87 mercruiser 350 / 260hp what parts do I buy for rebuild?

I recently purchased my first boat, a 19' 87 Century with 260hp & alpha one. The owner said it sat for 5 years and needed a starter. After rebuilding the starter and the carburetor it started and idled OK, but as soon as any throttle was applied it would make a tapping noise. I pulled the valve covers and took a look at everything, nothing obvious was happening.. so I put it in the water thinking it was a sticky lifter and hoping it would come out of it. The noise got worse and the engine didn't have much power. Thinking it was something more severe, I pulled the engine and stripped it down to find out it had a spun lower rod bearing and the piston was smacking the head. After further investigation, most of the cylinders are scoured and other crank bearing surfaces are damaged. Sooo, time for rebuild. Now that I've assessed the damage this is what I'll need as a minimum to get the engine back up to par (reliability and fuel economy being most important).

This is what I have for block and head casting numbers:
block:

638
A10
627
L-15
H14
5
GM 57LG
SGT
E040
14093638
V0523uSC
CHE543495

HEAD:
1410219
E090
8
88

I'm having trouble finding the volume of the heads, but anyway this is what I need help on; deciding what components to get:

* Over sized piston kit with D-dish type for .038-.040 squish clearance

* Crankshaft

* Camshaft, timing chain, lifters, oil pump, etc.

* Manifolds and risers (they have been welded)

I plan on re-using the valves and springs.

So can anyone point me in the right direction for my first 350 marine engine build? I've done lots of snowmobile, jet ski, atv and dirtbike engines but nothing like this.

You'll be okay, just keep a close eye on getting the right clearances, on piston rings, and crank bearings. A nice mild marine cam would be good here. One thing, when replacing the cam, make sure you line up both gear marks at 12 o'clock for cylinder #1, or both marks on top of one another for cylinder #6.

Ayuh,..... Buy a Long Block Crate motor,.....

You'll be Boatin', Waayyy Quicker, 'n no doubt Cheaper than yer planin' on doin',.....

bondo said:

Ayuh,..... Buy a Long Block Crate motor,.....

You'll be Boatin', Waayyy Quicker, 'n no doubt Cheaper than yer planin' on doin',.....

Click to expand...

Cheaper? Wouldn't I need an intake manifold & carb too? I really don't want to spend more than $1200 or so for everything. Not sure how much the d-dish pistons will run but for a standard rebuild kit on fleabay is about $300 then a crank for $150 and manifolds for another $300 or so.. the cylinder boring for about $200. Throw in belts and possibly an alternator and it'll be over $1000. Where can I find a long block crate motor for less / not much more? I saw US something engines and they seemed reasonable, but I don't want their baseline model and I'm thinking I can get better fuel economy + hp if I do it myself with the right piston + head gasket combo. Convince me otherwise??

OK so long block is not the same as big block. Got it, and I did consider the $1500 'long block' on US engine and some rebuilt ones on the auction website. The thing is, I'm thinking I can build my own motor better and save some money on fuel with the better pistons (since they probably use the standard dish pistons that this motor had). Yeah It'll be awhile and I probably won't even get a chance to get on the water this year but I should be able to get a better engine in the long run. Unless you guys have a secret place where you can get high quality remans for cheap, I'm thinking this is the way to go. Plus I have most everything needed already, just need to get my hands on one of those books and all of the components needed.

Good for you! You need to get in touch with RicardoMarine for advice, and maybe he can even set you up with the info, & parts you need? He's the engine guru. Send him a private message here.

I'm a big proponent of building a Q/E into this engine for any of our cruiser boats.
However, it is not as necessary for a small 19 footer....... nonetheless, I'd do it.

As for your D dished pistons, you won't be able to order these until you know the cylinder head chamber volume. Once the cylinder head combustion chamber volume is known, then your piston dish volume can be selected.
FYI:
D dish with the D shaped quench surface cylinder heads.
LCQ style with the Vortec quench surface cylinder heads.

The 1410219 cylinder head casting # doesn't come up for me. Are you sure that you have all digits?
There is a 14102191 and 14102193 being shown for 1987 to 1995 w/ 1.84/1.50. No mention of chamber volume.

As for the cylinder block, 1987 will be using the 1pc rear main seal crankshaft.
Cylinder blocks during and after this year model will allow your flywheel and starter motor to be used.


Select a camshaft profile suitable for Marine use.


When you set your cam followers (aka setting valves), do this ** prior to priming the oiling system, and ** prior to installing the intake manifold.
This will allow you to watch the cam follower plunger cup as it just begins to move downwards in the body.
This lets us locate a more true ZERO lash, IMO.

Use the 8 stop procedure.... not the 2 or 3 stop.
With the #1 cylinder @ TDC C/S, you will adjust #1 intake and exhaust.
Roll crankshaft 90*, and adjust for #8 cylinder.
Repeat right on down the firing order.

The 8 stop procedure, along with doing the above **, will prevent you from going back through these later on.

See your OEM specs regarding the fraction of adjustment nut rotation after ZERO lash.
(rocker arm ratio X's stud thread pitch X's rotation, sets the plunger depth correctly)

Once done... now you can prime the oiling system.


You will not make a mistake with the camshaft chain sprocket indexing, as long the dots align at one point or the other.
However, when you install the ignition distributor, you'll want to follow Mik's lead for #1 cylinder.




