inside look at cylinders MCM 165 (470)

[natemoore]

I'm not liking what I'm seeing, but I also don't have a lot of experience as to what is acceptable or not.

What do you think? Should I go ahead pull the engine and rebuild it?

Here are some pictures: http://s622.photobucket.com/albums/tt308/natemoore_2009/pistons%20cylinders/?albumview=grid

The whole reason I'm at this point is that I was troubleshooting a vanishing coolant/steam upon start up issue, and I validated that suspicion. You can see the areas where it looks like coolant discolored the sleeve.

 

[Don S]

Re: inside look at cylinders MCM 165 (470)

What does the valves and seats look like. Something has been in there that shouldn't have been. Are those grooves deep? some look like it. I would sure pull the pistons and have a look at the piston and rings. You may even need to have it bored. Just don't forget, it is a 470. How much do you want to sink into it?

 

[JustJason]

Re: inside look at cylinders MCM 165 (470)

looks like somebody droped a nut down the carb.

 

[natemoore]

Re: inside look at cylinders MCM 165 (470)

What does the valves and seats look like. Something has been in there that shouldn't have been. Are those grooves deep? some look like it. I would sure pull the pistons and have a look at the piston and rings. You may even need to have it bored. Just don't forget, it is a 470. How much do you want to sink into it?

Valves are here:
http://s622.photobucket.com/albums/tt308/natemoore_2009/valves/?albumview=grid

Well, I suppose between $1K and $2K. I'm doing all the work myself except for the machine shop work. I really don't have a choice to not rebuild unless I just want to turn the boat into a planter. Are there alternatives?

We paid $3600 for the boat, which is in really good shape, so if we're $5600 into it and we have a "new" boat (with no 72 month financing), then that is acceptable to us.

What "NLA" is going to bite me in the butt when I do this overhaul? It seems I can still get plenty of parts for it still.

 

[Don S]

Re: inside look at cylinders MCM 165 (470)

What "NLA" is going to bite me in the butt when I do this overhaul? It seems I can still get plenty of parts for it still.

I have no idea, I don't catalog what Merc has and doesn't have.
You might try this link, locate your engine and check on the parts you need. It will tell you if they are NLA or not.
http://www.crowleymarine.com/parts.cfm

 

[gettin'even]

Re: inside look at cylinders MCM 165 (470)

Valves are here:
http://s622.photobucket.com/albums/tt308/natemoore_2009/valves/?albumview=grid

Well, I suppose between $1K and $2K. I'm doing all the work myself except for the machine shop work. I really don't have a choice to not rebuild unless I just want to turn the boat into a planter. Are there alternatives?

We paid $3600 for the boat, which is in really good shape, so if we're $5600 into it and we have a "new" boat (with no 72 month financing), then that is acceptable to us.

What "NLA" is going to bite me in the butt when I do this overhaul? It seems I can still get plenty of parts for it still.

I am in the same boat............Kinda funny I just typed that. Anyways, I too just purchased a boat with a 3.7 Merc that I was told "RUNS GOOD"............Runs so good, the engine is dis-assembled on my garage floor as we speak after a couple miles on the local river. Mine wasn't eating coolant, but does have some scoring of the cylinder walls (similar to yours). I found this after pulling the head (engine still in the boat). I yanked the shortblock out when I saw the shape of the cylinders, as I knew that the engine needed a complete rebuild. I found broken pistons, piston rings and worn main bearings......


Parts for this engine are readily availabe. Alot of the internals (as well as the head) appear to be big block Ford stuff. Not exactly NLA, if you know what I mean. I found a piston/ring/bearing kit on E-Bay that uses brand-name parts for the 3.7 Merc for about $350.00. Also have seen several Reman heads on E-Bay.
My advise would be to have the block, head, cank and rods checked by a reputable maching shop, to make sure they are all useable. Also....check the camshaft where the oil/water seals ride. It's probably grooved/pitted. This can be fixed with Readi-sleeves.

Good luck to you...Looks like we both need a bunch of it!

 

[dr_bowtie]

Re: inside look at cylinders MCM 165 (470)

those verticle marks are normal scuffing....there isnt a real air cleaner on the engine and normal air debris can cause that...seen plenty of racing engines with the same thing...

