Do the openings on either end which are blocked with caps have any practical purpose? I was just wondering if there was a reason for the openings or why Toyota designed the plenum that way, and couldn't find any information in the TSRM or by searching the forums.
Intake Plenum curiosity question.
- Thread starter mirage83
- Start date
To remove the sand when being cast and on GE's to allow access to the boring head to machine for the ACIS valve.
When they cast parts like this they use a "core" in the mould that gives the inside shape while the rest of the mould provides the outside shape, the plug holes are an easy way to support it and then capped off in the finished part 
The back plug is where they put the MAP sensor on the Turbo-A... But yes, that's their original reason for being there is to get the sand out of the mold. Same with the block and people calling them "freeze plugs" when in reality they wouldn't save your block...
Thanks for the quick responses and info guys.
And btw, for anyone who hasn't already tried it cleaning up and polishing away the casting marks and such on the plenum is the very definition of "Bitch". It's coming along nicely but a slow go. Much more time consuming than the valve covers or 3000 pipe, not that that's really a surprise.
^Oh, since you mentioned the Turbo-A, does anyone have any idea how many are left in running condition given the limited numbers produced?
And btw, for anyone who hasn't already tried it cleaning up and polishing away the casting marks and such on the plenum is the very definition of "Bitch". It's coming along nicely but a slow go. Much more time consuming than the valve covers or 3000 pipe, not that that's really a surprise.
^Oh, since you mentioned the Turbo-A, does anyone have any idea how many are left in running condition given the limited numbers produced?
Nonsense. I've personally had an oldsmobile 350 (w30) that froze overnight (had straight distilled water in it - this was in my younger days) and I had 2 freeze plugs pop out.
They MIGHT save the engine, but most of the time they DON'T. It's a side effect of the plugs, not the reason that they are there.