I know there’s a few on here running blown mfi. I’ve developed a strange problem all of a sudden, don’t think I’m doing anything different vs the last 10 years, but kinda stumped.

I pull the chute levers before the stripe, chutes hit right about when I’m lifting, go to neutral, and hit the switch. Then bar the motor backwards after the pass.

I used to hit the leanout after going to neutral and wait a couple seconds before hitting the kill switch, but just seemed unnecessary and the leanout is slightly harder to get to in this car.

Whats the standard practice in fast bracket stuff. Kill switch with fuel on and back down afterwards, or always lean it out before hitting the switch?

quote:

Originally posted by BJs Wild Ride:


I pull the chute levers before the stripe, chutes hit right about when I’m lifting, go to neutral, and hit the switch.

Thats exactly how I always did it. At first I was pulling the fuel shut off to lean the motor but it just made it harder to start the next run so I quit doing it.

Also never turned the motor backwards either, that's a nitro thing

What's the problem your having?

Steve is correct on backing motor off. BBC does not have same thing with exhaust valve angle. Hemi only motor that will push fuel out valve when roatated backwards. Yes it is nitro thing because with high compression and any nitro in cylinder you will eat cylinder heqad if rotate with half shot glass of notron in cylinder if get compression.

quote:

Originally posted by Big Steve:

quote:

Originally posted by BJs Wild Ride:


I pull the chute levers before the stripe, chutes hit right about when I’m lifting, go to neutral, and hit the switch.

Thats exactly how I always did it. At first I was pulling the fuel shut off to lean the motor but it just made it harder to start the next run so I quit doing it.

Also never turned the motor backwards either, that's a nitro thing

What's the problem your having?

I’ve had motors crank super hard after a fuel-on shutoff is why back it down.

Do you dump your pump saver into the blower?

it smoked the #1 exhaust lifter at the stripe twice in a row. Granted, the second time the cam lobe was a little rough, but it made it all the way to the stripe and basically exploded the lifter body somewhere in the shutdown. I was thinking maybe all the fuel is going to #1 when the chutes hit and caused it to hydraulic and not be able to open the exhaust valve. If the top bearing is toast that would enforce that theory but I haven’t got a look yet.

Yes pump saver dumps into the hat nozzles to cool the blower. Mine was set at 135 psi so its only open for split second with the idle check opening at the same time when the throttle slams shut and returning to the tank