Lotus Elan and Lotus Elan Plus 2 Forums

Hi Folks

Stated a post in the mods section re an Emerald ECU
elan-mods-f31/plugs-setting-with-emerald-ecu-t32018.html
However cranking the engine has resulted in damage to the flywheel ring gear so am reposting here in the hope of getting any advice on what to look for / suggest to ensure that I do not get a repeat of the problem.

thanks in advance for any help

cheers

Bob

Hi Bob I think I would do two things.

1. You need a new ring gear. It looks like the ring gear was to soft and has quickly worn. It was probably overheated when fitted or not heat treated right in the first place.

2. It looks like the starter mounting needs to be modified to ensure the full correct engagement of the pinion and ring gear. This appears to be a common problem with some of these new starters

This assumes you have a standard crank and flywheel setup and that the flywheel and ring gear is in the right position versus the block. Check the end float on the crank to make sure the thrust bearings are still OK.

cheers
Rohan

Bob,
I had to reduce the thickness of the starter flange to gain full engagement of the pinion but I understand that the motor suppliers can also supply longer pinions.
Cheers
John

Bob,

I presume you are removing the engine in order to renew the ring gear. You can then check that the pinion and new ring gear mesh correctly, i.e. the teeth on both are compatible. Having fitted a new ring gear, I used my wife's oven to get an even temperature, without risk of localised over heating. The thin plate that separates the engine and gearbox (I don't know the correct name for this component) could be used to check mount the starter onto the engine to see if there is a radial as well as axial error with your starter. I have not done this radial check yet, but intend to before the engine goes back in.

Richard Hawkins

I have had the exact same problem and have have been wrestling with it since a Denso starter dissasembled its self as the bolts were too short and backed out of the caseand wrecked the first ring gear .Mine had the same wear pattern on the denso teeth and similar damage to the ring gear . I also bought the super race xcelo starter and that stripped the teethright off the ring gear I also received a note from the starter supplier who was willing to work to a solution so you may try that route , I'm on my 4th ring gear .i am returning back to the dreaded Lucas starter and retarding the timing to 5degrees advance . I had the machine shop install the gear at room temp .Do not exceed 300 degrees f ...Will let you know how my efforts go ....Ed

Bob.

As Richard says, check your starter pinion and ring gear compatibility, as not all twin cam engines used a 9 tooth pinion, especially engines derived from the 1600cc engine using the 711m block. My own engine uses a 10 tooth pinion.
Cheers
Chris

I had exactly the same problem on my S3. I thought the problem arose because the starter motor body only has two thin bolts holding it to the alloy plate, I found that I could flex the starter motor body whilst it was bolted up tight to the bellhousing.

Bob, your posting got me worried because I also am rebuilding my Elan Sprint using a WOSP starter. Mine has only been used to crank the engine sufficiently to build oil pressure. So it was a reasonable length of cranking, done in two or three bursts.

In my photos you can see the witness marks on the 9-tooth pinion and they are much more central than yours are. My pinion also only moves out by about 13mm. I notice that my starter is labelled as GBT08 Lotus Elan Twin-Cam and I bought it from Sue Miller.

Regarding the cable on the other side of the motor, I have photographed mine and it looks kind of squashed although there is plenty of room for it when installed. I can't recall whether it looked like this when purchased as it has been quite a while.

Can I safely assume mine will be OK?

Mike

There is no doubt in my mind these starters are junk yard dogs rebuilt . They only require a new set of points at the rear to become active again and a good cleaning to appear in good shape . My engines are both lotus one 4 bolt one 6 bolt and worked flawlessly with the Lucas starter but the constant failure of the units convinced me to convert to these units and I feel it was a big mistake .so now I'm stuck with about 1000 dollars in useless denseo And Bosh starters And out 500 bucks in starter gears along with many hours in garage time wasted and a car that has spent many months No make that 4 years unusable, .ed

Ok ..I just did the count on the ring gear and it is 110 teeth and the pinions are 9 tooth so starter goes into the ring gear 19..2/9 times...ed

Thanks for all the info folks

Currently I am looking at the issue being more the ring gear than the starter motor either heat treatmet or precise location or a combination of both. Motor and its assembly was nice and firmly fixed on the car. I am open to any further ideas on the subject

Mike your post suggests to me that the engagement of the pinion is quite a bit more than mine was. This would I expect reduce the stress quite a bit. The electrical connection seems to be in better condition than mine and I notice like you that the blue cover is not a tight fit like the black cover is . What does your ring gear look like at the TDC on compression point? I assume like me that the engine has not actually fired up yet.

thanks for all the comments

will follow this thread and post updates as I learn more and hopefully fix the problem

regards

Bob

I have run Bosch pre-engage starters for 30 years and 80000 miles with virtually no noticeable wear on either starter pinion gear or ring gear on my Plus 2. Similar duration and starter and result on my Elan with a 12.5:1 compression ratio though I have used 2 flywheels over that time as I have swapped engines for rebuilds a few times. Even with only half engagement the wear on your ring gear looks excessive to me. I like the Bosch starter as the pinion shaft is supported at both ends and will not deflect under load

cheers
Rohan

Thanks Rohan

I tend to feel that high mileage and many years is what one should expect I am leaning towards the starter ring being the bulk of the problem

What Bosch part do you use on your +2?

thanks for info

bob

The Bosch starter I used was from 1970's Escorts, it was also used on the Mazda 626 in late 70's and 80's I believe and maybe other cars where Ford and Mazda were sharing engine and car development from around that time. Bosch supplied a new 9 tooth pinion versus the 10 tooth one used by Ford. Its a 3 bolt mount but the two bolts line up with the Elan bell housing and you just leave the third bolt hole empty



cheers
Rohan

That's a nice hefty piece of kit Rohan. My new one looks weedy in comparison.

Mike