Vintage Tunnel power

[SJC]

I have everything mounted and ready to go, but it has been raining on my days off and sunny of the work days.

[PARKER RABE]

were all waiting....lol

[SJC]

I get that, but you have to keep in mind that I am not in FLORIDA!! Although it has been warm here lately (it broke 50 yesterday) when I go out I am just about the only boat on the water. Maybe a few nutty salmon fishermen. Temps will usually be in the low 40 around this time. I try to stay within swimming distance to shore just in case.

[wuhbbr]

please= always "test" with another boat / friend very close by. Tunnels blow over and they will hurt you. My worst blow over, I was testing. I had a buddy very close by. He pulled me in his boat. 8 days in the hospital. = I won't start me motor without my helmet, lifeline vest, working kill switch. Always have someone out there with you.

[Robby321]

please= always "test" with another boat / friend very close by. Tunnels blow over and they will hurt you. My worst blow over, I was testing. I had a buddy very close by. He pulled me in his boat. 8 days in the hospital. = I won't start me motor without my helmet, lifeline vest, working kill switch. Always have someone out there with you.

Don't worry it as he aint stupid nor a dumb kid. Damn?..he BUILT THE BOAT! Lives a 100 miles north me, and we are way up on safety Puget Sound, weather, and its the cool rainy season here. And I'm ready to get wet too, but not until late March.

[Instigator]

I get that, but you have to keep in mind that I am not in FLORIDA!! Although it has been warm here lately (it broke 50 yesterday) when I go out I am just about the only boat on the water. Maybe a few nutty salmon fishermen. Temps will usually be in the low 40 around this time. I try to stay within swimming distance to shore just in case.

I blew over in the snow one time. Lucky for me the boat landed right side up, and me right beside it.
Had buddies watching from shore that told me I was lucky cuz none of them were coming after me

Was wearing a vest and helmet.

[wuhbbr]

WOW!! Now that's really lucky & a angle ridin' shot gun.

[SJC]

My favorite little factoid is that the only way you can die from hypothermia in the cold water here (mid 40s now) is to wear a life jacket. Without the flotation, you seize up and drown in 15 or 20 minutes, the hypothermia takes much longer to kill you.
Fun stuff

[Instigator]

My favorite little factoid is that the only way you can die from hypothermia in the cold water here (mid 40s now) is to wear a life jacket. Without the flotation, you seize up and drown in 15 or 20 minutes, the hypothermia takes much longer to kill you.
Fun stuff

Yep in WW II in the Navy, they told my dad not worry about his life jacket.

[SJC]

Ok, did some back to back testing yesterday.

Set up, ran the boat, changed the prop, then changed the height, ran the boat, changed the prop.

Just a recap of changes made from original: Battery moved from midship to aft end, added 20 pound manual jackplate, added transom mounted cooling water pickups, added torque tab shaping to outboard skeg. Original set up had the prop centerline even with bottom of sponsons.
Original prop 14 x 24 chopper (well used)
New prop 14 x 26 Semi cleaver by Ron Hill (new)

Engine Merc 150 hp inline 6
Original setup performance: top speed 61.4 mph 6000+ rpm trimmed in tight, bow down. Lifting bow just lead to porpoising. Medium torque steer.

Now: motor jacked from prop centerline about 1" above sponson bottoms to 3" above sponson bottoms in several incredments.
Honestly, the motor height adjustment did not make any significant speed difference with either prop. Just a little difference in steering feel.

Top speed with Chopper 53.2 mph 6000 rpm wot. Minimal torque steer.

Top speed with Semi cleaver 50.2 mph 5000 rpm wot. Mild torque steer.

Chopper still unstable when trimmed bow up. Cleaver was stable at most trim positions. The cleaver felt better except for the engine loading.

I don't understand why the chopper lost so much speed.

My plan now: I am going to try to exchange for a 14 x 24 Semi cleaver and see what that does. Assuming that does not work, I will remove the jack plate, move the battery back, hang the nice shiny cleaver on the wall and enjoy my beautiful wooden boat

[brussrude]

Ok, did some back to back testing yesterday.

Set up, ran the boat, changed the prop, then changed the height, ran the boat, changed the prop.

Just a recap of changes made from original: Battery moved from midship to aft end, added 20 pound manual jackplate, added transom mounted cooling water pickups, added torque tab shaping to outboard skeg. Original set up had the prop centerline even with bottom of sponsons.
Original prop 14 x 24 chopper (well used)
New prop 14 x 26 Semi cleaver by Ron Hill (new)

Engine Merc 150 hp inline 6
Original setup performance: top speed 61.4 mph 6000+ rpm trimmed in tight, bow down. Lifting bow just lead to porpoising. Medium torque steer.

Now: motor jacked from prop centerline about 1" above sponson bottoms to 3" above sponson bottoms in several incredments.
Honestly, the motor height adjustment did not make any significant speed difference with either prop. Just a little difference in steering feel.

Top speed with Chopper 53.2 mph 6000 rpm wot. Minimal torque steer.

Top speed with Semi cleaver 50.2 mph 5000 rpm wot. Mild torque steer.

Chopper still unstable when trimmed bow up. Cleaver was stable at most trim positions. The cleaver felt better except for the engine loading.

I don't understand why the chopper lost so much speed.

My plan now: I am going to try to exchange for a 14 x 24 Semi cleaver and see what that does. Assuming that does not work, I will remove the jack plate, move the battery back, hang the nice shiny cleaver on the wall and enjoy my beautiful wooden boat

Personally I think you shoul dbe using a cleaver type prop for this hull. Also the fuel tank looks too far in front.. With this engine properly rigged you should easily see 70+

[wuhbbr]

I agree. Into the mid 70's, perhaps more. = Have any idea what the boat weights with you in it? Seems like the min weight for SJ was 900#. 910 -950 after the race is what we looked for. Also how much compression does your tunnel have? A couple of inches should lift the hull enough to "air it out" & get you shimming on top the water.

[milkdud]

Very cool looking boat. You did a great job.

My carlson didn't come alive and pack enough air until 55mph or so to balance out the porpoise. From 55 to 75 mph it would run smooth. 35-55 was porpoise and I usually just blasted through that window at full power.

I wonder if your boat is just starting to try and pack air at 55 and you need to let it ride up a bit with some up trim and load up the air a bit.

The picture of prop looks like your plenty high for now. I agree that tank is pretty far fwd.

If you can get someone from shore to do a quick video of yo doing a pass that would be awesome.

Thanks and be safe.
C

[milkdud]

Top speed with Chopper 53.2 mph 6000 rpm wot. Minimal torque steer.

Top speed with Semi cleaver 50.2 mph 5000 rpm wot. Mild torque steer.

The chopper seems to be higher than it can hook up properly. Its slipping a lot.

The Semi Clever is hooking up still.

[SJC]

The chopper seems to be higher than it can hook up properly. Its slipping a lot.

The Semi Clever is hooking up still.

That certainly seems to be the case with the chopper, it is slipping a lot. Is that normal performance for a chopper type of prop...as it is lifted out of the water it slips more than a cleaver?