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need creative enginering conversation

Posted: Wed Aug 08, 2007 10:41 am
by goldhunter_2
ok talking things out seems to always help me figure out what to do or at least what to try next so here goes.

apparently my ideas to use stock starter and alt for my engine where nevi and since they are required to be mounted on the accessory case so I can mount my gear box it is back to the drawing board with some creative engineering . Both the picture show two different set up for the starter (witch is the big deal in this mess) I am 98% sure I can make either method work but see a down side to each and would like to hear some others thoughts about each set up. Either way I have to get some extra parts machined witch I don't have the tools to do my self

1st method would mount in the top center hole on the accessory case (for left to right) the gear fits into the brass bushing in the case then the shaft extends out I would need a adapter plate to join the shaft and the next gear witch would act as a flywheel then replace the 1" plate that the starter is mounted on with a new on the fits the case hole and has a hole for a brushing that the shaft can ride in . starter would be bolted directly to the accessory case. my worries with this is the shaft being able to handle the starting of the engine without breaking

2nd method basically a little smaller gear because of confined space on my set up ( from engine out) fuel pump drive gear then need to make a adapter to weld in place form the end of the drive gear shaft to the gear shown starter would need to have a separate mount fabricated to hold it. also for added info I have a manual fuel pump on the engine witch will use this same gear drive also and the gear would be exposed pretty much as shown in the picture

comments :?:

Posted: Wed Aug 08, 2007 1:09 pm
by FP1201
You've got guite a delimma:
The second option looks a bit better, however the one thing that stands out as a hazard to the exposed gear; it'll be turning all the time, but with shielding might be safe.
Too bad you couldn't use a turbine setup: The starter/generator motor looks more like a round cylinder with a short splined shaft to engauge the gears. kinda like the PS pump on a HD Diesel engine.
AFAIK all the big players make em ie Delco-Remy, Prestolite, Leese-Nevill,...
While they are a bit on the heavy side, they are simple and you're eliminating a lot of other hardware...maby a pipe dream, maby a reality.

Posted: Wed Aug 08, 2007 1:58 pm
by goldhunter_2
You've got guite a delimma:

it seems that is the only kind I get :lol:

yep something like that would be nice but figure it is well out of my price range so trying to use stuff I have seems to be more realistic or me

At this point I am not even thinking about weight issue just want it all upfront and do away with the flywheel, I thought I had all that worked out before with stock stuff but it didn't turn out that way.
I am leaning more towards the 2nd choice because then I could use that 520 alternator in the top hole but yes I guess I need some type of shield if I go with that one since it is right under my rear seat floor and in the lower cockpit area

Posted: Wed Aug 08, 2007 5:45 pm
by FP1201
Another issue to consider is the starter itself: will it supply enough torque to spin the engine via the timing gears? On a conventional flywheel you're turning ~13:1
with that small gear it's proabable ~2:1
That would require a very solid and precise bracket, with the toughest part being the exact location for the starter drive to extend and engauge the gear.
Does the drive come off the crankshaft or camshaft? Off the crank won't be as hard to turn as off the cam.
What modle engine is this?
How about the redrive?

Posted: Wed Aug 08, 2007 6:17 pm
by goldhunter_2
yes I thought about the different size ratio between the chevy flywheel and the small gear but honestly have no good answer if that will effect it :oops: the gear drive fits in the lower left hole , and his is the one one for my boat 6 cyl GPU 520 conversation with 8:1 compression . the drive gear would turn the cam shaft gear witch then turns the crank gear

I was go to say I have now decided on the 2nd picture style as it only has one part to be made that I can't do my self and the other has several bu now you have me worried about the ratio to the starter , maybe someone could chime in with that info :?:

Posted: Wed Aug 08, 2007 6:28 pm
by NorthWestFloridaBoy
Hand prop. :lol:

Posted: Wed Aug 08, 2007 7:00 pm
by grant
Just a thought :D

Posted: Wed Aug 08, 2007 7:34 pm
by wade
Grant, You are a trip my friend. This could turn into something like the candy ass threads. Man I loved those :D

Posted: Wed Aug 08, 2007 7:36 pm
by goldhunter_2
smart a** :lol: :lol:

grant ,
that pull start would take up more room then the starter :lol:

what do you think about the point FP1201 brought up about the ratio of the gear compared to a flywheel ?

I watched cowboy hand prop my boat one night and it's nice to know I can if I had to, but I plan to stay away form doing that as long as possible, plus i am not sure how easy a gear reduction boat hand props

Posted: Wed Aug 08, 2007 8:03 pm
by grant
Goldhunter......I was just trying to be creative :D

Posted: Wed Aug 08, 2007 8:19 pm
by goldhunter_2
I know , I got a good laugh out of it :D

Posted: Wed Aug 08, 2007 8:29 pm
by Larry
You might want to check on the possibility of using an E-185 accessory cover, they look like they will mount to a gpu case and the E-185 mounts the starter and generator in it. That would solve both of you issues and you would not have to create adapters or brackets, just use existing aircraft parts.


