Is this an acceptable way to flush out engine block?

[SSSuper83]

Looking to flush the cooling system on my Merc 228 before I fire it for the first time. It has brand new exhaust manifolds but older risers which I hogged out and blew out with compressed air. All the scale I could find was removed.

I still have the drive and bellhousing off. I was going to open all the drains on the engine, manifolds, and risers, and connect a water supply to the intake hose and let water run through everything to flush out any scale in the rest of the engine.

I wont cause any water intrusion problems or any other issues if I do this, correct? Just trying to be extra clean when I get it fired.

 

[bruceb58]

Re: Is this an acceptable way to flush out engine block?

Any reason you didn't just replace the risers at the same time as the manifolds? Risers last only about half the time as a manifold. You used Mercruiser gaskets betweenthe manifold and risers right? The main spot you need to be worried about is the mating connection between the riser and manifold. If the metal has worn away so that there is no longer a large sealing surface, you need to replace the riser.

As far as flushing out the block, not sure you are really buying anything by doing that unless you ran through a bunch of sand and have to try to get that out.

 

[SSSuper83]

Re: Is this an acceptable way to flush out engine block?

Any reason you didn't just replace the risers at the same time as the manifolds? Risers last only about half the time as a manifold. You used Mercruiser gaskets betweenthe manifold and risers right? The main spot you need to be worried about is the mating connection between the riser and manifold. If the metal has worn away so that there is no longer a large sealing surface, you need to replace the riser.

As far as flushing out the block, not sure you are really buying anything by doing that unless you ran through a bunch of sand and have to try to get that out.

I am only using these 3" risers temporarily to get the engine fired up on water and I block sanded the bottoms of both. All the material was still there and actually they are in pretty good condition. I have a thru hull exhaust setup with new 4" risers, just using the old y pipe for testing purposes.

The gaskets are from Barr..stainless core.

If all the block drains are open..I dont see how the water could possibly get as high as the risers unless I am mistaken. The engine I just installed has sat dry for YEARS...and was winterized with RV antifreeze initially. I have found multiple spots where the RV antifreeze has crystallized in the old bellhousing, just want to make sure the block is clean.

 

[bruceb58]

Re: Is this an acceptable way to flush out engine block?

When I say risers, I really mean the elbows. Sounds like you are calling the risers the spacers. How old are your elbows?

Also, I would not use the Barr gaskets. Mercruiser only!

 

[SSSuper83]

Re: Is this an acceptable way to flush out engine block?

No, I mean elbows too. I spent an hour with a coathanger and a wire brush getting them clean. They are prob cleaner than most out there...

The final install are 3" riser SPACERS and a set of new 4" elbows. Again, these are just temporary to get the juices flowing through the engine and facilitate driveway testing. The engine came from a 100 hour boat that was kept in dry storage for years after the PO passed away. Was bought from an estate sale.

How are the Mercruiser gaskets better than anything else, if you dont mind me asking?

 

[bruceb58]

Re: Is this an acceptable way to flush out engine block?

How are the Mercruiser gaskets better than anything else, if you dont mind me asking?

They don't leak!

 

[SSSuper83]

Re: Is this an acceptable way to flush out engine block?

They don't leak!

I guess that would be the obvious answer...but since this is only going to be temporary (as in a couple days, running on land only) I am going to use them. I will get the Merc gaskets for the final installation. Oh and I should prob remove the thermostat too correct?

 

[HT32BSX115]

Re: Is this an acceptable way to flush out engine block?

Howdy,


Is your engine in the boat or sitting on a stand or cradle?

If it's on a stand or cradle, and you wanted to flush it REALLY good, you could remove the core plugs and clean it out fairly good.


This is what I did with my 454 before I installed closed cooling. I got a LOT of sand and rust and other debris out of the (120 hr since new) engine block.

I had all the core ("freeze") plugs, water pump and T-stat removed.


Cheers,


Rick