850 / 903 distributor

[B Carns]

I have a 1971 903, with the 850 transaxle from an 850 Spider in my 1961 Fiat 600. It has the Marreli distributor. Is there an 850/903 reverse rotation distributor that is shorter in height that will work in this engine? The engine lid will not shut as-is. Would like to keep the original look , have modified all else under neath. Thank You.

 

[Jeff Stich]

I have a 1971 903, with the 850 transaxle from an 850 Spider in my 1961 Fiat 600. It has the Marreli distributor. Is there an 850/903 reverse rotation distributor that is shorter in height that will work in this engine? The engine lid will not shut as-is. Would like to keep the original look , have modified all else under neath. Thank You.

You can try the earlier (1967-69) 850 Marelli distributor, as it has a shorter body height:

If you have an 850 engine + an 850 transaxle in your 600, why do you need a "reverse rotation distributor"? With that driveline combo, everything should be turning the normal 850 direction.

 

[kmead]

He is saying he has a Marelli distributor but the image shows Ducelier with motorcycle carbs (looks cool)

I think he is just asking for the normal rotation distributor for an 850 which is of course reverse rotation. I don’t think he is looking for a reversed, reverse rotation distributor

One could move to a crank toothed wheel and sensor to get to a distributorless system. More complex and clearly not in the spirit of a 600.

 

[B Carns]

Thanks to all for your advice. The engine (903) and transaxle are out of a 1971 Fiat 850 Sport Spider. Correct with only looking to replace the current distributor with a shorter one. The rotation of the eng. has not been changed to A112 cam, reversed pistons, like many 600 transplants do. A112 water pump ( idler used to run belt over pulley-changes counter to clockwise). 124 discs on rear, 850 spindles w 124 calipers front, 850 anti-sway bars frt. & rear, 124 master w/ proportion valve. 850 shifter ,124 e-brake. 850 gauges under dash, all Fiat stuff. You are correct on the current dist...my error.

 

[Jeff Stich]

He is saying he has a Marelli distributor but the image shows Ducelier...

I didn't look close at the photo, as the late Marelli & the Ducellier look similar (both tall-bodied), I just took his word for it.

I think he is just asking for the normal rotation distributor for an 850 which is of course reverse rotation. I don’t think he is looking for a reversed, reverse rotation distributor

When swapping an 850 engine into a 600, one has to be careful with terminology concerning engine rotation. The normal rotation for an 850 engine is counter-clockwise (CCW). Making the 850 engine turn in the opposite direction (clockwise/CW), as often done when transplanting into a 600 chassis (using a 600 transaxle), is what is termed as "reverse-rotation". The same can be said when transplanting a 127/A112 engine into an 850 chassis (with 850 transaxle), where there's a need to have the engine turning in reverse-rotation of its original design (from original CW to now-needed CCW).

There is no such thing as a "reverse rotation distributor". Both the 600 & 850 distributors rotate in the same direction - 1342 clockwise. Only the crank & camshaft turn opposite (as a group) between the two engine types. The mated drive gears on the cam & the oil pump/distributor drive shaft are what translate the CW (600/A112) or CCW (850) engine rotation into the "proper" CW distributor rotation.

 

[Jeff Stich]

Correct with only looking to replace the current distributor with a shorter one.

Here's one of the shorter-bodied early 850 Marelli distributors on eBay (not mine):

https://www.ebay.com/itm/232808716490

 

[B Carns]

Truly a world of information, would never have known about the distributors. This is my first Fiat. Willing to learn. My 600 is nothing new, only new to me. Thanks to all.

 

[Jeff Stich]

Truly a world of information, would never have known about the distributors.

FWIW, I measured one of my spare early 850 distributors; from the distributor base flange that contacts the cylinder head surface, vertically up to the top of the 850 Spider (side-entry) style distributor cap, measures 6.125" (at the very top/rear edge of the cap) or 6.25" (at the upper edge of the bevel on the top/rear of the cap) or 6.5" at the very top of the cap (front/sides of cap).

 

[56nobrakes]

I have a 1971 903, with the 850 transaxle from an 850 Spider in my 1961 Fiat 600. It has the Marreli distributor. Is there an 850/903 reverse rotation distributor that is shorter in height that will work in this engine? The engine lid will not shut as-is. Would like to keep the original look , have modified all else under neath. Thank You.

I know. 5 years later. I am new to the Fiat world (chevy guy). The way I understand it, I can get 903 motor and transaxle out of an early 850 and not have to reverse rotation on the motor? This fiat thing has me doing tons of homework but I am only getting a c- in the class so far. Thanks for any information

 

[fiatfactory]

903cc engine from an 850 will be a CCW rotation engine, if you put it in another 850 then you keep it rotating CCW.

If you want to put it in a 600, and mate it to a 600 transmission, then you'll need to make it spin CW.

If you take both the engine and transmission from an 850 and transplant that into a 600 then you don't need to reverse the engines rotation, but I believe it's not a straight in fit to the bodywork (otherwise everyone would simply do it that way - which they don't)

No matter if the engine spins CW or CCW, the distributor will need to spin CW in all instances. The camshaft and distributor drive shaft have opposite gear cut directions in CW and CCW rotation engines, so the outcome is the distributor spinning CW in both types.

SteveC