Posted: Wed Aug 08, 2007 8:45 pm
by Tony480
I believe the E-series case will fit on it but the oil pump on them is nowhere near as big as on a GPU.

Posted: Wed Aug 08, 2007 8:46 pm
by FP1201
Here's another possible source:
A huge concern is catistrophic failure. It'll proabably cost you more than planned, however that might be offset from the sale of un-used parts and the deduction of what it would cost to fabricate a bracket system that at best will be complicated, heavy, and akward. Sorry but that's just my opinion, hopefully I'm wrong.

Posted: Wed Aug 08, 2007 10:53 pm
by goldhunter_2
well I did try the aircraft parts stuff to begin with I have a continental starter that fits my other engine but not this one the gear and ride bushing line up different same problem with the continental alternator. I have a housing form a 0-200 I think that will fit with two new bolt hole but would be the same problem it is more getting gears to line up correctly. I don't have any e-185 housings to try so I need to figure out how to make what I have work
what do you think about the point FP1201 brought up about the ratio of the gear compared to a flywheel ?

I don't have one of those cases so I doubt I will go that route but if I do I could probably swap oil pumps, thanks

that's ok that is what I wanted everyone opinions they make me think twice about every thing
I do have a actual Continental aircraft starter and alternator, problem is they don't work with the GPU case :evil: at this point I am getting where I am just ready to make it work.
I can't really see a aluminum bracket being all that heavy to raise concern anyway. I have the scrap materials laying around to build that and i can do all that myself the only piece I can't do and materials need to outsource is a balanced turned shaft to connect the gear drive shaft to the new gear, if it was a pulley I would make my own shaft but with the gear I would want it perfect and need a metal lathe to turn it since I don't have that i would need to get that one piece made

I did a little more checking an measuring if I use the drive gear setup then I have strong mounting points for the bracket to hold the hamburger starter. I think after flipping it around a little more I am set on at least trying it but i am now wondering about using that small gear compared to the larger flywheel. I would think as it goes form gear to gear it would have a good ratio but I don't know how to find out for sure

Posted: Wed Aug 08, 2007 11:01 pm
by FP1201
I just tought about another thing to check out: Is the starter rotation correct for the gear? It really wouldn't be funny to build it and find out that it's turning the wrong direction. :oops:

There are few minds a creative as an Airboat builders. :lol:

Posted: Wed Aug 08, 2007 11:04 pm
by mudkat
I have a off the wall suggestion,what about one of those remote starters they use to crank up top fuel dragsters ,they start them off the belts to the superchargers,could you rig it up to connect the the crank?

Posted: Wed Aug 08, 2007 11:08 pm
by goldhunter_2
I think so but I'll have to set down and think about that for a little bit :?

Broke Redneck = Creative Engineering

Posted: Wed Aug 08, 2007 11:09 pm
by FP1201
mudkat wrote:I have a off the wall suggestion,what about one of those remote starters they use to crank up top fuel dragsters ,they start them off the belts to the superchargers,could you rig it up to connect the the crank?

That's really not a bad idea! The thought with a starter/generator was baised on the drive running all the time....sure would be interesting.

Posted: Wed Aug 08, 2007 11:10 pm
by goldhunter_2
I think I would have to put something on the prop end of the crank for that to work an I am trying to take everything off that end if what little sanity last long enough

Posted: Wed Aug 08, 2007 11:16 pm
by goldhunter_2
yep that starter gen thing would be nice

heck you keep coming up with interesting points, see this is why I like to talk stuff over. I got to go out an look at the gear rotation to make sure or I'll be up all night, be right back

Posted: Wed Aug 08, 2007 11:32 pm
by goldhunter_2
Ok just laid out some gear to check the crank gear turns the Cam shaft gear witch turns the fuel pump drive gear with I am adding the starter gear to it seems to turn the correct direction so that is ok

Posted: Wed Aug 08, 2007 11:38 pm
by Larry
My dad keeps the original gpu handcrank that goes into the end of the fuel pump gear in his boat, but we have never even tried to start it by that method yet. You would think that if the motor was designed to be started with the handcrank like that it would be ok with an electric starter.


Posted: Thu Aug 09, 2007 12:03 am
by goldhunter_2
Thanks larry that does make allot of sense :D your right if it can start the motor with a hand crank it should be fine with a starter an the starter would turn it faster then a hand crank I would imagine

Posted: Thu Aug 09, 2007 5:38 am
by FP1201
Hand cranks aren't that hard to use, just gotta treat it the same as hand propping. The down side is makeing sure there's enough clearance around the area to be able to clock it and lift the handle to start the motor. It's a bit of a PITA if you're used to least with the gear box on the end the prop isn't adding a lot of additional load to starting the engine. It's a lot easier to push start a vehicle in 2nd or 3rd gear than 1st. 8)