tuning problems

[FORZALANCIA]

Hi guys, I have finished my supercharged lancia setup! She was driving fine apart from the occational backfire out of the carby, then i didnt drive her for a little while and all of a sudden she wouldnt start, i managed to get her started, but wen she is idling, a slight amount of blue smoke is coming out of the exhaust? Also wen i start to accelerate the engine starts to sudder and a lot of smoke comes out of the exhaust, then she started running on 3 cyclinders. Do you have any idea whats wrong? Is it the points in the dizzy? Plus even before i had this problem she was hunting up and down at idle sometime from 1000-1500 rpm why is that? pressure leak? Also i was getting into a problem of wen i reached 3,500rpm on driving she started to backfire out of the carby and blew a hose clamp off, not good.
thanks
Ant

[Hamish]

Ant,
Presumably you've checked all the 'plumbing' to the carb :?: Is it running the standard carb :?: Worth stripping out the jets and giving them all a damn good clean. If you haven't done it already fit a good quality in line fuel filter.
I'd have a good long look at the dizzy. They're a pain to fix when they go wrong (and they usually do :evil: ).
It could be that there's more to this than simply carb/dizzy problems and long distance diagnosis isn't wise - so without wishing to teach you how to suck eggs :wink: I'd go through the engine top to bottom and check all ignition components (especially the plugs - colour/spark etc), the carb and
the timing.
I've had the occasional backfire on VX engines, especially when cold :?: and having gone through all the above I found there was an incorrect main jet - odd but that was it.
Have fun :wink:

[FORZALANCIA]

Thanks Hamish :P
I will try replacing the points & also the leeds,
I have noticed that the spark plugs are black with soot,
and i just put new ones in! Plus i clean them and after starting her they
go black very quickly?Too rich a mixture? I am running a 40 mm dollotero, sidedraft into a roots type supercharger(1.420L) with high lift cams and i have also advanced the cam timing is that bad? I have drilled the main jets out to about 240's, stock dollotero's being about 150, have i drilled too much? Is that why she is not running properly?
Ciao
Ant :roll:

[Fingers]

Sounds to me like that's wy too rich, dunno if you've got a cpy of the Guy Croft book, but he says to start on jets similar to a normally aspirated car. I'm busy doing much the same as you to my car, I have a GC cam, but I'm going to put a 45 Weber on my car, as a starting point I'm going to use 150 main jets and a 180 air corrector jet. Yours must be blowing quite a bit of black smoke too I would imagine if it's running that rich, maybe get some smaller jets to play around with, around the size I've mentioned above but maybe a little larger as you're using a 40. Take it for a good run with various jets and at various loads and check the plugs, ideally they should be a nice beige colour and no sooting. Or just take it to someone with a rolling road and exhast gas analyser to set it up, it shouldn't be too expensive and then t'll be pretty much spot on. I'd be interested to hear how you get on.

[FORZALANCIA]

Hi there, i finished my lancia project, ended up using a 45 weber sidedraft with 160 mains & 170 air correctors. She Flew!!! Blew off all that jap crap! & even a v8 runnign 13's pitty i blew the motor, but nothing could keep up, not even my clutch! The thing i couldnt understand is wen i hit 6,000 rpm it seemed like it started to gee force even more well thats wen i would pull past everything, i reved her to about 8,500 rpm. You guys should hear the sucking noise that comes out of the carby, sounds like a ferrari wen it opens up. Does anyone know how much the boost will go up if i run the vx setup on a standard block of compression 8.9-1? Or i might put a decompression plate which would bring the compression down to 8-1 how much boost will the supercharger give will this give compression?

[Hamish]

Strewth :!: You blew up the engine...... exactly what's gone 'pop' :?: It might be easier to re-build it :?: I'm not sure exactly what boost you'll get on a standard 2 litre engine if you add the VX conversion - a lot I guess. I know of a fiat 2 litre engine running a VX blower conversion, it's a standard set up on a standard 131 block and it's still going strong after 5 years so I guess it's possible - but if you're running sprints etc then it'll last 5 minutes :arrow: but that'd be a fun 5 minutes :twisted:
I guess it all falls on what you want the engine to do.
You'll need a paddle type clutch to cope with the power though (if you're being 'hard' on the transmission).
A rev limiter might also be a good idea :wink: