Author Topic: Color of Thermactor check valves for 1968 SJ 302  (Read 978 times)

Offline Gbailey1018

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Color of Thermactor check valves for 1968 SJ 302
« on: September 10, 2021, 02:57:56 AM »
I own a 1968 FB San Jose J code 4V 302 that had a non-working factory Thermactor system, which I would like to restore and re-install.  Can someone please tell me if the check valves on the smog tubes are supposed to be blue or natural metal color?  My system had valves with what appear to be natural metal color, but they have lots of surface rust on top and I don't see a Fomoco logo so it's hard to be sure.  Also, I have seen a few pictures online from credible sites that suggest the check valves on a 1968 302 should be blue.

Any input would be much appreciated.

Offline Bob Gaines

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Re: Color of Thermactor check valves for 1968 SJ 302
« Reply #1 on: September 10, 2021, 10:31:28 AM »
I own a 1968 FB San Jose J code 4V 302 that had a non-working factory Thermactor system, which I would like to restore and re-install.  Can someone please tell me if the check valves on the smog tubes are supposed to be blue or natural metal color?  My system had valves with what appear to be natural metal color, but they have lots of surface rust on top and I don't see a Fomoco logo so it's hard to be sure.  Also, I have seen a few pictures online from credible sites that suggest the check valves on a 1968 302 should be blue.

Any input would be much appreciated.
The check valves would typically be blue as they were installed prior to engine painting. Replacements would most typically be unpainted.
Bob Gaines,Shelby enthusiast, Shelby collector , Shelby concours judge SAAC,MCA,Mid America Shelby

Offline Coralsnake

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Re: Color of Thermactor check valves for 1968 SJ 302
« Reply #2 on: September 10, 2021, 11:32:52 AM »
The rails you show in your photo are not from 1968. The 1968 rails have the check valves set back towards the center slightly more than the (pre 1968) ones shown in your photo. In addition, the rails pictured are a left and right. In 1968, the left and right rails are the same design.

Mr Gaines is correct, the rails, antibackfire canister bracket and check valves were all painted blue. The original check valves are stamped FoMoCo.

Here is a 1968 smog rail for comparison

« Last Edit: September 10, 2021, 05:46:43 PM by Coralsnake »

Offline Gbailey1018

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Re: Color of Thermactor check valves for 1968 SJ 302
« Reply #3 on: September 10, 2021, 07:37:22 PM »
Thanks to both of you.  Just to clarify, are you saying that 1968 302 4V MT smog tubes would also be blue (in addition to the two check valves)?  Photo below is of the original smog tubes I took off the car.  The second photo in my first post (the one with the white background) wasn't my system.

Obviously it's been 50 years, but I never saw anything on the smog tubes that suggested that they were originally blue.  Is it common that tubes that were originally blue would show zero evidence of blue paint anywhere at this point?


Offline jwc66k

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Re: Color of Thermactor check valves for 1968 SJ 302
« Reply #4 on: September 10, 2021, 08:28:03 PM »
I was under the impression that sometime in the mid 1967 production year, that a different head was used for small blocks that eliminated the use of the tubes - see 1967 Ford Products Engine Equipment Assembly Manual, AM00157 pg 117. I know there is no 1968 equivalent manual and assumed that the 67 emission version would carry thru.
Jim
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Offline rockhouse66

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Re: Color of Thermactor check valves for 1968 SJ 302
« Reply #5 on: September 10, 2021, 08:56:10 PM »
Some SBF cylinder heads in this time frame used sort of a banjo fitting on the rear of each head and the air injection was internal to the head casting.  I am unclear on what cars got this style or when.
Jim
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Offline CharlesTurner

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Re: Color of Thermactor check valves for 1968 SJ 302
« Reply #6 on: September 10, 2021, 11:30:08 PM »
Thanks to both of you.  Just to clarify, are you saying that 1968 302 4V MT smog tubes would also be blue (in addition to the two check valves)?  Photo below is of the original smog tubes I took off the car.  The second photo in my first post (the one with the white background) wasn't my system.

Obviously it's been 50 years, but I never saw anything on the smog tubes that suggested that they were originally blue.  Is it common that tubes that were originally blue would show zero evidence of blue paint anywhere at this point?


Yes, they should be blue, along with the check valves.
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Offline Gbailey1018

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Re: Color of Thermactor check valves for 1968 SJ 302
« Reply #7 on: September 11, 2021, 01:01:02 PM »
Thanks for the feedback.  More follow up questions.

Can anyone share photos of the original blue tubes and check valves installed on an original or unrestored 1968 302 MT?  I looked through the unrestored picture thread gallery but couldn't find an example.

Also, does anyone have suggestions as to how to prep and paint my original tubes so the blue paint will last?  I took them to a place  that does powder coating but they said they couldn't work on them.  Someone else suggested https://www.jet-hot.com/coatings but so far their feedback has been a bit confusing and I want to be confident in whatever option I choose to pursue.

