1608 FI?

[Kevin1]

My '80 spider is currently dead in the water, 2 liter FI engine removed for a rebore/rebuild with higher compression and a ported 2l head. Sitting right next to the car I have a healthy 1608 with about 46K on it from a '72 that will be a long time before it is ready for a motor again.

Is there any reason that I could not or should not marry the FI from the '80 to the 1608 motor and put that into the car until the 2 liter engine is ready? Has anyone here tried a combination like this? I can go either way but the 2 liter will take me some time, and the 1608 is just sitting there ready to go. I really like the trouble free nature of the FI and would prefer that to messing with the dual IDF's that are currently on the smaller displacement engine.

Doe this seem workable, or am I just getting myself into trouble here?!?

[TX82FIAT]

I'm not sure this is a good solution. the L-Jetronic is set up for the 1998 CC or 2 Liter engine. The volumetric efficiency will not be the same and a 24% difference is considerable when thinking mass ratio of air to fuel present in a combustion process. My first reaction is that you would run lean because you would not have as much air in the cylinder per compression stroke. The L-jet simply is not sensitive enough to adjust the fuel mixture for the amount of air that passes through the MAF given the flap and system programing/measurements.

[Kevin1]

My understanding was that if the amount of fuel delivered was proportional to the amount of air being measured by the AFM the mixture would be correct for the amount of air was being drawn in. Even with the 2 liter engine, that is what the AFM does, isn't it?

Another way to explain my thinking is the example: If either engine is pulling 300 CFM of air, the AFM is seeing the same input whether if it is a 2.0 at 3500 rpm, or a 1608 at 4500rpm. Either way it delivers the correct amount of fuel relative to the air flow of 300CFM.

The difference I see is that at WOT the FI delivers as much fuel as the injectors can handle, and this might create a rich condition when you put your foot into it.

Isn't the VE of the 1608 is higher than the 2.0? In stock form it delivers 7hp more than the larger engine does (109 vs. 102) , the biggest difference being higher static compression.

Either way, I am not determined to make a case for this, just trying to gather information and understand what might or might not work.

[So Cal Mark]

I'd do it, the FI can easily be tuned. Get the car back on the road

[vandor]

The FI measures the amount of air entering the engine, so engine displacement does not matter. There should not be a problem during normal driving.
However, at full throttle the AFM flap is fully open above a certan engine speed and the fueling is based on a predetermined map. Under these conditions the mixture may be overly rich. I installed the stock Bosch EFI on a friend's 1800cc engine, and the car ran and drove very well.