Doozits Second

[Salty Techsan]

Steve,
Thanks for the update. Glad to see somebody else is tormented with this starter delima. I have burned many many brain cells trying to figure out how to make something work without shelling out the $1300 for the redrive that includes a starter. I had settled on the starter/generator option but Chuck at Airboat Pros said they quit using them as they had been problematic. Man.... What to do?

You still thinking you'll try the flex plate route?

[Doozit20]

Hey salty

Yes I am still planning on the flex plate route I just have to get the time to go find the parts out in a scrap yard. I'm thinking the Chevy 168 tooth from and automatic will work good and matched to a 12v mini starter shouldn't weigh up to just the stock flywheel. Sure there will have to be some machine work to make it work but there is a 6 bolt hole pattern in the flywheel so it shouldn't be too hard to fab up a useable hub. Ill also use the steel part thats cast into the stock flywheel as my hub. Let me know what you come up with as well.

Steve

[Salty Techsan]

Steve, What grade aluminum you planning to use for the new hull?

[Doozit20]

Aluminum will be 5052 and .090 thick for the hull and .063 for the decking with 6061 T-bar for stringers 3/16 thick and 1/8" angle everywhere else

[Salty Techsan]

Doozit, Any progress on the build? After much deliberation on the starter thing, I ended up adopting some of your idea. I bought a 14" flex plate from local auto parts store for $22 ( brand new), and had the local machine shop bore me some mounting holes in the front, rope start flywheel to bolt up to the 6 bolt flex plate pattern. The large holes in the flex plate lined up so as not to cover the notch in the fly-wheel so that in theory, I should still be able to rope start if the need arises. Ill take some pics as soon as I pick it up from the shop.

My original plan was to actually mount the flex plate to the back side of my aluminum Arrow prop hub.... Which would damn near work. The outer bolt holes on the hub were at the right degree, just a little larger and to the outside... If you could find the right flex plate, you could actually employ that method and get away with zero machine shop work by using the original aluminum flywheel housing (cut waaaay down of course) to mount the starter. In any case.... Stay tuned to see if my idea works

[Doozit20]

No new progress as of yet. Dad is in a toss up on me building the hull or waiting to try and find a deal on one somewhere that's already built. We did manage to choose a color so ill be painting the engine in a little bit. Also work has been keeping us from doing much airboat building...can't really complain though just glad to have work.
Im glad to see the flex plate idea may have some light. Im still going to go forward with it but ill be mounting it to the back side of the hub ill be making out of the stock flywheel steel insert. Mainly because I dont want to try laithing that taper when one is already there to be made but I just have to get the aluminum off of it first.

Salty,
You said you are going to mount it to the front rope start pulley? How are you going to mount a starter? Pictures pictures lol

Steve

[Salty Techsan]

cool deal.. what you going to prime the aluminum parts with?? I am wanting to get mine painted up fairly soon as well. Here are a couple photos of the flex plate mounting. I'm going to follow your lead and have ordered a lightweight mini starter off ebay for $68... I'll have to fab up a bracket to mount the starter.. still working through the details on that..... in retrospect.. I should have probably mounted the flex plate to the back of the hub as it would make mounting the starter a hell of a lot easier, but at the time I was concerned about impeding airflow to the center of the prop with that big 14" flex plate..

[Doozit20]

Very nice work. How much does that flex plate weigh? I think the wind won't be that big of a deal mounted on the prop hub because the engine itself is blocking more then that but hey give it a try just be sure you get the right rotation with the starter. Weither thats habing to mound the motor in front of the flexplate or along side the engine. I think a chevy runs the same way these do when viewed from the front looking back, if that makes since lol. The paint ill be using is Dupli-color engine enamel with ceramic. Its rated to 500 degrees according the the spray can.

