should 1 increase jet and shooter sizes when switching over to locked out timing? engine is very responsive wicking the throttle in the shop,,but is flat under any kind of load,like it cant take it correctly. did not jet it up for the conversion from an advance curve..below is from a google search on the subject..street driven mostly,,but the .650 roller loves the xtra timing at idle...twin holley 750 DP with 62 and 68 jets..timing is locked at 36.thanks.
""""When you increase the timing at idle the speed of the engine goes up.It goes up because the cylinders start to complete the burn earlier on the power stroke and that puts more energy into the crank instead out the exhaust pipe.When the piston is going down at the end of the exhaust stroke,it sucks in lots of atmosphere that has O2’s in it and this mixes with fuel from the intake and the rpm goes up.See,the throttle plates are shut so you don’t get much air in from them,but you get it in from the exhaust.The exhaust becomes an intake on the overlap.
When you increase the amount of timing at idle you change the amount of vaporisation time that the fuel load in the cylinder sees.The risk that you have when you do this is that it will generally force you to wind down the idle screw,due to the idle increase and this will upset the t-slot setting that is required to get a afr into the cylinders,so you end up with a lean condition in the cylinders and the engine cant take a load correctly.The fuel to run an engine on idle and off-idle before the mains come on ,comes from the transfer slot.
You need to get the timing correct together with the fuel settings.Timing and fuel settings go hand in hand,you just dont do one without the other.""""
""""When you increase the timing at idle the speed of the engine goes up.It goes up because the cylinders start to complete the burn earlier on the power stroke and that puts more energy into the crank instead out the exhaust pipe.When the piston is going down at the end of the exhaust stroke,it sucks in lots of atmosphere that has O2’s in it and this mixes with fuel from the intake and the rpm goes up.See,the throttle plates are shut so you don’t get much air in from them,but you get it in from the exhaust.The exhaust becomes an intake on the overlap.
When you increase the amount of timing at idle you change the amount of vaporisation time that the fuel load in the cylinder sees.The risk that you have when you do this is that it will generally force you to wind down the idle screw,due to the idle increase and this will upset the t-slot setting that is required to get a afr into the cylinders,so you end up with a lean condition in the cylinders and the engine cant take a load correctly.The fuel to run an engine on idle and off-idle before the mains come on ,comes from the transfer slot.
You need to get the timing correct together with the fuel settings.Timing and fuel settings go hand in hand,you just dont do one without the other.""""
