Riddle me this...
318 has a 4bbl and cam. Some of these numbers are average. If I floor it the rpms "stall" higher before it picks up and goes. My gut is telling me the torque converter because it shifts hard and doesn't feel like it's slipping. The torque converter feels like it's "loose"...
You're confusing me.
"
it shifts hard and doesn't feel like it's slipping. The torque converter feels like it's
"loose........ which is it?
Well if it's a 4bbl and a cam, then something ain't right, about the combo.
The stall rpm moves with the rpm.But it ain't called stall anymore.
At zero mph you get the 1800stall. If the engine is idling at 600 rpm than you can think of this as 1200rpm slippage or 300% slippage!
But the more rpm you put into it, the percentage will drop and drop until it hits a minimum..... based on the amount of torque being jammed into it by the engine.
Say it takes 50hp for your TC to stall at 1800.
If your engine puts out 50hp at 1800, then this 1800TC will be an 1800stall TC. But if you put 100hp into that exact same TC, it may stall at 2100. And with 150hp into it it will stall yet higher. The stall rpm is very closely tied to the torque inputted into it.
The stall rpm affects how quickly you are gonna accelerate from a dead stop. Because your engine will make more power with higher rpm.
But at say 30mph in first gear, that 1800 means nothing anymore. The math says 30 mph should be 3000 rpm at zero slip. Like if you had a manual trans. With a manual trans, your rpm would be 3000 no matter if the carb was floored or if it was closed.
But with an automatic, the TC is a fluid coupling, so if you take your foot off the gas, you might 3% or 5%, or some percent of slip. Your rpm at 30 mph could be 2850 at closed throttle. But if you floor it from cruising, the rpm might jump to 3300 or 10% over zero slip. This is almost normal. So your engine at 30 mph could be at between 2850 and 3300; and that could be normal.
Now, if at 30 mph and still in first gear, you back off the throttle for just an instant, and then hammer it, you will have the full range of 450rpm to slingshot your car forward. But if you were still accelerating mildly when you crossed 30 mph, and actually hit 30 at say 3150, then you would have a soft hit of just 150 rpm.
If you open the secondaries too soon or too fast, you can get a tip-in hesitation.Or even a bog. And those will affect your TC hit.
And if the secondaries open late, well then she is operating as a 2bbl,right?
So that could be part of your soft versus hard.
Another part could be the cam; or more accurately what the cam did to your cylinder pressure.
Big cams in small engine are very sensitive to
Scr/Static Compression Ratio,because the cylinder pressure goes away. The stock-compression ratio 318 is one of this type of engine. So If you did not bump up the Scr then you are gonna have low cylinder pressure........ and a soft hit no matter what.Especially with that stockish stall TC.