SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: garytcosta on June 28, 2016, 08:49:49 PM
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Newbie, with my first jet boat & I think I screwed up already……
Finally got my Rogers on the water for the first time this past weekend. Everything was looking good at first, then she started overheating. Ended up pegging the temp gauge. Limped back to the dock & shut down the engine. Everything was hot including the logs & risers, & could hear the water boiling or creating steam in the block & exhaust.Even though I have logs & risers, I thought I would be a bit too clever & install a pressure relief valve. During the run the valve was leaking & I am pretty sure I had it adjusted to too low of a pressure. After getting it back on the trailer & thinking about it I am pretty sure the pressure relief valve was bleeding off enough pressure that the engine wasn't getting enough water volume from the pump, but that's just a guess. Checked the dipstick & didn't see any water in the oil, & engine ran well before I cooked it…..
[/size]The main questions I have are: Is it possible that I have fried or compromised the engine by running it that hot? Any ideas on what to do next to determine if I caused any damage?[/color]
(454 BBC, mild flat tappet cam, rectangular port heads, compression ratio unknown, probably around 10.5:1, pump just rebuilt.)[/font]
Any advice or suggestions?[/font][/size]
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Three things to do simply for piece of mind.
First, compression test, cheap, quick and easy.
Pass that, leak down test. A little more difficult and time consuming, but will give you a good idea of engine condition.
Pass that, pressure test the blocks water side.
Pass that, let her buck.
GT
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Three things to do simply for piece of mind.
First, compression test, cheap, quick and easy.
Pass that, leak down test. A little more difficult and time consuming, but will give you a good idea of engine condition.
Pass that, pressure test the blocks water side.
Pass that, let her buck.
GT
Thanks GT,
The compression test I could probably handle, + I've got #s from doing a comp test before this incident to compare to.
Would doing a cold test at this point be o.k. as a go-no-go indicator?
Have never done a leak down test myself, so would need expert help with that….
If you don't mind, how would one go about pressure testing the block?
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Three things to do simply for piece of mind.
First, compression test, cheap, quick and easy.
Pass that, leak down test. A little more difficult and time consuming, but will give you a good idea of engine condition.
Pass that, pressure test the blocks water side.
Pass that, let her buck.
GT
AND get a GATE VALVE
Dan'l
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If you don't mind, how would one go about pressure testing the block?
Pretty simple really.
Plug the thermostat outlets by putting the hose on both fittings Then pressurize the inlet of the water pump holes at the tee. Put 15 psi of air on it and listen.
The compression test cold would be enough information to see if it has to be pulled apart IMO.
GT
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AND get a GATE VALVE
Dan'l
Dan'l
It's got a gate valve, probably 8 years old by now. It seemed to be working o.k. A new ball valve would be up upgrade though?…..
G
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Dan'l
It's got a gate valve, probably 8 years old by now. It seemed to be working o.k. A new ball valve would be up upgrade though?…..
G
Gate, not ball.
Trust me here.
GT
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Gate, not ball.
Trust me here.
GT
Got it. If the old unit I got on there now is not leaking & is operable, good to keep, or toss & go new?
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Pretty simple really.
Plug the thermostat outlets by putting the hose on both fittings Then pressurize the inlet of the water pump holes at the tee. Put 15 psi of air on it and listen.
The compression test cold would be enough information to see if it has to be pulled apart IMO.
GT
GT,
Cool, that does sound pretty simple.
I want to hear no air leaking = good?
If air is leaking, or where the leak (sounds like it) is coming from, is going to indicate? Cracks, or blown gaskets, or??
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Got it. If the old unit I got on there now is not leaking & is operable, good to keep, or toss & go new?
Can't beat an old working valve.
If it works, let it buck.
GT
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GT,
Cool, that does sound pretty simple.
I want to hear no air leaking = good?
If air is leaking, or where the leak (sounds like it) is coming from, is going to indicate? Cracks, or blown gaskets, or??
Head gasket, cracked head, broken block.
She should hold 10 psi for quite a while.
