can I use automotive piston rings in L6 Mercruiser

[rabristol]

I have an inline 6 Mercruiser (Chevy 250 CID). Can I use automotive Rings? Are the ones sold for marine use better?


Thanks

 

[Haut Medoc]

Re: can I use automotive piston rings in L6 Mercruiser

There is no such thing as marine rings, to my knowledge....​

 

[Bondo]

Re: can I use automotive piston rings in L6 Mercruiser

Ayuh,....

Basically Speaking,...

The Internal parts of your Mercruiser I6 are the exact same parts as a Chevy pickup truck of the same Vintage........

 

[mcleaves]

Re: can I use automotive piston rings in L6 Mercruiser

But if there WERE a difference, why would you be interested in using automotive? Please tell us it's not to save a buck.

M

 

[KaGee]

Re: can I use automotive piston rings in L6 Mercruiser

But if there WERE a difference, why would you be interested in using automotive? Please tell us it's not to save a buck.

M

While I understand the basis of your post, what difference does it make to you what another decides is acceptable for their situation?

My factory manual has an * beside most of the engine internals saying to consult your local Chevy parts dealership. For non-fuel/electrical/safety related parts, what's wrong with a backyard-hack saving a buck if possible?

 

[starsnstripers]

Re: can I use automotive piston rings in L6 Mercruiser

I do it all the time if i can save a buck and not cause a safety or CG regulation problem, then yup there are some things you can save on and get near the same result. The internals should be the same except maybe the cam on some engines but on the l6 i'm told their so close to the truck motor you wont tell the difference. The newer v6s v8s i think are more crutial and a must for a marine cam for optimum performance anyway. I'm just boating and sport fishing so my 250cid truck engine should do fine. I'm not sking or in a big hurry. Put the rings in and git r done!!! The season is just about here!

 

[MikDee]

Re: can I use automotive piston rings in L6 Mercruiser

Back in the mid 80's I rebuilt my 1972 -165hp/250cu in 6cyl. Mercruiser which was siezed from saltwater intrusion, using 3- Speed Pro pistons, and Speed Pro rings, and a Speed Pro gasket kit, from the now defunct local U.S. 1 Auto Parts store, they were original equipment replacements, and to my surprise, they were an exact match to what was in the old Mercruiser block.

 

[mcleaves]

Re: can I use automotive piston rings in L6 Mercruiser

While I understand the basis of your post, what difference does it make to you what another decides is acceptable for their situation?

My factory manual has an * beside most of the engine internals saying to consult your local Chevy parts dealership. For non-fuel/electrical/safety related parts, what's wrong with a backyard-hack saving a buck if possible?

Because if I went through the trouble and expense of tearing down a block to get to the rings I'd sure as hell want what the OEM specified in there, especially over the small cost of rings!

Just trying to understand the reasoning. This isn't the same as using an OEM oil filter for 10.00 and getting one from NAPA for 5.00.

If the manual says it's interchangeable go for it. But in this case the post seems like a "can I get cheaper parts" post, not a what is interchangeable. There are some things that are just not worth screwing with.

So I just wanted to know why. Clearly the OP had an idea there might be marine specific rings (even though there isn't) and was still asking if he could use automotive. If you have that idea why do you head down that path over something like the cost of rings?

I am not questioning the choice of interchangeability where there IS no difference. I am questioning why one would want to interchange parts where there IS a difference, especially with a labor intensive part like rings

 

[Mkos1980]

Re: can I use automotive piston rings in L6 Mercruiser

Geez, all the guy did was ask if he could use automotive rings. He didnt know if they were the same or differant. He didnt say he was going to use automotive ones if they were differant.

 

[mcleaves]

Re: can I use automotive piston rings in L6 Mercruiser

Read the post. He asked if he could use automotive. And he asked understanding there may be a marine version. Rings are cheap in the grand scheme of a teardown. I just want to know why someone would do that.

Guess you aren't allowed to ask questions here.

M

 

[mkast]

Re: can I use automotive piston rings in L6 Mercruiser

OEM specified in there

The Mercruiser OEM ring is the stock ring used by GM in that motor.
Mercruiser comes up with a specification, xxx horsepower in a four, six or eight cylinder engine. Any engine manufacturer (man.), who feels like one of their engines can fill the bill will submit a price per unit (for xxx,xxx units) to Mercruiser. The cheapest bid is usually the one Mercruiser takes (a horsepower is a horsepower is a...). Now, the engine man. doesn't setup a different engine assembly line to produce engines for Mercruiser. The engine man. takes the engines off the existing line, paints them black, then will add the marine accessories (water pump, dist, starter...) to the engine. The block, heads an internals are EXACTLY the same as the truck/car engines already being made.

