Another ignition curve question... 2.7 cis engine with carbs

[unclebilly]

If I take a stock 2.7 cis engine and put on carbs, what ignition curve will give the best results with the cis cams and pistons? This is for a low buck track car and changing cams and pistons is not allowed.

I am going to be running mega jolt so I can change curves easily.

[larrym]

when i built my 2.7 with solex cams & webers, Steve Weiner (Rennsport) recommended & recurved it for me to be "all-in" at 4000 rpm - cost about $100

you should do some searching about the carbs on CIS cams isue however - generally not a good performance result

.

[snbush67]

In a track car I don't think you will spend more than a couple of seconds at less than 3k ,so just put it all in at 26 deg. at 3-4k and let the idle fall where it may, adjust the mix to keep it running at idle.

Listen closely for detonation and back some timing out if you need to. You should be relativity safe with CIS pistons and good gas, but you never know.

All In should net you about 26-32 degrees advance if you are getting full mechanical advance. The curve doesn't matter because it is over by the time you need it.

[1976 TN Porsche]

Contact Barry Hershon at IAE inc. 313-532-5350. Look at his website.