Starter Motor Wiring.

I have got a Visteon starter motor for my sbf 302 and I'm wondering how to wire it up. (It doesn't use the conventional centrifugal gear) There are two contacts a large one that I think stays live to the battery all the time and the other being a smaller contact that pushes the starter gear forward and acts as a solenoid for the main starter motor.
Having tried 12v on each this seems to be the way it works.
Is it o.k. to have 12v always on the large contact ?
Do I still need a separate solenoid for the ignition ?

Hi Paul

Looks normal to me - permanent +12v to the large right hand terminal.

Powering the other terminal then engages the gear and also bridges internal contacts to supply power to the motor armature and hence spin the starter.

Not quite sure what you mean about a separate solenoid for the ignition? /ubbthreads/images/graemlins/confused.gif

I had another starter motor before this that only had one terminal on it - (the gear just flew forward with friction) With this starter motor you had a separate solenoid that goes between the starter and the battery (I presume just a large relay) so the power doesn't go via the ignition.
My question is if powering the solenoid on my starter is too much for my ignition switch or should I use a separate solenoid or relay for this.

The wire that triggered the starter "relay" before can directly trigger the starter. For ease of installation, I might be tempted to use the "relay" still and just have a small wire running to the solenoid (14 guage is more than ample). If you dont already have all your battery cables etc hooked to the old relay, then, it really isnt easier either way.
Lastly, if you want it to work like your old starter, put a small jumper wire (14 awg) between both of those terminals and use the same big wire from the old "relay" and leave the old system intact.

Paul,
These starter are known as 'pre-engagement' starter motors, because the flywheel ring gear is pre-engaged before the main motor torque comes on. It reduces ring gear wear, because there is no torque on the pinion when it actually engages with the flywheel, and is also quieter than the inertia type for the same reason. These starters have been around for some time - in my experience for at least 25 years.
The main terminal should be permanently connected to battery +, because there is an internal solenoid that only closes a motor contact at the ends of its travel, after the ring gear has been engaged.
The engagement solenoid usually takes a fair bit of current, so it's necessary to put a solenoid in the starter line to protect the ignition switch. A normal 30A fused solenoid, obtainable from Premier Wiring Systems, is quite adequate.

IMHO, Eric, your advocacy to connect the two terminals etc could be highly counter-productive. You would be trying to use a pre-engaged starter as an inertia one, when the gear design is completely different, and is definitely not meant to have torque on it as the pinion engages. The old inertia gear locked into engagement under torque; pre-engagement gears have no locking facility, being designed to be held in mesh by the solenoid.
Finally, the pre-engagement design was introduced when starting currents associated with high-torque starters became too high for conventional wiring to handle. Don't do it!

Tony
I have to disagree with you on the last half of that. I say it makes no difference when you power that large wire, it will work exactly the same way as wiring it normally. It could be on its own switch if you want, turn 1 key energize the solenoid, turn the other, fire the windings. Or vice versa, the motor gets power first and then energize the solenoid wich will switch the motor windings when it is needed. Either way, there is no current passing through the motor windings until the solenoid pulls in and completes the cicuit. So, if we power both at the same time, well, the solenoid still has to travel that inch meanwhile the windings will have power sitting there waiting for the big moment as usual. Agree??
Not that I would wire it like that myself, you are just adding something else that is pointless and could fail. But if the wiring is all in place already, it would be alot less work to use the relay, join those 2 starter terminals, and run the big wire to the starter.
As for what size fuse to run. Not sure I totally agree that 30amps is needed but my yougest son is asleep 2 feet away and i dont want to turn the light on to find my manuals to look up what most cars use. So i will leave that one alone as 30 amps would work either way, and I could be wrong.
Please tell me if this doesnt make sense and I am totally leading everyone astray.

Totally makes sense fellas - It's as I thought just needed somebody else to confirm what I thought, Cheers.