6 replies to this topic

[ac427]

Are they as good as each other, if the inertia type has the pinion distance to the flywheel ring gear set correctly?

 

My starter motor spins sometimes when it fails to engage the ring gear. I presume this isn't a problem with the pre-engaged type?

 

 

 

 

[Retro_10s]

Pre-engaged is generally preferred over the inertia type ,. if you have the choice, and they are of course, all newer.  But It's a sort of trade off,... Inertia can mash your ring gear on the flywheel because that's what it does to engage,... but is cheaper to fix IF it breaks,... where-as pre-engaged are stronger starters,.. but more expensive. 

 

Bear in mind that the solenoid on the Pre-engaged starter will have a higher draw than the inertia solenoid, And should be routed through a starter relay to avoid risking ignition switch burnout.

 

I can't remember but there may/may not be a difference between ring gears used,... can someone else confirm/deny this?

Edited by Retro_10s, 08 August 2023 - 05:46 PM.

[KTS]

i believe inertia starters used a 9 tooth pinion with a 107tooth ring gear, and pre-engaged used an 11 tooth pinion with a 129 tooth ring gear

[floormanager]

Different ring gear for each starter however, some clever people on here (Spider) have sourced pre-engaged for inertia starter rings

[DeadSquare]

Are they as good as each other, if the inertia type has the pinion distance to the flywheel ring gear set correctly?

 

My starter motor spins sometimes when it fails to engage the ring gear. I presume this isn't a problem with the pre-engaged type?

It sounds as though your Bendix may be clogging up with dirt.

 

It would do no harm to remove the starter and wash the Bendix thoroughly with Jizer, then water, or petrol, and before replacing, lubricate it with powdered graphite, often sold by locksmiths.  Unlike oil, it is much less likely to trap dust.

[nicklouse]

The things to remember are they engage with the flywheel from opposite sides. This is the main difference.

 

in operation you have a smash and grab set up and an engage and spin set up.

 

my light flywheel does not have a separate ring gear and as such needs a pre engage starter. Less wear happens. My other light flywheel that has a separate ring gear uses inertia. Both work fine and can manage high compression builds but care is needed to make sure you use the correct parts.

[68+86auto]

On the ring gear topic, all the auto engines that I have use a 9 tooth starter. That is two 1968s (inertia) and a 1986 (pre-engaged). I also have an SPI auto but I haven't checked it's starter.

 

 

Edit: Now I am questioning myself on the pre-engaged starter tooth count but the inertia ones definitely have 9 teeth.

Edited by 68+86auto, 09 August 2023 - 05:37 AM.