Hey guys, I just bought an MSD 6a box, not the one with the rev imiter, and I told my friend about it. He said that it's very likely that my engine could blow if it doesn'y have a rev limiter. Is there any truth to this, I thought that rev limiters were just these little things that prevented us from revving our cars past a certain RPM?

 

Its possible to blow up your engine at any rpm. Usually small block chevy's are good to 6000 rpms.

 

The "truth to it" is you have a misinformed friend. Your stock, factory engine is "rev limited" by the limits of it's induction system, in other words, when it stops making power, you will hopefully in the case of a manual transmission shift to a higher gear.

Think about it, how long have you gone without a rev limiter? Engine still together? Hmmmmm.....

Rev limiters are useful when you have a more modified engine and could concieveably over rev the valve springs ability to close the valves, or the oiling system's ability to keep a film of oil on the bottom end bearing journals at high RPM.

As far as the MSD 6a, well, some people swear by them, claim better fuel economy, quicker starts. But on a stock or mildly warmed over engine a good functioning stock igniton will do just fine. I installed a Mallory Hy-fire 6A on an otherwise bone stock V6 in my wife's '91 RS because I had it, and I wanted to see if it would yeild better fuel economy. On a 330 mile highway trip that I have made several times I noted no change, 24-26 mpg at 70-80 mph with the AC on. Not worth the Sunday afternoon I spent putting it in, other than I have a shiny geegaw under the hood with a cool LED light on it now.

However, if you are going to run some sort of nitrous or forced induction, yes then it's a near necesity but you will need a better box than the 6a, you'll need something like the 6BTM which has inputs to retard the timing proportionate to boost or nitrous shot.