View Full Version : 1968 Cowl Plenum Install
dannystarr
04-19-2023, 03:46 AM
Well, I dug out all my parts. I ordered a boot. And decided to see if I could make it happen. Been 8 years collecting parts on and off. Set it on for a dry run and it sat WAY up at an angle. Smog tube hose in the way. Removed the right-side smog tube assembly. I had one with a 90 on it. So I installed it with the valve, and to my surprise the original hose was long enough and fit. The hose cleared the air cleaner body. JUST touches, doesn't hold it up. It looks kinda normal factory. I temporarily screwed down the duct and lined some things up. From under the hood. The hole in the fire wall was existing and too far to the right. If I slide it to the left where it fits better, there is an open hole on the right. So I left it there. Not excited about patching the fire wall and such. So that's that.
Tried 4 or 5 different air filters with no luck. 3-1/16th is too short, and 4-1/16th is too high. So I have one coming tomorrow from NAPA that is about 3.50" high. We will see. ... Danny
dannystarr
04-19-2023, 03:48 AM
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dannystarr
04-19-2023, 03:54 AM
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dannystarr
04-19-2023, 03:55 AM
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dannystarr
04-27-2023, 04:29 PM
FINALLY found a filter that fits perfect. System installed permanently. Took for test drive, pulls like hell. Better than before. I know I have read that it makes no difference, and is just a conversation piece, but it does for this car. I noticed a big difference in torque. Danny
dannystarr
04-27-2023, 04:40 PM
Almost forgot...The filter is a K&N E3029R. It is a 2-ply track racing only filter. The highway use filter is 4-ply, and the number is E3745. I just ordered that 4-ply. I am curious to see if there is a torque difference. 4-Ply is for regular driving use. I didn't know the 2-ply was a racing one when I purchased it. I was so excited about the measurements being good, I just ordered it. Danny
RamAirBirds
04-28-2023, 12:33 PM
I am currently putting back what i assumed to be a "owner installed" cowl plenum back onto my 68 Z28. Have the correct A/C and what appears to be a modified firewall duct...possibly from a Chevelle. This was done way way back in the day and so it needs to go back on. I bought the last made boot a member here had that is correctly seamed together on the bottom. I am curious on both where you got your boot AND are you going to put the factory staples back in place on the AC side. That is the last hurdle I have to do...I have heard they used both Round and Square staples (similar to a box staple). My original Air Cleaner clearly had small "round" holes so this is what i am going to use. I am thinking that the staple used for putting the flaps on the front wheel wells should work. Just curious what you are thinking of doing if anything.
RA
dannystarr
04-28-2023, 03:01 PM
My boot was purchased from a friend who makes them. The rubber is a little thicker. Which keeps the assembly more secure, and the boot doesn't collapse like others. The seam is made of the correct burlap type material. You could smear/sprinkle some baby powder or the like on the rubber for a show display. To get a more realistic visual of an old one. I don't know if he is making more or if he has any in stock. I will check with him and send you a PM. Note: He also has a guy that makes the top lids. From a copy of his original. They are fiberglass. That is what I have. I am looking for an original top. He doesn't come to these sites. And I am not sure he wants his info offered. I will have to check with him.
I jumped on it a couple times during test drive. And the boot pulled away from the air cleaner side about an inch on the front half. So probably going to follow the holes and punch through the rubber. I have a friend in SSF that has a bunch of staples connected to old rusty front ends. I am going to beg him to pull some for me. He doesn't know it yet.
I think you are correct, probably the same staples. I thought there was a build thread here or another site, maybe Chick's BY car, that showed someone buying the wire stock and cutting, sharpening and making their own. But I can't find that link. I'll be in touch... Danny
black69
04-29-2023, 01:11 AM
Great results! looks great. Man that setup is rare. Have to ask, is that smog equipment bypassed? Looks like its all functional.
Really nice to hear there is a performance difference. That had to be fun.
RamAirBirds
05-01-2023, 11:21 PM
You can cut and past this link for the Chick staple info..
Seems good...My Air leaner has original holes so i will have to create the size for the modified "pliers" to bend the Galvanized Steel Wire...
https://www.camaros.net/threads/time-for-another-68-z-28-to-be-restored.182584/page-53#post-3381545
dannystarr
05-02-2023, 05:19 AM
The smog is all original, hoses, pump, pulley, tubes, clamps etc. However, I cannot run a belt as the pulley is froze in place. And as you know, there is no way to lubricate. So it would have to be gutted. Not in the space for that right now. So I install a belt at shows for the visual.
Then when the show is over, I remove it and toss it in the trunk.
Thank you for the link, I will go check it out right now... Danny
X66 714
05-02-2023, 02:50 PM
The smog is all original, hoses, pump, pulley, tubes, clamps etc. However, I cannot run a belt as the pulley is froze in place. And as you know, there is no way to lubricate. So it would have to be gutted. Not in the space for that right now. So I install a belt at shows for the visual.
Then when the show is over, I remove it and toss it in the trunk.
Thank you for the link, I will go check it out right now... Danny
Danny. Unless you fix the smog pump or make the total system inop, the exhaust fumes & condensation will eat up the rest of the system from the inside out. If you need help on how to inop it I know the precedure without welding....Joe
dannystarr
05-05-2023, 02:16 AM
Joe,
I will PM ya when I am ready for that job. And thank You... D
dannystarr
05-05-2023, 02:22 AM
Got my galvanized tie wire out and made some staples. Marked everything with small sharpie marks. Took it off, lined up the marks and punched the boot. Installed the 6 staples and put the unit all back together. Ready to roll!
Fun Trick..... FYI wrap your wire with duct tape all around except the top. Pull the wire from the inside top as needed. Works great. I go to other shops and see giant nightmare rolls of wire falling all apart in many directions. Danny
black69
05-05-2023, 04:45 PM
That looks so dam good, I would kill for that metal air cleaner for mine. Put me on your list for most likely suspect if you leave this car un-attended :)
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