Originally Posted by chvy285
I have a 355 with lunati 285 235@50 510 lift 108degree lobe sep edelbrock performer eps intake 305 heads runnin very sluggish cant figure out why it seems to take very long time to get any speed at all edelbrock 600 carb could this be my problem is not enough carb??? LOST if anyone could give me any ideas would greatly appreciate it i know the 308 gear isnt helping but truck was alot quicker before cam intake and headets thanks for the help
This can be a lead in to a lot of tuning issues but this is a pretty big cam that has moved the power band way up the rev range. For sure the 3.08 gearing isn't helping because the engine's power band and the gearing to get up to it no longer match. The 305 heads unless you put in 350 valves and did some porting aren't helping either as about the time the engine revs to the cam's power band unmolested 305 heads are out of breath. You may also be looking at detonation with these small chamber heads, they have the spark plug way off to one side with a lot of compression on a 350, the plug location brings the slow burn of large chamber heads with a lot of compression. This will put the point of maximum pressure late in the power cycle where it isn't effectively pushing the piston and creats a situation where the piston has moved so far down the bore that the quench function is no longer a viable method of damping the excess temperatures that cause detonation of the unburnt mixture ahead of the flame front. More advance that comes in quickly will help getting the peak cylinder pressure earlier but will increase any detonation tendency. There are some cures for that of which richening the mixture is the quickest without backing down the advance. The 600 cfm carb won't be the best at feeding the engine where it has to go for max power on this cam, but that's probably the last issue to chase as it will do well enough to at least tickle your fancy for power but won't satisfy it.