I'm having some tuning issues and I can't figure out if it's a timing or carb adjustment issue. The car runs fine through the primary range and even when the secondaries open as long as it's gradual. If I get on it fairly hard I get a lot of pinging and smoke. I changed carbs last year and it's been doing it since. I've rejetted the primaries so the car is not running too rich or lean. I believe the timing is set to 14 DBTDC (need to double check this). I recently changed the secondary jets from 66 to 69 and haven't noticed a change. At this point I'm thinking of reducing the timing a few degrees or changing the secondary spring (both on suggestion from different friends who are more knowledgeable than me but don't seem to agree).
The engine is a 289 that has been decked 0.10. The heads are ported and polished 351W heads with roller rockers, double valve springs and stainless valves. It has 10.5:1 pistons, the cylinders are bored 0.30 and it's got a 0.512 lift/292 duration cam. I changed the carb from a Holley 670 street avenger to a 570 street avenger.
I know it's hard to diagnose a problem this way but I would be interested in knowing which avenue I should head down and I'm also wondering if the problem may be that the carb is not big enough for the engine mods. I appreciate any advice, thanks!!!
The engine is a 289 that has been decked 0.10. The heads are ported and polished 351W heads with roller rockers, double valve springs and stainless valves. It has 10.5:1 pistons, the cylinders are bored 0.30 and it's got a 0.512 lift/292 duration cam. I changed the carb from a Holley 670 street avenger to a 570 street avenger.
I know it's hard to diagnose a problem this way but I would be interested in knowing which avenue I should head down and I'm also wondering if the problem may be that the carb is not big enough for the engine mods. I appreciate any advice, thanks!!!