Zach F100

If I ever rigged my own twin engine boat, that would be the way I would want it.

My guess: 1936

SC288

1,770#....been following this from the beginning....absolutely awesome project! Glad I was able to meet you at the Muskegon Powerboat Weekend Dinner.

BigSilverCat

not sure what you mean by prop guard? The cavitation plate on the #8 or the tunnel extension?

the tunnel extension is there to add lift at high speed to try to make it more efficient, and to add buoyancy when stopped. The props stick out a foot and half behind it.

The "prop guard" on the arneson was not a prop guard necessarily, it was the steering rudders. They are beside the prop instead of under it.

im not sure yet when we trim it all the way down if it will clear the bottom step because when I trim it down really far it hits the ground so I will have to wait to check that till it's on the trailer and see how much farther it will trim. But right now it clears the bottom step when turned all the way.

The notch in the tunnel extension is for tie bars to clear. Originally I was not going to have a tie bar because you cannot use a tie bar on arnesons which is the only reason we ended up taking them off. My tunnel extension is longer then most to try to get more lift from the tunnel.

We used the extension boxes for two reasons, one was to get the prop back farther from the boat to try to make it more efficient and gain leverage against the boat for trim, the other was to move the drive back so that the tie bar would have a better chance of clearing.

outonsafari

iTrader: (4)

forgot about the tunnel extension, so the bustle ? i thought over the drives was built to a specific length so you wouldn't hit the prop if you fell off, and aids in the water prop changes
my memory on some things, but thought it was referred to as a prop guard at some point.

i figured the extension boxes where more to get the prop in the same or close location as the prop on the arneson, therefore same location, similar prop results.

thanks

BigSilverCat

yes the reason we have a bustle is so if you were sliding off the back of the boat you would clear the prop, and for changing the props in the water so you can drop the prop straight down onto the shaft., there are companies that make prop guards that bold into of a drive that go right around the prop and some people have braces sticking off the back of the boat behind the props to keep you from backing into something with the prop, so I thought you meant something like that by wording prop guard.

the main reason for extension box is for tie bar to clear, another benefit is the leverage it gives to be able to trim the boat more accurately. The props are actually back a little farther then with the arneson and we can change the height of the props with spacers in the lower so it was not really to get the prop to the same place. The prop results will be totally different. The way a drive trims compared to an arneson, gear ratio, hp, ect.

BigSilverCat

Here is a graph of the weight guesses so far.

JaayTee ??
Azmidlyf 900.0
20outlaw 1035.8
PigNaPoke 1067.3
# Skater 6.7 1240
TopSpin80 1255
ntesdall 1266.3
JerrodGlover 1300
SKammeraad 1340
Wobble 1350
obsessed1 1367
#Mercury 700 1370
1 MaidenAmerica 1380
hotrod77 1420.5
FreeSurface 1475
Wally 1480.7
#Mercury 1350 1500
30ftpanter 1511.5
#cummins 550 1530
AZBrummett21 1555.8
sutphen 30 1568
Pstorti 1649
TylerBurich 1650
RidnMcNasty 1711.3
sc288 1770
NHbaja 1785
keytime 1834.2
wannabe 1838.7
Scagburner 1862.7
all_in! 1863.6
iaoutlaw 1925.5
outonsafari 1935.9
Zach f100 1936
jvcobra 1974.5
Indy 1975
class6 2021
#Seatek 950 2300

BigSilverCat

One hour left, any last guesses?

BigSilverCat

The engine weighed 1240 lbs complete, that is including transmission, flywheel, starter, intercooler, ect. a complete running engine package. Everyone thinks the diesel would be a heavy engine, and compared to a normal naturally aspirated big or small block they are heavy, but when comparing to an engine with blowers, intercoolers, turbos, ect. its not that heavy. Keep in mind a 1350 Merc. with transmission is 1500 lbs.

Looks like Topspin80 (1255 lb) was the closest, and ntesdall (1266.3 lb) got second place.

SKammeraad

damn. i was only 100 lbs high. thats really not that bad weight wise.

BigSilverCat

Here is the final chart of weight guesses, The normal thinking is that a diesel engine is heavy as you can see from the chart. I would have thought that a diesel would be alot heavier also. In the chart the yellow bar is the Diesel engine that is going in my boat (1240 lbs). There were only a few that guessed lower. The purple bar is a Mercury 700 (1370 lbs). The red bar is a Mercury 1350 (1505 lbs), The blue bar is the factory Cummins marine 550hp (1530 lbs), The green bar is a SeaTek 950hp (2300 lbs).

The main difference in all these engines and mine is that they have closed cooling which is heavy. And the turbo ones have water jacketed exhast manifolds and water jacketed turbos which are heavy. If you put the water jacket exhaust manifold and turbo on mine and closed cooling it would weigh as much as the merc. 1350 and factory cummins 550, but it would still be alot lighter then the seatek.