I have noticed in photos an item on Holley carburetors that I do not have on mine. I have been told it is called a dash pot. I have a February 12 1968 GT350 4 speed with the aluminum intake and Holley carb. My question, should I have one of these on my carb and if so does anyone have any available?
Thank you, Corey
Excellent! Thank you Charles.
I would respectfully disagree, I think both of the the S8MS Holley carbs were equipped with a dashpot (4spd and Automatic)
Agreed. All 68 Shelby carbs used dashpot
GT 350 uses same as GT 500 set up
Don, you got a pic?
You guys sure? I have examples of both. My '68 (2152) was judged at several MCA/SAAC nationals over the years and never had a deduction for a missing dashpot. I went back through the judging sheets to be sure. MCA judging sheets don't mention the dashpot though.
Tim, the big block dashpot has the long push rod, right? In the examples I have a small blocks with a dashpot, it's the style used on 65-66 automatic cars.
Well this is interesting. So to my second question does anyone know where I can get one that is correct for my car including the bracket that mounts it?
I know of a car that went through SAAC judging and was painted the wrong color. It never received a deduction. None of the codes were changed.
😉
Quote from: CharlesTurner on November 09, 2020, 06:33:52 PM
You guys sure? I have examples of both. My '68 (2152) was judged at several MCA/SAAC nationals over the years and never had a deduction for a missing dashpot.
Tim, the big block dashpot has the long push rod, right?
Not surprised on judging. Until I really researched 350s about 8-9 years ago there was not a lot known out there about 350s. Sure everyone knew 500s and KRs but the 350s nobody had really seen many that were done correctly. Regarding the style of dash pot, when you say longer pushrod you're thinking of the cobra jet carburetor which is true on a KR. The 6566 used a autolite style which is a totally different Dash pot and bracket. 6 68 350s and 500s had holley dashpot with a rubber boot around the plunger. If you look at 68 GT 390s you will see the same style used. Let me see if I can find a picture
Found a picture, I asked 'Pete to post it since it's from his collection
(http://www.thecoralsnake.com/c8zx3.JPG)
https://www.ebay.com/itm/NOS-Motorcraft-Mustang-Fairlane-C8OZ-9B549-A-Holley-390-4bbl-Choke-Dashpot-67-68/153958081250?epid=0&hash=item23d89de2e2:g:XP0AAOSwvKBe1vg-
Bracket is what's hard to find
Is the belief that only 4sp Holley carbs should have a dashpot or also 4300 4sp should have one? I found a reference noting for the 4300, a dashpot only applied to auto trans cars... and was like the earlier cars except with a longer shaft and slightly different bracket.
Guess I'm not completely convinced, maybe some original photos/low mileage examples would help? Any documentation? ;D
Pic of the bracket would be nice, I have several, but they're all mixed style.
OK picture of autolite 4 spd dashpot coming
hi per Tims request here is an early autolite dashpot photo
autolite dashpot
autolite dashpot
I think the question focused specifically on the Holleys used on later GT350s.
The Autolite carbs used the dashpot.
After chatting with Tim, it appears the Holleys also used the dashpot and the photos are representative of the dashpot used.
Great guys I am making progress! I purchased the dash Pot Tim pointed me to. Now I need a bracket. I found the bracket shown below on MAC's Auto Parts. Does this look correct? Does anyone out there have an original they would like to part with?
Now a few more fine detail questions. What hardware is used to mount this bracket to the carb?
Finally in Kevin's pictures of the autolite carb there is a spring used. Is this spring used on the Holley? If so any idea what this spring is or where to get one?
Thank you so much for the incredible help.
Corey
Corey in the first 2 pictures you posted that i sent youin the beginning of this string of the dashpot on my car, there is not exposed spring like on the autolite. I suspect that the spring is underneath the rubber boot
Kevin,
I am referring to the spring shown below. Does your Holley have this spring?
Corey, No mine doesn't have that spring on it
Thank you Kevin.
Can you tell if your bracket looks like the one I posted?
That spring has nothing to do with the dashpot. Its for the arm.
Late to this topic, but including a photo of the correct '68 500 dashpot and bracket. Notice the bellows does not have an external coil spring. Ford complicates this part by continuing the part # (without changing the engineering revision suffix) when servicing the "long arm"/plunger version that was used on CJ and B9, etc.
Now, the question of 350 application and tranny---I have not studied.
Don
Quote from: 68blk500c on November 10, 2020, 10:03:32 AM
Late to this topic, but including a photo of the correct '68 500 dashpot and bracket. Notice the bellows does not have an external coil spring. Ford complicates this part by continuing the part # (without changing the engineering revision suffix) when servicing the "long arm"/plunger version that was used on CJ and B9, etc.
Now, the question of 350 application and tranny---I have not studied.
Don
I've wondered too - why does a 4-speed car (as stated in the opening post) have a dash pot? I thought those were only used on automatic equipped cars, were they used on later (after '67) 4-speeds?
Quote from: 68blk500c on November 10, 2020, 10:03:32 AM
Late to this topic, but including a photo of the correct '68 500 dashpot and bracket. Notice the bellows does not have an external coil spring. Ford complicates this part by continuing the part # (without changing the engineering revision suffix) when servicing the "long arm"/plunger version that was used on CJ and B9, etc.
Now, the question of 350 application and tranny---I have not studied.
Don
Don,
Thank you for the picture it is very helpful. Your bracket looks similar to the one I posted but not identical. So if anyone has the correct bracket or know where I can get one please let me know.
Thank you all, Corey
Quote from: KDunne on November 09, 2020, 09:56:57 PM
hi per Tims request here is an early autolite dashpot photo
Which carb number?
Corey: It stands to reason that the dashpot and bracket should be the same for a 68 Holley, regardless of 350 or 500. The relevant dimensions of the carb would be the same. I looked through my pictures of original cars, but didn't find a shot that will help you.
Can I ask, what was the purpose of the dashpot? Was it to prevent stalling of the engine when letting off the throttle abruptly? Why would some models have one but not others? Thanks!
Terry
Thanks to this Forum and the wonderful folks here I now have the correct dash pot and correct bracket on its way to me.
Thank you all so much.
Corey
Quote from: 68blk500c on November 10, 2020, 01:14:11 PM
Corey: It stands to reason that the dashpot and bracket should be the same for a 68 Holley, regardless of 350 or 500. The relevant dimensions of the carb would be the same. I looked through my pictures of original cars, but didn't find a shot that will help you.
Yes if you are referring to the non CJ carbs. Dashpot and bracket very different on them. As a side note many things changed when cj carbs came out. Different style metering blocks, throttle plates and linkage. I remember once talking to Jon Ernyart about a cj throttle shaft he send me for a 500. He said " there's only 5 people in the world that would even know they're different "
I told him I was worried about the other 3 😁
Right, Tim; non-CJ. I learned well after Jon's passing about throttle shafts and base plate variations.