Would the smog tubes and check valves have been installed prior to paint at the factory, which would suggest that only the parts of the ferrules that were exposed would have received paint and the portion screwed into the block would remain natural/phosphate?  Or would the tubes have been painted first and then installed (which would suggest the ferrules should be completely painted?)  Same question for the where the check valves are screwed into the top of the tubes?

Offline Bob Gaines

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Re: Color of Thermactor check valves for 1968 SJ 302
« Reply #8 on: September 11, 2021, 04:42:58 PM »
Thanks for the feedback.  More follow up questions.

Can anyone share photos of the original blue tubes and check valves installed on an original or unrestored 1968 302 MT?  I looked through the unrestored picture thread gallery but couldn't find an example.

Also, does anyone have suggestions as to how to prep and paint my original tubes so the blue paint will last?  I took them to a place  that does powder coating but they said they couldn't work on them.  Someone else suggested https://www.jet-hot.com/coatings but so far their feedback has been a bit confusing and I want to be confident in whatever option I choose to pursue.

Would the smog tubes and check valves have been installed prior to paint at the factory, which would suggest that only the parts of the ferrules that were exposed would have received paint and the portion screwed into the block would remain natural/phosphate?  Or would the tubes have been painted first and then installed (which would suggest the ferrules should be completely painted?)  Same question for the where the check valves are screwed into the top of the tubes?
Reread reply #1 . Tubes were installed prior to engine painting process.
Bob Gaines,Shelby enthusiast, Shelby collector , Shelby concours judge SAAC,MCA,Mid America Shelby

Offline J_Speegle

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Re: Color of Thermactor check valves for 1968 SJ 302
« Reply #9 on: September 11, 2021, 08:30:06 PM »
Thanks for the feedback.  More follow up questions.

Can anyone share photos of the original blue tubes and check valves installed on an original or unrestored 1968 302 MT?  I looked through the unrestored picture thread gallery but couldn't find an example.

Yes since this is a manual transmission thing not that many cars got the systems - will look though details are often hidden with the engines in the car


Also, does anyone have suggestions as to how to prep and paint my original tubes so the blue paint will last?  I took them to a place  that does powder coating but they said they couldn't work on them.  Someone else suggested https://www.jet-hot.com/coatings but so far their feedback has been a bit confusing and I want to be confident in whatever option I choose to pursue.

For a restoration not sure why your trying to recreate the wheel. Just follow what the factory did in this case and be done with it


Would the smog tubes and check valves have been installed prior to paint at the factory, which would suggest that only the parts of the ferrules that were exposed would have received paint and the portion screwed into the block would remain natural/phosphate?  Or would the tubes have been painted first and then installed (which would suggest the ferrules should be completely painted?)  Same question for the where the check valves are screwed into the top of the tubes?


Yes tubes, check valves and at least the canister mount at the front of the engine were installed were attached prior to the engine getting painted. IMHO the pump mounting bracket along with attaching hardware were attached also based on the original cars I've seen and the systems I've removed.

All the parts would have received a nice coat of blue and of course the tubes all the way to the bases on the heads. Original pictures show much of the top half of thew exhaust manifolds had engine color over them that would discolor as soon as the engine was tested before it was installed and that increased as usage continued
Jeff Speegle

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Offline Gbailey1018

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Re: Color of Thermactor check valves for 1968 SJ 302
« Reply #10 on: September 12, 2021, 11:33:02 PM »
Thanks for the feedback.  Would love to see some photos of the tubes and check valves installed, even if they are partially obscured.

Re: the smog tubes, I have no desire to recreate the wheel.  :)  I'm just trying to determine whether I should try to strip the tubes (and if so, how) before spray painting them.  I'm guessing that if I don't, the paint will start coming off after a few months, which might be what always happened but I would still prefer to keep the blue color.  Any suggestions are always appreciated!

Offline CharlesTurner

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Re: Color of Thermactor check valves for 1968 SJ 302
« Reply #11 on: September 12, 2021, 11:47:59 PM »
There might be some ceramic coating options, but if you intend to drive the car on a regular basis, most likely will just have to touch up the tubes from time to time.
Charles Turner - MCA/SAAC Judge
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Offline J_Speegle

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Re: Color of Thermactor check valves for 1968 SJ 302
« Reply #12 on: September 17, 2021, 06:06:58 PM »
Just to add to what already has been offered  and to provide some more examples for others that will find this thread in their time of need

Tim Lea asked that I post the following picture




And while doing that found this one from my collection




and two examples from a thread that discussed the early and late versions of the manifold

« Last Edit: September 17, 2021, 06:09:27 PM by J_Speegle »
Jeff Speegle

Anything worth doing is worth doing concours ;)