DANMAN
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| posted on 26/9/14 at 11:38 AM |
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Electric reverse, which starter motor?
Hi guys. I am looking at ditching my horribly noisy Quaife reverse box and going to a two piece prop shaft with centre bearing, then using an electric
starter motor mounted off the side of the engine with a gear sandwiched between the output prop shaft adaptor and prop shaft as my reverse. I have
figured that my Ultrabatt battery at 14Ah can supply 100Amps of current to drive a 1kw starter motor for 8.4 minutes (although I don't plan on
reversing for that long!). This being the case I should be able to run a 1kw starter for a minutes worth of reversing without too much trouble but I
am planning on using one with a built in reduction drive to increase torque if I have to. The question for those of you out there who have done this
before is, is a 1kw starter enough to move a 440kg car without much trouble or do I need something bigger?
I have a maximum diameter of 140mm for the gear that goes between the output prop adaptor and the prop shaft.
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dave_424
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| posted on 26/9/14 at 12:02 PM |
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We used a subaru starter, one that has a gear reduction between the motor and the gear, top centre of the picture below. This engages to a very large
gear on the chain drive diff, 9 teeth on the starter and about 110-130 teeth on the diff, turning big 30" tall tyres is okay for reversing on
the flat. That's somewhere around a 13:1 gear reduction.
Say you have a 3.62:1 diff, you would need around 4:1 between your starter and your gear, meaning your gear needs at least 36 teeth, a gear
that's around 140mm diameter will have much more so I think you will be fine.
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theprisioner
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| posted on 26/9/14 at 12:50 PM |
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I wish I knew more about it but here are some pictures of what is fitted to my Westfield:
http://westfieldbusa.blogspot.co.uk/2013/10/transmission-tunnel.html
It works fine on a flat piece of ground but I would not expect too much on any sort of slope it just dies. It is however efficient in that it only
consumes any power while being used. It also allows me to comply with road going class at sprints etc.
It engages with a leaver in the tunnel and brings the reversing LED cluster on. Great if you get stuck unparking.
I would also like to know the motor origins as you never know with these things.
http://sylvabuild.blogspot.com/
http://austin7special.blogspot.co.uk/
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DANMAN
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| posted on 26/9/14 at 12:59 PM |
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Thanks for the prompt reply guys. Dave, any idea what model Subaru or which engine the starter motor came from?
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dave_424
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| posted on 26/9/14 at 03:53 PM |
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This is pretty much the starter we used, you want to look out for the motor is offset from the gear indicating that there is a gear reduction
increasing torque. This style of starter is used on many of the Subaru impreza engines.
STARTER MOTOR - SUBARU IMPREZA SALOON 2.0 TURBO GT 4WD 1994-2000 LRS01253
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dave r
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| posted on 26/9/14 at 05:37 PM |
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look at the duratec starter... geared for certain
I'd love to give my imaginary friend a great big hug,
but this jacket makes it impossible.
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K13JOB
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| posted on 26/9/14 at 09:45 PM |
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I would look at using an electric winch motor rather than a starter.
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dave_424
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| posted on 26/9/14 at 09:51 PM |
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quote:
Originally posted by K13JOB
I would look at using an electric winch motor rather than a starter.
Electric winch motors only get their high torque and slow speed from a high reduction planetary gear set up. You want the motor to run at a reasonable
speed since you have gear reduction at the gear on the prop and also the diff
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