90 ETEC on a Potter 20 CC???

[JohnC]

Originally Posted by Terry England

John, If you "mash" on my name it will take you to my 'Members Page". If you go there, on the right side one of the albums is the Dredge Marshtackie. It was a 19' (-6") 1967 Seacraft Bowrider I cut up to make room for sheets of plywood and PT 16' - 2" X 12"'s I need to haul to Cayo Costa (but, it wasn't a Safari like afishin82's). It is very light - like a Seacraft "Panga" would be. No center console, no windshield, no tee top - just a little side console like a 13' whaler and a bimini. I glassed a couple of tabs on each side and have a "drop in" bulk head to stop the dive tanks and coolers from walkin' back and mash'in my toes, because we sit in the back like a flats boat. Just fall over the side and climb in the back ladder. Hit and Run, brother.
I ran a 120 VRO on it from 1998 to 2007 and then downsized to a 90 e-tec. The VRO was only happy at 4,000 and I played throttle man all day when I need to run easy because it was rough off of Bayport where it is very shallow for long way out. The little 80 cubic inch E-tec triple planes off 4 divers, 9 tanks, fish and food coolers and 4 sets of dive gear at 3200, runs happily at 34-3600 and makes about 18 knots there. Spooled up to 5800, she'll touch 30 knots with that load. The best deal is that my trips off of Bayport or down to Sarasota to raid Conner and Danny's hogfish spots are usually between 60 and 80 miles - I have never put 22 gallons in the boat to top it back off. I understand the E-tec 90's actually puts out 102 Hp at he prop shaft. Be sure to include a new fuel tank and 10 micron fuel filter in your project costs. If you run a slug of H2O through that DI system it is painfully expensive. The 90's do not have water sensors. That day I was really glad it only has three cylinders.
Circle back if you find something that is interesting for a project and don't be too quick to break out the saw-zall. Learn from all our mistakes.

Thanks for the input! It looks like you have almost what I want. I would guess that your rig is a little lighter than a 20 with a few bells & whistles but it's good to see the performance you are getting with the 90 ETEC.
Are the hogfish spots you are raiding in the middle grounds? that's a pretty good haul from Tampa area in a 19' boat - and damn impressive fuel #'s.

[Terry England]

Originally Posted by JohnC

Thanks for the input! It looks like you have almost what I want. I would guess that your rig is a little lighter than a 20 with a few bells & whistles but it's good to see the performance you are getting with the 90 ETEC.

John, the boat is light but it's not like I run around with a spinning rod and tackle box. I have plenty of ballast with those tanks, coolers and dive gear. The 4 old, fat divers plus gear and tanks = 1800-2000#'s. I think I read where Carl Moesly put a little more forefoot in the old Bowriders than the other Seacrafts to carry the extra weight "up front". All I know is that the boat refuses to "plow" regardless of how much "stuff" I put in the bow. She always rides
"with her point(s) stickin' up, proud and high" as Bob Seger said.

Are the hogfish spots you are raiding in the middle grounds? that's a pretty good haul from Tampa area in a 19' boat - and damn impressive fuel #'s.

Dude, 60-80 miles round trip, not 60-80 miles out, in the Middle Grounds! I ain't that crazy! I get 3.5 miles per gallon average, with that load. Those hogfish are from 50' of water off of Sarasota and 25' of water off of Bayport. We went scouting Memorial Day weekend at Bayport for the Gag's, which don't open until July 1st here in the Gulf from 35' to 25' of water. Picked up our limit of hogs and a couple of Red Groupers over 20", but saw "Toad" Gags everywhere. I saw one in 25' of water that I swear was 4' long and had the girt of a 5 gallon bucket. NOAA and National Marine Fisheries are Clueless!

