rollerized valve train

[SacRiverRat]

But just be careful not to pull a wakeboarder before hr 10, or heaven forbid you use synthectic oil before hr 100...

[WakeGirl]

But just be careful not to pull a wakeboarder before hr 10, or heaven forbid you use synthectic oil before hr 100...

Yeah, we never did anything like that.

[johnsvt]

I always liked to run it hard. My stinky ford small block gets one pass down the strip on horsepower then every pass after that it's all the NOS she can eat. How about for a boat you make one pull with your in-law attatched on hp and then the next time he/she gets a pass with a little juice.

[BillFooter]

Yes, the injectors make a clicking noise. Some of the engines let quite a bit of gas bypass the rings and dilute the oil. Mine does this and the lifters get noisey when the oil starts to get diluted.

If you would of broke your engine in the way edwin recommends you wouldn't have this problem.

you gotta let it eat man!

OR, if Indmar had used different rings when they built it it would not have that problem either!

I'm going to switch to synthetic oil next spring & also pull the valve covers & make sure valves/lifters are set up right. How does Edwin recommend breaking in the engine? & what kind of rings does Indmar use?

Indmar used low friction rings in SOME, not all engines. The low friction rings alllow the fuel to get past the rings and dilute the oil. Breaking in the engine different will not cure this problem.

[88Skier]

I thought Indmar buys assembled crate engines, (block and heads), and installs the electronics and fuel delivery systems, and marinizes them.

BillFooter are you on a small ski lake? A discussion here awhile ago said the problem often was associated with boats on small ski lakes that typically get run hard from idle to speed and back to idle and never get broken in properly.

[BillFooter]

I thought Indmar buys assembled crate engines, (block and heads), and installs the electronics and fuel delivery systems, and marinizes them.

BillFooter are you on a small ski lake? A discussion here awhile ago said the problem often was associated with boats on small ski lakes that typically get run hard from idle to speed and back to idle and never get broken in properly.

I am not on a small lake. In fact it is about 5 miles from the dock to where I ski. One of the dealers that participates on this site sent me a bulletin from Indmar that said to run the boat at 3500 RPM for 10 -15 minutes to warm the oil enough to evaporate the gasoline from it. I have tried that too. It does not work either. So instead of oil changes at 50 hours Indmar suggests that the oil be changed at 25 hours in the boats that have engines with the low friction rings.

[vette-ski]

I thought Indmar buys assembled crate engines, (block and heads), and installs the electronics and fuel delivery systems, and marinizes them.

BillFooter are you on a small ski lake? A discussion here awhile ago said the problem often was associated with boats on small ski lakes that typically get run hard from idle to speed and back to idle and never get broken in properly.

Well, I mentioned that above in post #22 and I guess nobody saw it. GM builds marine motors: http://www.gm.com/automotive/gmpowertrain/...arine/index.htm

The hammerhead is also a GM crate motor but not shown on the list. Do a search on hammerhead on this site and you will find more info. I remember somebody asking not long ago "what does it take to make a 383", or something like that. I'm most certain Indmar does not break down the GM engine at all. "Marinizing" involves specific head gasket too, and GM installs those.

IIRC, the fuel/oil issue was with people who ski the course and that's about it. The short bursts were not long enough to heat up the oil to burn off the fuel. As for the rings? What engine do you have Billfooter? I can maybe see different rings in the hammerhead, but I do not think there are some monsoons with regular rings, and some monsoons with low tension rings because like I said I'm sure GM built them and would not have two different ring options in the same engine.

Too much fuel is a tuning issue. Fuel will get by the rings whether they are low tension or not. So if this is a hammerhead issue, then it is a HH tuning issue, not because of the rings. Just this morning I worked in the garage trying to diagnose a problem with my car (coincidentally a 383). I pretty much have it narrowed down to either the ecm crapping out or a problem with the chip we burned. It's pig rich.....and I drained 11 qts of fuoil (fuel/oil mix) out of a pan I only put 7 qts of oil in. Not good for a $10k motor. So I'm getting a bunch of fuel past the rings, and they aren't low tension.

[BillFooter]

If you will read my post you will see that I said this is a problem in SOME engines. Mine is a Hammerhead 365 and GM installed low friction rings per Indmar spec.

GM assembles the engine with parts specified by Indmar.

This problem is NOT specific only to ski course use. The reason I mentioned the issue with rings in the first place is because the original post was about valve train noise. Oil diuted with gas produces valve train clatter.

