Technical 69' 500L Transmission Upgrade Recommendations

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Technical 69' 500L Transmission Upgrade Recommendations

Naples500L

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May 14, 2011
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Washington D.C.
Hello all,
Currently living in Naples Italy where I purchased a 69 500L. A nice "blank canvas" on which my ultimate goal is to make it a dependable daily driver that can keep up with average highway traffic (100-120 kph/ 60-75 mph).

The first item I'm looking at tackling to increase the top end cruising speed is the transmission. Currently the car's top speed is between 90-100 kph. Fully understand that I'll have to upgrade suspenion and engine eventually. Just wanted to start with the tranny first.

I've disocvered a 5-speed transmission conversion at MrFiat.com, however I've had some people tell me that a trasmission from a 126 is the best way to go.

I'm open to suggestions. Thank you in advance.
 

Bambino

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Aug 3, 2009
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Location
Sunshine Coast, Australia
Ciao Napoli,

It's been a while since you posted and probably have an answer by now, but as I had to remove the engine from my car because of a big-end knock (therein lies a story), I thought that I'd post a couple of photos of the gearbox bellhousings.

My car was originally a 500F but has been converted to a 695 with a 126 gearbox, though I still have the original gearbox.
The differences are in the bellhousing - the 500D/F/R/L has the starter motor mounted vertically and the 126 has it mounted at the 3-o'clock position and as such they are not interchangeable unless you also change the crankcase (= engine).
Similarly, I'm told that the bellhousings can't be interchanged on the boxes either. So if you want a synchromesh gearbox on a 500, you'll have the change the engine as well. I've just finished doing this and there are no major problems.
If you do opt to change over, the most important issue is to change the halfshafts as the 126 rear track is wider than the 500 rear track. I believe that the halfshafts on your 500L would do the job admirably.

As to the 5 speed conversion, I don't know - sorry. Even if you do fit it, you'll still have a non-synchro box.

Hope this helps,
Chris.

PS: Welcome the the forum. If you wish, post some photos sometime.
 

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Naples500L

Naples500L

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Thanks for the response Bambino and you're incorrect in me having an answer.....you're the first and I appreciate the information. Also thank you for the welcome to the community. I'm hoping for many more friendly exchanges like the one you posted.

Sounds like you've done quite a bit on 500's and experienced the same..... I don't anticipate making a 695 conversion or for that matter a synchromesh change-over. While I fully appreciate the benefits of both, I'm trying to minimize the amount of labor intensive modifications. Make no mistake, I'm no stranger to auto-mods and restoration.....however I'm more interested in simple "bolt-on" improvements that require as little machining/cutting and grinding as possible. MrFiat.com has a wealth of bolt-on parts that seem to be exactly what I'm looking for, however the more and more I learn about this car.....like the syncromesh conversion, the more interested I become in what's involved with the modifications. You're detailed description of the starter locations and half-shaft mods answered those questions right from the begining.......again thank you.

Truth be told.....I don't mind grinding the gears when shifting.

What other recommendations do you have? Again......looking to make a highway reliable "daily driver" that doesn't "fuss" too much when stopped and started several times in high heat, (planning on shipping it back to Texas when we head back to the States). What kind of carburation are you running? What about ignition? I recently purchased one of those "123Ignition" distributors....thoughts? Thanks again for all the help.
 

Bambino

Shed Troglodyte
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Messages
1,502
Location
Sunshine Coast, Australia
These would be my suggestions -

1) 650cc engine plus gearbox/differential.

The only modifications necessary are to the rear engine mount, the halfshafts and the starter.

The standard 126 rear engine mount studs are too short and need to be exchanged for the longer ones off your 500 engine.

The halfshafts will be too long and will need to be replaced with shorter 25mm shafts from the later model 500s. These are available new.

The 126 starter has a solenoid rather than the cable mechanism, so you'll need to wire up a starter button - very easy.

The 126 gearbox has synchros on 2nd, 3rd and 4th gears and also better ratios for cruising. A five speed conversion would be interesting, though I've not done it.

You'll also need to 'panelbeat' the metal cabin airducting so it clears the front (electrical end) of the starter motor.

2) Engine work.

The standard 650 is powerful enough though can be improved with a little effort.