I would be more concerned with the marks on the piston and how they got there...

as long as you dont find anything still in there in any of the cylinders and the scuffing isnt deep it would be fine to run....

I would have done a compression test before the tear down and see what is was...if it was still in spec with would be fine...

I have had some with scratches in the bore and it was only down 10psi on cylinder pressure...

but it's iffy either way...chances are you can rebuild it and after a few seasons it is going to look like that again...

I can see where water has sat in the cylinder by the rust ring...so water has been in there before and the rust being scraped off can have definetly made the scuffing marks....it got in the rings and the rings constantly turn while running....

 

[natemoore]

Re: inside look at cylinders MCM 165 (470)

I did a leak down and compression test before on a different thread.

http://forums.iboats.com/showthread.php?t=335145

 

[natemoore]

Re: inside look at cylinders MCM 165 (470)

I am in the same boat............Kinda funny I just typed that. Anyways, I too just purchased a boat with a 3.7 Merc that I was told "RUNS GOOD"............Runs so good, the engine is dis-assembled on my garage floor as we speak after a couple miles on the local river.

My forensic investigation revealed a gallon of antifreeze stashed behind the doghouse. Hmmm. Do you think the guy was aware of an overheat/coolant loss problem? I also noticed some crosshatch hone marks on the #1 cylinder, which makes me think someone recently broke down the engine and maybe began to rebuild it, but then said "oh, screw it, I'll just put it back together and dump it on someone." Who knows. 20/20 hindsight: I should have gone home and researched engines for a day or two, but when you're looking at a beautiful boat with the wife and kids and "someone's coming to look at it later this afternoon," and you tend to trust people, we bought it.

Please post ALOT of information about your rebuild...you know, that GOTCHA stuff you always encounter.

Nate

 

[gettin'even]

Re: inside look at cylinders MCM 165 (470)

My forensic investigation revealed a gallon of antifreeze stashed behind the doghouse. Hmmm. Do you think the guy was aware of an overheat/coolant loss problem? I also noticed some crosshatch hone marks on the #1 cylinder, which makes me think someone recently broke down the engine and maybe began to rebuild it, but then said "oh, screw it, I'll just put it back together and dump it on someone." Who knows. 20/20 hindsight: I should have gone home and researched engines for a day or two, but when you're looking at a beautiful boat with the wife and kids and "someone's coming to look at it later this afternoon," and you tend to trust people, we bought it.

Please post ALOT of information about your rebuild...you know, that GOTCHA stuff you always encounter.

Nate

Hey Nate,

Here's where I'm at in the rebuild process, as of this afternoon.....


I dropped the block/ main caps, pistons/rods, cylinder head and crankshaft off at the machine shop. "Al" the machinist gave a quick look at all the parts. Said it looked like the block can be saved with a .020, maybe .030 ov erbore. The crank looks like it needs to be just polished, and the head needs to be at least resurfaced (he's gonna check the valves/seats, guides, etc tomorrow). He's gonna measure everything tomorrow, and let me know the oversizes for the pistons/rings. Al prefers that I get all the parts, as it saves him from "shopping" for parts. Works for me.
Right now, I'm guessing this rebuild will cost about $1200.00 with me doing all the labor, sans machine work. Good frigin' thing the boat is in great shape, AND I got it cheap!!

Any updates/progress on your end???

 

[natemoore]

Re: inside look at cylinders MCM 165 (470)

Hey Nate,

Know, I'm guessing this rebuild will cost about $1200.00 with me doing all the labor, sans machine work. Good frigin' thing the boat is in great shape, AND I got it cheap!!

Any updates/progress on your end???

$1200 huh? I'll have to add about $200 to that because I need a compete new head because of excessive rust around #3 and #4 exhaust ports due to dripping salt/brackish water over the years. I can live with that, I guess. Better than having 71 payments left, for sure.

I secured the use of a cherry picker and I hope I can pull the engine this weekend. When you're done with your specialty tools, sell them to me for half price. Then in 5 years when you need them again, I'll sell them back to you for half that amount, and so on...

You know the tank that sits on top of the exhaust manifold? When I removed mine, I looked down into the manifold and saw a good amount of coolant. Did you have this? I guess the gasket between the two was leaking. Do you think a machine shop could resurface those two too because that looks like a critical and problem prone area to leak.

