adapter plate questions..

[dwilfong]

thanks that's what I need....now is the tube just 3/4" copper?

[tlwjkw]

never checked... may be some merc "odd ball" stuff with stupid dimensions....

[texasvector]

We modded a 280 plate to work with a steel 200....plugged dump holes ...drilled 3/16 holes....plugged and relocated drain holes in block....put diverters in....poppet blocked....3/16 washers in heads

Works great

[dwilfong]

I have bin studying this 2 piece plate and it is easy to see where the water goes and the size of all the holes.
So let me ask this what size and how many holes total for the bottom dump system?

[dwilfong]

Ok let me put this out there
this is the main water passage. It is 1/2" now mill this to 3/4"


this is where the tube mounts to the adapter. mill this so the 3/4" tube , grommet and retainer fit.


This is the main water passage to the block that you se in the first pick. mill this to 3/4"
Now we have a 3/4" main water setup all the way to the block.

[outasite]

We modded a 280 plate to work with a steel 200....plugged dump holes ...drilled 3/16 holes....plugged and relocated drain holes in block....put diverters in....poppet blocked....3/16 washers in heads

Works great

I've used a small stainless aircraft washer and a large stainless cotter pin in the dump holes to restrict them.That also causes the water that goes past to spray around in the mid to help cool it,The paint don't discolor.

[tux974]

never checked... may be some merc "odd ball" stuff with stupid dimensions....

.....not 3/4 not 5/8.....a Merc special dem.
I have been wanting to check 3/4 refrigeration cooper tubing just have not had the chance!

We modded a 280 plate to work with a steel 200....plugged dump holes ...drilled 3/16 holes....plugged and relocated drain holes in block....put diverters in....poppet blocked....3/16 washers in heads

Works great

Good and important info above!!!


I drill and tap existing 3/8" holes with 1/4 NPT (go slow, check fit to not over tap and have the plug drop when screwing in place) I use stainless or brass flush plugs, red loctite and drill center 19/64 or tad smaller. I also make sure the plug is flush with surface them I counter sink to make sure water never sits in the plate when sitting.
You can also weld them and redrill to desired size..

[dwilfong]

So with the poppet blocked off. The two 19/64 holes are the only drain from the bottom of the block and the two 3/16 at the stat holes are the only drains from the top of the block?
So what is the OD of the water tube? can always turn down to size at the ends.

[outasite]

The small tube is just copper pluming tube.Im surprised the bigger one is not standard stuff. OBTW not to confuse,but this is how I control my 280 in Michigan water.You can Change the orfice size in about 30 seconds.The water sprays out behind the skirt,runs down and cools the mid.

[dwilfong]

what size tube is in the plate in your pic? small one or large?

[outasite]

Small,Our damm water is so cold here,I have not found a need to go big.Lots of 260s ran big numbers in southern water for years,before the big tubes came about

[dwilfong]

So let me ask this then why is every one saying a 2piece plate not cool the eng running over 7000 for a extended time?

[moparbarn]

David, check out the different "schedules" of copper tubing. Different schedules/pressure ratings have different wall thickness, not 100% sure if OD changes. I've got a few different diameters of schedule K (refrigeration copper) that I have used for cheater bars & bearing drivers since the early 80's, it's thick! Another thought, milling or changing hole sizes in the plate or mid is hard to reverse. Swaging a copper tube to size is easy, & leaves the rest stock. A lot easier to deal with, should you need to when you're far from home. One off unobtanium is way cool, but can be difficult later.

[dwilfong]

Robin this is my thinking......I can open up the main water passage in the plate to 3/4" and change tubes as needed. easy to change a tube but not so much milling the passage way in the plate.
As far as the dumps can block off the inside one from the poppet port ( remove the poppet valve) to the mid chamber and drill and tap for a fitting to the out side I can change easy.
This way I can fiddle with it to get what I need and not have to drill or machine any thing later on.
The main thing will be making the mount to the plate universal for different tube sizes. Think using different schedule pipe as you said may be the ticket here. Can turn down the ends on them so thy all fit in the same plate mount setup.
Will get the 3/4" bushing and retainer and build the mounting around that.
Have the time to plan it and do the work now as I build the eng up.
Just what I have in my head so far.
Ain't any different than controlling the temps on a CMB 1.01 just bigger........LOL

[moparbarn]

"Ain't any different than controlling the temps on a CMB 1.01 just bigger.......LOL"

Ain't much faster, either........LOL

I would just go with stock size on the feed end, restrict it for temps on the exit side. The washers can be changed to control flow/temps. Just find the washer that has the right OD, then adjust the ID by brass brazing different washers on it. There are 10's of thousands of hot rod Mercs with stock plumbing on the feed end of the system that don't run hot, even down there. They all need to restrict the outlet to build temp........KISS