testing...sun, moon, tides, proper mental framework. I have
20 inches of setback (original bracket plus a Bob's Machine 10 inch jackplate). My engine is sort of an experiment. 2.5 litre stock 175 carb powerhead that I have installed a 220 Laser Fuel injection system on. 40 amp dual reg charging system, Boyesen dual stage reeds, solid mounts...the usual stuff. I completely rewired the boat and put in new guages.
Dual fuel guages, dual head temp, dual pyrometer, water pressure, tach, volt, Nordskog GPS speedo (can't wait to see how that works!). I also installed fuel pressure guages to monitor my onboard electric pump that pushes fuel through a Racor on to the engine. Then I also set up a guage to monitor the high pressure pump on motor. I am most concerned about whether or not the analog ecu will provide proper fuel curve for my setup...so I am watching exhaust temps closely.
I have run the motor for about an hour on my dyno at various rpms and it seems like it is going to be ok....but I am very nervous with all the time and effort involved (not to mention bucks). My goal is 80mph. I know it will take alot of experimenting with props and gearcases. Running an old CLE for starters, but have a small diameter XR6 that may be the ticket (after first rebuilding). Just need to get over my nerves and put this thing in the water and start putting some time on it. If I have serious success I will post my results....going to be awhile though as I do believe in breaking things in carefully. I understand these boats are pretty heavy and slow so I am very interested to hear about other Laveycraft that are approaching high 70's with similar rigging.

[fasteddie]

Your lavey is very capable of 80 with a stock 260.
The 26 re should work well.
I found that the boat no matter what prop will not carry the bow well but the re should cure the porpose problem.
A nose cone will also help if you are not running one.
Mine like an engine height of propshaft centerline even with the pad.
I did not run a hydralic plate so this height was an all around setting.
The boat was faster higher but had a hard time planing.
I think you will be very satisfied with the boat.
The do like power and are a very stable and forgiving hull at speed.
Mine with a modified 2.5efi turn a 24pitch Hoss hawk 9200 rpm at aprox 96 mph.
good luck,
ED

[Dewey]

Thanks Eddie,
Do you think a Bob's nose cone will make that much of a difference over the sportmaster lower unit I currently have? Would Bob's give any additional bow lift?

[fasteddie]

I can't honestly give you an answer to comparison with sport master.
I have never owned a sportmaster.
My experiences have been between a CLE and a Bob's
I really didn't notice any more bow lift just that the boat gained aprox 3mph with the nose cone vs. the CLE

[LaveyT]

welcome aboard!My Lavey is Eddies old Lavey.Sounds like you are on the write track.Setback,Lowerunit style and props are what this boat is all about.A 20.8 is supposed to be a bit slower that a 20.2.You canot get to much bowlift with this hull!The thought of a cleaver on my boat makes me want to puke!Round ear high rake is the way to go.Use a prop slippage program to fine tune your rig.A spinelli blue printed Chopper was the lowest slip 13% I achived with the Merc/Bobs cone combo.16% with a yamacopy.I have 12.5 inches of set back but more was needed,If you have a hydralic also you should be at 16inches or more of set back.I would think that would be sufficent.With the Merc and two pepole in the front the Lavey would not go past 80mph and it had a nasty hop.Put the passenger in the back and 88.7 was achived.No passenger was 91.7(yamacopy)With the Chopper 94.4 was the best I saw and the propshaft broke and Eddies freinds prop went to the bottom of the Ohio river!I now have a 225H.O./Raker combo,no torktab,no low water pickup,83mph max,but my slippage caculates to 3% and the boat never hops no materwhat the load!Im not sure if its the 450 pound motor or the stock lowerunit.But Im fixin to find out.I have a lowerunit with a bobs on the way.I want to raise the motor 3/4 of an inch temporaraly plug a couple more waterpick ups,get some numbers,then put my new lowerunit on and get some more numbers.I will let you guys know what happens.Also after you get some numbers with your new prop try a stock lower unit if you can get water pressure,I suspect it would be faster.Good luck,Keep us informed,good news or bad,Later

[Dewey]

Hi guys,
I just got back from the shop and I have a total of 20" of setback. 16" from the bracket and 4" from the jack plate. I will have to wait until I get it home before I can measure the propshaft height I can't wait to see what the RE will do if it ever gets here.

