Rev limit a blown alcohol engine

Is there a safe way to put an RPM limiter on a blown injected alcohol engine?
Reason is that its in a circuit boat & it came out of the water & had an over rev & we shattered a roller lifter. This is getting a bit expensive .Just trying to prevent this type of thing from happening again.

 

Yes.What type of ignition are you running?

 

Should have mentioned from the start that we are using an upgraded Mallory super mag VI. I know its not the best ignition around but thats what the customer has to live with at the moment

For our use, what do you guys think of the MSD 10 units ? Do they have rev limiting capabilities ? What are the pro's & con's of this electronic system ?

 

You can always use a PSI rev limiter with the Mallory. They work really well. If you don't want it to come back on when the engine speed comes down, you can use a latching relay with it. There's too much fluid in the cylinders to do that with a nitro setup, but lots of folks use them on alcohol just fine with no problems. There are lots of good used PSI limiters out there.

An Autometer Pro Control can be used just fine with the points-style Super Mags. It isn't selective either, but it works ok.

Spud
www.fuelinjectionent.com

 

How about a Mag 20

 

I used to run a super mag with a psi rev limiter and blew up my motor due to over revving.The best way to limit rpms on a super mag is a rpm activated switch to a relay that will ground the + side of the coil when selcted rpms are reached.The mag 20 is the way to go.

 

Rev-Limiter

Kaboom, Bang, Kaboom Man That Hurt!!!!

 

Are you saying the PSI rev limiters don't work correctly ?

Or that when they "come on" it does stop the rpm from going higher, but then the engine loads up with fuel ?

 

I don't think he's saying either.

The way I read it is this.

Grounding the coil until the RPM's come down is a bad thing.

Using a PSI isn't all that bad, because there's at least a centrifugal weight in there that bounces the ground on the coil randomly.

The MSD is the best, as it's a digital limiter that can cause the mag to simply not fire when it's supposed to and still not lose track of the RPM.

 

I am glad I never hit the rev limiter when I had it set up that way!!!The one time I blew up the trans with the psi it still saw the moon and shattered.