GT
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I thought I would be a bit too clever & install a pressure relief valve. During the run the valve was leaking & I am pretty sure I had it adjusted to too low of a pressure. After getting it back on the trailer & thinking about it I am pretty sure the pressure relief valve was bleeding off enough pressure that the engine wasn't getting enough water volume from the pump, but that's just a guess.
If its a pressure relief valve Remove and replace with a Gate valve
Dan'l
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If its a pressure relief valve Remove and replace with a Gate valve
Dan'l
Right. I had the pressure relief valve plumbed after the gate valve. Abandoning that experiment though & eliminating the PRV…...
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Right. I had the pressure relief valve plumbed after the gate valve. Abandoning that experiment though & eliminating the PRV…...
With logs and snails, just slowing the water down a bit is enough (gate valve). 140-150 at idle, and 125-135 at cruise is fine.
Dan'l
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Head gasket, cracked head, broken block.
She should hold 10 psi for quite a while.
GT
GT,
Which of the three tests would you recommend doing first, compression, leak down, or pressure test?
I have some time after work today to get started on this.....
G
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GT,
Which of the three tests would you recommend doing first, compression, leak down, or pressure test?
I have some time after work today to get started on this.....
G
Compression test is the easiest and will tell you right away if you need to tear stuff down.
JMHO
GT
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Compression test is the easiest and will tell you right away if you need to tear stuff down.
JMHO
GT
GT,
Thanks.
Gonna get to that tonight. I'll post the results.....
G
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Compression test is the easiest and will tell you right away if you need to tear stuff down.
JMHO
GT
GT,
O.K., did a cold compression test & a pressure test on the water side per your instructions.
Compression test: #1 -150 #2 -149
#3 -149 #4 -149
#5 -150 #6 -149
#7 -149 #8 -150
These numbers are similar to what I had before the overheating event.
Plugs looked good, or at least nothing abnormal, I think. Insulators are a toasty brown, & air/fuel rings showing maybe a bit of a rich mixture. (If there was water getting in the cylinders & burning with the fuel would they look washed out or clean?)
For the pressure test on the water side, I put around 12-15 lbs of air in the system after sealing it up. I could hear the air as it was filling up, then listened pretty carefully around the block, logs & didn't hear any air escaping. Used a length of 5/8" hose to listen into each spark plug port & didn't hear any air entering there. Now, to be honest, noticing a subtle leak is probably beyond my skill level, plus a bit of ambient noise were I was doing the test (just outside my garage) might have prevented the test from being absolutely conclusive?…..
Thoughts?
G
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GT,
O.K., did a cold compression test & a pressure test on the water side per your instructions.
Compression test: #1 -150 #2 -149
#3 -149 #4 -149
#5 -150 #6 -149
#7 -149 #8 -150
These numbers are similar to what I had before the overheating event.
Plugs looked good, or at least nothing abnormal, I think. Insulators are a toasty brown, & air/fuel rings showing maybe a bit of a rich mixture. (If there was water getting in the cylinders & burning with the fuel would they look washed out or clean?)
For the pressure test on the water side, I put around 12-15 lbs of air in the system after sealing it up. I could hear the air as it was filling up, then listened pretty carefully around the block, logs & didn't hear any air escaping. Used a length of 5/8" hose to listen into each spark plug port & didn't hear any air entering there. Now, to be honest, noticing a subtle leak is probably beyond my skill level, plus a bit of ambient noise were I was doing the test (just outside my garage) might have prevented the test from being absolutely conclusive?…..
Thoughts?
G
I say make the necessary plumbing changes and run it.
Doesn't sound like you hurt anything at all.
GT
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I say make the necessary plumbing changes and run it.
Doesn't sound like you hurt anything at all.
GT
GT,
Thanks. I have read a bunch of your posts & you are very generous with your experience & offer a lot of great advice here on SCJB, so I trust your opinion.
Gonna x-out the PRV & go back to the stock plumbing configuration, & try to dip it back in the water in the next couple weeks.