FYI: regardless of where the cam sprocket is (12:00 or 6:00), when the crankshaft sprocket is at 12:00 O'clock, #1 piston will be at TDC.
The camshaft indexing determines which stroke we're on!

For your purposes, you'll be catching this at #1 TDC C/S (C/S = compression stroke)



Have fun!


.

Looks like the heads are 14102191, 64cc D-shaped (non vortec) heads. I used a graduated cylinder ant 64cc fits into the combustion chamber cavity with a slight convex meniscus. I've been looking around and having a hard time finding the right type of pistons. Should I just go with the flat top type and call it good? Will this increase the compression too much? I can always mill some out I suppose.

Inert_Production said:

Looks like the heads are 14102191, 64cc D-shaped (non vortec) heads. I used a graduated cylinder ant 64cc fits into the combustion chamber cavity with a slight convex meniscus. I've been looking around and having a hard time finding the right type of pistons.
1.... Should I just go with the flat top type and call it good?

2.... Will this increase the compression too much?

3.... I can always mill some out I suppose.

Click to expand...

1... Only with the 76cc combustion chambers, and only with the 5.7L 3.480" stroke.
With F/T's and 64cc chambers.... your static C/R will be too high for Marine cruiser use.

2... Yes!

3.... Not adviseable.
Taking a 64 out to anywhere near 76 likely cannot be done.
Even if it could be.... it will cause problems.



With your known values.... use an online C/R calculator, such as these.
http://www.csgnetwork.com/compcalc.html

http://www.summitracing.com/expertadviceandnews/calcsandtools/compression-calculator


Know what the desired Static C/R will be..... enter your data.... and play with the numbers.
You'll be able to select a piston profile that will offer the quench, yet also the correct dish volume for your C/R.

Keep the quench around .038" for Marine cruiser use.
(the "quench" dimension is the total of the piston deck height dimension and the compressed head gasket thickness)

Any good piston manufacturer will be able to supply the correct piston for you.


.

I have a 64cc non vortec head motor too, I will be watching your build. I'm very interested in which pistons do best. From my reading it seems like a boat motor needs to keep the compression down. I think one of the calculators I used came up with a 12 cc piston volume for a standard bore to get 9.5 compression. You'll be working from larger cylinders though.
It also seems like the hypereutectic pistons will do well too. Forged are probably too much money and even more brittle than hyper. And in my limited searching I haven't seen any d dish cast pistons, do they make them?
You are smart to figure your quench in there. It allows a little more timing and compression than standard pistons. So there's more power than the dished smog pistons it was born with.
I doubt any of the rebuilders have your small combustion chambered heads with quench oriented pistons in their rebuilt stock. Not without more money.

Just to let you know Comp Cams XM262H, which they claim to be most you should put through a sterndrive, runs fine above my stock bottom end. It's even smooth, though they claim it has "noticeable idle". Maybe with loud pipes, but I don't have those.

Where would one find the compressed thickness of marine head gaskets? And do they offer different thicknesses?

NHGuy said:

Where would one find the compressed thickness of marine head gaskets? And do they offer different thicknesses?

Click to expand...

Since you are asking this question, I'll assume that you are interested in a quench dimension!

Any of the major head gasket manufacturing companies can give you their compressed thickness information. But before you ask this question and go anywhere with it....., you will need to determine what your piston deck height will be!
The deck height may need to correspond with the type of gasket that is needed and/or available.

If this engine will be fitted with a closed cooling system, a high-grade automotive head gasket will do just fine.



.

So true, but I am not doing the bottom end right now. Just some thinking ahead.

NHGuy said:

So true, but I am not doing the bottom end right now. Just some thinking ahead.

Click to expand...

Ok..... then your piston deck height is already established. You'll need to work with what you have.

Lets say that your piston deck height is .015", and you're aiming for a .038" to .040" quench.
.038" - .015" = .023"..... or .040" - .015" = .025"

So either .023" or .025" would be your target compressed head gasket thicknes.

Keep in mind that the average Marine head gaskets may not address a good quench dimension.
Some of these are around .039" or so ...... and that does not include the piston deck height.
Add .015" to .039" and you have .054"! Any chance of a good quench dimension is now out the window.

If the engine will be closed system cooled, your head gasket selections increase some.


.

RicardoMarine said:

1... Only with the 76cc combustion chambers, and only with the 5.7L 3.480" stroke.
With F/T's and 64cc chambers.... your static C/R will be too high for Marine cruiser use.

2... Yes!

3.... Not adviseable.
Taking a 64 out to anywhere near 76 likely cannot be done.
Even if it could be.... it will cause problems.

.

Click to expand...

I should have specified that I would machine the pistons not the heads. Was thinking about getting flat tops and milling pockets in each.

Inert_Production said:

I should have specified that I would machine the pistons not the heads. Was thinking about getting flat tops and milling pockets in each.

Click to expand...

Perhaps see post #9 again. The Q dimension is the sum of the piston deck height and the compressed head gasket thickness!

You will not need to machine your pistons because you will be able to find a piston profile that matches all of your criteria.

Let's say you have: 3.480" stroke..... 4.000" or 4.030" bore..... xx CC combustion chambers.

Plug your numbers into one of the on-line static compression ratio calculators.

If the heads are pre-vortec, a D-dish with xx dish volume gets you the desired C/R!
If the heads are vortec, then a LCQ style with xx dish volume (works best) gets you the desired C/R!



The only machining of the cylinder heads would be if the surfaces were not flat.