I found this awesome spreadsheet on this forum (I think) that had plenty of places to find oversized crank bearings, rod bearings, and racing pistons, etc. It might have been on the Breezeworks forum. If you want it, I'll email it to you. This guy documented the entire rebuild and got his for about $900 five years ago.

Nate

 

[dr_bowtie]

Re: inside look at cylinders MCM 165 (470)

parts are cheap...it's the machine work that kills...

cheap machine shops dont usually keep with the tolerances...or dont do them all...

I have been building engines over 20+ years and I have tried cheaper shops...I am still at the same one I started with back in high school...

if you buy pistons and/or rods ALWAYS have the recip re-balanced...with the flywheel...

depending on your engine Eagle makes or has a recip package that is cheaper than having your current stuff re-done...

I get small block chevy stuff for 5 bills...crank/rods/pistons with rings and bearing and it just needs the final balance...cheaper than doing the freshen stuff on the old...

 

[natemoore]

Re: inside look at cylinders MCM 165 (470)

if you buy pistons and/or rods ALWAYS have the recip re-balanced...with the flywheel...

depending on your engine Eagle makes or has a recip package that is cheaper than having your current stuff re-done...

I get small block chevy stuff for 5 bills...crank/rods/pistons with rings and bearing and it just needs the final balance...cheaper than doing the freshen stuff on the old...

You went over my head a little. Is this a process where the machine shop puts the crank/flywheel/pistons etc together and gives it a spin then balances by drilling here and there? I'm just guessing.

 

[dr_bowtie]

Re: inside look at cylinders MCM 165 (470)

yes exactly...

stock or aftermarket parts hold a tolerance between runs and some are out...resulting in vibration if not balanced and that wears out parts...

for the cost of the balancing it is well worth doing considering the money spent to do the job again in a few years....

 

[natemoore]

Re: inside look at cylinders MCM 165 (470)

Good info. Thanks.

 

[gettin'even]

Re: inside look at cylinders MCM 165 (470)

$1200 huh? I'll have to add about $200 to that because I need a compete new head because of excessive rust around #3 and #4 exhaust ports due to dripping salt/brackish water over the years. I can live with that, I guess. Better than having 71 payments left, for sure.

I secured the use of a cherry picker and I hope I can pull the engine this weekend. When you're done with your specialty tools, sell them to me for half price. Then in 5 years when you need them again, I'll sell them back to you for half that amount, and so on...

You know the tank that sits on top of the exhaust manifold? When I removed mine, I looked down into the manifold and saw a good amount of coolant. Did you have this? I guess the gasket between the two was leaking. Do you think a machine shop could resurface those two too because that looks like a critical and problem prone area to leak.

I found this awesome spreadsheet on this forum (I think) that had plenty of places to find oversized crank bearings, rod bearings, and racing pistons, etc. It might have been on the Breezeworks forum. If you want it, I'll email it to you. This guy documented the entire rebuild and got his for about $900 five years ago.

Nate

Hope the cherry picker reaches........... I used the forklift at work to pull the engine. I was gonna get my buddies engine crane, but it wouldn't reach.

I didn't have anti-freeze in the manifold, but the gasket was leaking (to the outside). A new gasket with some high-temp sealant might do the trick.


Keep us posted on the rebuild. I will do the same.

 

[mrsemi05]

Re: inside look at cylinders MCM 165 (470)

please do as i might have to rebuild mine when i get home from iraq. i got my boat for free with a bad head gasket right before i left

 

[gettin'even]

Re: inside look at cylinders MCM 165 (470)

Talked to the machinist today. The head is warped, the block deck is warped, the crank stills needs to be mic'd to determine if the journals need to be polished, or turned. It still looks like I'll be $ ahead if this pile of junk is rebuilt vs. getting a remanufactured engine.

 

[natemoore]

Re: inside look at cylinders MCM 165 (470)

please do as i might have to rebuild mine when i get home from iraq. i got my boat for free with a bad head gasket right before i left

Make sure you bring your head back with you!

 

[mrsemi05]

Re: inside look at cylinders MCM 165 (470)

i cant it already is gone