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mrG
09-16-2006, 04:03 PM
Got a Fake-a-lake in the mail today, went out and hooked it up to my 92 PS 190 and started it up. With the hose on full and engine at idle the water came out in surges. I would thought it would come out at a constant rate. Maybe the raw pump gulps more than I thought.

But more interesting to me is the unequal exhaust output from the exhaust flaps. At idle and up to RPMs of 2K most if not all of the exhaust comes out of the left side. If I hold my hand over the left flap to keep it closed the exhaust then exits the right side. Cooling water is flowing equally out from both sides.

Is this normal? The next time I'm on the lake I'll try and observe the output at high RPM.

88 PS190
09-16-2006, 04:11 PM
That's odd, the exausts are not linked together on our boat, ie 4 left cylinders go left 4 right go right.

Surging water is normal if you have the boat on a trailor, it builds up then the exaust blows out a bunch, then the water has to build up enough, if you had the bow higher so the exausts were level or lower in back then it would flow more constantly.

mrG
09-16-2006, 04:16 PM
I have the SilentMaster exhaust system. Both manifolds connect to a common muffler. The two exhaust lines to the back of the boat both tie into the muffler.

east tx skier
09-16-2006, 04:23 PM
Mine comes out in surges when it's idling on the bucket. It's pretty even left/right thought.

mrG
09-16-2006, 04:26 PM
It's strange. I don't know if it is a problem or not.

Archimedes
09-16-2006, 04:33 PM
[QUOTE=mrG]Got a Fake-a-lake in the mail today, went out and hooked it up to my 92 PS 190 and started it up. With the hose on full and engine at idle the water came out in surges. /QUOTE]

Mine always came out in little surges, but I didn't think you were supposed to run the Fake-a-lake with the hose on full pressure. I could be wrong, but I thought I recall that you just wanted moderate flow.

T Scott
09-16-2006, 05:03 PM
Since the left right exhaust is connected via the SilentMaster muffler, if the boat is not level on the trailer, or the driveway is slanted, it will cause more water to come out the lower side.

TMCNo1
09-16-2006, 05:06 PM
I have the SilentMaster exhaust system. Both manifolds connect to a common muffler. The two exhaust lines to the back of the boat both tie into the muffler.

If the boat is not level from port to starboard, it quite possibly will have more exhaust out one side more than the other due to water build-up in the low end of the crossflow muffler.
As far as water surging out of the pipes at idle, it happens, on land from a fake-a-lake, bucket or otherwise, just as it does when in the water idleing. At planning speeds, the higher rpm and the pickup having water forced into it and the pumps circulating the larger volume of water, you will have a constant flow. The raw water pump injects into the cooling system and the circulating pump circulates a very large volume of water to remove the additional heat generated up by the higher rpm, if not they would not hold the lower temps that they do. If you will notice when you slow down, back to idle after a high rpm run, the temperature gauge will rise momentarly from heat soak due to less cooling water coming in the engine. The lower rpm water catches up removing the additional heat and the engine cools down due to the less heat generated at idle.

TMCNo1
09-16-2006, 05:08 PM
Since the left right exhaust is connected via the SilentMaster muffler, if the boat is not level on the trailer, or the driveway is slanted, it will cause more water to come out the lower side.


And more exhaust gasses coming out the higher side.

TMCNo1
09-16-2006, 05:16 PM
[QUOTE=mrG]Got a Fake-a-lake in the mail today, went out and hooked it up to my 92 PS 190 and started it up. With the hose on full and engine at idle the water came out in surges. /QUOTE]

Mine always came out in little surges, but I didn't think you were supposed to run the Fake-a-lake with the hose on full pressure. I could be wrong, but I thought I recall that you just wanted moderate flow.


You can open up the faucet wide open, because the excess water will be blown out around the cup before you start the engine and until the raw water pump sucks in at the same volume that the water hose is delivering. If your rpm is above the flow rate of the faucet you have a chance of starving the raw water pump of water and overheating the engine. Just watch the temperature gauge, anytime you run it on land in any manner of water supply.

