changing dist weights and springs ?

[NOPHO84K30]

I bought a new dist ..proform.. recently drives alot better now. But Is there a difference in the car dist vs truck dist. Only reason I ask is my truck red lines at 3200 or aleast sounds like it .
Any car this would be in would be higher . Should the springs need to be looser so they open at a lower rpm advancing the timing faster. Just wondering if im way over thinking it

 

[chengny]

I thought that the "red line" was the RPM that the motor should not be operated above for any appreciable amount of time. Doing so may damage the engine.

I don't mean to sound like a wiseass but if you feel that you are operating above "red line" ... well, maybe don't push on the gas pedal so hard.

I vote for "over thinking it" (and you might be listening to people who spout buzzwords and perpetuate myths).

But then again, performance is not my best subject.

 

[NOPHO84K30]

No 3000 rpm at about 80 mph is about as fast as ive pushed it and it loud and sucking gas just like it should . It just dosent rev over 3000 rpm. Ive read up on the recurve all the parts ud need to change the timing.... base...mechanical. ..vacuum...its a cluster f in my mind dont kno if its worth messing with

 

[chengny]

I am not into performance so this subject is not all that familiar to me but I think this is the basic concept:

Installing a center plate with the 375 cam contours, a set of 41 fly-weights (and often a set of lighter fly-weight return springs) is actually what is commonly referred to as "re-curving" a distributor. A recurved distributor is intended to more quickly advance the timing using the centrifugal advance mechanism. This allows for somewhat quicker acceleration during periods of heavy load change. It will not increase low end torque.

A 375 center plate has the cams cut in such a way that it cranks the timing up (advances it) faster during an initial heavy load application - i.e. - WOT.

When you first start to accelerate, for the first few seconds, the timing is controlled only by the mechanical advance part of the distributor. That includes the center plate, fly weights and springs.

The vacuum advance acuating diaphram is attached by linkage to the center plate, but it is out of the loop during conditions of WOT. It does not come into the picture until the throttle is no longer wide open. At some point sufficient vacuum is developed in the intake system to stroke the diaphram and linkage of the vacuum advance system.

Then, until the throttle opens wide again and vacuum drops, the actuating linkage of the vacuum advance overrides the mechanical advance and continues to regulate degree of spark advance.

As long as intake manifold vacuum remains high enough, the vac advance stays in control. The function of vacuum advance is primarily one of fuel economy.


I posted the above in response to a kid who wanted to recurve his distributor - it was audited by another member who knows about this stuff (Jims86) and checked out okay.