1996 5.7L 260 - swapping intake and marking distributor for removal

[Blueghost924]

After waiting way too long, I'm going to remove the darn aluminum intake from my 1986 350 and replace it with a carbon steel one. I plan on rotating the engine by hand and aligning the balancer mark with timing mark at #1 TDC. In following the shop manual, it talks about marking the distributor with a scribe line from the rotor tip to the distributor body and down to the engine. I looked at the dizzy in relation to where it is, and the only place on "the engine" I can see to make the scribe line would be on the intake manifold..the exact part I'm going to replace.

Any thoughts or ideas?

 

[Rick Stephens]

Set everything to TDC #1. Rotor pointing at "1 contact in the cap - then just re-stab the thing after your swap. Not that hard to reset the timing. Need to re-time even if you scribe a mark.

 

[Scott Danforth]

Any thoughts or ideas?

stabbing a dizzy is HS shop mechanic 101. they teach you to pull dizzy, turn motor over, then figure out TDC and #1 and go from there. i think that is taught prior to righty tighty lefty loosy

as Rick mentioned, get motor to TDC on #1 before pulling dizzy and your life will be much easier.

why are you going from aluminum to cast iron?

 

[Blueghost924]

.

why are you going from aluminum to cast iron?

The aluminum intake is starting to corrode. The very bottom base for the thermostat housing has areas that are starting to flake and may have small chucks break off soon. I'm a salt water boater...

 

[Scott Danforth]

instead of adding 40# of weight going to cast iron, get a proper marine aluminum intake that has the brass water passages and not an automotive one.

salt water only comes in contact with naval brass

thats why Barr developed the dual-alloy casting as used by Volvo Penta, Mercruiser, Ilmor, Indmar, and edelbrock

 

[Blueghost924]

Scott - thanks for the tip on the duel alloy intake. I'm still fixing/replacing items that the previous owner put on the boat & engine, so this is next on the list. Yep - that seating surface for the thermostat housing is real pretty compared to mine.

BTW - completely forgot that it's a mute point about marking the intake manifold from the dizzy scribe mark. I can put my thumb over #1 spark plug hole and feel the compression as the balancer mark comes around to the timing mark (and watching the rotor position). Better yet, I have a compression gauge.

 

[Bt Doctur]

But if you not disturbing the engine you dont have to do anything like that. Simply remove the dust cap and turn the motor untill the rotor tip is pointing at a convenient spot. do your repairs and install it in the same spot

 

[achris]

Turn the engine to where you're happy, or even don't bother turning it at all. Your choice. Make a mark on the distributor that is the straight front. Pull the distributor. As you pull out you'll notice the shaft turn. Once it's out, mark on the body where the rotor is now pointing. When you go to put it back in, just start with the rotor pointing at that spot again, line up the 'front' mark and drop it in.

Chris. ...

 

[Blueghost924]

Got it, and thanks for the replies. Just for convenience, I went ahead and lined up the balancer mark with the timing mark with #1 at TDC (again just for convenience).

I pulled off the intake manifold, and saw this at the rear passages at #7 and #8 cylinders. I don't like the looks of this.

 

[achris]

Check the (old) manifold. It may not have a passage through there, in which case that is just gunked up goo and nothing to worry about... I would clean it out and make sure the passages are clear before dropping the new gaskets and manifold on....

Chris.......

 

[Blueghost924]

I'm almost never that lucky. Here's a picture of the underside of the intake manifold in the back corner that sits over the #8 cylinder on the head.

 

[Rick Stephens]

Yuck.

Salt and Aluminuminum.

 

[Blueghost924]

Thanks and yes salt with aluminum. There's someone here locally that's selling a Volvo Penta 3856270 aluminum intake with the brass passages in great condition. It uses the same 8 bolt pattern as my current old one, and has the 4 barrel carb intake. Any idea if it would work on my Mercruiser 1986 5.7 260? I have a 4barrel Rochester quad jet carb.

 

[Rick Stephens]

Only hiccup would come from whether that one is straight bore or spread bore like your Roc. You may not have room for an adapter. The adapters usually increase carb height by about an inch.