TMCNo1
09-16-2006, 05:22 PM
Since the left right exhaust is connected via the SilentMaster muffler, if the boat is not level on the trailer, or the driveway is slanted, it will cause more water to come out the lower side.


And more exhaust gasses coming out the higher side.

mrG
09-16-2006, 10:02 PM
I had just finished repacking the shaft log with GFO and decided to put the boat in to check and adjust. While sitting there idling I looked behind the boat to obsereve the exhaust pattern in the water. The left was the strongest with a small amount of exhaust bubbling up from the right side. The same as when it was in the driveway.

As far as the boat being level on the trailer/driveway; everything is level.

TMCNo1
09-16-2006, 11:35 PM
I had just finished repacking the shaft log with GFO and decided to put the boat in to check and adjust. While sitting there idling I looked behind the boat to obsereve the exhaust pattern in the water. The left was the strongest with a small amount of exhaust bubbling up from the right side. The same as when it was in the driveway.

As far as the boat being level on the trailer/driveway; everything is level.

Then is must just be the nature of the beast. As long as it doesn't give you any problems, like high water temps or burnt exhaust piping, I don't think I would worry too much about it. Just keep a good check on everything.

Jesus_Freak
09-17-2006, 12:02 AM
I assume that the answer to the obvious....Does the exhaust line piping spread symmetrically?....is yes? I like TMCNo1's point about the water interfering with the gas phase discharge. Is there any reason the water should be discharging, by design, asymmetrically? I am not familiar with this boat, so these may be dumb questions.

edwinfuqua
09-17-2006, 01:49 AM
Got a Fake-a-lake in the mail today, went out and hooked it up to my 92 PS 190 and started it up. With the hose on full and engine at idle the water came out in surges. I would thought it would come out at a constant rate. Maybe the raw pump gulps more than I thought.

But more interesting to me is the unequal exhaust output from the exhaust flaps. At idle and up to RPMs of 2K most if not all of the exhaust comes out of the left side. If I hold my hand over the left flap to keep it closed the exhaust then exits the right side. Cooling water is flowing equally out from both sides.

Is this normal? The next time I'm on the lake I'll try and observe the output at high RPM.

Pick up your flaps and look up inside and see if you have blisters in the exaust. If not there then the primary hose is blistered. Blisters cause uneven exaust flow with water and gases. Hope you don't a blow out because that's below the water level and you will probally sink.

Check your hose carefully, check your flappers, if you have major blisters in your hose you need to change 'em out and replace your empeller and check for leaks in the exchanges. Double up on all clamps. Take no chances. This freak stuff has really cost me in the past season.

Edwin

edwinfuqua
09-17-2006, 01:56 AM
I assume that the answer to the obvious....Does the exhaust line piping spread symmetrically?....is yes? I like TMCNo1's point about the water interfering with the gas phase discharge. Is there any reason the water should be discharging, by design, asymmetrically? I am not familiar with this boat, so these may be dumb questions.

What I'm going to do over the winter is get rid of all the primary rubber exaust hose and replace it w/ stainless steel - through the straight pipe to the final exaust rubber. If I can get rid of the final exaust rubber and rubber flappers I will. I hope to go straight from the manifold to the flappers (hopefully stainless steel) without any rubber. "Best Town by a Dam Site" that's what Hartwell, GA says on their police cars. But that same attitude is what I'm going to do on my PS190. SS All The Way. NO RUBBER. More on that later.
Edwin

JDK
09-17-2006, 02:38 AM
At idle and up to RPMs of 2K most if not all of the exhaust comes out of the left side.

I wouldn't be running the engine up to 2k on a fake-a-lake. As TMC #1 says, if water isn't leaking out of the cup, the raw water pump is starving.

Jesus_Freak
09-18-2006, 11:27 AM
I just saw this dramatically unequal exhaust flow in a test drive in a 94 205 this weekend. I was skiing behind it at ~30MPH and noticed it. I could see nothing wrong while looking in the doghouse or looking into the flaps with a flashlight. Are these "blisters" just like the name suggests...raised places? I just dont know what I am looking for. :confused: I am about to buy this thing and need advice.

east tx skier
09-18-2006, 11:50 AM
On the 94, everthing is separate exhaust wise from the thermostat on. So if you're not getting exhaust out of one side, sounds like something is blocked.