Next questions for you all. What would cause a bog or hesitation/stutter in an 2.5 EFI motor upon the initial attempt to plane or when making turns. I was thinking the water separator may be full or the filter clogged or something. I asked the guys at the shop to check it out while it was there and he said they found some chipped and frayed reeds. I thought reeds would only effect throttle response and idle. Any ideas? if it was water, can water in the fuel system damage the injectors or anything else?

I am almost getting the impression the boat sank at one time, but when I asked about it they said "not that we are aware of". I come to this conclusion because the speakers have all been removed, the stereo casing has water damage, it has a new interior, all new Gaffrig gauges, and this little hesitation/bog thing it pulled on me the other day.

Last thing. How does the ECU monitor air fuel ratio in the efi motors. All of my others have been carbed so I am new to the efi stuff. Can I run avgas in this thing without damaging any sensors? I want to run premium unleaded and klotz at 32/1 during family weekends, but when the guys go out for a trip, out comes the big wheel and the good gas. Is this cool?

Thanks again.

[Techno]

On your last part. You can run kerosene if you want there is really only 2 sensors, MAP and temp the rest are gravy. Your thinking of a O2 sensor used on closed loop EFIs. 2 sensors and a non adjustable fuel map programed into it adjust the fuel/air mix

You can run kerosene if you want. If your engine isn't high compression to use the Av gas your wasting your money and probably reducing power( you can always swap high comp. heads for the weekend). High octane fuels are slow burning to allow engine mods with out destroying the engine. With out the mods the fuel offers no advantage.
I'm not sure on the oil but I don't think you want to go that low a ratio. I think it's highly dependant on the Rpms run but I'm not totaly sure. I thought that 2.5s used 50:1

[Bob T.]

Dewey.With your added setback, your engine now sits lower in the water at rest.It takes time for the exhaust to clear the water of the midsection ,causing the hesitation. Try raising the engine to its old hieght relative to the water ,for your take-off and you'll find out.Hope this saves you some search'n.BT

[alan knight]

I don`t know if Techno is confused or going to confuse you. But the ratio of oil to gas of 50to1 is not what you want on a 2.5 if it is to be run for high perf. boating. etc. run hard regularly. I think that I would run at least 32to1. OH! also if you buy kerosene to run bring a paddle as this ain`t no diesel or turbine.....

[Dewey]

Techno, thanks for the input, but I disagree with you on the race gas issue and the oil ratio. Although oil ratio is generally a personal preference. I am going to stick with the 32/1 since my 2.5 is a high rev engine. I did alot of research when I was younger and racing mtorcycles and all of the research I found showed two strokes last longer and make more Hp at 32/1.

As far as race gas goes, any motor will run better on race gas than on pump gas if properly setup and the motor is healthy. Race gas does not necessarily burn slower so to speak, but is more resistant to preignition. When it does burn, it will burn with more energy than pump gas. If you look at the flashpoint and specific gravity of avgas or race gas it is more volatile and lighter than pump gas. I have a friend at F&L race fuels and could probably get more info with specifics if you would like.

[fasteddie]

I would like to see these specifics on the race fuels.
I have done a lot of testing with avgas and race fuels and have found that with compression below 150 psi cranking the is a noticable power loss.
I believe that a lot of the engine builders out there will tell you the same thing.

[Dewey]

Are you saying there is a power loss with race fuel or with pump gas? on carbureted engines, regardless of compression, you can run a leaner jet with race gas. Leaner mixture means more hp. EFI is the same concept accept you adjust the fuel map.

[fasteddie]

The power loss came when I used race gas with low compression.

[Dewey]

Eddie,
I will e-mail my partner and see what info I can get from him. I have run avgas or race gas in just about everything I have ever had.

C-ya,

Dewey