Thoughts on OEM parts VS. non OEM

Joined
May 28, 2011
Messages
61
Hi,
I just bought my first boat and like every other toy I've bought, it's a total fixer-upper.
It has a 1980 Mercruiser 470 3.7L, 170 HP. It will be our family boat, so it must be safe, dependable.....and safe. I'm not taking any short cuts to do something that's cheap for now, but will be a problem in the long run. With that said, I'd like your opinion on cost VS. quality of parts. I will be doing all the work myself, so labor is not an issue.

Right now, I have the out drive off. I've replaced the water pump and the lower shift shaft seal. I also need to replace the oil seal in the drive shaft as well as shifter cable and the bellows, gimble bearing and the steering cable.

I've rebuilt the carb and is running pretty good. The compression is 125,120, 110, 110. There is a lot of oil from the back of the engine, which I'm assuming for now is a blown head gasket and repalcing that will even out the compression. It will still be low, but usable for now.

So the questions are:

Are OEM parts worth the cost?
What other manufacturer would you recomend?
If I decide to buy an engine rebuild kit, who would you recomend.

Also,
The floors and stringer are shot. I'm thinking about Seacast for the stringers, any thoughts on that?

Thanks.
 

sharkin95

Petty Officer 2nd Class
Joined
Jun 2, 2007
Messages
106
Re: Thoughts on OEM parts VS. non OEM

But a new boat....The 470 or 3.7 was probably the worst engine merc tried to make.aluminum block with steel heads,water pump runs off of the cam and prone to wear which in turn leaks I had one I know,do yourself a favor and buy a 4.3 v6 vortec engine. if the stringers are rotton what else is?????
 
Joined
May 28, 2011
Messages
61
Re: Thoughts on OEM parts VS. non OEM

Hi,
Good point on the cam driven, water pump. If I had known what I know now, a month ago, I would have bought something else, but I'm about $1500.00 in to it now and there ain't no turning back. Plus I really enjoy taking a junker and turning it into something useful.
I recon I will probably rebuild the engine, Just to replace the cam seals and new rings and bearings.
The boat has about 900 hours on it now and has been gone through at some point. i know it needs a LOT of work, but that's what I want.
Any thoughs on OEM parts VS. Non OEM.

Thanks
 

Monte1961

Lieutenant Junior Grade
Joined
May 8, 2011
Messages
1,180
Re: Thoughts on OEM parts VS. non OEM

I have seen it both ways. A $15.00 part that That sells somewheres else for $25.00, same product but under different label. So you just got to watch! But with that being said, watch out for knockoffs, cause there generally cheaply made and not worth a sh*t!. Happy Boating.
 
Joined
May 28, 2011
Messages
61
Re: Thoughts on OEM parts VS. non OEM

Thanks,

What are some thoughts on Sierra parts. This seems to be a popular brand and easily avalable.
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: Thoughts on OEM parts VS. non OEM

On seals, gaskets, bearings and belts, there are only so many manufactures for these parts. Oem's buy them from someone and remark them. I use a lot of aftermarket parts, I just make sure that I use a quality part. There are some parts that can't be bought anywhere else but the dealer, that's just the way it is.
 

Pete104

Lieutenant
Joined
Apr 30, 2011
Messages
1,439
Re: Thoughts on OEM parts VS. non OEM

You are pretty limited on what OEM parts are available anyway!
 
Joined
May 28, 2011
Messages
61
Re: Thoughts on OEM parts VS. non OEM

Hi and thanks for the reply,
So I guess the big question now is how to identify a quality part and who to stay away from.
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: Thoughts on OEM parts VS. non OEM

Buy your parts from a quality parts store, one that the local auto repair shops use
 

mkast

Lieutenant Commander
Joined
Nov 6, 2002
Messages
1,934
Re: Thoughts on OEM parts VS. non OEM

I think NAPA sells Sierra parts.
 
Joined
May 28, 2011
Messages
61
Re: Thoughts on OEM parts VS. non OEM

Hi again and thanks for the tips.
NAPA has always been my favorite auto store, but there isn't one here for 50 miles. I've been buying from an online source and they seem to be pretty reliable. I am curious about the Sierra name brand, so far I've bought a lot of Sierra stuff, are they any good.
Again, this is my first boat and I know nothing about them. This site has been like having a boat mechanic for a best friend who lives next door.
I think I can get the boat going and on the water for another $2000.00, but buying quality parts is also very important.
 

Bamaman1

Lieutenant Commander
Joined
May 15, 2011
Messages
1,895
Re: Thoughts on OEM parts VS. non OEM

The 470 is a custom aluminum Mercury block with the head off a 460 Ford and GM electrics/carb. They were hand built by highly skilled machinists, and every bearing was custom fitted to that engine. The engine had good horsepower at medium and high rpm's, but was a little weak coming off idle--like other 4 cylinder 4 strokes. My 16 1/2 foot v hull was pretty fast on top end (52 mph), and have the torque to push a high pitch prop. The engine is very easy to work on.

My 470 dropped a thrust (middle) bearing bolt--into the oil pan--and the engine partially locked up. I had all the machine work done, but never got around to assembling the motor 10 years ago. I do have a new full gasket kit and head gasket available. I have a reconditioned head still in the plastic , a starter and other engine parts. I also have a good 1.64 outdrive, a 23 pitch stainless propeller and a set of Bennett electric trim tabs. I'm at 256-768-0599 if interested.

There are two good Mercruiser 470 motors on EBayMotors.com. The wanted $800 for one and $1100 for the other. Since your motor is not actually worn out, fixing your engine may be preferable.

Good luck!
 

kilowatts

Petty Officer 1st Class
Joined
Apr 3, 2009
Messages
299
Re: Thoughts on OEM parts VS. non OEM

Hi Guys:

My thoughts are:

With your engine most parts are NLA so you're stuck with after-market. I usually buy price for most things but for critical items I tend to go for OEM. I've read such a lot of poorly informed opinions regarding OEM vs After-market that in the final analysis it's up to the buyer. Sometimes it'll work and sometimes it won't. Good luck.

kilowatts
 

mkast

Lieutenant Commander
Joined
Nov 6, 2002
Messages
1,934
Re: Thoughts on OEM parts VS. non OEM

they were hand built by highly skilled machinists, and every bearing was custom fitted to that engine.

What?
I wonder how much a company would pay a "Highly skilled machinist", as opposed to someone off the street with eight hours training?
By "Hand fitted", do you mean some one's (off the street) hand picked up the bearing and inserted it into a connecting rod?
This reminds me of the guy who insisted his Volvo engine was built like a Swiss watch.
No, it was built like every other production internal combustion engine.
 
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