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Posted by: Wew Apr 5 2021, 09:59 AM

Hi all,

Have been working on my engine and transmission rebuilds. Almost there.

Question is I had new heads machined and now notice there are no vacuum ports on the heads like my old ones.

I borrowed this schematic from another member and added the thin red line, circle and arrow to the drawing to show what I am talking about.

Do I just remove that piece and plug the hole on the air cleaner?
Do I reroute some lines?

Anyone who has been down this road I appreciate you input.

Thanks,

Gary

Posted by: rjames Apr 5 2021, 10:25 AM

Get rid of the T fitting and route the hose from the air box to the port on the oil filler.

Posted by: Wew Apr 5 2021, 10:32 AM

Awesome...

Thanks Robert!

Posted by: JamesM Apr 8 2021, 12:56 AM

QUOTE(rjames @ Apr 5 2021, 08:25 AM)

Get rid of the T fitting and route the hose from the air box it to the port on the oil filler.

Also need to replace the PCV on the oil filter with an open port. Ideally you would want to replace the oil filler and air filter housing with the later style ones with a larger port as the single 13mm hose doesent provice adiquate venting without the heads ports.

Posted by: Wew Apr 8 2021, 08:20 PM

Thanks for the input James.

Much appreciated.

Posted by: 914werke Apr 9 2021, 10:48 AM

QUOTE(JamesM @ Apr 7 2021, 11:56 PM)

QUOTE(rjames @ Apr 5 2021, 08:25 AM)

Get rid of the T fitting and route the hose from the air box it to the port on the oil filler.

Ideally you would want to replace the oil filler and air filter housing with the later style ones with a larger port

what they said

Only challenge is finding the new hose in that larger 20mm size ... & the late airbox top that accepts it

Posted by: Wew Apr 10 2021, 11:38 PM

Looks like I am on the hunt for some more parts.

Thanks for the input.

Gary

Posted by: Wew Apr 11 2021, 11:57 AM

Hi all,

I found both of these on EBay.

Is this what I need?

A 75-76 air filter box and a no pcv just air vent port oil filler housing.

Rich had mentioned a hard to find vacuum hose of 20mm

Can anyone shed additional light on that or share your experiences and resource on solving this?

I plan on keeping the fuel injection on the car, just for clarification.

Thanks,

Gary

Attached Image

Posted by: Wew Apr 22 2021, 08:44 AM

Hi all,

I did my searching and purchase a 75/76 air cleaner housing and oil filler housing with the bigger vacuum opening.

I have some questions about vacuum hose routing.

Per the pic attached and numbered my questions are as follows:

1. Circle #1 Oil filler opening to #2 on air cleaner (large 20mm openings)
a. Please confirm if this is correct.
b. Anyone know of a source to purchase these large diameter vacuum lines?

2, Circle #3 Two vacuum/vapor lines running from the frunk to the engine
compartment.
Question: Two lines and a single port left #4, how should I route these?

As always many thanks to the braintrust on the forum.

Thanks again

Attached Image

Posted by: JamesM Apr 22 2021, 02:10 PM

QUOTE(Wew @ Apr 22 2021, 06:44 AM)

Hi all,

I did my searching and purchase a 75/76 air cleaner housing and oil filler housing with the bigger vacuum opening.

I have some questions about vacuum hose routing.

Per the pic attached and numbered my questions are as follows:

1. Circle #1 Oil filler opening to #2 on air cleaner (large 20mm openings)
a. Please confirm if this is correct.
b. Anyone know of a source to purchase these large diameter vacuum lines?

2, Circle #3 Two vacuum/vapor lines running from the frunk to the engine
compartment.
Question: Two lines and a single port left #4, how should I route these?

As always many thanks to the braintrust on the forum.

Thanks again

Attached Image

#1 Yes, 20mm oil filter to 20mm air filter. dont know of any source for the original hose, you may need to go aftermarket silicone.

#2 Those are the lines that run to/from your charcoal canister on your gas tank. on the engine bay side one end connects to a port either on your fan housing or engine tin (depending on which fan housing and engine tin you have) and the other side goes to your air filter.

You may need to get a little creative with your house routing as the 75-76 cars had the charcoal canister in the engine bay so #3 in your picture didnt exist and the ports moved around a bit.

Posted by: Wew Apr 22 2021, 03:01 PM

Awesome.

Thank you James!

Posted by: bbrock Apr 23 2021, 04:46 PM

Is the larger hose 20mm ID or OD? Belmetric sells 14x20 braided hose and I thought that's what the larger ports were (vs 12mm ID of the earlier ports). https://www.belmetric.com/braided-metric-hose-oem-c-14_138/

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