LOOPER TECH TIP's.........

[Captain75]

Lets go back to the cooling topic:
When I am looking at my 3L closed deck I am having a hard time understanding the cooling water path... I know this is really basic and below all your levels, but you know, if you dont ask you never learn. The pic below is the only cooling scheme I have found, but it doesn't really make sense to me. Is The only way to the heads through the blow-off and the thermos? My block has small holes in the places shown by the barbecue sticks on pic 2. Why are there only 2 holes on the port side if nr2 is an issue? Can I drill another hole next to nr 2 in the similar way as nr 1?

[Captain75]

I found these on this board, can find the thread right now, but they carries the user name daselbee...
Can anyone comment on these? Drill bit size? drill dept between cyls?







I hope the creator don't mind me posting these!

[lokinutz]

Those are great pictures of how it is done, but that isn't everything. There is more work to be done on the water inlet into the block from the adapter plate. I don't have pics, and can't explain it, but you have to drill and tap and plug some stuff. Sorry. If you only do what is shown in those pics, you will have huge problems.

[Captain75]

Ok, I understand. Hope someone else can show the rest!

[Captain75]

No one?

[John Rork]

Can we please revive this thread? There's so much great info for dummies like myself to learn, I've read this thing a bazillion times but hate that it's died off. Let's get it going again....PLEASE :-)

[Captaincj]

Agree. Any additional OMC Looper Tech tips appreciated.

[Instigator]

Cant remember if we did one on squish clearance??

That was my problems w/my Frank III 3.3 project. Another tip is to mock everything up and check all tolerances before final assembly.
I was sloppy on this build and did not do that.
This is especially critical if you are mixing parts as most of us OMC guys do.

On the squish clearance issue, Al taught me to use solder and Ive done so ever since.
We're normally using .038" as a minimum between top of piston and bottom of heads. On OEM
styled V-6 looper pistons the will be on the outter, flat area of piston.

You do it by using a large diameter of solder cut to a 4" or 5" pc bent at a 90* at about mid length.
You put it through the spark plug hole and turn it to be vertical to check at 12:00 and 6;00 positions. You do it in that position so as to not allow the piston to rock at TDC when it compresses the solder.
Your doing that by turning the crank w/a breaker bar, You'll feel it stop when the piston hits the solder and it takes some ass to spin it past that point.
You then remove the pc of solder and mic it.

I actually cut off a long enough pc of solder to bend it into a large "C" shape which helps to know its in the correct position for your test.



Capatin75 Im sorry I did not see your cooling questions earlier. Havent had much time for computer boating lately.
It is confusing and has changed several times through the yrs.

[rude tim]

I don't know much, but would like to throw this out there... i have been lucky enough to witness and understand Al's cooling mods (I went through my block with a fine toothed comb when he did mine) and have seen how well it works. OK, let me wipe my nose off...

But, something that hasn't been discussed much in this thread is the fact that these motors will always be prone to pop like in Gary's '27 fische boat example due to the non-ratcheting lower unit. These things will be drug slowly down through the worst conditions with the ignition firing away relentlessly (at a very retarded timing since you are out of the throttle...causing it to heat the hell out of the exhaust side of the piston) as the carbs just don't deliver the fuel necessary. Combine that with the longer more efficient exhaust runners on the top two carbs, and well, we know what happens.

Gary, you are always welcome to shoot holes in my theories.

Al does it all the time, he just does it in PM's so I don't look like a complete moron!

I always hit the primer and wait intil the engine starts to lay down before I get out of the throtle. I also use 2 primers one for each side.

[C.C.Hiliner]

I ususally dump a can of Sea Foam into the 40 gallon tank on my boat on every other fill up. So my 98 200 OMC v6 runs on a cocktail of this stuff.

That being said, would it still be benificial to use the OMC Engine tuner? or am I sort of doing the same thing?

[Instigator]

Good routine and basically doing the same thing.

I ususally dump a can of Sea Foam into the 40 gallon tank on my boat on every other fill up. So my 98 200 OMC v6 runs on a cocktail of this stuff.

That being said, would it still be benificial to use the OMC Engine tuner? or am I sort of doing the same thing?

[baja200merk]

Brendan power had a good point when checking squish use 2 pieces of solder at 12 & 6 o’clock so there’s no chance of seeing a couple thou of piston rock.

[Instigator]

Read back a page.

Exactly what I described.

Brendan power had a good point when checking squish use 2 pieces of solder at 12 & 6 o’clock so there’s no chance of seeing a couple thou of piston rock.

[Qshot1989]

I just gutted my thermostats because they were stuck open, I put the spring and the washer like piece with the hole in it back in. Ill be sure to see how it cools. Goint to run through some of there tips and see if any of them are the cause of the prob I'm currently having.

Not trying to revive a dead post, but I am new to these motors and thinking about cutting the tip off the end that opens up. Mine are not opening properly.

[racer]

New thermostats are cheap best to replace and have the engine run at the proper temp. If its been awhile since water pump was replaced get a new OEM kit to install.