A couple more questions: 1. A few folks had mentioned changing the oil as a precaution. Do you think that would be a good idea, or necessary? (Current oil only has about about an hour on it including tune up time out of the water.)
2. Loaded question: what weight oil do you recommend? (I know there is a lot of discussion about this, but since I am new to jet boating, I have no real frame of reference...)
Thanks again & I'll let you know how it works out.
G
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GT,
Thanks. I have read a bunch of your posts & you are very generous with your experience & offer a lot of great advice here on SCJB, so I trust your opinion.
Gonna x-out the PRV & go back to the stock plumbing configuration, & try to dip it back in the water in the next couple weeks.
A couple more questions: 1. A few folks had mentioned changing the oil as a precaution. Do you think that would be a good idea, or necessary? (Current oil only has about about an hour on it including tune up time out of the water.)
2. Loaded question: what weight oil do you recommend? (I know there is a lot of discussion about this, but since I am new to jet boating, I have no real frame of reference...)
Thanks again & I'll let you know how it works out.
G
Thank you for the kind words.
As for changing the oil.
Two different avenues of thought.
One, what if something happens to contaminate the new oil? It seems to me I would run it and ensure nothing is jacked up. Otherwise you would have wasted the oil for nothing.
Second, I am a huge fan of an oil analysis. If the oil is clean, let it buck.
I have been known to replace the filter and top it off, cutting the filter apart looking for issues that may exist.
As for oil weight, it really depends on too many factors to get into on a forum, but honestly, a quality 15w-40 with the proper compounds for the cam package you have is likely adequate. I actually like running straight weight oil simply because the winter rated number will never be an issue if you boat in the summer (the "w" number notes the weight of the oil at 32°F, the other number is at 212°F).
For example, I run 50 weight Amsoil full synthetic in my garbage.
Roller cam 496 Chevy.
Flat tappet camshafts should really run a zinc fortified oil. Anymore it's easiest to run an oil specified for diesel engines, like Rotella or Delo.
A little research will help you in that decision.
Check out
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=cfrm
There is a ton of great information in there, not just the forum, there are a bunch of in depth articles worth the read.
Hope this helps.
GT
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GT,
O.K. Gonna run it for now with the current oil. It looks clean & has very little time on it.
Changing the filter is a good idea, though. Gonna do that & open up the old one, seems like the easiest way to get an idea of what's going on inside the engine......
AS far as topping her off, since I have no idea of what weight oil is in there now, thinking that a quart of VR1 or Lucas Classic 10w40 would be a safe bet?
Registered on Bob The oil Guy forum. Waiting for confirmation, but looking forward to learning. (was asleep for most of my chemistry classes in high school, so hopefully I can muddle through the technical stuff......)
Thanks 2X,
G
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Update on the overheating issue:
Took the boat out to Elsinore today for a test run. she started overheating pretty much right away. No joy. Went right past operating temp & kept going up. Luckily was only about 75 yards or so from the dock, so the temp was (only) about 220 by the time we got her back. Surprisingly, other than overheating, the engine ran fine, in spite of my inadvertent attempts to kill it……..
I thought, after it overheated a couple weeks ago, that the PRV that I had plumbed in after the gate valve was the culprit. Although it may have contributed to the problem, eliminating it did not solve the issue.
Here it is in a nutshell:
-Boat overheated.
-Did compression check ( all cylinders around 150 psi)
-Pressurized block with about 10-15 psi of air & didn't hear any discernible leaks.
-Changed the filter & oil ( cut open the filter & it seemed to look normal. Oil was somewhat dirty, not unusual, & no water except while draining, at the very end, a little swirl of milkshake, no more than a couple of ounces)
-Eliminated the PRV between the gate valve & the logs
-Took her out again today & had same overheating issue
- got her home & decided to see what kind of water flow was going through the engine & pump. Pulled the water lines going to the risers, plugged them into a tee fitting, with a 1/2" hose going outside the hull. Ran some water through the engine & logs.
