Anyone know if I can use automotive rings on my 4.3 LX Gen+

[fatcity94]

So the iron piston rings I ordered through advanced auto for $43.00 don't fit my engine. I found the correct part from mercruiser for $129.00 it part 8018611. My guess is that the mercruiser part is also just a cast iron ring and no better quality then the advanced auto "Sealed power ring" that's approx 1/3 the price. The other nice thing is that unlike mercruiser, sealed power actually gives you the specs of each ring so you can mic it and get the right ones. With mercruiser I think they just give you the part number with no details about what you are getting.

So does anyone know what the GM equivalent is to mercruiser part number 8018611

 

[Chris51280]

Look at summitracing. that's where I got mine. Different quality available but stock is fine. They have them for over bored pistons too. Just make sure you got your gap and orientation right at install. It's a GM engine so also GM pistons and rings

 

[Chris51280]

https://www.summitracing.com/search...ortBy=Default&SortOrder=Ascending&keyword=4.3

 

[fatcity94]

none of them seem to be an exact match. My top and second ring measure 1.44 mm and my bottom ring (oil ring) measures 2.87 mm. The closets I can find on summit racing is 1.5 mm (top), 1.5 (second) and 3.0 (oil ring). The oil grove in the piston itself is only 2.97 mm, so I am afraid it won't work. Any thoughts.

 

[Scott Danforth]

if you need rings, you also need new pistons and will need to bore and hone the block.

that begs the question, why are you replacing the rings and not doing a proper re-build? most of the times if a ring goes, the piston skirt has collapsed and the walls are no longer round

Volvo Penta gets the motor complete from General Motors. the Tonawanda engine plant in new york to be very specific.

your rings would have been the same as the 4.3 in the same year truck. you will need to get GM rings for GM made pistons.

rings are seal power and specially specified for the GM "RPM" (Revised Permenent Mold) pistons used after 1995

I believe these are the rings. you will need to verify https://www.gmpartsdirect.com/oem-parts/gm-piston-rings-88894219

 

[Chris51280]

As scott is right about doing it the right way and rebuild it with boring and honing and new pistons. This is absolutely the right way to do it. If you have a an old very used block, than this would be the right way

I just deglazed the bores from my donor block and since it had already 60 over, I just went ahead and replaced rings.

 

[Rick Stephens]

When I bored my 4.3 I found it was much cheaper just to purchase the matching piston n ring set for a 350 V8 and toss the extra pair. I can't imagine wanting to purchase repackaged and expensive Mercruiser branded stuff for internals.

 

[fatcity94]

I took the motor out if the boat because a spark plug had basically rusted off into the cylinder head. I ended up having to take the head off and bring it to a machine shop to have the plug removed. The rusting was caused by a manifold leaking sea water onto that part of the engine. Since I had the engine out and the heads off, I decided to disassembled it a bit further and removed one piston for inspection purposes. I brought the block to a machinist and he told me the engine was in good shape. I have homes the cylinders and plan on using a dial indicator to measure the bored, but I don't anticipate any issues.

 

[Bt Doctur]

Rings are ordered for the bore size to match the size of the piston.You just cant put oversized rings on a stock piston.Plus you must check the end gap on any ring you plan on installing

 

[Chris51280]

You can just order new pistons that will fit your new rings. That solves the problem of trying to match rings to your piston. What year is your engine. what is the engine code

 

[Bt Doctur]

any particular size he should order? .005,.010, .020., .030
Pistons are selected AFTER the bore has been measured, honed or bored . The new pistons will come with the correct size rings.

