Croozin2

Is anybody on the board running the Crane boxes on carbed motors? I'm having an interesting problem at WOT. I've had the limiters set at 5200 since I installed the new motors in May. Took it very easy on the girls until I felt confident that I had the carbs dialed in. Now, when I stretch it out, I occasionally get a bang noise from the engine compartment. If I back off to 4000, even 4200, no bang. The engines pull right up to the 5200 limit so I'm sure the limiters are activating. However, one of Crane's selling points was "no banging or popping" with their digital rev limiter. I'm planning to contact Crane regarding the problem but was just wondering if anyone was running a similar set-up and getting the same problem.

Also, this one's for you EFI guys, does the rev limiter on the EFI motors cut the fuel and the spark, or just the spark?

KAAMA

I highly doubt you'll hurt your engines if you set your rev limiters to a higher limit----like 5500rpm or so. Mine are set at 5700rpm. I have carbed naturally aspirated 540 inch engines with the Crane HI-6M ignition. Perhaps someone else can add some input in here to help you out as well.

formula31

I set mine at 6000 on the formula and it saved an engine when a drive went south. Never had any popping going on.

Croozin2

Well, hopefully Crane can shed some light on the subject. The rev limiter is the only thing I can think of at this time. I am going to turn them up to 5500 this weekend and see what happens. Both engines run perfect just the banging at WOT. It happens about every 20-30 seconds.

What I was thinking is the same principle as when you were a kid and would shut off the ignition on your truck, pump the accelerator and then turn the key back on - BOOM. I'm thinking that the carbs are flowing so much fuel at WOT that when the ignition reignites that particular plug you get the same effect. Don't know. Scratchin' my head...

Cignificant

I set mine at 6000, but have never hit them. Sorry I can't be more help..