Got a nice stream of water exiting out the 1/2" hose. (ran off the garden hose with a WP regulator set to about 15 psi)
Checked for any obstructions on the pump side by running some water back thru the pump past the gate valve. Got what seemed like plenty of water exiting the pump nozzle.
Feeling like I'm ready to wave the white flag at this point.
GT, any words of advice, or suggestions?
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Update on the overheating issue:
Took the boat out to Elsinore today for a test run. she started overheating pretty much right away. No joy. Went right past operating temp & kept going up. Luckily was only about 75 yards or so from the dock, so the temp was (only) about 220 by the time we got her back. Surprisingly, other than overheating, the engine ran fine, in spite of my inadvertent attempts to kill it……..
I thought, after it overheated a couple weeks ago, that the PRV that I had plumbed in after the gate valve was the culprit. Although it may have contributed to the problem, eliminating it did not solve the issue.
Here it is in a nutshell:
-Boat overheated.
-Did compression check ( all cylinders around 150 psi)
-Pressurized block with about 10-15 psi of air & didn't hear any discernible leaks.
-Changed the filter & oil ( cut open the filter & it seemed to look normal. Oil was somewhat dirty, not unusual, & no water except while draining, at the very end, a little swirl of milkshake, no more than a couple of ounces)
-Eliminated the PRV between the gate valve & the logs
-Took her out again today & had same overheating issue
- got her home & decided to see what kind of water flow was going through the engine & pump. Pulled the water lines going to the risers, plugged them into a tee fitting, with a 1/2" hose going outside the hull. Ran some water through the engine & logs.
Got a nice stream of water exiting out the 1/2" hose. (ran off the garden hose with a WP regulator set to about 15 psi)
Checked for any obstructions on the pump side by running some water back thru the pump past the gate valve. Got what seemed like plenty of water exiting the pump nozzle.
Feeling like I'm ready to wave the white flag at this point.
GT, any words of advice, or suggestions?
Risers plugged with shit.
Pull the exhaust hoses and check for chunks.
Pull the 90 into the riser and check for chunks.
Check each log individually.
Does one side get hotter than the other?
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Risers plugged with shit.
Pull the exhaust hoses and check for chunks.
Pull the 90 into the riser and check for chunks.
Check each log individually.
Does one side get hotter than the other?
GT, thanks,
I'll check those areas. Figure on pulling the logs/risers as well & running some water and air through them to see if they are clear, & check for debris.
(I did have the logs& risers polished a month or so ago. When I pulled them, it looked like they hadn't been messed with in quite a while . Cleaned out the water passages pretty good, I thought, & removed more than a bit of corrosion.
(One thing I forgot to mention: Along with doing the compression check, etc., I replaced both exhaust hoses thinking they might have gotten damage from the first overheat. (The originals didn't look thrashed i.e. no blistering, etc.)
It seems like both sides (logs) get equally hot. I mean, everything seemed hot, even the water in the hoses going all the way back to the gate valve was hot.
The way I ran water through the engine @ home this afternoon, seemed to indicate that water was getting through both the logs, & block. Since the risers are where the water exits, those being plugged by debris or corrosion would cause the cooling system to be over pressured?
Just a thought: Based on what I saw today @ Elsinore, it kind of seems the engine is getting very little, or no pressurized water from the pump bypass, just the amount that would naturally enter the cooling system from the intake & bowl being underwater.
A blockage, in the system after the pump bypass/gate valve, would probably act like that too, which seems like where you're headed with your suggestions?
Is it even possible that the pump is not providing enough pressure or volume from the bypass to adequately cool the engine, or is that just my inexperience talking?……....
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The relief valve is between the jet and the gate valve? If so, it is bypassing all the flow before it has a chance to get to the engine, which is just getting a trickle of flow.
Don't run it on the trailer, you are going to burn up that new pump!
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The relief valve is between the jet and the gate valve? If so, it is bypassing all the flow before it has a chance to get to the engine, which is just getting a trickle of flow.
Don't run it on the trailer, you are going to burn up that new pump!
