i have been reading threads on the 3800 issue and as i perused the subject looking for info on harnesses, i came across ideas about how to plumb the heater into the car. As we all know, the 3800 has two holes that plumb into the heater thru the alternator housing. Which one to use and which one to delete? Opinions differ, at least as i can tell when people use words to describe things: this hole that hole, big hole small hole etc. Well here is a pic i posted for my own information. Tell me whatcha think?



Note the orange cord in the water pump. IMHO water from the heater core will flow INTO the water pump from the rear (left) hole and INTO the water pump from the radiator in the front (right) hole. The hole in the lower intake manifold is to be blocked off, as the water flows OUT of the engine thru the thermostat housing. Whatcha think?

jon

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Astronomy says we will find a coded signal from outer space. Then we'll KNOW that life exists there, for coded signals aren't by chance.

Biology says there are coded genetic signals in every cell, but we KNOW that no intelligence created life.

I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 4-wheel drifts are fun!

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Astronomy says we will find a coded signal from outer space. Then we'll KNOW that life exists there, for coded signals aren't by chance.

Biology says there are coded genetic signals in every cell, but we KNOW that no intelligence created life.

I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 4-wheel drifts are fun!

Those of you that have been following this thread mite remember that i put Freya's battery in the front, many years ago, and then two winters ago i moved it to under the passenger headlight. Well the battery cables i made up were jury rigged and spliced. A 3800 SC deserves better than that (not to mention Freya), been looking for one of these for years.

A trip to Kenny U-Pull uncovered this off a Buick:



And the ground cable:



And check out the condition: it looks brand spankin new. Flambant neuf! i thot it would be hard to get it out of the car but 15 minutes later it was in my bag. Only 20 bucks at the checkout, and a new one from Buick couldn't look better. This car was beautiful, no rust, leather, no rips, clean, but wrecked slightly in the R front. Made me sad to tear into it like i did.

i'm gonna use the extra hot wire to run back to the alternator, using parts of the existing hot from the battery, and i'm gonna ground the battery to the frame and then from there run back to the block using the existing battery ground. i believe in having as little IR drop as possible. ;-)

N then, thats not all - i got an alternator from a late 90's S10 with the 4.3, cuz it looks like it will be easy to build the bracket holding it in place.



i also got a tensioner - i need a ribbed one for the accessory belt, however this one pulls clockwise, and i need one to pull counterclockwise. i'm gonna combine the dogbone with the tensioner as one unit. Gonna have to engineer it in conjunction with the alternator bracket.



But wait! Thats not all! You also get the OBD2 port, which i failed to pull off ol Betsy, so i got it off another Pontiac with a 3800NA



Gonna go back and get some stuff for Charlie, my 92 S10.

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Astronomy says we will find a coded signal from outer space. Then we'll KNOW that life exists there, for coded signals aren't by chance.

Biology says there are coded genetic signals in every cell, but we KNOW that no intelligence created life.

I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 4-wheel drifts are fun!

Plywood mockup of the alternator bracket.



And from head on, showing the belt routing.

jon

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Astronomy says we will find a coded signal from outer space. Then we'll KNOW that life exists there, for coded signals aren't by chance.

Biology says there are coded genetic signals in every cell, but we KNOW that no intelligence created life.

I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 4-wheel drifts are fun!

Here is my alternator bracket showing the supports (mocked in cardboard) to the front of the alternator.



And here is a look at the back showing the brace to the block, also mocked in cardboard. Dunno at this time what gauge metal i will use for the braces. 3/16 is too heavy (?) and 16 gauge is too light. Another trip to the steel supply?



jon

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Astronomy says we will find a coded signal from outer space. Then we'll KNOW that life exists there, for coded signals aren't by chance.

Biology says there are coded genetic signals in every cell, but we KNOW that no intelligence created life.

I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 4-wheel drifts are fun!

Alternator braces ready for welding. i used the 3/16" steel for braces.



i'm really pumped that it lined up the first time. 1/4" plate put it right in the rite spot. Don't have 1/16" marks on my rule. ;-)

jon

[This message has been edited by longjonsilver (edited 05-13-2020).]

And here it is painted with the back support to the block to keep it from flexing.



And the cardboard mockup beginning of the upper tensioner and dogbone combo bracket.



Tensioner to be put in this location, but in combo with the dogbone.



Disregard the yellow mark, the green circle is where its at!

jon

------------------
Astronomy says we will find a coded signal from outer space. Then we'll KNOW that life exists there, for coded signals aren't by chance.

Biology says there are coded genetic signals in every cell, but we KNOW that no intelligence created life.

I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 4-wheel drifts are fun!

The progress today:

The completed alternator bracket, including brace back to the block:



Beginning of the dogbone, tensioner bracket:



jon

------------------
Astronomy says we will find a coded signal from outer space. Then we'll KNOW that life exists there, for coded signals aren't by chance.

Biology says there are coded genetic signals in every cell, but we KNOW that no intelligence created life.

I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 4-wheel drifts are fun!

Alternator in bracket on motor:


Base plate of dogbone/tensioner bracket:
upload your image free

View from front showing positions:


jon

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Astronomy says we will find a coded signal from outer space. Then we'll KNOW that life exists there, for coded signals aren't by chance.

Biology says there are coded genetic signals in every cell, but we KNOW that no intelligence created life.

I'm the original owner of a white ' 84 2M4 purchased Dec 10, 1983 from Pontiac. Always garaged, no rust, 4-wheel drifts are fun!