NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

[ChevyPower]

Just bought a '78 boat with an older (pre '82) Chevy 305 5.0 small block. I was very anxious to get this boat and stupidly overlooked the most important thing to check for in ANY automotive purchase.. The oil.
The boat cranks up, runs, but has the infamous milky (whitish color) oil. Water mixing with oil. The water/oil level is pretty high and I've been poking around and realize any number of things could be wrong. I hooked water up and ran the engine anyways to check the condition of the outboard and realized there was water GUSHING from the risers or exhaust manifold. I'm hoping (fingers crossed) that this is my problem. Since they need to be replaced anyways, both sides, I started looking around the internet and found several of the newer style manifolds, but the only older style ones I found were WAY out of my price range.

I basically need help with two things. If anyone could help me with this water/oil mixing problem it would be greatly appreciated.

Also, if anyone knows where I can get some affordable exhaust manifolds for the older 305's that would be even MORE greatly appreciated. I would even consider a conversion to the center-style risers if the price is right

SOMEONE PLEASE HELP THIS NOOB OUT!!! LOL

 

[ChevyPower]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

bump

 

[greg82255]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

I'd convert to center risers, theyre supposedly more efficient anyways. Check out this link, you can get a set for about 400:

http://www.mooreperformance.info/Mercruisermanifoldkits.html

Whatever you do, don't buy a used set. Always replace manifolds and risers with NEW manifolds, risers, and gaskets.

 

[ChevyPower]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

I did a little research. I don't think the problem is coming from the risers. The water is gushing from where the manifold goes into the block on the starboard side. On the port side i noticed a small leak from the same area. Could this cause water to leak into the block? And if so would it cause the milky stuff to be in the valve covers too? And would it cause the oil/water levels to rise very high on the dipstick?

I've owned a car that blew a head gasket, that was my first guess. But apparently marine engines aren't that simple :/

 

[ChevyPower]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

I'd convert to center risers, theyre supposedly more efficient anyways. Check out this link, you can get a set for about 400:

If I convert from end risers to center risers what else would I need to buy? It doesn't look like they'd be an exact fit

 

[greg82255]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

Sounds like your manifolds are cracked.... A leaking manifold could definitiely leak water into any cylinder wtih an open exhaust valve, through the rings to the oil pan. Once you turn the key, all the water that got into the pan gets mixed with oil, and it turns milky and gets pumped everywhere. Time for some new manifolds and risers

 

[Riegfrghtl]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

If you live in an area that is subject to freezing temps it is more than likely the boat was not properly winterized and you have a cracked block!

 

[greg82255]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

You would also need a 4" pipe that turns down about 85 degrees to fit onto your Y-pipe. The same site I showed you earlier sells these pipes too, but they are made of stainless and are a little expensive here. You can get aluminum pipes from other places - I think CP Performance sells them.

http://www.mooreperformance.info/MercruiserV8conversionkit.html

As for the above post, he is absolutely correct. A cracked block could also be the source of your milky oil.

 

[ChevyPower]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

A cracked block is my biggest fear, it would pretty much mean the end of the line for this motor
I know absolutely NOTHING about the boats history or the previous owner. I just hope he wouldn't be that stupid.
If it's a cracked block how do I test before I go waste 500 on manifolds/risers?

 

[ChevyPower]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

Thanks greg for all the helpful links!!
It looks like I might be able to fabricate this conversion myself. All I really need to do is get a pipe with a 75 degree bend. I'm sure aluminum would work just as well as stainless. The hoses and clamps can be found at an auto store I'm pretty sure. I don't know why I didn't think of this sooner...

 

[Riegfrghtl]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

I would do a pressure test on the motor. Use the search feature and you should be able to get a pretty good explanation as to how to do it for your motor. After doing this you should get a good ideas as to what you are facing. Good Luck.

 

[ChevyPower]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

Who doesn't check the dipstick or open the oil cap before buying a vessel? Just wish I wouldn't have jumped the gun so fast. If it turns out to be the block.. I'm inclined enough to do automotive engine work, even something as big of a PITA as this. The outboard however scares me. I'm assuming that would have to come out right?

 

[ChevyPower]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

A pressure test wouldn't work if the manifolds are cracked. Would a compression test tell me the same story?

 

[NHGuy]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

No, you do want to pressure test the cooling system. Compression test only checks your combustion chambers.
I think I saw on another thread that you found block cracks, is that true? If so the other thread is your "real" one.

 

[ChevyPower]

Re: NEED HELP WITH MERCRUISER 228 (305 Chevy) RISERS!?

Yes I posted this thread before I created the other. I was unaware of the cracks in the block when I posted this thread. Thanks again!