Gridgway Posted May 31, 2023 Author Share Posted May 31, 2023 No, the starter motor man used his own test etup including solenoid. However I have thoroughly cleaned the contacts and tested the solenoid and questioned the starter motor man. He said he'd never come across a solenoid that impaired a starter motor. They either work or they don't. I also tried a direct feed to the solenoid +ve from the battery and it didn't make any difference.When I have done my testing, the engine stops being cranked by the starter motor as it comes up to a firing stroke, so the setup isn't man enough to keep the motor turning through the firing of a cylinder. If I disconnect the coil so there's no sparks, the starter motor will happily crank with a 10-11v cranking voltage.We'll see how the new starter gets on! Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted May 31, 2023 Member Share Posted May 31, 2023 ThanksJonathan Link to comment Share on other sites More sharing options...
rkeywood Posted June 1, 2023 Share Posted June 1, 2023 Are you sure the current starter and ring gear aren't mismatched ie a 9T inertia starter gear into a 135T pre-engaged ring gear? Sounds like it could be binding under load with the gears not meshing properly - are there any witness marks on the starter gear? Link to comment Share on other sites More sharing options...
Gridgway Posted June 1, 2023 Author Share Posted June 1, 2023 #28 now that is a very good question which I don't have a definitive answer to. However I do know that with no ignition the starter spins the motor perfectly well and there are no witness marks.But before I try the new starter I'll grub around and count the teeth through the starter motor hole to be certain.I'll report back! Link to comment Share on other sites More sharing options...
rkeywood Posted June 1, 2023 Share Posted June 1, 2023 Counting in a PITA! You should be able to see from the tooth shape - square for the pre-engaged whilst inertia have a taper Link to comment Share on other sites More sharing options...
Gridgway Posted June 1, 2023 Author Share Posted June 1, 2023 Agreed, but I reckon with a torch, a white marker pen, turning the engine by hand with the plugs out, you should be able to count the teeth for a revolution as well! Link to comment Share on other sites More sharing options...
Gridgway Posted June 1, 2023 Author Share Posted June 1, 2023 And just for clarity (my sanity), the 10 tooth inertia starter (which I have) should be paired with the 135 tooth ring gear?The new starter motor has arrived with 9 teeth, even though I specified 10 teeth to the starter motor man. 9 teeth starter is for the 110 teeth ring gear? Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted June 1, 2023 Member Share Posted June 1, 2023 Previous discussions:https://www.caterhamlotus7.club/forum/techtalk/crossflow-starter-motorhttps://www.caterhamlotus7.club/forum/techtalk/what-starter-motor-am-i-xflow-5-speed which includes a list of the possible combinations.Jonathan Link to comment Share on other sites More sharing options...
Gridgway Posted June 1, 2023 Author Share Posted June 1, 2023 Right, serious confusion or perhaps serendipity time. Here's what we know:The inertia starter has 10 teeth and worked seemingly fine before the engine rebuild (inc new lightweight flywheel)It doesn't do the job now.The current ring gear has 110 teeth (what a pita to count) with the lead in on the rear (facing towards the back of the car) for inertia starters.The new powerlite pre-engaged starter has 9 teeth.Can we deduce that:The old flywheel had 135 teethBy pure chance the new starter should work with the new flywheel 9/110 (engagement problems not withstanding)?GrahamPS now I think back, the splines/teeth of the old starter were well chewed up and I replaced the pinion with a new one. Maybe the old flywheel was 110 teeth too? Link to comment Share on other sites More sharing options...
rkeywood Posted June 2, 2023 Share Posted June 2, 2023 Not sure I understand that fully but the OE 'inertia' ring gear is 110T and the pre-engaged 135T (132T pre '70). The Lucas OE inertia pinions were usually 9T but also supplied as 10T and are 29mm pinion gears. The pre-engaged pinion gear is smaller (25.5mm). I wouldn't worry too much about the OE starter variations as the gear reduction replacements are made to suit either of the ring gears. Both Edge and Powerlite will supply with 9T 29mm pinions for 110T ring gears so looks like you're good to go. Is it an RAC109? Link to comment Share on other sites More sharing options...
Gridgway Posted June 2, 2023 Author Share Posted June 2, 2023 I think it's all because it's non-oem flywheel. It's a TTV steel flywheel with 110 teethWe clearly didn't communicate enough in the build! The starter is an RAC418.I'm waiting for a call back, but I think the 9 tooth starter should work, so I will strangely be ok! Link to comment Share on other sites More sharing options...
Gridgway Posted June 3, 2023 Author Share Posted June 3, 2023 Right, we have a happy ending.After taking some reassurances from the engine builder, I bolted the starter in. The main battery cable didn't reach. I was going to use the wiring in place from the solenoid and use a "link" wire on the starter. But as I had some wiring work to do, I bit the bullet and rewired to remove the solenoid as well. That took some time and a new battery cable, but the results are much simpler and tidy.And to the main news. Re-connected the ignition to get sparks, turned the key, cranked and fired into life not a drama or even a slowing, super duper. Not really going to know the problem - wrong number of teeth on the starter pinion? Just not man enough? My engine builder consulted a starter expert who actually said he didn't think 9 or 10 teeth would make much difference with 110 teeth on the ring gear - who knows?Now I need to find time to get it on the rolling road to set up the carbs and the timing, get an MoT, some insurance and tax (not in that order) and we are blat-ready!Thanks everyone for the help and encouragement. Fab as always.Graham Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted June 3, 2023 Member Share Posted June 3, 2023 Well done.Jonathan Link to comment Share on other sites More sharing options...
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