I got an alternator in yesterday that ill be trying on my boat and if it works good ill be putting one on my dads. The one i got off ebay is a mini 1-wire one 30 amp. After some measuring of the pulley on the alternator and the rope start pulley I think the rpm on the alternator is going to be around 9000 rpm which i think might be a little too fast so im going to machine an aluminum pulley so that when the engine is at 3000 the alternator will be spinning at 6000 rpm and at that spees its rated to put out 60 amps. The rope pulley is roughly 5 3/4" and the small alternator pulley is 1 3/4 in the smallest bottom of the v-belt pulley. Im going to make a pulley bout 3" at the smallest to get the rpm I'm after and so I dont have to worry about burning it up too quickly.

[Doozit20]

Scratch that, I just found an aluminum pulley that has a flat belt design onn it that ill modify to use a serpentine or cogged v belt design for around $15. Ebay strikes again lol

[Papee]

Nice work guys. The starters have to be mounted in front of the flywheel not beside the motor to get he right rotation. This has been done, I think there are photos here somewhere. I think it is one of alaskadudes posts, I forget his screen name but his name is Nick. I'll look for the photos, if they are not posted on the forum I think I have them somewhere on my computer.


Edit: His screen name is eskimoboy and here is the thread where he posted photos.
http://miniairboatassoc.com/forum/sh...-Starter-setup

[Doozit20]

I saw that post. I think it's a snowmobile starter and ring gear.

Update alert!!!!!!! We just found a hull for my dads build and will be picking it up this Saturday. Realllll excited haha!!!!!! pictures to come then

[Papee]

Hey I could use the fan off that if you aren't going to be using it. I need them for the new reduction drives I am building.

[Doozit20]

Hey papee I'm actually going to use the flywheel on it to make the hub. Ill be turning it down and machining in a bolt pattern in it.

[Doozit20]

Here we go as promises pictures of pops hull we got today. 10'6" long and 7' wide. It has poly on the bottom so that will be removed so that it will shed a few pounds. Right now the hull weighs in at 300 lbs. Hopefully the poly will help loose at least 50-60 lbs. Weigh in will be as I go along. My other boat complete full of gas and battery weighs around 575.

[Doozit20]

Ok got poly off and it weighed right at 60 lbs plus a few pounds for the stainless screws. So hull right now weighs roughly 240 which isn't the worst starting point. Have to fix quite a few rivet that were missing down the center rib.

[buster]

Hey guys,

I see you are talking about rigging a starter for an 084 engine. Do you realize you are reinventing the wheel? If you can dig up my posts
about my Aircat 084 build, you can see how I did it with a lawn tractor ring gear, and a Suburu starter.

That way the starter mounts alongside the engine (opposite side from the oil filter), and the starter turns the right direction.

I don't have pictures anymore, but maybe Papee can dig them out. It worked beautiful, and if I had to do it over I would do it exactly the same!

PM me if you have any questions.

Dave

[Doozit20]

Hey dave thanks ill see if I can find it in the old posts.

Steve

[buster]

Doozit,

I don't remember the diameter of the ring gear but that should easy to figure out when you get a starter and hold it in place.

The reason I used a Suburu starter is that it turns in the correct direction. Also, I knew it would have enough power, since it was designed to turn a 4 cyl. car engine.

I tried an old Escort starter I had on hand first, and that worked good, but I didn't have the room to have it sticking out the front to get the right rotation direction.

Dave

[Doozit20]

The starter im planning on using for my dads boat is a mini starter used for chevys. I know thatll have enough torque. Im going to mount it the way the stock starter was since the chevy starter and flexplate are roughly the same in diameter and spin the same direction. Yeah the flexplate might be a little big but I think itll help with that old thing. An object in motion tends to want to stay in motion. Or something like that lol

[Doozit20]

Ok here are a few pics after we got the poly off the bottom. Looks worse then it really is. I think its just a bunch of old steal-flex on there. It chips right off. Also a pic of a few ribets that were replaced already. The center rib needs a lot of rivets replaced but again no big deal really. And a pic of that mini alternator I installed on my boat. Haven't had a chance to see how well it charges or how much it drags on the motor but I did crank it up without wiring in the alternator to see how it tracks on the pulley which seems to stay pretty good on the pulley. Oh thats a serpentine belt as well.
Steve