Jesus_Freak
09-18-2006, 11:54 AM
If everything is separate, it would not make sense that it was the way I remembered. I must have been seeing things.?.? The engine ran too strongly and smoothly to imply a significantly blocked exhaust line. Are those rubber hoses (3"?) hard to reach...dont remember?

chudson
09-18-2006, 12:00 PM
Schools in today!!! That's one thing I enjoy about this Forum, if you are not learning something your just not reading.

east tx skier
09-18-2006, 12:06 PM
If everything is separate, it would not make sense that it was the way I remembered. I must have been seeing things.?.? The engine ran too strongly and smoothly to imply a significantly blocked exhaust line. Are those rubber hoses (3"?) hard to reach...dont remember?

I wouldn't expect blockage in the exhaust hoses aft of the mufflers. No, they are not hard to reach in front of the mufflers. If it was blocked anywhere upstream of that, I would think you'd be seeing cooling problems.

86mc
09-19-2006, 10:11 PM
Hello:

This year I over heated my engine and replaced my raw water pump. What I found when I was running it in the driveway was the water exhausting was unequal left & right. Thought it was odd but did not pursue. Next week or so put it the lake and found same unequal exhaust in the water. Pulled the exhaust hose which comes off the manifold to find the hose collapsed in the center closing a clear flow of water. One side much worse then the other. Just a thought even if you didn't over heat the engine it's a quick check.

Regards,
Tom

mrG
09-20-2006, 09:26 AM
I wouldn't be running the engine up to 2k on a fake-a-lake. As TMC #1 says, if water isn't leaking out of the cup, the raw water pump is starving.

These were only short revs up to 2K RPM and no thermal spikes of indicated water temp. Seems that I read on a site somewhere that that was the max design RPM while using a Fake-a-lake. Having said that, I would not recomend running at RPMs much above idle due to fear of cooling water starvation. With my garden hose at full pressure the Fake-a-lake plunger was at times collapsing from the vacuum caused by the water demand.

I'm not sure if the term vacuum applys to a hydraulic situation but you get the point ;)

Jesus_Freak
09-20-2006, 11:16 AM
"Vacuum" most certainly applies to hydraulics. We get you. Thanks.

east tx skier
09-20-2006, 11:32 AM
These were only short revs up to 2K RPM and no thermal spikes of indicated water temp. Seems that I read on a site somewhere that that was the max design RPM while using a Fake-a-lake. Having said that, I would not recomend running at RPMs much above idle due to fear of cooling water starvation. With my garden hose at full pressure the Fake-a-lake plunger was at times collapsing from the vacuum caused by the water demand.

I'm not sure if the term vacuum applys to a hydraulic situation but you get the point ;)

My boat has picked a fake-a-lake up off the ground at just above idle, which is why I drop a hose in a bucket. But that's another thread.

I think the max rpm on a hose, bucket, fake-a-lake, etc. is 1,200 IIRC.

MYMC
09-20-2006, 12:10 PM
A gasoline is engine is nothing more than an air pump. (Using a sbc as an example) 1/2 the displacment is on the 1,3,5,7 and 1/2 is on the 2,4,6,8 side (number 1 can be located by looking at the engine from above, it is the cylinder at the very front of the engine...you'll see the offset when viewed from above). Each cylinder displaces approx 43.75 CID and you should get equal output from both sides. If you aren't then any of several things could be wrong, but most likely a blockage is the culprit.

When you have as 2 into 1 muffler all bets are off as the gases will take the path of least resistance, and to figure that out you need to apply the theory of nonlinear dynamical systems...but that is a whole nother story.

BTW: do yourself a favor and throw away the fake a lake...

Jesus_Freak
09-20-2006, 01:57 PM
...to figure that out you need to apply the theory of nonlinear dynamical systems...but that is a whole nother story.

