Differential and converter ratio selection for 440 magnum.

[68-500]

Ok if uncle Tony says that works I believe that works. You still need to check piston to valve clearance further down the bore. Piston is coming up the bore as the exhaust valve is open. And the Intake valve is opening faster than the piston is going down the bore

 

[thcmaly]

Yes, exactly. Before the piston reaches TDC, the intake valve opens and the exhaust valve is almost closed. If I understand correctly (according to Tony's video), when the piston is at TDC, both valves should be in the same position. In my case, at TDC, the intake valve is very open compared to the exhaust valve, which is almost closed. The distance between the valve and the piston is still large, so I'm not afraid of collisions. However, I wonder if this situation (with the intake valve open at TDC more than the exhaust valve) results in more torque and power in the upper RPM range or in the lower RPM range? Or maybe delaying the intake valve opening so that both valves are equally open at TDC will have a better effect on the lower RPM range? I'm writing through google translate, so if something is unclear, please let me know.

 

[68-500]

Delaying the camshaft events moves power up in rpm. So your early intake opening tells me the cam has advance ground into it. Thus moving the power down in rpm. Without careful measurements I wouldn’t advance the camshaft any further.

 

[thcmaly]

Thank you, now I understand, that's what I meant, whether I won't worsen the parameters at low revs by delaying the intake valve. So for now I won't move it until I take accurate measurements.

 

[thcmaly]

Today I measured the camshaft with a degree wheel (only on cylinder 1 and intake valve). The centerline according to the camshaft spec should be 106*, mine is 106.5* after 4 measurements, so it is good. Lift 0.501, ignition timing is also 292 as spec. Does it make sense to move the camshaft 4 degrees to make the line 102* to get more power down low? Or will it make little difference?

 

[thcmaly]

Engine installed in Charger. Runs decently, idle speed 950-1000 rpm, idle speed 750 rpm. Ignition 18 degrees idle, 38* at 2500 rpm. The only problem is of course the low vacuum 9" at 950 rpm. Because of this the brakes are a bit weak and the PCV valve does not work well (after releasing the gas the rpm does not always drop to 950 rpm, sometimes it stays at 1300 rpm for a while). Will adjusting the camshaft 4* earlier give me a noticeably higher vacuum, e.g. 12-13"?

 

[68-500]

Is your vacuum advance connected to ported or manifold source? Manifold might gain you som more idle vacuum.

 

[furious70]

Is your vacuum advance connected to ported or manifold source? Manifold might gain you som more idle vacuum.

Would definitely do that before the cam timing

 

[thcmaly]

yes. everything is connected correctly. I measure the vacuum directly from the intake manifold. Basically everything is fine with the ignition (it works properly), I just can't get more vacuum on this camshaft. And here's my question: will setting the camshaft 4* earlier in the timing give me a vacuum increase in the range of 12-13". If not, I'll just buy a vacuum pump. I just don't want to needlessly disassemble the engine if I can't get better vacuum.