Author Topic: NG3 conversion  (Read 493 times)

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Offline Blitzen

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NG3 conversion
« on: Saturday,October 03, 2020, 09:38:12 AM »
Some questions for swapping out my 352 for an NG3 on my 73 tcs.
Getting parts is always slow so would like to get everything before I start. My parts list so far is the
- NG3 input shaft bearing/seal
- 2 output shaft oil seals for 352 (assume they should be for 352 as they get swapped in)
- speedo drive oil seal NG
- bell housing gasket
What other parts should I order?

I’ll be farming out the welding/machining of the bell housing, what size is the hole for input bearing?  Will any competent machinist know the correct size based on the input bearing?

Offline BDA

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Re: NG3 conversion
« Reply #1 on: Saturday,October 03, 2020, 10:37:19 AM »
I bought a kit which included parts for the linkage from Richard (now called Lotus Supplies at https://www.lotus-supplies.com) so I can't advise you about some of the details other than refer you to this page (http://www.greytower.com/jon/lotus/europa/gearbox/gearbox.html). I didn't have any welding done on my bell housing and didn't know it was advised till I saw that page. So far so good but at some point, I might have it done.

I don't think you'll necessarily need the output shaft oil seals. I wouldn't bother with the bell housing gasket either. For that as well as the end cover gasket (which I believe is NLA), I'd use Permatex Right Stuff.

I'm not sure about the speedo drive oil seal but if you plan on using the stock speedo and cable, you'll need another speedo gear. I'd recommend an electronic speedo (Smiths makes one as well as speedhut.com. Speedhut allows you to customize the face of the gauge so you can get it reasonably close to the original Smiths). The electronic speedos can be driven by gps with an antenna, a hall effect counter, or I think you can get a counter that plugs into where the speedo cable goes in the tranny. I have the gps drive and I like it except that the first mile doesn't get registered in my odometer.

I think you will be able to use your 352 rear hoop but it may require some modification. Our own Andy Harwood did that modification. You may be able to find a picture of it but basically it looks like he flattend part of the tube to make room for the tranny.

Good luck!

Offline Blitzen

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Re: NG3 conversion
« Reply #2 on: Saturday,October 03, 2020, 10:57:39 AM »
Good info, thanks.   I forgot to mention I have the cable shifter kit from Dave and rear support from John
Any idea about where to get the correct speedo gear?  I’ll check out  speedhut . Slight preference for the stock speedo but will likely go with the simplest option.

Offline BDA

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Re: NG3 conversion
« Reply #3 on: Saturday,October 03, 2020, 11:40:13 AM »
Nisonger has a process to correct the speedo. It involves pushing your car a measured distance and counting how many times the speedo gear turns. You send your speedo to them and they adjust it for you. The speedo gear in my NG3 shredded itself so I didn't have that luxury.

For parts, I forgot to mention Michel at http://www.alpine-america.qc.ca. He speaks English with a very heavy French accent. Unless you know French, it might be better to email him and use google translate to translate back and forth. Another option is http://www.mecaparts.com/index.php. I've never used them but others on this forum have and say they're good.

I've heard a lot of good things about cable shifters. That's a good option!

Offline Rosco5000

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Re: NG3 conversion
« Reply #4 on: Sunday,October 04, 2020, 09:52:14 AM »
 This will be an interesting thread to watch. I just acquired an NG3 as well. I thought you needed to change rear suspension because the NG3 can’t take suspension loads?
Ross
1974 Europa Special
1969 Europa S2
1970 Lotus Elan +2
1978 Austin Mini - 1275, big brakes
1991 Ford Explorer - Lifted on 33s, custom lift and radius arms
2005 Chrysler 300C - chipped, lowered 22s
2011 Cadillac Escalade - Stage 3 cam, Headers, CAI, 2,600 stall converter

Offline BDA

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Re: NG3 conversion
« Reply #5 on: Sunday,October 04, 2020, 09:57:29 AM »
I thought I read that somewhere too. Did JB mention that here or the lotuseuropa group? I got Richard's twin link kit at the same time as my NG3 so I never had to worry about it. Richard Mann came up with a clever twin link set up that might be simpler. A buddy of mine implemented it on his S2. If anyone needs, I can ask him about it.

Offline jbcollier

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Re: NG3 conversion
« Reply #6 on: Sunday,October 04, 2020, 03:32:17 PM »
With an NG3 transaxle there are two ways forward:

- swap in the short output shafts and seal holders from your original Europa transaxle.  Now you can run the suspension as stock.  Shimming the diff gears may require machining up custom shims to suit.

- fit a twin-link kit (or equivalent) AND shorten the half-shafts so they work with the longer output shafts (any driveshaft shop can do the work).

I fit an 395-10 transaxle so was ok with the seal holders.  I replaced the whole diff assembly with a Quaife unit (short output shafts).  I could have stayed with the stock suspension but used a Twin-Link system regardless.  It all works beautifully.