Actually, that is what I do for a livin', and I can tell you now that solving the transient, coupled equations for stratified liquid/gas flow will be a bear. Dont try it on your home PC ;)

MYMC
09-20-2006, 04:47 PM
Actually, that is what I do for a livin', and I can tell you now that solving the transient, coupled equations for stratified liquid/gas flow will be a bear. Dont try it on your home PC ;)
I thought that in general, analytical solutions are possible only if equations can be made linear, because non-linear terms naturally drop out or because nonlinear terms are small compared to other terms that they can be neglected. If the non-linearities in the governing equations can't be neglected, which is the situation for most engineering flows, then numerical methods or some special computational techniques are needed to obtain solutions. Am I wrong?:confused:

6ballsisall
09-20-2006, 04:56 PM
Has Hoosier Bob been around your boat???? This could explain alot! After spending the weekend with him at MM I now know he has progressed from Sheep to clean boats! Ask him!!

Ok I am outta here, you guys are talking smart people talk ^^^^^

east tx skier
09-20-2006, 04:57 PM
Did someone stick a banana in your tailpipe?

Jesus_Freak
09-21-2006, 01:21 AM
I thought that in general, analytical solutions are possible only if equations can be made linear, because non-linear terms naturally drop out or because nonlinear terms are small compared to other terms that they can be neglected. If the non-linearities in the governing equations can't be neglected, which is the situation for most engineering flows, then numerical methods or some special computational techniques are needed to obtain solutions. Am I wrong?:confused:

Analytical solutions can indeed be found for non-linear ODEs and PDEs. Often though, like you say, in pratical flows we drop some of this for convenience. In multiphase flows, like liquid/gas flow in a bounded surface, a 3-D system of non-linear PDEs is sought through numerical means. PM me for more interest.

Leroy
09-21-2006, 01:52 AM
Jesus: I'm not sure how you could tell this at 30MPH????

I believe all exhaust systems have across member, ICBW! It that is true, and MYMC is right all and the engine is a symmetrical pump then the problem must be the flaps or how the water coming through the exhaust is changing the exhaust flow.


I just saw this dramatically unequal exhaust flow in a test drive in a 94 205 this weekend. I was skiing behind it at ~30MPH and noticed it. I could see nothing wrong while looking in the doghouse or looking into the flaps with a flashlight. Are these "blisters" just like the name suggests...raised places? I just dont know what I am looking for. :confused: I am about to buy this thing and need advice.

Jesus_Freak
09-21-2006, 01:58 AM
I agree with MYMC. It took a few posts and days of thought before I understood what was happening in my soon-to-be new boat. I understood the theory before, but not the manifold design. Now, I am convinced I was seeing things when I was skiing...like when I see myself coming perfectly around number 3 ball, when I actually missed it by 3 feet.

Leroy
09-21-2006, 02:05 AM
Jesus_Freak; So you are about to close on your new boat? How about some pictures on a new thread?

tdaines@hotmail.com
09-21-2006, 11:51 PM
It's not a problem - air is like water and electricity in this respect - it will flow where there is the least amount of resistance. At idle in your driveway, there is little or no resistance to that side exhaust flap.

I wouldn't be concerned at all about it. The water surging is also normal when your in your driveway, because it can pool in the exhaust system if the bow is lower than the stern.

Another thing to point out is that the way the engine idles/runs will be quite different when it's in your driveway, because it's never under load. A lot of guys with carb or fuel problems work in it in their driveway, and it seems to be running perfectly. Once it's in the water, it has problems. This is due to engine loading and jetting. Boats are jetted to run right under load all the way from low to high rpm.

JimN
09-22-2006, 12:28 AM
Doug- the banana in the tailpipe thing doesn't work, they debunked it on Mythbusters.

tdaines@hotmail.com
09-22-2006, 01:05 AM
Did someone stick a banana in your tailpipe?
Good one, East TX Skier. You seem like a cool guy. If you're ever in UT, drop me a line, I'd love to hang out with you on the lake sometime. Of course, March - October are preferrable times...

TIM tdaines@hotmail.com

tdaines@hotmail.com
09-22-2006, 01:05 AM
Did someone stick a banana in your tailpipe?
Good one, East TX Skier. You seem like a cool guy. If you're ever in UT, drop me a line, I'd love to hang out with you on the lake sometime. Of course, March - October are preferrable times...

TIM tdaines@hotmail.com