I have a new-to-me 1980 Commander 410, with twin Marine Power 454's.
We rebuilt the carburetors, and were eventually able to get the engines to start. The port engine has a loud rattle indicating stuck lifters. The friend that helped me rebuild the carbs said we cold take the heads off to repair the lifters, and see if anything else needed attention.
However, a surveyor I spoke with suggested that before we remove the heads - we should pull the plugs, and pour some Kroil penetrating oil in each cylinder, wait 24 hours, turn the crankshaft 1/4 turn, pour in more penetrating oil, and repeat through 4 cycles. Then do an oil change, including a half quart of Marvel Mystery Oil (or Sea Foam), and then try starting the engine.
The surveyor suggested that if the lifter is just stuck (and not compressed), that the above process would be much less expensive (and work) than pulling the heads.
Kroil is difficult to get - and it's EXPENSIVE. Researching it on the internet, it appears that Liquid Wrench does about as well (or maybe slightly better, depending on which test you look at) - for much less $$. In this case, it's not really so much about the money as availability. I can get cans of Liquid Wrench anywhere.
Would spraying Liquid Wrench into the spark plug hole and turning the engine have any chance of making the problem worse? How much should I spray in? A good squirt, or a good LONNNNNG squirt? (Is there such a thing as too much?)
Would spraying Liquid Wrench into the spark plug hole and turning the engine (letting it penetrate for each turn as described) be likely to help? Or is this kinda' like spraying carb cleaner into a carburetor and hoping that you won't have to rebuild the carburetor??
How is pouring any kind of lubricant into the cylinders going to get to the lifters?
It would be interesting to know what you exactly mean by a rattle as that is a very generic term. Sticky valve lifters are more like a click. A tinny sound might be a cracked damper plate on the transmission or a rough running engine.
Normally a stuck lifter will not be a loud rattle. It is more likely that you have a stuck valve or even a couple. It is also possible that you simply have a misfire and the rattle you are hearing is actually the transmission gears making noise from the rough running engine.
If you have a stuck valves(s), these will cause the push rods on the associated valve to make a pretty significant noise. The big block Chevys have canted valves so sticking valves may cause valve damage as the stuck valve head will make contact with the piston as it come to top dead center.
To check for this condition, you remove the valve covers and check for a bent push rod, rust around the valve stems, and valves that do not rapidly return as the push rod moves it.
I would be rotating the engine by hand to investigate what is wrong with your engine. I would not be running it as it sounds like there is more going on then you realize.
Pulling the plugs is a good idea and I would be specifically looking for a beat up plug electrode, indicating a dropped valve. A rusty spark plug would also be a sign of possible further engine corrosion damage. It would also be good if you inspect each cylinder with a bore scope, checking for severe bore rust, damaged piston tops, and possibly a valve head buried in a piston top.
You do not need to remove the heads to get to the valve lifters. You do have to remove the intake manifold if you go this far. You should not have more than a few stuck lifters. If you do, it is very likely that there is something wrong like coolant in the crankcase that put water/anti-freeze in the lifters on the problem engine. If this has happened, all of the lifters will need to be replaced as they are likely all seized from corrosion. It also means the coolant is finding its way into the crankcase. This leads you to a blown head gasket, cracked head, bad exhaust riser(s), and or bad exhaust manifold(s).
There is also the possibility that you have no oil pressure making the lifters all make noise. Have you verified that you actually have the specified oil pressure? There is also the possibility that the "rattle" you here is a spun rod bearing though this would be a knock. Have you checked your oil for metal particles?
I am somewhat concerned with the advice you have been given. As Jim said, how does oil in the cylinders lubricate the valve lifters? Pulling the plugs and the oil is a way to try to get stuck piston rings unstuck and or to help get rust off the cylinder walls. Even by doing this, it really is a salvage operation if that is the internal condition of the engine.
I would suggest that you go slow and be very methodical with this engine. You have a very wide range of what could be wrong and just diving in will only slow you down in determining what is wrong and will likely cost you wasted hundreds of dollars. A very thourough visual inspection doing the above things I suggested will give you a good assessment of what is going on and give you a good indication of where you will end up cost wise.