Flusher,
Hey bud.
Pressure relief valve is gone, just a gate valve now.
Now way I'm gonna run it on the hose with the $$$ pump connected. I'll pull the driveline for that.
What I was doing today was more of a manual flush, to see if there were any blockages, or major restrictions in the cooling system from the engine side of the gate valve on up & thru the gate valve back out through the pump….
Now that i got you here, what do you think about the possibility that the pump might not be providing enough pressure or volume of water to adequately circulate water through the engine? Impossible?
No disrespect brother, just expressing my cluelessness.
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O.K.,
More wild guessing: water volume vs. water pressure
So, before putting the boat on the water, while the pump was out being rebuilt, I did a baseline tune running the engine on the garden hose. Had a water pressure regulator with gauge, on the hose set to 15 psi. Ran the engine for upwards of 10 minutes, & it stayed cool the whole time. was able to regulate the water temp between 120 & 140 degrees just by turning the spigot open or closed just a little bit. The WPR gauge reads zero the whole time, which indicates that the same amount of water going in is going out, right? The regulator limits the pressure but not the volume, so I have 15 psi., max, with a decent volume of water going to the engine, & everything is peachy. Get it back on the water, setup is the exact same only now the new pump is providing water to the engine.
Could it be that, lets say, the water passages in the block, heads or the exhaust manifolds are restricted or crudded up enough that they would pass enough water to keep the engine cool when fed by residential water line volume, but not with the kind of volume that you would get from a pump under normal operating conditions, even if, lets say, the pressure provided in either situation is around 15 psi.?
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Just a question-
You said the gauge went over 220, But was the engine hot?
Just thinking about a mismatched Temp gauge and sender.
Dan'l
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Just a question-
You said the gauge went over 220, But was the engine hot?
Just thinking about a mismatched Temp gauge and sender.
Dan'l
Had that happen before, first time we took the Hankey boat out with the blower motor. Gauge pegged 250 thought motor was done. But happen to just be mismatch sender.
BECKY WITH THE GOOD HAIR!
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Good call, FWIW, you can't touch over about 190°F without evacuating a swear word. 150°F you can set your hand on for several seconds.
GT
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Just a question-
You said the gauge went over 220, But was the engine hot?
Just thinking about a mismatched Temp gauge and sender.
Dan'l
Definitely hot.
First time it happened a couple of weeks ago, after shutdown, I could hear water water steaming & boiling in the block. Temp gauge was pegged at 240.
Yesterday, not so much, but got it shut down by the time it hit 220........
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Pressure is result of resistance to flow. In order for flow to occur, there must be a pressure differential and a flow path. There is no way that just the pump being submerged could cause any flow to occur.
On your boat (sitting level), the water pump mount on your block is about 10" above the cooling line fitting in the jet pump and the thermostat housing flange on the intake manifold is about 17" above the cooling line fitting. Because the weight is aft, the stern will sit lower in the water than the bow, increasing these numbers. The block won't even fill with water until you start the engine.
If you are observing flow through the engine while under way, that has to be produced by the jet pump. I just can't see that the jet pump isn't producing enough flow to cool the engine yet produce enough flow to generate bowl pressure, and thrust, with the water exiting a 3.125" nozzle opening.
Barring the possibility of a ski rope or something getting sucked up, winding around the back side of the impeller, and creating a seal between the back side of the impeller and the suction housing; the the restriction has to be between the jet pump cooling line fitting and where the water returns to the lake. I believe you wrote that you tested flow in both directions.
I would lose the pressure relief valve. I would verify that your gate valve is opening/closing all the way as it should be. Start with it all the way open and adjust down from there.
I also think Dan'l is spot on with what he just said. I would add, make sure that the sending unit is getting a good ground.