 

[fatcity94]

Not looking to by new pistons. Why stop there, why don't I buy a new motor. The new motor will come with piston and rings. Wait, why don't I just buy an new boat. The new boat will come with a new engine. Wait, why don't I just buy an mansion on the water that has a boat that conveys with the property. I am being ridiculous of course. I know there are a lot of perfectionist on here that want to overthink everything. Sure there is a small possibility that I may run into trouble not spending tons of money having the entire engine rebuilt, however I believe this to be basically in good condition. A engine builder who builds several thousand dollar motors for race application said it was a good motor. I am just looking for the GM rings to put back into the motor. I have not bored the block, simply honed the cylinders a bit (not enough to require new pistons).. It's a 5K boat at best. I am not looking to do something unnecessary. I'll probably just order the mercruiser rings for approx $129.00 even though they are probably no better then the $45 dollar rings at autozone for car/truck version of this motor. The only difference is probably that they say mercruiser on the box. I was hoping someone could tell me the Summit racing version of part 8018611. I believe an earlier post sent me a link but not sure if ist the correct ring or not. The reason I not sure the link Chriss sent me will work, is because the specs of the rings don't match exactly what I measured. Maybe because mine are slightly worn....IDK. Eiether way it's not worth the time or money to find out simply to save $60 -$70 bucks. The man got me this time. Oh well.

 

[fatcity94]

I just order the mercruiser part. Got them for $107.00. Not worth taking a chance. Thanks for trying guys.

 

[Chris51280]

I hope the rings fit. If not I hope you can return them

 

[fatcity94]

So I am totally pissed. What a scam. I hate Mercruiser. So I got the package from ordering the official Mercruiser Ring set part number 39-8018611. Guess how mercruiser defines a set? Yep, you got it .....one piston worth. For over $100.00 you get a ring set for one piston. So I guess you have to spend well over $600.00 if you want to put mercruiser official rings back into your engine.

Maybe not a total loss because maybe some info can be gathered from this rip off. I can not find piston rings that have the exact same measurement as my rings. Again my old rings measure top 1.43mm, middle 1.43mm and finally oil ring 2.89 mm. The mercruiser part that came in today ( one cylinder worth) measure Top 1.45mm, middle 1.45, and finally oil 2.91mm. IMO these are very close. The only rings I can find buy going to summit, or hastings website seem to be the following. Top 1.5mm, middle 1.5mm, oil ring 3.0 mm.

So the one million dollar question is weather or not the 1.5 and 3.0 rings at summit will work. Is the variance negligible?I certainly do not want to spend another $500 to get the rest of the mercruiser part 39-8018611?

 

[Scott Danforth]

mercruiser repackages the GM rings and charges about a 5550% markup

those are GM spec'd sealed power rings originally made at the federal mogul plant in Manitowoc WI.

FYI - the rings aint metric, they are imperial.

go to your local GM dealer for rings for the factory pistons. or get a new set of pistons and rings for about $200

 

[fatcity94]

That's odd that most of the measurements for the vortec replacement rings are in metric. I think I have it narrowed down. My boat is a 1996, so I looked at the rings available for a 1996 chevy astro van 4.3L. It appears that there are not that many different sets after all. There are lots of part numbers, but they are simply oversize and undersized options so most of the part number is the same. So for the Sealed Power it is E920K and for the Hastings set it is 4862. Both of these sets give there measurements in metric being 1.5 (top and middle) and 3.0 mm for the oil ring. The only odd part number given for the 1996 chevy vortec is the one that advanced auto sold me that created all this confusion in the first place and that is Sealed Power E-229X (WRONG PART). IT WILL NOT WORK IN 1996 MERCRUISER VORTEC 4.3LX GEN+.

I believe if I would have purchased E920K from the onset I would never had started this discussion. The specs for both Sealed Power E920K and Hastings 4682 are 1.5 mm (top and middle) and 3.0 oil ring. This is slightly different then what my old rings measure 1.45mm (top and middle), however when I convert to standard the difference ends up being .002 inches. A piece of thin binder paper is .009 inches for perspective. My rings now seem to have a little clearance, so I don't think the .002 inch thicker part will create a problem. I am going to purchase a feeler guage and see if .002 inches plus my current rings easily fit into the piston groove and if they do then I will go ahead and order E920K. Any thoughts.

 

[Chris51280]

If it is a 4.3 engine then this would fit:
https://www.summitracing.com/parts/slp-e-920k/overview/

 

[Chris51280]

seems like they made them with metric rings at some point. wonder why

 

[Scott Danforth]

same reason they call 4.000" bore 101.6mm