Stock Vacuum Readings 2.8L?

[LoneRanger3O2]

What are you guys getting for stock vacuum readings at idle for these motors? Wanna make sure im gonna have the right baseline going with the carburetor before i put it on. Thanks!

 

[RonD]

18-21" is usually at sea level to about 2,000ft on idling engine, under 800rpm

Cranking vacuum should be 2.5" or higher, throttle closed

Manifold vacuum is measured between throttle plate and intake valves
So Carb vacuum ports can't be used for this, they are Ported Vacuum not manifold vacuum.
Some carb have vacuum ports under the throttle plates, they could be use

 

[kimcrwbr1]

Make sure base timing is set at 10dbtdc you can use the vac guage to adjust the idle air needles. Anything above 17hg is good but the higher the better. One at a time slowly turn the needle out for max vac pressure. Do them both a few times where the vac just begins to drop if you screw them in. Then count the turns in then back out the same. The two needles should be within 1/2 between the two. Mine runs best on the rich side all I do now is preset the needles out 4 1/2 turns and getting 18-20mpg. Be sure and install#42 jets and save yourself some time beating your head against the wall. Also install spacer felpro#60529 with two new gaskets on each side if your installing a non feedback carb. If it is still running on the computer disconnect the idle speed motor before you adjust the needles or the computer will give you shit.

 

[LoneRanger3O2]

Make sure base timing is set at 10dbtdc you can use the vac guage to adjust the idle air needles. Anything above 17hg is good but the higher the better. One at a time slowly turn the needle out for max vac pressure. Do them both a few times where the vac just begins to drop if you screw them in. Then count the turns in then back out the same. The two needles should be within 1/2 between the two. Mine runs best on the rich side all I do now is preset the needles out 4 1/2 turns and getting 18-20mpg. Be sure and install#42 jets and save yourself some time beating your head against the wall. Also install spacer felpro#60529 with two new gaskets on each side if your installing a non feedback carb. If it is still running on the computer disconnect the idle speed motor before you adjust the needles or the computer will give you shit.

So start the engine on TDC but turn it out to 10° BTDC at idle, or START at 10° BTDC, before i even fire it up?

So should the crank be at TD or 10° BTDC, with distributor pointed at #1?

Or should i start it all out at 0° = TDC and then turn the dizzy to 10° BTDC?

What is my total timing, and at what rpm? Thanks.

And ok ill keep that in mind. I am using a 350 Holley. Probably too much carb on stock motor but i got a good deal on that and i believe what appears to be a 1.08 venturi 2150 carb. Got rid of all the EEC-IV stuff and traded it out for a 1979 Pinto dizzy and HEi setup.

 

[kimcrwbr1]

Start the engine and disconnect the vacuum advance and plug the hose then adjust base timing at 10 degrees. Yes it starts at ten degrees base vacuum advance adds 10 degrees and mechanical advance adds another 15 degrees at around 3200rpm. Depending on what carb your running you can run vacuum advance from the tree or the carb. It will idle faster from the tree (manifold vac).

 

[LoneRanger3O2]

Start the engine and disconnect the vacuum advance and plug the hose then adjust base timing at 10 degrees. Yes it starts at ten degrees base vacuum advance adds 10 degrees and mechanical advance adds another 15 degrees at around 3200rpm. Depending on what carb your running you can run vacuum advance from the tree or the carb. It will idle faster from the tree (manifold vac).

So is my total timing somewhere in the neighborhood of 34-35°? That sounds like a lot?

 

[LoneRanger3O2]

So anyway, vacuum should be around 18-21in Hg for me since i am at 500-1000ft elevation then?

 

[LoneRanger3O2]

I'm only getting 15-16inHg at idle (750-800rpm) reading from manifold....gets 20 around 1500rpm and then falls back down....what gives? It has bad valve stem seals.....is this the issue? Replaced intake gasket but it did this BEFORE I did the gasket as well. Thanks in advance.