Strainer and Water questions
 

I'm putting new drives on my 382 and they will have IMCO lowers. I am concerned about excessive water pressure, so I have two options.

1: Add a strainer with a pressure relief valve and add a water dump out the back.
2: Just add a pressure relief valve and add a water dump out the back.

I'm thinking I would rather go the strainer route which could save me some time if I ever get around to adding closed cooling, and it might save me some money later down the road anyway.

Does anyone have sea strainers for their engines on the 382? I'd like to get your suggestions (and photos if you have them) of where to mount the strainers. Also, any recommendations on where to put the water dumps would be appreciated. I'm sure I want them out the back, but debating about where on the back to put them.

Thanks,
Garrett

Re: Strainer and Water questions
 

Anyone? Buehler? :)

Garrett,

Did you ever figure out a good place to mount sea strainers? I'm thinking about adding them to mine while I have the engines out.

Hi Chris,

Sorry for the long pause. I haven't been online much. Been planning the big upgrades. :)

Yes I did. Here's a pic. Not a very good one. I'll take some more this weekend while I'm working on it. I like the way it turned out. I'd almost be tempted to pull the flip up steps out completely and move the strainers forward and use the strainers from stainless marine if I was going to do it over.

The strainers I have clog up too easily because the don't have enough surface area. I plan to put some stainless screen wire in them this year to prevent them clogging. I had this happen on the sacremento delta after about 12 boats followed a guy into a shallow area and sucked up a bunch of plant life. Geez, was that a nightmare. I also didn't put a shutoff valve on the intake side of the strainer. I may add that this year too. The problem is that if the strainers are below the water line. Take off the lid, and the boat starts filling up with water. And, I've discovered, that the bilge pumps can't hardly keep up, especially if you take both lids off at the same time. :eek:

Garrett

Garrett,

Thanks for the input. Want to add these if I can find a good location to rig them. OSO Steve recommended the Stainless Marine also ... think I will go with them.

Are you feeding water from the drives or did you go to a hull pick-up?

I kept the feed from the drives. I think there might be some advantages to adding hull pickups, but I didn't really explore it. I've also heard that it is a good idea to keep water going through the drives to help with cooling even if moving to hull pick ups. I guess that the drive water would just go straight to dumps in this case. I put dual dumps on each side and put a pressure relief on the strainer. My opinion is that the pressure relief should go on the clean water side of the strainer to prevent starvation from dumping water as pressure builds on the dirty side as the filter starts to clog.

The water intake goes through the strainer and then to the raw water pump.

The reason I chose to not use the stainless marine strainers are that they are quite a bit taller than the one I used. I can't remember now all the trade offs, but I know I couldn't mount them where I have the current ones mounted, and I *think* that I would have had to remove the flip up steps to have enough clearance for the stainless marine ones.

I have also *heard* that some of the bronze strainers are better strainers. Several of these strainer companies have been around for a long long time building strainers for off shore boats/yachts. I didn't find this out until after I already had mine in, but I think I'd check this out more if I was doing it over.

Here's a external pic of the dual water dumps. I only use one dump tube on each side with a pressure relief valve on the strainer. But, I thought, hell, if I'm drilling holes in a perfectly good boat, why not drill a couple more. :drink: I figured it would be good to have just in case I get more exotic on the power some day. Believe me, I sweated drilling those holes. Not to mention I drilled them in August last year in Phoenix. I did it at night. I drank a beer after it was over to relax. :drink: :drink: :drink:

I like the way I have mine mounted. It is solid. I used 3/4" x 1.5" aluminum bar mounted in to the aluminum that the steps are on. I used all stainless cap screws and nylock nuts w/ flat washers. If I hadn't been in such a hurry, I would have powder coated the aluminum white first, but there always time for future projects.

The new drives are on the boat in this pic. They hadn't even been in the water yet.

G.

Garrett,

How did the shorter drives work out and what are the DPM stickers on your drive? I assume someone that beefed up the drives for you ...?

Can you explain the need for pressure relief valve/water dump to me?

Thanks,

Chris

I just found this thread and am real interested in this too!!!

Russ,

See my thread in G.D. section also. Good information coming back.

