Pressure Drop on 2-Hole CLE

[Dave Strong]

Thinking the guide tube is melted to the water tube. Pics will tell the story.

Dave

[TEXAS20225]

the 3/4 is the same exact top except its got a coupler that supposed to be glued to it and dont come off apparently yours came off from being cook by the exhaust heat no water pump has a tube on the outside of the housing ive done 100's and 100's of merc lowers

[tux974]

Like mentioned above, tops are the same except for the mods, cut tube height and 3/4 hole bore.
I have personally found that a 1/2 and 3/4 top has yield the same pressure with a good/fresh water pump. The motor will only process so much water depending on your personal setup, adapter plate, stats, popet dumps etc.
NOTE: the white/clear top on left is an after market (Sierra) but is just to show the tube height.
This may help!

[WillySteve]

I'll get pics today. however I hate yanking and pulling hard enough to break something, (I'm mail order away from any part I would need), and I need to be on the water this afternoon.
Let me say this though....If the center right pic of the tube and it's collar were set at just the correct height inside the down housing and the ID of the collar were of just the correct size then the stock pump would fit inside the collar without any mods!
As far as melted? How would you get the collar over the stock pump snout to begin with unless it already would fit over it?

That's what I keep saying. This is what I have....the stock pump upper fits INSIDE the piece, (collar/adaptor/wtf ever), in the down housing like a glove.
Just FYI, I have also done 100's of v-6 mercury waterpumps. I was a service manager at Buddy's Marine in Tulsa back in the late 60's while attending school for my FAA A&P license.....not bragging in any way, just letting you know that I'm not just some dummy/piddler on this matter, (sometimes we need to know who we're dealing with before we can knock heads properly....LOL)!!!

Now, I'll say once again...This is the way this engine came from Mercury with the exception that it came with the 4-hole CLE. The very 1st time I replaced the pump....Years Ago...I remember well... I had to really study to figure out just what they'd done as I had never seen this particular setup where the pump housing went to the inside of a pipe and went up dead nuts when the LU was bolted up!
I will also say this, as you know, it makes no diff if the housing fits inside or out, as long as it seals! The original engine ran for 20 years like this.....sometimes running 25+ miles flat out on Lake Texoma with never a heating prob!
The original 4-hole had the same setup. If it had of been different then when I went with the 2-hole I would have changed it to whatever the 4-hole had!
BTW, this '95 260, Ser #OG205480 engine came with the Later style pistons & pins, early bottom guided rods and flat wrist pin washers (not stepped).....go figure....it's a Mercury!
Pics coming tonight!

[transomstand]

I'm not just some dummy/piddler on this matter

Oh yea????? Well....I'll bet I'm dumber than you

So there.

[Onetime]

Chances are the tube and adapter are just stuck on there which is quite common as the rubber dries out and locks on to them.
Sometimes would have to grab on to them with pliers to pull them out and could potentially damaged either part.
Sounds like whoever sold you the two hole CLE set it up with the 3/4" water pump housing and circumstances went your way. When you pulled the old lower the tube and adapter stayed in the mid and you bolted up the two hole that had the correct body and no adapter so it bolted up.
The factory usually used RTV silicone to seal the adapter to the pump housing. You say you put some on before reassembly so you're probably ok. I prefer to install and RTV the adapter to the pump housing before putting it on the Gearcase so I can be sure none went inside the water passages. Blobs of RTV are not good traveling around in the cooling passages. They tend to clog or restrict and you don't want that.

[WillySteve]

OK guys, here's the pics!

The pic of the white housing is a standard Seirra which I greased to see how far it went into the adapter! As you can see, it is a perfect fit lengthwise. A short housing would be too short to reach the collar/adapter.
The second (stock/with impeller) shows how far the total housing goes into the down housing. Measuring everything the depth is just about perfect.
The only thing though is the diameter of the stock outlet neck is a little small for the adapter which I've just always used RTV on it.

This time I took a 3/4 schedule 40 water pipe (which fits nice into the adapter and is a little larger than OD of the pump nipple). I cut 1/2 inch from the stock housing's nipple, used a cut off 1/2" tube's guide sleeve which fits inside both the nipple and the PVC, cut the PVC to 1/2" long (to replace what I'd cut from the nipple) and used PVC glue to attach all to the pump! Now the length is still right on and the fit inside the adapter only takes a small amount of RTV to seal!
Are we mixed up yet??? LOL
It appears that for some reason this 3/4 pipe is shorter than it should be?

[TEXAS20225]

the part that your looking at is the coupler most likly welded to 3/4 tube on mercury tops most ive seen are glued on but some are loose and the neck is a little bit shorter on the hipo models look at pixs of tonys stock 1/2 tube top has a longer neck , im not knocking heads i was just trying to help your the one with all the questions

[Onetime]

I don't think anybody is trying to knock heads here. Doesn't matter when and how it came from the factory we are all just trying to help the guy out. I think it's pretty funny when some old guys who have built many gearcases are trying to remember specifics. I know my memory ain't what it used to be!

Looks like a standard pump housing was stuffed into the 3/4 adapter. Had to push the tube and adapter up for it all to fit.

Now making adapters from sch 40 pipe, guessing out of some plastic material, and forging a new set up other than mercury's. Well now you're pretty much on your own. As I said before these engines don't like aerated water or not enough of it.

[WillySteve]

Knocking Heads was just a pun I've used for years actually meaning, getting our heads together on the same subject!!!! Sorry it evidently came across wrong as it certainly wasn't meant to be derogatory in any way!!!
Now that said, I went out this afternoon and nothing's changed as far as water pressure?
I know it's sealed good now, but it was sealed even before so the prob ain't the pump. It makes me think maybe it's not being able to draw as much on input as the 4-holer did? I did blow air through the ports while I had it apart just to make sure they were clean and clear.
It's Still at 4 pounds @ 5K and zero up to 2K but has a good steady stream out the pee tube both at idle and RPM....and definitely not getting hot!
The cooling system is completely stock 260....washers in the thermostats and just a cover on the Poppet with a 5/16 hose for a pee tube! The pressure gauge is in the top of the exhaust plate between the heads, same as it was when I had the 4-holer lower and it showed 20# at 5-6K!
Maybe my next step should be to try another pressure gauge!
BTW...I know what you mean about the jogging the old memory!!!

[Dave Strong]

Dude the 2 hole can't supply enough water, been there with the updated exhaust plate just never had press as low as you have. As long as the flow is good and it runs normal temps you should be good. Pressure is not everything.


Dave

[tlwjkw]

THIS.............

Dude the 2 hole can't supply enough water, been there with the updated exhaust plate just never had press as low as you have. As long as the flow is good and it runs normal temps you should be good. Pressure is not everything.


Dave

both my first 260's, stamped '90 and '92 were doin' good ta make 7/8 lbs at 7500+.........

[WillySteve]

UPDATE on the 2-hole CLE.
I pulled this 2-hole CLE from my 260, switched the top half of the waterpump back to a 1/2" inlet top and installed the lower on an '02 PM225x.
Initially the 2-holer had 5psi at idle and 16psi at speed. 30-45min into testing the pressure dropped back to 2-3psi.
I haven't pulled it to check because of the weather however I am presuming a blown pump gasket. Any Thoughts?

[WillySteve]

The pressure drop was found and I forgot to repost!!!!
Pressure is running normal again after I cleaned some very small pieces of gravel/sand out of the water line fitting at the head!
I should have known after seeing the immediate drop in pressure!
Thanks for all the input Guys!!!