 

[SuperNova]

Re: can I use automotive piston rings in L6 Mercruiser

A better question would've been whether or not to use standard cast iron rings or go with the moly-faced ones. Not that I am asking; I'm just saying it would've been a better question if it was a question of cost.
--
Stan

 

[mcleaves]

Re: can I use automotive piston rings in L6 Mercruiser

The Mercruiser OEM ring is the stock ring used by GM in that motor.
Mercruiser comes up with a specification, xxx horsepower in a four, six or eight cylinder engine. Any engine manufacturer (man.), who feels like one of their engines can fill the bill will submit a price per unit (for xxx,xxx units) to Mercruiser. The cheapest bid is usually the one Mercruiser takes (a horsepower is a horsepower is a...). Now, the engine man. doesn't setup a different engine assembly line to produce engines for Mercruiser. The engine man. takes the engines off the existing line, paints them black, then will add the marine accessories (water pump, dist, starter...) to the engine. The block, heads an internals are EXACTLY the same as the truck/car engines already being made.

My post agreed there IS no difference. That isn't the issue. The issue is the OP thought there MAY be a difference and wanted to know if he could use automotive instead of OEM (were there to be a difference).

So my question stands. Why would you do that IF, and I'll say it really loud in big letters, IF there WERE a difference, especially with something like rings.

Never said there was a difference, and I know there isn't. I agreed with that.

 

[SuperNova]

Re: can I use automotive piston rings in L6 Mercruiser

The engine man. takes the engines off the existing line, paints them black, then will add the marine accessories (water pump, dist, starter...) to the engine.

I think Merc gets the longblock and adds the marine accessories themselves...along with the paintjob. Other than that, I agree 100% with the rest of the statement. It's the parts sellers that have everybody so worked up about marinized engines. I even popped the core plugs out of my '86 4.3L once and they were the regular silver steel ones- not brass. And I have yet to see a "marine" headgasket that was any different than than any of the laminate style automotive gaskets.

 

[Mkos1980]

Re: can I use automotive piston rings in L6 Mercruiser

Hes allowed and he got a good answer. He didnt need to be thrown in the corner with this "But if there WERE a difference, why would you be interested in using automotive? Please tell us it's not to save a buck."

 

[SuperNova]

Re: can I use automotive piston rings in L6 Mercruiser

So my question stands. Why would you do that IF, and I'll say it really loud in big letters, IF there WERE a difference, especially with something like rings.

Simple...you wouldn't..and that is why he was asking if there was a significant difference....to make sure he could use the automotive rings with no ill-effects. Seems like a simple question to me. I think you're reading too much into it for no real purpose other than to make a point only you care about.

 

[mcleaves]

Re: can I use automotive piston rings in L6 Mercruiser

I meant MY question apparently is not allowed. You post further suggests it's not.

Maybe you all missed the thread on the EFI conversion. Sure liked like it was OK to question why someone would do something over in that one.

Why don't you guys let me know what's OK to ask and not ask.. I refrain from posting until I get some clarification on the rules. Seems pretty ambiguous to me from this point of view.

M

 

[mcleaves]

Re: can I use automotive piston rings in L6 Mercruiser

Simple...you wouldn't..and that is why he was asking if there was a significant difference....to make sure he could use the automotive rings with no ill-effects. Seems like a simple question to me. I think you're reading too much into it for no real purpose other than to make a point only you care about.

You are right. I do care about whether someone would go through he trouble of tearing down a block, get to the part where you are going to change an inexpensive part like rings and consider using an automotive equiv when there may be (in his mind) a marine rated version. That concerns me. If there is reason other than being cheap (and foolish) I wanted to know what it was. There may have been a legitimate reason for him wanting to do it that way which is not cost related which IS interesting to me. If it is cost related, well, I feel calling him crazy is in line. Or do your guys think it'd be great to do it also. Again the marine version does NOT exist, but in the original post the question was asked thinking it might.

I asked a simple question. Why would you want to do that. All I am getting is flames.. Bizarre

M

 

[starsnstripers]

Re: can I use automotive piston rings in L6 Mercruiser

Right! And if there was a marine version he would most likely use them! Geesh, We dont need to disect a simple question. IMO People like to know their options is all.

 

[rabristol]

Re: can I use automotive piston rings in L6 Mercruiser

It is about money; however, I will not compromise in reliability. I have four kids to take care of and money is a factor. A good set of automobile rings go for $60 and the marine set for $160. A savings of $100 is a lot to me; however, I will not compromise on quality. If the automobile rings are the same I will use them, If not , I will buy the rings from a marine dealer.