[vette-ski]

I did read your post, but it wasn't clear if you meant SOME monsoons and not others, or SOME model years and not others, or SOME displacements and not others.

I work for GM, so I have some degree of experience on how they operate. The point I was trying to make above is I really don't think the rings in the Indmar engine are unique to Indmar, they are the same rings used in other Vortecs (truck engine) in the case of the Monsoon, or the same 383 crate engine used for the HH.

My post might not have been clear, but I didn't mean that it only happens on ski course runners, but it is more common on boats that run the course and do nothing else. Anybody who does short burst running, and idles around the rest of the time can see the same problem.

I can't verify your point that oil diluted gas will cause lifter clatter though. As I mentioned above, I dumped oil from the pan in my car and it had over a GALLON of fuel in the oil. I had no lifter noise whatsoever. Other than lower than normal oil pressure and fuel/oil mix pouring out the rear main seal, you'd never know there was a problem.

[BillFooter]

When my oil starts getting diluted my lifters will clatter after a long barefoot run which is 3 to 5 minutes at 4200-4600 RPM. Change the oil and the clatter goes away.

Indmar service advisory SV2006-4 talks about oil dilution. It can be caused by use on small lakes, a faulty thermostat, coolant temp sensor, MAP sensor, faulty fuel pressure regulator, or sticking injector(s).

It also states that low tension rings are used in all GM marine engines and that these low tension rings are susceptible to gumming and sticking in the ring grooves, another possible cause of oil dilution.

I had my electronics checked by a Malibu dealer, and was told that everything is working properly. If Indmar has a tech center in Memphis, I would like to take my boat there next spring.

[vette-ski]

It's odd you see that since you do longer footing runs and that should be enough to burn off trace oil contaminants; sounds like you are getting quite a bit of contamination. All those potential problems mentioned in the bulletin could lead to an overly rich condition, which is basically what is causing this problem. Does your oil smell like gas when you drain it? I had lifter clatter symptoms like you describe in another engine once, but it was caused by trace water getting to the oil via a leaking intake gasket. But fuel/oil looks a lot different than water/oil.

[BillFooter]

Yes my oil will smell pretty strong of gas. No water is in the oil. The rear of the boat and platform do not get any more black exhaust build up than any of my friends boats. If you are at the platform when the engine is running the exhaust does not smell any stronger/richer than theirs either. I am hoping to get it cured this spring.

[88Skier]

Yes my oil will smell pretty strong of gas. No water is in the oil. The rear of the boat and platform do not get any more black exhaust build up than any of my friends boats. If you are at the platform when the engine is running the exhaust does not smell any stronger/richer than theirs either. I am hoping to get it cured this spring.

Can anything be done, other than a rebuild?

[BillFooter]

I think that it has to be mostly a tuning issue. If all GM marinized engines are using the low friction rings, there would be a widespread issue. My Hammerhead 365 has aluminum heads and a more aggressive cam than the Monsoon. I would imagine it is set up run pretty rich to protect the engine from detonation. Indmar says the dilution will not damage the engine if you change oil more often. It's just a pain in @$$ to do so

[MoonDawg]

......Indmar service advisory SV2006-4 talks about oil dilution. It can be caused by use on small lakes, a faulty thermostat, coolant temp sensor, MAP sensor, faulty fuel pressure regulator, or sticking injector(s)....

If your engine is making oil my bet is on a leaking injector.

a) pull your spark plugs an look for one that is wet with gas/oil. Most likely that is the cylinder with the leaker

B) remove the fuel rail on the side with the suspected leaking injector. (see pages 313-325 of the Indmar inboard shop manual on how to do this)

You may actually see the injetor leaking if there is residual pressure in the fuel line.

If not and you are handy you can build an injector testor like the poor man's tester

Or you can have the whole set cleaned and reconditioned by a pro so they run like new.

