2.0 vs 1800 question

[RRoller123]

Thanks for the info Csaba. Is there anyone here who has shaved a mm off the block (2l) and could comment on the result in terms of performance increase, resulting street and idle manners, etc? Much appreciated it be, all the experience here resides.

[131]

I've got a 2 litre in the shed I've been building. With an 1800 head, 0.8mm off the block, slightly domes OEM pistons (1.4mm?), I've measured it and calculated static compression at 11:1.

[MrJD]

I've got a 2 litre in the shed I've been building. With an 1800 head, 0.8mm off the block, slightly domes OEM pistons (1.4mm?), I've measured it and calculated static compression at 11:1.

Wow, hope you have some freakin great gas down there! Weekend car run on aircraft fuel? Like 110 octane or something? lol.

[131]

Wow, hope you have some freakin great gas down there! Weekend car run on aircraft fuel? Like 110 octane or something? lol.

It was originally going to run on LPG, but I picked up another car so the LPG car was scrapped. The plan now is to use the same bottom end with a 2 litre head and a 2mm decompression plate, with the pressure bumped a bit with an Eaton M45 supercharger, if I ever get my blower back.

[bradartigue]

back when i worked as a line mechanic at the fiat dealership in the early 80's o2 sensors were on perpetual back order an fiat sent a tsb that said to cut the wire from the old o2 sensor and take it out of the loop, as a bad o2 sensor hurt performance where not having one actually helped

This would be correct, L-Jetronic operates in either a loop with or without the sensor, and has a pattern for whether it is receiving current from the sensor or not. K-Jetronic, the mechanical predecessor, had a lambda sensor loop as an option as well, with an ECU and a mechanical frequency valve to regulate fuel (http://www.k-jet.org/articles/informati ... detail/#LS). In either system the override was the complete failure of the probe, not partial failure, and bypassing it would produce better results.

One thing I always tell people is the O2 sensor isn't going to cause or no-start or no-run condition or even very bad running condition regardless of the probe's state. This is why it can be hard to diagnose on old cars (new cars will report a failure to the ECU and trip a warning lamp). Your best bet in diagnosing FI systems is to assume the sensor is bad, bypass it (or not), fix whatever else is wrong, then, when the motor is running nicely, replace the thing. Otherwise you keep contaminating it and it keeps needing to be replaced.

I can't imagine how many of these failed on the early implementations, not just FIATs. Most first attempts at FI were just like the FIATs, a formerly carbureted engine and head design with L-Jetronic layered on top. A minor errant turn of the (mechanical) air flow adjustments could hose a lambda probe on a very cold or very hot day...

[MrJD]

Wow, hope you have some freakin great gas down there! Weekend car run on aircraft fuel? Like 110 octane or something? lol.

It was originally going to run on LPG, but I picked up another car so the LPG car was scrapped. The plan now is to use the same bottom end with a 2 litre head and a 2mm decompression plate, with the pressure bumped a bit with an Eaton M45 supercharger, if I ever get my blower back.

Custom kit? What are your power goals?