John, everybody on this site has a prettier boat than mine. The Marshtackie is an "Axe", but I believe the best thing about a Seacraft is the part under the water you don't see. They are a great "fishing" platform, even if you use 5' Stainless Steel plugs, while on "life support". Mine works pretty good just as Carl designed it with a splash well and a 360# motor. I'm think'in a 25" - 115 E-tec with a raised 25" transom well and manual adjustable 5" offset jackplate like Kmoose is running would be close to what Denny ran all over the Bahamas with in the 80's with a 115 Cross-flow Johnson on his Safari. Be careful with mess'in with too much, or you will change the "center of buoyancy" and you'll start "hobby Horse'in".

http://www.classicseacraft.com/commu...reply&p=227205

[Bushwacker]

John, you and I are on exactly the same page regarding engine power and weight! Based on Terry's info, I think the 90 E-TEC would do exactly what you want, but here's another relevant data point: I ran my Seafari for 31 years with a 300 lb 1975 115 V-4 (rated at powerhead) on the transom, which probably developed just about the same power at the prop as Terry's 90 E-TEC, although it was a 100 cu. in. powerhead, so it may have had a bit more mid-range torque. Although the bare hull of the Seafari weighs 1800 lbs, vs 1400 for the CC and 1300 for the 19' Bowrider, it rode VERY well, planing at about 12 mph, and cruising at about 20 kts @ 4500 rpm with a very heavy Bahamas-type load (ran it over to Green Turtle, Gt. Guana and Man-O'War Cays in the Abaco's a half dozen times back in the late 70's/early 80's).

On one trip with large following seas, I learned that there's an advantage to having a small motor wound up pretty tight. At 4500, when I started "uphill" on a swell, I found it starting to fall off plane, so I bumped the throttle up to 4600-4700, and problem solved, no more throttle jockeying required! It would easily hold plane going uphill, since peak torque occurred at maybe 47-4800! One time with the motor off, I had someone move and mark the control lever while I watched the throttle & spark advance linkage. I discovered that for about the first 75% or so of throttle travel, all it did was advance the spark;the throttle plates barely moved! The throttle plates opened almost 90 degrees during that last 25% of control travel, and they were just beginning to move at a typical 4500 rpm cruise setting. When I got up to around 47-4800 the motor got much louder (visualize a toilet flushing as all 4 carbs started to open up!), accompanied by a similar increase in torque!

When I repowered with a much heavier motor on a bracket, the effects on ride and min planing speed of the shifted CG, which I think moved aft about 18", were dramatic and quite negative! (The details are described in my "Pros & Cons of Brackets" thread.) With the 427 lb "150" E-TEC (165 HP at prop) on a 30" bracket, optimum cruise is at 37-3800 and about 23-24 kts and 7 gph. In 3' seas, the boat will be airborne about half the time at that speed, so I'd have to slow down to about 20 kts! That's down around 31-3200 rpm, and although the motor actually gets the best fuel economy at that speed in flat water, it's clearly on a very steep part of the torque curve at that point, because speed is not very stable. When trimmed for max economy at ~20 kts, even a slight wind gust or wake will cause it to start slowing down, so much throttle jockeying is required to hold a steady speed unless I change engine trim or tab setting. If it gets rough, I can drop the tabs and trim motor down and ride very comfortably sitting down 8' fwd of transom in 3' seas at about 12 kts, but fuel economy REALLY drops off! In that situation, I think a 90 hp motor wound up higher on it's torque curve with a larger (more thermodynamically efficient) throttle opening would burn less fuel and require less throttle jockeying than a bigger motor.

The 19 & 20' hulls are virtually identical below the chines, since Moesly modified a 19' mold to make the 20 (see Carla's website at http://www.moeslyseacraft.com/20-cc-seacraft.html), so Terry's performance numbers would apply equally to a 20. If you add a bracket, I would minimize the setback (Don Herman can build his with 18, 24 or 30" of setback), and try to move the gas tank and console far enough forward to keep from moving the CG. Couldn't do that in the Seafari, so I've had to run a 4B prop and a Doelfin to get enough stern lift for acceptable min planing speed. The extra drag of those items have knocked about 10 mph off my WOT speed, so, although I love the bracket for diving, the extra space it provides and the safety of the solid transom, the performance improvement claims of a bracket are very misleading and way overblown IMHO!

You could also consider the new 90 HO, which is actually a detuned 115 V-4 with a V-6 lower unit and a 2.25:1 gear ratio instead of the 2.0:1 of the 90. It's 105 cu. in. vs 79 cubes on the 90 so it'd be a torque monster! Probably cheaper than a 115, but also MUCH (70 lbs!) heavier than a 90, so you'd be better balanced with the 90. Good luck with your decision! I probably haven't made it any easier! Denny