Remove the head and install slightly bigger valves - The 500s had 32mm inlet valves and the 650s had 33mm valves. Exhaust valves were 28mm on each (I think). I've installed 34mm inlet and 29mm exhaust. Easy to do and worth the effort.

Install a 'sport' camshaft. Various height/duration cams are available.

The little Weber 24IMB should be replaced by a slightly bigger IMB (28mm) - these are also available. The IMBs are OK but do tend to flood/vapour lock in warm weather making the cars difficlut to hot start. The 30DIC is supposed to be a better carby, though I have no experience with them. Some people go as far as fitting a later model Panda twin port head and a twin throat carby, but I've heard that this doesn't give much of a performance boost unless you do a lot more to modify the engine. Also, the standard tinware will not fit if you use the Panda head. After a lot of hunting around, I fitted a Dell'Orto FZD to my single port head.

A sports exhaust system makes the little beast sound better and the twin pipes look good.

Electronic ignitions are great. Like you, I've installed a 123ignition distributor and have not regretted it.

3) Suspension.

You can lower the car but it is not really necessary. Decent shockies are worth it, just don't go too hard as these little cars are already fairly bouncy.

4) Brakes.

Standard 500 brakes are OK, though you can upgrade to the 126 hubs with little difficulty. This then gives you a more modern wheel stud pattern (4x98) which means that you have a greater variety of wheels to choose from and also can fit more modern tyre patterns. I have front disc brakes, 126 rear drums and 126 wheels fitted with 145/70R12 tyres. One day I'll get myself a nice set of 12" mags. You can go up to 13" wheels and fatter tyres, but I've heard that there are problems with rubbing, so you end up flaring the guards.

That's really about it.
These little cars are great fun just as they are, but can be modernised a bit so that you can at least keep up with the traffic.

Let us know how you get on,
Chris
 
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Naples500L

Naples500L

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Chris,
I'm overwhlemed with you experience and wealth of information...not to mention the time you've taken to share you experience with me. Before I forget,...a resounding "THANK YOU!" from a fellow "gear-head" who knows how valuable the experience of others can be with respect to identifying what parts will and won't work, and how that translates into time, money, and frustration, saved. Thanks again.

There's an abundance of parts here in Naples and parts houses that sell most, if not all of what you've recommended. I will take your suggestions to heart and make an educated decision. I'll use this "thread" to post the results of modifications and let you know how things progress (including photos).

Anything you need from bella Napoli, just let me know and I'll see what I can do. Thanks again for being the warmest welcome I've ever received to a new forum.
 

Miramontesj

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Oct 4, 2011
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Living in Sicily
I really enjoyed your exchange on this thread. I also just purchased a '69 500L and I'm planning on doing similar upgrades to my car. I'm in Sicily now and will be shipping the little car to the US in a few years. I'm driving the car to work everyday and I can't wait to start working on it.
 

Bob de Bouwer

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Oct 23, 2011
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Amersfoort, Netherlands
I'm new to this Forum but I have some experience with swapping trannies. You can replace an old tranny with one from a 126 with no problem. You just need to swap over the bell housing and the axles if you are sticking with the 500cc motor. If you want to upgrade the motor to a 650cc then you'll only need to swap out the axles. 126 axles are to long for the F/L s It's a little work but not a big deal if you keep it clean. Replace the axle boots or you'll regret it later. If you are moving to Texas the 123 igintion is a good idea. two more thing are good as well. A bigger alu oil pan. They come in many sizes. I have a 3.5 liter on mine. These pans hold more oil and cool a lot better than the orginal ones. In Texas you need all the cooling you can get. They do have oil coolers as well but if really don't need it if you get one of these oil pans. Another good idea is engine cover lifters, sorry forget what you call them in English. They extented the engine cover out on the bottom so you get more air flow through the engine compartment. Lastly, think about moving the coil to the other side of the engine compartment. It's get hot where it now sits. I relocated mine to the lefthand side just left of the regulator. Hot air from the cooling system blows directly on the coil and you can cook them in a hot climate.
 

OperationResto

"wilsonnw" from Benzworld
Joined
Feb 20, 2012
Messages
9
Sorry if someone's already answered this but - is the MrFiat 5 speed box the same one you get from Ricambi? Or are they different? If anyone can shed any light on that I'd be grateful. Cheers.

Nat.
 
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