I agree with all the above. There is no way for lubricant to get from the combustion chamber to the lifters. bad advice. Taking off the heads on those motors is also bad advice. They are accessible in the lifter galley. Remove the intake manifold and they are right there. Start with the valve covers. Without watching the pushrods and rockers, you have no real idea of what is going on below. If you are really sure its collapsed lifters, try the Marvel. It works sometimes. The lifters are just little hydraulic pumps. They can gum up. The marvel sometimes frees them up. Good luck, but no are-sols in the spark plug openings :)
BTW: Kroil is very easy to get on their site. It may be more expensive that the others, but the difference is it works. IMHO
Thank you all for the insight and advice. Yes, proceeding slowly definitely seems to be called for. I have a usb camera - will be interesting if that will show me much in the cylinders.
Interesting side note on Kroil - I saw a number of YouTube posts where people did experiments to compare Kroil vs. PB Blaster vs. Locktight, Seafoam, and others... All acknowledge that Kroil has a serious cult following. All also acknowledged that Kroil was roughly 4X the cost of some of the others. The tests seemed to indicate that there wasn't a huge amount of difference in the performance.
Remember, if you think it is the lifters, all you will see in the combustion chamber is valves that are not opening. The real story if it is the lifters, will be seen under the valve covers or in the lifter galley under the intake manifold. I also think that at this point of diagnosis, I would be doing a compression test.
I also agree with Ron, you need to define this noise a little better. You could be chasing something that is not internal engine related at all. Get out your stethoscope and go listening.
Good luck and keep us posted
Whomever says you have to remove the heads for stuck lifters need NOT be in your engine room. (or your wallet)
Valve Covers and Intake Manifold is all you need for lifter access.
This boat was a non running boat when the John bought it. Low hours on the Hobbs, etc. Apparently sat for years without running. If you go look at his early posts in Feb. you can see where he started and has come to today.
I suspect that there is much more wrong then stuck lifters on the one engine.
I bought the boat in early March (3/10/20). My buddy pulled the carbs and rebuilt them, then we waited to have the boat hauled out for bottom work. The boat was on the hard from 4/3/20 till 7/17/20 (over 3 months!!) for the boatyard to grind the bottom down to fiberglass, repair a TON of blisters from small to over 3", some stretching out in a string. New epoxy barrier coat was applied (they claim 4 coats), and new bottom paint was applied (they claim 3 coats). The thru-hulls were replaced. I was not allowed on the boat - only the yard could do the work, and they weren't nearly competent enough to rebuild the thru-hulls. I have new Marelon thru-hulls. They also replaced the supports for the swim platform.
Before the boat was hauled, we were able to get both engines to start (not run solid, but at least start). The port engine sounds like it has a lifter issue. It is clearly in the top of the engine, and not in the transmission.
Now that the boat is back in the water, my first job was to remove enough of the carpet to reveal the hatches over the port engine. Now we have access to work!!!!. I also replaced the old florescent light in the engine room with a new LED shop light. Ed pulled off the old water pumps, and is rebuilding them with the "minor repair kit", and replacing the bearings in the water pumps. I've ordered new belts, and new hose. We hope to be able to have all that back together this weekend. The water pumps were a top priority, due to the age of the impellers. Ed said they were both "shot".
With rebuilt water pumps, clean carbs, new belts, new water hose, and new batteries, we'll hopefully be able to start the engines again. The valve covers appear to be easy to remove. Depending on what we see, we can remove the intakes if necessary, and then (only if necessary), remove the heads if they need work.
Hopefully in a week or so, I'll have more to report. If we have to do much with the lifters, I'm hopeful that we'll be able to resolve that in several weeks. We'll see how it goes...
The whole boat needs an entire restoration. About the only thing that works is the refrigerator (and I'm not holding my breath!).. The AC's need to be replaced, along with the heads. The entire plumbing system is suspect. The entire 12V electrical system is suspect at best - none of the DC cabin lights work, none of the running lights work.
The boat has one of those "ancient" Lorance depth finder units with the concentric rings, and the light that flashes on the ring to tell you the depth. The one on the helm at least powers up. There's a second display in my bin of stuff - no idea if it works or not. If anyone knows of a maritime museum that would like one, let me know.
I'm also planning to see if I can clean up the old Groco seacock/strainer combo units. Even though I couldn't reuse them on the boat - they look really cool, and I'd love having one on display.
You may want to take the valve covers off and measure the valve movement the cam may be worn. I know ours was way worn on a couple of lobes with fairly low hours probably from the previous owners not running any Zinc in the oil just a guess