Challenger 4tec Upgrade
- Thread starter IDoSeaDoo
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IDoSeaDoo
Well-Known Member
Thanks. Don't run it on the hose too long though, i would hate for you to cook your carbon seal.
MPower
Active Member
Yea, I'm really hoping this is in fact normal, but somehow I doubt anyone out there has ever run their boat without the PCV valve to check this. It seems bizare that this much smoke is normal, but then again, this is my first encounter with a 4tec engine, and I don't know how superchargers affect things. The motor has plenty of power and perfect compression. It's hard to believe that the rings are shot... I will still do a leak down test once I get the pump cone off.
I got side tracked last night when I finally got to the nozzle. It turns out that my GTX and the RXP nozzles are exactly the same. The only difference being is that the RXP one has a gimbal ring for trim control and the GTX just has spacers to take up the extra slack where the ring WOULD have been. So having two, I decided to try and port one to a wider diameter, as suggested by my friend [MENTION=52309]MPower[/MENTION]. I used these coarse honing stones I had laying around and widened the nozzle from the stock 83mm to 84mm.
Today, i will go and fill in those vestigial siphon holes with jb weld and sand smooth. Hopefully, having the ability to move more water will give me better hole shot and eliminate the cavitation when I give her full power from stand still. Even when water enveloped the carbon seal and stopped all possible leaks, it still cavitated under that condition. At this point, I can't imagine what else it cam be but improper pump setup.
Nice job. Keep in mind that when you increase the diameter of the nozzle it will be easier for the motor to spin your prop, so it may put you on the limiter depending where you are now. If that is the case just add a degree to the trailing edge of the prop (should drop you R's around 100 rpm).
One additional note on that is right now is great air/weather so you are making great power. Come summer your relative HP is going to drop. So while you may need to add a degree to the prop in April weather, Come June it may be perfect as is.
IDoSeaDoo
Well-Known Member
Hmm, well, I'm already on the limiter, but most of that is due to cavitation. I'm getting a new carbon seal this week, but even when I had my old one submerged in water, the motor was still able to break through and cavitate at the very top of the throttle. It was a nasty shuddering sensation.
I can't seem to figure out the pitch of this impeller. It's supposedly a stock replacement from SBT, but I'm not sure the pitch. The manual and some sites claim the SC 185 GTX had a 13/23, other sites claim it's a 12/20. I'm leaning toward the manual, but am not 100%. 13/23 seems super tall for this application. The 215's all had 10/21 BUT they also had the 159mm pump vs my 155mm. Guess we'll just have to test with the new seal and see.
I can't seem to figure out the pitch of this impeller. It's supposedly a stock replacement from SBT, but I'm not sure the pitch. The manual and some sites claim the SC 185 GTX had a 13/23, other sites claim it's a 12/20. I'm leaning toward the manual, but am not 100%. 13/23 seems super tall for this application. The 215's all had 10/21 BUT they also had the 159mm pump vs my 155mm. Guess we'll just have to test with the new seal and see.
hotrodssnova
Member
Just thinking about the crankcase pressure, do you have a boost gauge you can plumb in? I wonder if the seals on the sc are leaking? Does the sc get oil from the engine supply pressure or is it self contained?
I watched the video and it looked like water vapor coming out of the hose. If your head gasket was leaking under boost, it can push water into the crankcase but seal on a compression test. Cylinder pressure is way higher then 150 psi. I've seen head gaskets pass a leak down test, but fail under boost.
Have you tried to capture that vapor and let it condense back to a vapor? Any distinct odor?
I watched the video and it looked like water vapor coming out of the hose. If your head gasket was leaking under boost, it can push water into the crankcase but seal on a compression test. Cylinder pressure is way higher then 150 psi. I've seen head gaskets pass a leak down test, but fail under boost.
Have you tried to capture that vapor and let it condense back to a vapor? Any distinct odor?
IDoSeaDoo
Well-Known Member
Hmm good idea, I think I have just the thing to get these vapors into a container. I'll do that tonight and let you know.
Now this head gasket was replaced two years ago. I haven't run it for 2 years since I replaced it, but I used new head bolts and torqued everything down according to the book. I have an endoscopic camera that I can stick down into the spark plug hole. What kind of signs would water intrusion show?
