Starter motors and stuff

Talk about the E-Type Series 1

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cactusman
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Location: Hertfordshire
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#1 Starter motors and stuff

Post by cactusman » Fri Sep 14, 2018 3:12 pm

The recent thread on high torque motors here

http://forum.etypeuk.com/viewtopic.php?f=4&t=13106

prompted me to relay the following thoughts and observations.

Firstly I have nothing against high torque motors....if your starter has really died they provide an excellent solution...although it seems from the above post that due care needs exercising when fitting to avoid problems.
My 3.8 starter seemed to be struggling to crank the engine a couple of years back. I got as far as ordering a new brush and bearing set for the motor and also peered at new high torque options but they are not cheap. Prior to removing the motor for investigation I decided to check the wiring and the solenoid.....mine has a remote solenoid on the near side (exhaust side). All seemed ok but I measured the voltage at the wire going to the motor when cranking...less than 9 volts. I measured the voltage across the high current terminals of the solenoid. When not activated it was 12 volts as expected. When cranking it was a volt or more....moved about a bit. Obviously the contact resistance was far higher than ideal and voltage (and significant power...heat) was being lost in the solenoid. They are cheap so I replaced it. Bingo. Stater churned furiously once again....not yet got around to even removing the starter motor....
So before you junk your trusty Lucas unit do check (a) that all the high current cable terminals are really tight and (b) check too that the solenoid is not faulty.
In addition I was recently given to look at...an old Lucas starter from a mk2 as the owner had similar issues to mine and had put in a high torque unit. Outside it was a bit shabby but to be expected as it was fifty years old. I opened it up. Inside it was mint....and I mean almost factory. He assured me it had been on the car 20 + years and to his knowledge had never been rebuilt. The brushes were maybe a mm shorter than the new one I have....bit of dust but that was it. Quick clean and drop of oil on the besrings. Scrapped and rattle can painted the outside. Insulation tested the armature and field coils...fine. reassembled and no load tested. Fine. Drew 45 -50 amps. The only thing I found amiss was a broken spring washer on the terminal post....my guess is it broke and the consequent loss of tightness on the terminal was why the crank speed dropped....it is ready to be returned to its owner incidentally :bigrin:
Julian the E-type man
1962 FHC
1966 MGB....fab little car too

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Mark Gordon
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#2 Re: Starter motors and stuff

Post by Mark Gordon » Fri Sep 14, 2018 3:38 pm

Good info, Julian. Your experience mirrors mine with what I am assuming is my original, untouched Lucas starter. A few years ago I was having some reluctance from the starter to spin the engine. I cleaned the contacts and installed an extra ground cable to the engine. Bingo! I understand that the gear reduction starters are lighter and easier to R/R, but I see no other advantage over the Lucas. If it's in good condition and its electrical connections are sound, it will spin the engine with authority. Any difficulty in starting an XK engine is usually traced to ignition (first) or fuel problems. If those systems aren't in good fettle, then spinning the engine faster is unlikely to solve hard starting problems. My '67 with 123 dizzy and SU carbs starts as easily as a modern FI, EDIS car, regardless of ambient temperature or humidity.
Mark

67 OTS 1E14988, 2002 VDP

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Topic author
cactusman
Posts: 1574
Joined: Wed Nov 14, 2012 11:09 pm
Location: Hertfordshire
Great Britain

#3 Re: Starter motors and stuff

Post by cactusman » Fri Sep 14, 2018 4:12 pm

Exactly Mark....really they only spin for a few seconds while starting....the rest of the time they are chauffeured about doing nothing so really wear within them should be low...unlike the dynamo which spins furiously all the time the engine runs....I did 're bearing and 're brush the dynamo a year or two back....
Julian the E-type man
1962 FHC
1966 MGB....fab little car too

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