filling in vacuum ports
 

i'm soon to be going to single and have eliminated just about everything that uses the vacuum ports underneath the manifold. i was just wondering what i could use to fill those with. is jb weld or a similar metal epoxy type good enough or is it better to have them welded shut?

You mean the little vacuum nipples on the LIM and such, Just get some silicone vacuum nipple caps. I dont think i would permanently block them off... Those little caps will hold on just fine but be sure to get the silicone ones so they can withstand the heat, Ive got a number of them on my car and they have worked great...

i've tried using the caps and they either won't stay on or they start cracking from heat. i've got some silicone line with screws in them for plugs, but i don't want it like that because it looks tacky. i don't plan on using any of them again and if i do, i could just drill the material back out. where could i find some high quality silicone plugs online?

the caps suck. they last less than a year before cracking. i just got some nylon plugs im going to try banging them into the nipples. if that doesnt work then its on to other non permanent ideas. ill let you know how it goes.

what i was thinking, was get some of that titanium epoxy or similar item from autozone. says it's good to like 30k+ psi, plus it bonds to metal. i figure if i ever need to use the port again, i can use small drill bits to open them back up. does that sound like it would work to anyone else?

Nah, just do it right. Either find a friend with a mig that is using alum. wire, or an actual tig welder and fill them, sand them and polish the whole thing. If you don't know anyone, most welding shops won't charge you much at all to fill them in.

Here's an example of what can be done, but with the charge pipe of the y-pipe. My roommate did this, and is in the process of working with an UIM to *fully* weld, sand, polish anything that isn't needed. (every hole filled, and like a good porn flick, its going to be fucking awesome.) Same goes for the LIM, there is *alot* of stuff that is removed because of the ACV elim...

Charge pipe:
before:
http://www.stlrx7club.com/images/rx7...pipebefore.htm
after:
http://www.stlrx7club.com/images/rx7...lowerypipe.htm

And the secondary intake pipe:
before:
http://www.stlrx7club.com/images/rx7...pipebefore.htm
after:
http://www.stlrx7club.com/images/rx7...opipeafter.htm

:cool:

Jason

im sure any epoxy will be fine. its not a particulary hot nor high pressure application. i would use regular jb weld and rough up the hole a bit just to be extra safe

another good way i think would be removing the nipples and drilling and tapping the manifold for 1/8 npt or 10/32 and screwing plugs in. then if you want to use them later you can just screw in a hose barb.

Weird, i bought some silicone plugs from hosetechniques.com when I did my vac hoses and they have worked just fine and they are still nice and squishy like when I got them...

I see tanks for an oxy-acetylene torch, hope you're not calling that a MIG welder :D

MIG would be pointless for alum., TIG is much, much cleaner & more fun to use...

Obviously you haven't used aluminum wire in a MIG. But I totally agree, TIG is much much cleaner and more fun. However, if you are going to just sand and polish the weld, how clean it is doesn't matter. That charge pipe I linked to was done with a MIG with alum. wire. Believe it. ;) And its plenty strong of course.

Hhahaah, yes, that isn't a MIG. We just had it out for cutting on his Yukon's suspension.