Install a timed vacuum port on 94 carb?

[40cpe]

Just thinkin'. Has anybody tried to tap the cast base to a point above the butterflies? It looks like there is room to tap for a 1/8" pipe thread.

[JSeery]

What are you attempting to accomplish?

[40cpe]

I'll be running a chevy dist with vacuum advance on my 276" and thinking of advance options.

[Mark's 37]

Check with Ted Eaton on the Yblocksforever forum at (http://forums.y-blocksforever.com/Default.aspx) or at his website Eaton Balancing (http://www.eatonbalancing.com/blog/category/y-block/). He put up a photo step by step some years ago on how to modify a 94 with the spark delay port used with the dreaded loadomatic distributors to ported vacuum advance. I saved it on my computer somewhere but can't find it now.

[Mark's 37]

Whoops... I found it. Here is his link to the article.

http://www.eatonbalancing.com/blog/2...-distributors/

[40cpe]

Sponsored Links (Register now to hide all advertisements)

Thank you, mine just happens to be a 2100.

[flatheadmurre]

So what ar you trying to gain from running ported instead of manifold vacuum ?
I want the vacuum advance at idle for 2 reasons better idle with a hot cam and engine running cooler at idle.

[40cpe]

I'll surely try it both ways, that was my point. I had a carbed 5.0 that ran much better off idle using ported vac. You guys have been there, done that, much more than I have but sometimes I just have to see for myself.

[Ol' Ron]

I always use intake vac. This gives max adv at idle. Which is just about perfect for the flathead. This drops off as you accelerate, coming back in cruise. using the Delco dist.

[flatheadmurre]

Porrted vacuum gives you some emission advantages at idle with lower advance, might be one of the reasons it was used...

[expavr]

Originally Posted by flatheadmurre

Porrted vacuum gives you some emission advantages at idle with lower advance, might be one of the reasons it was used...

The other reason is if the engine is supercharged.

[Charlie ny]

Gene,
I agree with Ron , the Delco requires intake vac for best results. I have
some bases as shown in Marks post except I modified them to collect vac below the
butterflies.
Your goodies went out this morning.
Charlie

[40cpe]

Originally Posted by Charlie ny

Your goodies went out this morning.
Charlie

Charlie, thank you

gene

[Bruce Lancaster]

I agree on manifold...but Mallory (good Mallory, long ago!) once specified ported vac for one of their '50's 8BA distributors. The instruction sheet was interesting...they simply supplied a little plug, not much more than a tiny nail, that was to be shoved into the stock loadamatic port in the carb. Putting it in straight plugged off the venturi port, leaving only the downward passage that supplied ported vac.

[scicala]

I have done this modification using the upper hole for the ported vacuum. It can be done either way (lower or upper port).

Sal