Now this head gasket was replaced two years ago. I haven't run it for 2 years since I replaced it, but I used new head bolts and torqued everything down according to the book. I have an endoscopic camera that I can stick down into the spark plug hole. What kind of signs would water intrusion show?
hotrodssnova
Member
I wouldn't look for intrusion into the cylinders, if it's the head gasket, you might be pushing cylinder pressure by a coolant passage and crankcase junction, or you could be pushing boost through the turbine shafts seals.
IDoSeaDoo
Well-Known Member
The sc has all new seals too though. Oem and correctly assembled. I guess I need to get a boost reading on the manifold? Anyone know what the specs should be? Why would sc leaking boost push steam into the crank case?
Surely this crank case pressure build up is an issue with the pipe attached to the intake.
If this was releasing the pressure into the intake like normal then the issue would not exist. If pulling the dipstick tube out fixes it then there must be a blockage somewhere. As the dipstick tube is tiny and I'm guessing the breather is much bigger this has to be the case.
As a vehicle mechanic and engineer I think we're looking at this the wrong way, unless your developing masses of pressure ie, more than the breather can cope with which I doubt is the case with what you have already said about the engine.
I assume you have taken all the pipes off and cleaned all the in line filters and ensured the pipes aren't clogged with carbon from the years of use?
Andy
If this was releasing the pressure into the intake like normal then the issue would not exist. If pulling the dipstick tube out fixes it then there must be a blockage somewhere. As the dipstick tube is tiny and I'm guessing the breather is much bigger this has to be the case.
As a vehicle mechanic and engineer I think we're looking at this the wrong way, unless your developing masses of pressure ie, more than the breather can cope with which I doubt is the case with what you have already said about the engine.
I assume you have taken all the pipes off and cleaned all the in line filters and ensured the pipes aren't clogged with carbon from the years of use?
Andy
IDoSeaDoo
Well-Known Member
Well, because the air filter elbow I had handy had a 1/4" barb already built in, I figured I'd reduce the crank case ventilation hose to plumb it right into the Intake (as in the original design). This entailed me to use a 1" to 1/4" reducer fitting. When I ran it with that fitting attached, I saw pressure start to build in my manometer. When used a 1" to 5/8" reducer and the 4' of 5/8" hose (in the Youtube video), the pressure didn't increase anymore. The original setup for this engine had the crank case vented with a solid 1" pipe going to the intake piping before the supercharger. The only difference between my setup and stock setup was that 1" to 1/4" reducer. Seems that it needs more diameter to properly vent. Come to think of it, I've never seen any internal combustion engine that had anything less than 5/8" PCV piping.
I wish I had another ski to verify this with.
I wish I had another ski to verify this with.
hotrodssnova
Member
I was thinking it might be a possibility and the, vapor (what I will call it for now) might be blow by.
On my car, Mitsubishi 4 cylinder turbocharged, I have blown the dipstick out while at the drag strip. This is while the engine sees the 30psi and 6000+ rpm. Moving pistons at that rpm create a lot of crankcase pressure.
Does the vapor continue all day? Could it be condensation? Does it stop after the engine has been run for an hour on the water?
Coolant level same or dropping?
snikwad003
Well-Known Member
Have you pressure tested the closed side of the cooling system?
hotrodssnova
Member
Posted at the same time. You're gonna need a bigger vent then 1/4 inch. I didn't catch that in my multiple reviews
IDoSeaDoo
Well-Known Member
Wait, are you a DSM tuner? Only eclipse I know that can take 30psi of boost is a built 4g63. Those were awesome cars. I had a gen 1 a long time ago.
Anyway, it seems like it does blow this vapor all day, though I have probably run it for only (MAYBE) 2 hours total since I got that new oil cooler on there and actually got it on the water.
I haven't checked the coolant levels yet because my cooling system was finalized only last week, and I was running straight water in there. I'm not sure how much I filled it to.
I'm going to do a test today and capture these vapors in a chilled bottle. As well as a leak down test
IDoSeaDoo
Well-Known Member
Hmm you know, I have not thought to do so. I'll do that too
hotrodssnova
Member
Yep, I am a dsm'r. I have a built 4g63t. 92 laser.
IDoSeaDoo
Well-Known Member
Water jacket lost maybe 1psi on 10 min holding 10psi. I think I'm good on that score.
Ran it through a cold jar and just got some oil residue and water vapor. Water is normal byproduct of combustion. The jar smelled like rich exhsust, but not as sweet as the gasoline behind the gas cap. I think it's just blow by... about to do a leak down test
BTW, how does this plug look to you?