Lastly, I would check your tune. Tuning on the trailer is much different than with the engine under full-load. You might be leaning out. I will share this little tidbit; my engine leaned out, while cruising, as a result of a hose failure on the main fuel line between my fuel pump and barrel valve. The engine got so hot that I could feel the heat radiating on my back at about 50 MPH. It felt like the back of my neck was getting sunburned, but the sun was in front of me. I run full pump pressure through my engine, which renders my water temperature gauge useless, because it never registers any temp unless I am idling for long periods of time. The surface of the heads got hot enough to blister my finger when my dumb @$$ touched it.
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Pressure is result of resistance to flow. In order for flow to occur, there must be a pressure differential and a flow path. There is no way that just the pump being submerged could cause any flow to occur.
On your boat (sitting level), the water pump mount on your block is about 10" above the cooling line fitting in the jet pump and the thermostat housing flange on the intake manifold is about 17" above the cooling line fitting. Because the weight is aft, the stern will sit lower in the water than the bow, increasing these numbers. The block won't even fill with water until you start the engine.
If you are observing flow through the engine while under way, that has to be produced by the jet pump. I just can't see that the jet pump isn't producing enough flow to cool the engine yet produce enough flow to generate bowl pressure, and thrust, with the water exiting a 3.125" nozzle opening.
Barring the possibility of a ski rope or something getting sucked up, winding around the back side of the impeller, and creating a seal between the back side of the impeller and the suction housing; the the restriction has to be between the jet pump cooling line fitting and where the water returns to the lake. I believe you wrote that you tested flow in both directions.
I would lose the pressure relief valve. I would verify that your gate valve is opening/closing all the way as it should be. Start with it all the way open and adjust down from there.
I also think Dan'l is spot on with what he just said. I would add, make sure that the sending unit is getting a good ground.
Lastly, I would check your tune. Tuning on the trailer is much different than with the engine under full-load. You might be leaning out. I will share this little tidbit; my engine leaned out, while cruising, as a result of a hose failure on the main fuel line between my fuel pump and barrel valve. The engine got so hot that I could feel the heat radiating on my back at about 50 MPH. It felt like the back of my neck was getting sunburned, but the sun was in front of me. I run full pump pressure through my engine, which renders my water temperature gauge useless, because it never registers any temp unless I am idling for long periods of time. The surface of the heads got hot enough to blister my finger when my dumb @$$ touched it.
Flusher,
Thanks for the detailed response!
Yesterday, I ran her with just the gate valve. (Removed the PRV & re-plumbed before getting on the lake.) Gate valve was 100% open.
Didn't get above 1200 rpm's, basically idling and the temp kept climbing. I believe it would have passed 220 if I hadn't shut it down.
I like the leaned out theory, & wish it was that, but I didn't really get much past the idle circuit while it was running. If it was that leaned out, I don't think it would even idle?
It's looking more like, as you said, a restriction of some kind on the engine side of the jet pump cooling line fitting.....
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It's looking more like, as you said, a restriction of some kind on the engine side of the jet pump cooling line fitting.....
Including the fitting! It isn't somehow restricted, is it?
What about timing? It's not crazy retarded, is it?
I don't remember what it is, but something struck me as weird on your boat. Is your water plumbed through the exhaust before entering the engine? I was not involved in the work and whatever it was was not something that we were involved with. I'm trying to learn to STFU because every time I say something, it opens a can of worms.
Only other thing I got is engine clearances. Pull the spark plugs and turn the engine over with a breaker bar, feeling how much torque it takes to turn it. If the clearance is too tight, you should be able to feel it.
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Fwiw.. I had a timing issue with my street car once after a distributor swap, car ran and drove fine but started overheating really bad,something it never did before, after it cooled down I fired it a night to check it out and the headers were glowing red! Turned out the distributor was f'd up and way retarted, locked it out at 36 degrees and problem solved...
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Fwiw.. I had a timing issue with my street car once after a distributor swap, car ran and drove fine but started overheating really bad,something it never did before, after it cooled down I fired it a night to check it out and the headers were glowing red! Turned out the distributor was f'd up and way retarted, locked it out at 36 degrees and problem solved...
I wish it was as simple as timing being too retarded
Timing is at 13° btdc initial, 34° all in.
I'm reserving the retarded part for myself.