Aluminum intake and vacuum fusion snafu - now what?

[geezer#99]

Looking at your pics shows you better chase those threads and clean them up or you might get real unlucky and have no threads to work with.
Tightness on fittings depends on the use of sealant and on what you’re trying to seal off.
Vac fittings don’t need to be torqued tight. Coolant ones with sealer need tight enough to not leak.

More parts, more tools!
Hang in there. Perfection takes time.

[msg]

Ok, here is what Ive done. First I plugged the 2 front ports with brass fittings and liquid teflon. The fittings I spun on without the teflon just to test and they ran smooth as can be, no issues. I tightened till firmly snug.

[msg]

Then came the dice roll. I took this super tacky duct tape and placed it underneath with alot of upward pressure around the base of the vacuum port to seal it.

[msg]

then put the tap and die set to work with the tapping fluid added to the tap. I held my finger under the port keeping pressure on the tape upward and made sure I didnt tap down so far as to cause the tape to push away.

[msg]

next the remnants that were inside the port I took a shop vac and sucked it all out. I took a toothbrush and scrubbed the threads as well making sure the tape was still tight underneath.

[msg]

Then the brass fitting I tested spun down just fine so I paired up the vac tree fitting with the brass with some liquid teflon and tightened those two up on the bench vise. And for now spun it back on not tight yet but just to see how tall the thing is now and to make sure I have clearance the the right tube aligned to the brake booster. Ill mount up the distributor tonight and see if the tree fitting clears thats needed then put some teflon on the brass and thread it down.

[geezer#99]

Two plugs in front.
So you don’t plan on the need for a heater hose or a place for a temperature gauge.

[msg]

Maybe I messed up, I thought that with the Vintage Air System there is no water heater component. Isnt there a temp sensor on the block for the engine temp?

[geezer#99]

Ya got me!
Don’t know on the vintage air.
Temp sensor might be on the head. Drivers side. Between #1 and #3 plugs.
You’ll need to find it. I think they’re different threaded than stock is though.
Might be nothing there, or open. Not sure.
Check between #6 and #8 plug too.

[truckster]

Member A1971Blazer does a really nice job of turning down temp sensors to fit the stock location in Vortec heads. PM him if you need one.

[AcampoDave]

Yes, the vintage air "sure fit kit" has a heater. Btw, nice work on fixing the manifold. The tape thing was smart....I'm gonna remember that one!

[tdangle]

Originally Posted by truckster

Member A1971Blazer does a really nice job of turning down temp sensors to fit the stock location in Vortec heads. PM him if you need one.

I got one from him for my crate engine with Vortec heads, Worked perfect.

[geezer#99]

Another pain to add to the list.
Your motor might need a bypass hose from the intake to the water pump.
Like a big block has.

Does your intake and water pump Have the right ports for the bypass.

[msg]

Originally Posted by truckster

Member A1971Blazer does a really nice job of turning down temp sensors to fit the stock location in Vortec heads. PM him if you need one.

Originally Posted by tdangle

I got one from him for my crate engine with Vortec heads, Worked perfect.

Thanks for the heads up fellas, I didnt know that a temp sensor on the shelf wouldnt fit.

Originally Posted by AcampoDave

Yes, the vintage air "sure fit kit" has a heater. Btw, nice work on fixing the manifold. The tape thing was smart....I'm gonna remember that one!

Thanks Dave, Im glad I heard that right about the sure fit kit. Its still on order been over 2 weeks now.

Originally Posted by geezer#99

Another pain to add to the list.
Your motor might need a bypass hose from the intake to the water pump.
Like a big block has.

Does your intake and water pump Have the right ports for the bypass.

Thanks Geezer, that pain is in progress here. Im hoping that 45 degree fitting will line up decent so I can use the hose I bought. The hose that came with the intake was just a straight one with little chance of connecting to the long water pump I have. I guess I could loop it like a pigs tail and get it to connect.

https://67-72chevytrucks.com/vboard/...d.php?t=811209

[truckster]

Originally Posted by msg

Thanks for the heads up fellas, I didnt know that a temp sensor on the shelf wouldnt fit.

The temp sensor threads are smaller on the Vortec heads, and the temp sensor for the Vortec heads has a different ohm range, so your gauge would be off.

[msg]

Originally Posted by truckster

The temp sensor threads are smaller on the Vortec heads, and the temp sensor for the Vortec heads has a different ohm range, so your gauge would be off.

Great info thanks.

I was placing the distributor in to see how things looked and wondered if RTV is supposed to be used with the gasket on it or not. What do you guys do?

[truckster]

No sealant on the distributor gasket. You want it to turn easily to adjust timing.

[toolboxchev]

Originally Posted by truckster

I recommend using brass fittings with aluminum intakes.

Very good. Learn something everyday. I would run a tap through there, whether new threads or chasing the old ones.

[msg]

I ran into an issue with the carb and the 3 port tee I added the brass fitting onto, its too tall now and runs into the vacuum advance on the carb. I thought about removing the brass and trying it again but chickened out and tried finding a new port. I bought a 2 port instead and then realized I had recently in this restoration included a vacuum gauge in the instrument panel. So my question is can I run a t fitting off the port to run both the instrument vacuum gauge and then have the other end run to the transmission? Does that mess things up?

[americanmusc1e]

Originally Posted by Ziegelsteinfaust

Always antiseize aluminum.

You should be able to use that fitting.

Anti-seize is your friend I use it on almost every bolt I touch on a classic truck. It's not ideal for sealing NPT, but it would probably work fine on a carburetor vacuum port since NPT threads are pretty much self sealing anyway. Teflon paste would also probably work.