Tips for accessing V8 block drains, 240SD MPI

RaceCarRich

Member
Oct 22, 2017
86
Boat Info
‘05 240 Sundeck
Engines
5.0L MPI Bravo 3
Out of abundance of caution, as part of my winterizing water draining, I want to drain the block directly at the drain ports... the one on each side down above oil pan rail.

Any tips on how to access on a 240SD (especially starboard side)? Do you try a reach around at the bottom or lay on the motor and try to squeeze an arm next to manifolds or....?? Is this even possible?

Appreciate advice.
 
It’s very easy.......with the manifolds removed.

Very difficult with them in place.

Here’s what I do every fall...

Remove the bulkhead in front of the motor.
Reach down to the drain manifold below the crank pulley.
The 2 small hoses attached to the rear of the manifold, slightly to starboard side, are your block drains.
I remove them and alternately blow compressed air then water into them.
This eventually clears out any muck and assured that the block actually drains.

Reattach with new hose clamps.

FYI, first time removing the hoses is a bi£€h. I removed the manifold and filed the barbs down so its easier to do each year.
 
I was thinking about the same approach but how do you know you really get all the water out? Perhaps you broke through the crud, water started flowing then the drain hole replugged? I know I’m thinking worst case scenario but I the consequences of a mistake can obviously be severe.

Do you define “very difficult” as impossible or just painful? Any tips or real world experience from anyone who has done it?

Thanks
 
If it clogs poke it again. Painfull maybe, Get a light and a mirror on it so You can see what you need.

But never done a 240 sundeck
 
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I was referring to Espos4’s method of blowing air up the hoses rather than poking which is what I want to do.

@scoflaw, are you saying you’ve been able to get to the block drains without removing the manifolds?
 
Hell yes and often. But never a 240 sundeck. Have a look-see and you'll have the answer.
 
I’ve done on other boat/motor configurations too but those seemed easier. Next time I’m at the boat I’ll have a look but looking for best practices... over and down, under and up, 4 universal joints on a flexible ratchet extension (lol) or don’t even bother trying, etc.
 
Exactly you got it, If it has all that fancy hosing that goes with the easy crack system, ditch it and go with the older style drains. Short pc of tubing OEM and the blue wingnut plug on the end make life simple in the future
 
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I was referring to Espos4’s method of blowing air up the hoses rather than poking which is what I want to do.

@scoflaw, are you saying you’ve been able to get to the block drains without removing the manifolds?
Not just air, but water as well.
I made a fitting with an old washing machine hose that connects to the block drain hoses and lets me shoot water from the hose in and stir up all the crud that settled in the block.
 
Cool!
How do you know when it’s fully drained and that it didn’t clog up again mid-drain? Does shooting up one hose cause water or air to come out the other side’s hose and vice versa?
 
First couple of times I get murky water draining out when I pull this fitting off of the drain hose. After that, it runs clear.

One hose for each block drain, and no, it doesn’t shoot water out the other side. Maybe it would if you filled the whole system with the garden hose, but I only do about 10 second shots of water at a time.

I also remove the plugs on the underside of the manifolds and flush them out as well.

Once everything Is clear and closed up, I manually fill the cooling system with antifreeze.
 
Thanks! I was thinking about doing something similar but feel more confident now.
 
I was thinking of putting a radiator petcock in the place of the 1/4" npt plug, BUT anything you leave threaded into that port will restrict that already small hole .
 
I used to have petcocks in the block drains on my race cars (closed cooling obviously), and they would still often clog and need to be removed to poke the drain holes at the end of season.
 
Thought I would report back. I pulled the two thin lines at the manifold at bottom under the engine balancer. No way they were coming off without being destroyed. Doubt they’ve ever been off before. The hose was just ripping as I pried at the nipple so I just cut them flush. One was long enough to reuse as is but the other required me to splice in a piece of hose working under the engine with my face against the valve cover. Pure hell.

Anyway, they were clogged. Using a high pressure air gun repeatedly broke through the clog. What poured out looked like used motor oil. I knew I was good when the air started blowing out through the thermostat vent.

Reattaching the hoses was also pure hell. Still waiting on the bruises to heal. If I ever have that manifold off I will definitely file the barbs down as suggested. They were made for Jiff push lock hose (no clamp needed when using that hose so very tight).

I’m still not convinced it was all necessary as none of the professional mechanics around here go to this length (I asked) hence why those hoses had never been off before. They assume some water will remain in the block and be sufficiently mixed with antifreeze. But my opinion is not here to start a debate, more an FYI.

Anyway, for the exhaust manifolds, I was told to remove the hoses from the stat housing and fill them up and that antifreeze should come out the drive water exit holes. I did that but think only a very little came out each exit. Hoses were filled. Looking at the 3 hoses going to each manifold, they all seem big enough to not clog. Other than the one I filled (on each side) from the stat housing, the other two go down to bottom were the water distribution drain is. My question is related to what could be a check valve (??) or something were the 2 hoses connect to the bottom of each exhaust manifold. What is it and could it realistically clog? Am I good as is or is there a valid reason to also pull the hoses off the bottom of the manifolds (only 2 years old)? I think I’m good but double-checking.

Thanks
 
Personally, I like to physically see that the block, manifolds, raw water pump and fuel cooler are all clear before I add the pink stuff. BUT, to answer your question about filling the manifolds... if you weren't able to get the hoses held up high enough over the manifold elbow, then you may see very little pink stuff coming out the drive's exhaust holes. Sometimes you really have to stretch those hoses out - or use the upper hose - or just quickly add a short section of scrap hose into the existing one - or even blow into the hose! There is no check valve - AF should pour out very easily if the hose is held high enough.

FYI... regarding access to things... sometimes all of these models tend to blend together for me, but I thought that the lower engine cowl (the part that touches the cockpit floor) is only held in place with a few screws and is easily removable? But I may be mis-remembering...
 
Hi. Thanks! Holding the hose higher is something I’ll gladly do .

Yes, the cowl/bulkhead was removed and I was mostly laying on the deck. Still was a nightmare mostly because of the access and the lack of compliance of the push lock hose. Still had to reach down below deck then under the engine. Would’ve been easier if I removed the crank pulley.
 
Not sure where you live, but we usually get a few “below zero” nights here in NY during the winter. Those are the nights that I sleep easier knowing that I got all the water out and the block is protected.
 
I’m right at the NY/NJ border.

I hear ya. Funny thing when I was draining the block hoses I swore I was not antifreezing the engine next year and that I would pay a pro. But then I realized that none of the pros around here would drain the block either and I’d just be paying for their insurance plan.

Just having a hard time understanding why not draining the block is good enough for the pros (doing many, many more boats) but not good enough for us DIYers. Are we being over-zealous?
 
I’m right at the NY/NJ border.

I hear ya. Funny thing when I was draining the block hoses I swore I was not antifreezing the engine next year and that I would pay a pro. But then I realized that none of the pros around here would drain the block either and I’d just be paying for their insurance plan.

Just having a hard time understanding why not draining the block is good enough for the pros (doing many, many more boats) but not good enough for us DIYers. Are we being over-zealous?
No all pros don't drain - many still drain and then backfill the system.

You got your raw water pump and fuel cooler, right?
 

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