[vette-ski]

I'm only throwing this out there again because it is a real world experience I have had with this exact same problem; the only difference is it is in a car and not a boat. Like I mentioned I had a ton of fuel in my oil. I thought it had to be a failed injector or fuel pressure regulator as you said Moondawg. The first thing I did was check the resistance of all the injectors to check them electrically. They were all within .2 ohms. That's ok. I pulled the fuel rail off, leaving the injectors on the rails. I left the electrical connectors off of the injectors and hit the key expecting to see one or more spray and nothing happened. They held pressure fine. I pulled a vacuum on the regulator and no fuel came out so it is fine. Fuel pressure past the regulator is good too so it's doing it's job limiting full fuel pump pressure. Then I did the same key-on test, only this time with the injectors plugged in. Still nothing leaking. Everything checks out mechanically. The only thing left that controls amount of fuel into the motor is tuning - either the ecm is going out or more likely the chip had rattled loose from the socket and the car was in limp mode (rich). I thought there was no way a bad tune could dump that much fuel in but it's the only thing left that I can think of. The funny thing, there was so much residual fuel in the motor (the car was last started over a month ago) that I hit the key and the car ran for about 5-10 seconds with no fuel injectors in it.

So you can check those things - make sure an injector isn't stuck open, or that you don't have a failed fuel pressure regulator putting too much pressure behind the injectors. Too much pressure will cause the injector to flow more than designed. You can check the injectors too w/o removing them - just look for bleed down on a fuel pressure guage installed on the fuel rail schrader valve. Turn the key on, then off - it should hold pressure for a couple hours. But my bet is if Indmar issued a bulletin, it's a known issue and it's more likely an overly rich fuel table.

[TRBenj]

I thought Indmar buys assembled crate engines, (block and heads), and installs the electronics and fuel delivery systems, and marinizes them.

BillFooter are you on a small ski lake? A discussion here awhile ago said the problem often was associated with boats on small ski lakes that typically get run hard from idle to speed and back to idle and never get broken in properly.

Well, I mentioned that above in post #22 and I guess nobody saw it. GM builds marine motors: http://www.gm.com/automotive/gmpowertrain/...arine/index.htm

The hammerhead is also a GM crate motor but not shown on the list. Do a search on hammerhead on this site and you will find more info. I remember somebody asking not long ago "what does it take to make a 383", or something like that. I'm most certain Indmar does not break down the GM engine at all. "Marinizing" involves specific head gasket too, and GM installs those.

Dont forget that marine engines are built with larger piston-valve clearance than their automotive counterparts. Thats the biggest difference between the actual blocks.

[vette-ski]

Dont forget that marine engines are built with larger piston-valve clearance than their automotive counterparts. Thats the biggest difference between the actual blocks.

How much difference? Have specs, or a source for this info? I personally don't think there's any difference in the blocks. If you've ever built an engine, you'll know there is a lot of variables that affect piston-valve clearance, and block deck height is only one of them. Cam lift, duration, and LSA; pushrod length; rocker arm ratio; head gasket thickness; head milling; and more. I know the head gasket is different for marine, and I know the cam is different. I haven't taken the time to look at part numbers to know if the valve train is different for marine. I'm betting these make the differences you are referring to. Another tip off to me is the static compression ratio is the same between the marine and street engine. If you think about what goes into the compression ratio calculation, you'll see that there is no difference between the block or heads.

[TRBenj]

Dont forget that marine engines are built with larger piston-valve clearance than their automotive counterparts. Thats the biggest difference between the actual blocks.

How much difference? Have specs, or a source for this info? I personally don't think there's any difference in the blocks. If you've ever built an engine, you'll know there is a lot of variables that affect piston-valve clearance, and block deck height is only one of them. Cam lift, duration, and LSA; pushrod length; rocker arm ratio; head gasket thickness; head milling; and more. I know the head gasket is different for marine, and I know the cam is different. I haven't taken the time to look at part numbers to know if the valve train is different for marine. I'm betting these make the differences you are referring to. Another tip off to me is the static compression ratio is the same between the marine and street engine. If you think about what goes into the compression ratio calculation, you'll see that there is no difference between the block or heads.

Whoa, major brain fart on my part. I meant piston-cylinder wall clearance. Whoops!

That is a crucial difference between marine and automotive block/piston selection. Ive read that piston-bore clearance needs to be on the range of .0030"-.0045" for marine engines, as opposed to ~.0015" for automotive. Interestingly, this has more to do with the cylinder running cooler (due to raw water cooling) than the piston running hotter (as one might expect from high marine engine loads).

Youre absolutely right about everything else. There are no differences that I know of between automotive and marine heads or valvetrain. Im running GT40p heads from an Explorer on my boat, and will be installing FRPP roller rockers next spring. My cam is custom for my application, but it would be equally at home in a car or truck- theres nothing special about it that makes it a "marine" cam (other than the intended powerband).