3.0 to rebuild or replace?? Help!

[viper122]

So Upon discovering that my engine needs to be rebuilt or replaced, I have been heavily weighing my options this past week. My current motor (3.0 liter mercruiser) has rusted cylinder walls and seized pistons. I'm trying to decide what the best and most economical choice would be for this:

1) attempt to locate a used running engine between 800-1200 and hope for the best as fAr as interal condition

2) locate a block, hAve machine shop inspect block and cylinder head, and rebuild.

I can get a lower end (block, crank pistons, etc) from a salvage yard. What would I be looking at to have it rebuilt if u use my current cylinder hEad? What would I be expecting to replace in parts and such besides for a gasket set?

Also, do I need to take this block And cylinder head to a machine shop that specializes in marine engines? I am having trouble locating one in my area- I do however have plenty of automotive machine shops around me, but can they do what is needed to the block and cylinder heAd as far as Inspection/repAir?

These are def. Newbie questions but I definitely appreciate any advice given!

 

[HT32BSX115]

Re: 3.0 to rebuild or replace?? Help!

Howdy,


And Welcome to iBoats!


That 3.0L engine is one of the best 4-bangers ever put in a boat........It's also a pretty durable engine. I would take it to a good reputable machine shop and ask them to evaluate rebuilding it. They can do the head and bore (probably needed if the pistons are seized) the block.

Any good shop should be able to do the job.

Your block should be usable if it's not cracked.

You're probably not going to find a used block in a wrecking yard.......that engine was never used in a car.....


Regards,


Rick

 

[viper122]

Re: 3.0 to rebuild or replace?? Help!

It's not an auto salvage yard, we have a salvage yard With 50+ acres of boats here that has cone in handy a few times so far. What would be a ballpark figure to get this engine rebuilt again? If anyone may know from a similar experience? And will a normal automotive machine shop be able to evaluate the block? I dont have a machine shop around me that specializes in marine engines...

 

[Fishermark]

Re: 3.0 to rebuild or replace?? Help!

A good machine shop should be able to evaluate the block and do a good job for you regardless of whether they specialize in marine engines or not. So far as the internals go - there isn't any difference. Just let them know it is a marine engine and see what they say. They can also give you a ball park figure of what the price will be.

 

[HT32BSX115]

Re: 3.0 to rebuild or replace?? Help!

I dont have a machine shop around me that specializes in marine engines...

They don't have to.......

You could find another engine out of a boat maybe......but you run the risk of getting one with a cracked block. I wouldn't expect a wrecking yard to winterize an engine in any junk they have on hand....

If you have a good block, you're money ahead to rebuild it.

A local machine shop up here in the NW gets about $1600 to rebuild a 3.0L engine. (add $500 if it's cracked) http://www.usengine.us/mercruiser.html

 

[petermarcus]

Re: 3.0 to rebuild or replace?? Help!

I have a '93 3.0L that I overhauled. It had been dunked and stored badly, but the pistons and cylinders were okay (I had the block honed, but not re-bored). I brought the block and head to a local machine shop (just a regular auto machine shop) and paid just under $300 I think. The rest I did myself (pics in the thread in my sig). Overall, I spent probably about $1500 doing it myself. That includes the shop, but also includes things like piston rings and lifters and timing cover and a new manifold/riser. Other things like the ignition coil and alternator tested out fine and I reused them. If you can find a decent 3.0L in that junk boatyard, you might be able to part it out and use the best parts from each.

(If you do go the parting-out route, make sure the engines are pretty close in year. The 3.0L and 3.0LX apparently have some differences, and some 3.0Ls have a 12" flywheel while others have a 14". Little things like that pop up from time to time).

 

[viper122]

Re: 3.0 to rebuild or replace?? Help!

My cylinders are in a fairly rusted, I am able to scrape a lot of I off with a plastic scraper so I'm confident that I could get away with honing or boring it out instead of junking it. if If it has to be rebored will I have to replace pistons with oversiZe ones? I should have pics of it up here soon

 

[Fishermark]

Re: 3.0 to rebuild or replace?? Help!

My cylinders are in a fairly rusted,

If this is just surface rust, you may get away with just honing. If that is the case, you should be able to reuse your pistons. Simply buy new rings.

if If it has to be rebored will I have to replace pistons with oversiZe ones?

Yes, if it is bored out, you will need new pistons and rings.

 

[mkast]

Re: 3.0 to rebuild or replace?? Help!

Find the local tech college, enroll in the night engine class, $100 tuition should get all the machine work on the engine finished in one semester.

 

[viper122]

Re: 3.0 to rebuild or replace?? Help!

So I callEd a local machine shop today, they told me they can hot tank and magnaflux the block for around 60 and hone the cylinders at 9 per cylinder. Boring would cost me around 18 per cylinder. They also would microm my pistons and crank. He was unsure if he could pressure test the water jackets though, but he would attempt to do so. Is this pretty essential to have inspected as well with the block? He said all of this would run me about 150 for alll work. Does this sound reasonable and is there anything essential that i should also have checked out on the block? I'm concerned that he can't do the pressure test and from what I'm reading it sounds important to have checked.

I was also thinking of bring my cylinder head to have checked for cracks and bad valves, good idea or something that I can save money and replace valves myself?

Advice and opinions greatly appreciated!