- Joined
- Dec 2, 2003
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- 780
On gas boats, we inject water into the end of the stinger to quiet the boats down (3db). Why isn't anyone doing this on nitro? Just curious.
Brian
Brian
This would also act to lengthen the pipe.....we used water injectionOn gas boats, we inject water into the end of the stinger to quiet the boats down (3db). Why isn't anyone doing this on nitro? Just curious.
Brian
On SAW boats, we sometimes water inject the pipe towards the header to make the pipe seem long during startup. Then shut off the water once the speed gets up.
The water injection I am refurring to is located at the end of the stinger.
We will not be in Seville. We are going to the real boat race in Hillsboro.
Injecting water into the K&B 11/13cc lower units is an option. It does reduce the noise along with slightly reducing top speed. However, water into a tuned exhaust system would seem to be a different thing than water into a lower unit muffler.Is it just me or do the stock K&B 11 and 13CC Outboards use water in the exhaust to muffle the noise? Seems to me that this was thought of long ago by the ones who brought us the infamous "Fuel to noise convertors" (Thanks JD)
Chris I seen the same on Jerry 60 mono. he was guessing that the water pressure @ one point exceeded the pipe pressure & let the engine have plenty of water thru the pipe KILLING the brgs...Not trying to be negative.. I saw jerry crowther at the nats.. he tried teeing into the water line and shooting water up at the end of the stinger on a either 90 or 1" motor mono.. he burned up the motor at the nats..
Not sure why it happened other than just took away from the cooling of the motor and he said he didn't see or hear any difference other than he thought is sounding like it was making bubbles. but he said it was still to loud..
chris
I think most of us understand how a tuned pipe works but what i do not understand is why you would not have a water reversion problem with water injection. Water reversion is when water runs back into the motor thru the exhaust system. Can anyone explain?
Sincerely,
Allen
Hmmmmm. It would seem that enough water to wash out a set of bearings would have put the flame out & stopped the motor from running. I'm thinkin' if he T'd off the cooling line the motor got cooked from running too hot but was rich enough to keep running. I did this once, had a water line split but had enough water that it kept running. It was fast too, never realized I had a problem that is until it quit on the cool down lap at the end of the heat. When I checked why it stopped & sounded really wierd trying to unsuccessfully fire it up, I found it burned a hole clean thru the piston. Besides, Chris said Jerry was shooting water AT the stinger end, not into it, I don't believe there is enough pulse reversion that far downstream to draw water in all the way back to the motor. I've seen the gas guys have success with sending water in the back of an add on muffler flowing in the same direction as the exhaust gases. Also they either use a seperate water line or use the DISCARGE side of the water jacket & do not take away any water meant for cooling the motor.Chris I seen the same on Jerry 60 mono. he was guessing that the water pressure @ one point exceeded the pipe pressure & let the engine have plenty of water thru the pipe KILLING the brgs...Not trying to be negative.. I saw jerry crowther at the nats.. he tried teeing into the water line and shooting water up at the end of the stinger on a either 90 or 1" motor mono.. he burned up the motor at the nats..
Not sure why it happened other than just took away from the cooling of the motor and he said he didn't see or hear any difference other than he thought is sounding like it was making bubbles. but he said it was still to loud..
chris
The way I rember it Jerry's boat it was the bearings had welded itself to the crankshaft. No hole in piston.Hmmmmm. It would seem that enough water to wash out a set of bearings would have put the flame out & stopped the motor from running. I'm thinkin' if he T'd off the cooling line the motor got cooked from running too hot but was rich enough to keep running. I did this once, had a water line split but had enough water that it kept running. It was fast too, never realized I had a problem that is until it quit on the cool down lap at the end of the heat. When I checked why it stopped & sounded really wierd trying to unsuccessfully fire it up, I found it burned a hole clean thru the piston. Besides, Chris said Jerry was shooting water AT the stinger end, not into it, I don't believe there is enough pulse reversion that far downstream to draw water in all the way back to the motor. I've seen the gas guys have success with sending water in the back of an add on muffler flowing in the same direction as the exhaust gases. Also they either use a seperate water line or use the DISCARGE side of the water jacket & do not take away any water meant for cooling the motor.Chris I seen the same on Jerry 60 mono. he was guessing that the water pressure @ one point exceeded the pipe pressure & let the engine have plenty of water thru the pipe KILLING the brgs...Not trying to be negative.. I saw jerry crowther at the nats.. he tried teeing into the water line and shooting water up at the end of the stinger on a either 90 or 1" motor mono.. he burned up the motor at the nats..
Not sure why it happened other than just took away from the cooling of the motor and he said he didn't see or hear any difference other than he thought is sounding like it was making bubbles. but he said it was still to loud..
chris
Once again you've missed the point. The hole in the piston was only an example of how HOT the motor could get & keep running..........The way I rember it Jerry's boat it was the bearings had welded itself to the crankshaft. No hole in piston.Hmmmmm. It would seem that enough water to wash out a set of bearings would have put the flame out & stopped the motor from running. I'm thinkin' if he T'd off the cooling line the motor got cooked from running too hot but was rich enough to keep running. I did this once, had a water line split but had enough water that it kept running. It was fast too, never realized I had a problem that is until it quit on the cool down lap at the end of the heat. When I checked why it stopped & sounded really wierd trying to unsuccessfully fire it up, I found it burned a hole clean thru the piston. Besides, Chris said Jerry was shooting water AT the stinger end, not into it, I don't believe there is enough pulse reversion that far downstream to draw water in all the way back to the motor. I've seen the gas guys have success with sending water in the back of an add on muffler flowing in the same direction as the exhaust gases. Also they either use a seperate water line or use the DISCARGE side of the water jacket & do not take away any water meant for cooling the motor.Chris I seen the same on Jerry 60 mono. he was guessing that the water pressure @ one point exceeded the pipe pressure & let the engine have plenty of water thru the pipe KILLING the brgs...Not trying to be negative.. I saw jerry crowther at the nats.. he tried teeing into the water line and shooting water up at the end of the stinger on a either 90 or 1" motor mono.. he burned up the motor at the nats..
Not sure why it happened other than just took away from the cooling of the motor and he said he didn't see or hear any difference other than he thought is sounding like it was making bubbles. but he said it was still to loud..
chris
Allen
And how do acomplish cutting off the water prior to killing the engine?Nearly every gas boat in our club runs a water injected stinger muffler using water from the engines cooling water outlet. If you couple this with an inverted stinger, the results are really impressive. There are no problems with water getting into the engine, power loss, or changing tuned pipe pperformance. We have also done dyno and on the water testing of water injection into the header. This "lengthens" the pipe and broadens the power band considerably. We use a tee off the engine's cooling water inlet. Here, you do need to be careful not to get water into the engine when the boat is moving but the engine is shut off. This won't be a problem if the water is shut off before the engine.
Lohring Miller
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