I am doing a 20B conversion on an FD and need to create a vacuum point for the brake servo.
I was thinking of using the redundant emissions point on the back of the plenum shown open in the image below.
However I thought about this and then wondered if this point is not going to see any vacuum now with the blanking plate on the side of the plenum? If so is the best place to tap and vac point into the side blanking plate or direct into the upper manifold somewhere?
Thank you
Lee

 

the stock cosmo didn't use vacuum assist for the brakes, it uses a hydraulic thing.

with mine i just used one of the 4mm nipples in the rear of the intake, i know its "too small" but with the engine running i could pump the pedal, and that short length of 4mm hose was able to keep up.

i'm not sure what you're trying to show in the picture, that flanged connection is for the "split air" system, which doesn't have vacuum in it anyways

 

I just drilled and tapped the back of the plenum for a 3/8" hose barb. Works fine for me....

 

I was trying to show the flange with the studs and nuts on the rear of the LIM. I guess this is the split air flange you are referring to? I thought there would be no vac with the blanking panel on the side of the LIM now.
If I tap a fitting into the blanking panel on one side or other will I be able to pick up a vacuum from here?
I would prefer to go up to a 3/8 fitting to be sure I get sufficient vac. With a road car I don't want to take any chances!
Could take the UIM and tap a fitting into it but I don't really want to again!

Cheers
Lee

 

yep.

there wasn't before the blanking plate, air pump air exited there

if you tap into the right place i think so, if you tap into the wrong place you'll hit exhaust