Ran it through a cold jar and just got some oil residue and water vapor. Water is normal byproduct of combustion. The jar smelled like rich exhsust, but not as sweet as the gasoline behind the gas cap. I think it's just blow by... about to do a leak down test
BTW, how does this plug look to you?
hotrodssnova
Member
Plugs look good. Most cooling systems run at 13 psi...... 0.9 bar what does the manual say?
IDoSeaDoo
Well-Known Member
No worries Nike.
Ya, it's a 13psi system, the cap says so. That's why I went with 10, figured I didn't want to set off the cap and have it get stuck a little or something, and maybe give a false reading.
Anyway, I popped of the pump cone and held the pistons while I did the leak down. It was 0%. Perfect score. Soooo I'm left thinking this is either normal, or just residual water from when my oil got contaminated with water. I also decided to buy a catch can to run this through.
Ya, it's a 13psi system, the cap says so. That's why I went with 10, figured I didn't want to set off the cap and have it get stuck a little or something, and maybe give a false reading.
Anyway, I popped of the pump cone and held the pistons while I did the leak down. It was 0%. Perfect score. Soooo I'm left thinking this is either normal, or just residual water from when my oil got contaminated with water. I also decided to buy a catch can to run this through.
hotrodssnova
Member
Logical thinking. Might take some time to burn off the water. I took on water in the boat when a drain plug popped out at the local watering hole, half sunk the boat. I'm paying for it now, lost a crank due to frozen bearings. We tubed all day, after pumping out the boat and clearing the engines of water. I even fogged before I put the boat up. 1 week later, engine was locked up . ; (
snikwad003
Well-Known Member
Not all catch cans work right so make sure its not a pos
034 motorsport makes a good one that acts as a centerfuge (sp?) And has a drain to drain off what it catches, kinda spendy tho
034 motorsport makes a good one that acts as a centerfuge (sp?) And has a drain to drain off what it catches, kinda spendy tho
IDoSeaDoo
Well-Known Member
Damn hotrods, that sucks about your crank. Was that on a 2-stroke? Can't believe it still froze up after you ran it...
Snick, I know what you mean about those cheapo catch cans. Under $60, they're just hollow. I didn't want to spend over $100, so I bought the cheapest square body with large enough fittings. Those you can take apart and add your own baffling. Going to fill it with stainless steel scrubber material and add a little baffle at the top. I will use clear hoses, so I'll be able to see how well it's working, and if not well, I'll rip it apart and mod it some more. Honestly, I don't think much oil comes through there anyway, as the Seadoo crank-vent system is already designed to catch most of it. Originally, it was all just plumbed to the intake pipe, where it coated everything with a thin layer of oil film. No biggie. The trick is to slow the gas/oil stream down enough so that there is not enough velocity to carry it up to the outlet. A catch can is perfect for that, it acts like an intake resonator. I realized that that hose I had on there was only 1/2", and that was enough to not cause any back pressure. So anything more than that should be perfect. I hope to put 5/8" fittings on there and mod my intake with a similar barb and be done with it.
This week, while I wait for the carbon seal, I'll be concentrating on the cosmetics. Cleaning and buffing the hull, and looking for vinyl samples to redo my seat backs with.
Snick, I know what you mean about those cheapo catch cans. Under $60, they're just hollow. I didn't want to spend over $100, so I bought the cheapest square body with large enough fittings. Those you can take apart and add your own baffling. Going to fill it with stainless steel scrubber material and add a little baffle at the top. I will use clear hoses, so I'll be able to see how well it's working, and if not well, I'll rip it apart and mod it some more. Honestly, I don't think much oil comes through there anyway, as the Seadoo crank-vent system is already designed to catch most of it. Originally, it was all just plumbed to the intake pipe, where it coated everything with a thin layer of oil film. No biggie. The trick is to slow the gas/oil stream down enough so that there is not enough velocity to carry it up to the outlet. A catch can is perfect for that, it acts like an intake resonator. I realized that that hose I had on there was only 1/2", and that was enough to not cause any back pressure. So anything more than that should be perfect. I hope to put 5/8" fittings on there and mod my intake with a similar barb and be done with it.
This week, while I wait for the carbon seal, I'll be concentrating on the cosmetics. Cleaning and buffing the hull, and looking for vinyl samples to redo my seat backs with.
snikwad003
Well-Known Member
Pack it like a still column. I like it.
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