Chris

Hi Chris,

I didn't have a chance to take more pics. I'm taking days off work to finish the boat. :)

DPM is ****'s Performance Marine. **** Tryce (aka Mr. Gadget on OSO) built the drives for me. They XR uppers with some build modifications that are supposed to increase lifetime of upper gears. The IMCO lowers contain all standard Mercruiser parts to make it easier to get parts if they break.

Since my drives were too low (stellings boxes were added after the original build and drives were not raised), the shorties worked out great. I was expecting to lose some speed with the XR drives vs. XZ, but I didn't. My only thought is that the 2" shorties eliminated some drag that existed from the drives being too low before.

The IMCO lowers supposedly will generate a lot more water pressure than the Mercury lowers. A lot of people run pressure reliefs to compensate.

I have seen 74.8 GPS on salt water with the new setup. I think the drive oil gets hot on long runs and reduces internal friction because it won't do that right off the dock.

Garrett

My 302 came from the factory with bronze strainers, I think they are Gils. It was all part of the Kaama package.

I don't believe that pickup tube running through the drive amounts to a hill of beans for cooling, compared to the whole leg emersed in water. On a Bravo, I'd probably run it to a drive shower if I went to transom mount intakes.

If drives depended on the water pick up tube to cool the drive, how do Trs survive so long? There is no provision for water pickups in the drives at all.

Garrett


That is the same spot I put mine. You need a valve in front of it to be able to turn off the water since they are lower than the water level. It would be safer with those. People have had the tops break before! You never know.....

Nort,

What brand of strainers did you use?

Any shots of the mounting brackets and hose routing?

Thanks,

Chris

Hi Chris......no I don't have that. When I think of it...I'll snap some shots. I forget who made them....but I know they are blue! :)

Thanks, Nort. Whenever you have time between diaper changes!:D

Hope the baby, mom, and dad are doing well!

I know. I plan to add the valves on the input side soon. It also makes it easier to clean them on the water if needed, without watching the bilges fill up with water.

Well there isn't a water pickup in a #6 drive either, but I don't think #6 drive lifetime has anything to do with Bravo lifetime any more than I think TRS lifetime has anything to do with Bravo lifetime, water pickup or not. I'm positive that drive lifetime has a lot more to do with other design decisions besides water pickups.

I'd agree that the lower unit being in the water will do more cooling than the water going up the top inside. Personally, I've never tested the temps with and with out water being picked up at the drive. I wouldn't want to bet money on it either way. I never really pursued it since I never planned to block the drive pickups. Your mileage may vary.

I like your drive shower idea.

Garrett

Generally, you aren't running the lowers when out of the water, but I still don't doubt that just air flowing over the drive when out of the water cools it more than a small tube running up the center of it.

Here's some pics
 

Finally got some pics for you guys.

The top left photo is the starboard side strainer. The water inlet is at the top and on the bow end of the strainer easily visble here. The pressure relief valve is also on the front and is barely visible right below the clamp holding the hose on the strainer. The output on the starboard strainer is a straight fitting going straight towards the stern. The hose makes a 180 into the raw water pump which is on the far right of the engine (left side and not visible in the photo.)

The second photo shows the Port side strainer. Both water hoses go in the stern side of the port strainer.

The third photo is also of the port strainer taken down between the engines. The top red hose is connected to a 90 degree fitting taking water into the top of the strainer. The bottom red hose comes out of the strainer with a straight fitting and does a loop back into the raw water pump which is also visible in the photo.

BTW, all those drops of oil and runs of oil is what happens when you leave the engine oil fill cap off one of the engines for a long run. I still don't have it all cleaned up.

More pics
 

Some More - Don't look at my dirty bilge.

This is the starboard strainer again.

Thanks for the pics, Garrett.

Are the brackets just secured to the frame of the step in the engine compartment?

Did you use stainless or aluminum brackets?

Hi Chris,

Duh, I should have photographed that too. One of the pics shows a ~1.5" (or 2"?) x 3/4" aluminum bar that the strainer mounts on and goes to the frame step and on past it probably another 8 to 12 inches. Then there is a 1/4" x 2" aluminum flat piece that goes up from the bar to the angle that is part of the step mount where the wood screws down. The 1/4 x 2 also goes down to the stringer.

I'll take another pic of the mount system, but I can't get back in the boat for about 2 weeks. :(

Garrett