Can ya'll explain the PO's flushing kit on my new boat?

[JonnyQuest]

There obviously are components that the previous owner added to the boat to flush the engine, but it does not look complete. Can ya'll help me out by identifying what this bypass hose is for and how I am to use it?

I have them in my online MobileMe photo gallery since there were so many shots of my engine compartment. The water flushing system parts are the last 9 (numbered) photos.

Link: http://gallery.me.com/thomasbaileyjr#100139

I can't figure this setup out and can really use the help here.

Thanks

[rigspelt]

The brass cap in #9 closes a 6" nipple that drains the coolant from the aft end of the engine block. There is another plug on that side of the engine forward, and a plug or plugs on the other side of the engine/manifold (I forget the other side arrangement offhand).

#7 and #8 show the hose discharging hot raw water coolant into the hot section of the exhaust, where it cools the exhaust gasses.

#6 might show the discharge end of coolant flow from the manifold. Is this an early model Atomic 4? That might be the bypass arrangement of an early style engine that allows for controlling the coolant temperature? But I'm puzzled and have not had time to study all the images. Woke up late and have to rush to work. You've got me curious now, so I'll study this in a day or two, unless the others get it figured out first.

[hanleyclifford]

Rigspelt is right about #6. In fact the "T" is the thermostat. I don't like this arrangement because it almost eliminates discharge into the exhaust system until the thermostat opens. The abandoned thru hull is probably the discharge side of the flushing loop - underwater, very slick. Since you are going to FWC I wouldn't spend a lot of time learning this system. I'll go back to the other thread to discuss that further.

[keelcooler]

You have a Dole thermostat w/ recirculation bypass coolant line fitted to a T equipped w/ ball valve. When the engine is cold most of the raw water is returned to the pump intake T. Your raw water intake thru-hull is a bronze ball valve fitted to galvanized reducer fittings below water…that’s a dissimilar metal mix no no, replace w/ bronze fittings. Forget about trying to fix that SS water lift, replace it w/ fiberglass type. Check, clean or replace mixer as needed and replace hot section insulation. Caution, looks like you have asbestos.

Reroute your exhaust from muffler to transom discharge. The photo shows a low sag in the hose after the 90 degree pipe fitting. After the water lift muffler the discharge hose should travel up to high point loop under aft deck and gravity drain down to transom thru-hull. I see no vented loop fitting above water line before raw water discharge into mixer. You want to install one to prevent a back siphon.

You have a late model engine and maybe two thermostats.You may want to block off side plate T hose to head thermostat and have a full flow early Dole system. The inline fuel polishing filter is best located between fuel pump and carb.

[JonnyQuest]

Rigspelt and Hanley-- that all makes sense. And you're right about not wasting too much time learning this system since I will be converting to a FWC system. However I do want to give the system a good acid and pressure flushing before the conversion, right? If so, I need to figure out how to perform these tasks on the in-place system. As far as the abandoned thru-hull, it would be best to remove the rubber hose and replace the brass 90 elbow with an end cap, right? (and that is pretty slick having the discharge through the bottom of the hull!)

You have a Dole thermostat w/ recirculation bypass coolant line fitted to a T equipped w/ ball valve. When the engine is cold most of the raw water is returned to the pump intake T. Thanks for pointing out this T is a thermostat; that clears up a lot of my confusion on what this portion was accomplishing. Your raw water intake thru-hull is a bronze ball valve fitted to galvanized reducer fittings below water…that’s a dissimilar metal mix no no, replace w/ bronze fittings. Good eye, thanks for the suggestion, I'll do it. Forget about trying to fix that SS water lift, replace it w/ fiberglass type. Ditto on the fiberglass water muffler. Check, clean or replace mixer [mixer? what does this refer to?] as needed and replace hot section insulation. Caution, looks like you have asbestos. Yep, will get a mask and wet down the wrapping for the asbestos removal, thanks.

Reroute your exhaust from muffler to transom discharge. The photo shows a low sag in the hose after the 90 degree pipe fitting. After the water lift muffler the discharge hose should travel up to high point loop under aft deck and gravity drain down to transom thru-hull. Does anyone have any handy photos of what this would look like? Not so clear to me. Would this be forming a simple loop attached to the bottom side of the cockpit sole and then sloping back down to the through-hull in the transom near waterline? I see no vented loop fitting above water line before raw water discharge into mixer. There's that mixer again...what's the mixer, and how is a vented loop fitting accomplished? You want to install one to prevent a back siphon.

You have a late model engine and maybe two thermostats.You may want to block off side plate T hose to head thermostat and have a full flow early Dole system. So the Dole system is the T fitting that goes from my manifold to the hot side piping, correct? And the side plate T hose to head thermostat--I didn't photograph that, but is it something that is inline between the water pump and the thermostat housing on flywheel end of engine? Seems like the Dole system was for early model A4s and the, uhm "other system" is for late model A4s, correct? Is this odd to have two thermostats installed at the same time? The inline fuel polishing filter is best located between fuel pump and carb. Yep. A final step I needed to tend to after replacing the carb and fuel pump in October--didn't have the proper fittings to place the polishing filter between fuel pump and carb at the time. Thanks for the reminder here too.

These are all great suggestions and a ton of them too. I highlighted my responses in blue above, as most of them I need more info for. Thanks again for all the help. this is such a helpful forum and truly a great group of users. Beers for everyone--that is if we ever meet!

I look forward to your responses.

JQ

[keelcooler]

JQ, Your mixer is at the top of the exhaust loop and wrapped w/ insulation. The mixer fitting is where the dry exhaust gas is mixed w/ the hot raw water that comes off the manifold, in your case the Dole thermostat.

A high loop to your cockpit sole level may not be adequate. Cockpit sole level may work as long as you can achieve about an 18” down hill gravity drain to the transom discharge. It does not appear you have the needed cockpit sole height to accomplish this down sloping trajectory. Accordingly you may wish to route up to cockpit seat or deck level before looping down to the transom.

A vented loop must be installed above water line. This would be installed in the Dole to mixer raw water discharge hose. It prevents a siphoning of raw water into the mixer after shut down that could fill up the water lift and flood the engine.

If you plan on installing a closed FWE system you will want to remove the Dole and use your late model head mounted thermostat system. I see no benefit in having two thermo’s. Your MMI manual has good instructions on acid and power flushes. An exhaust system search should reveal many concept diagrams of properly thought out wet exhaust systems. The best one I recall was from this old boat. Good luck.