ArdWrknTrk Posted April 19, 2020 Share Posted April 19, 2020 Must be a new Holley thing as I have never seen that on a Holley carb before only the one on the side. Dave ---- Holley's have changed some Dave, since they installed the blowout check valve's and non adjustable floats. Link to comment Share on other sites More sharing options...
Rembrant Posted April 19, 2020 Share Posted April 19, 2020 Thanks guys. I'll pickup a Tee and use the full vacuum port at the base of the carb to feed both. Dave - this is from the manual. Not sure if there is a good reason to use one over the other - I just chose the bottom one to keep the line out of the way. Well that's interesting. My 4160 is relatively new...purchased only about 2 years ago, and it has the two angled barbs like the upper right hand picture above. I can tell you that the bottom barb on mine is full manifold vacuum as that is the port I used for my vacuum gauge when I was getting everything set up. I wouldn't be able to use it for the distributor in my situation as I would have full vacuum advance at idle. Link to comment Share on other sites More sharing options...
grumpin Posted April 19, 2020 Share Posted April 19, 2020 Thanks guys. I'll pickup a Tee and use the full vacuum port at the base of the carb to feed both. Dave - this is from the manual. Not sure if there is a good reason to use one over the other - I just chose the bottom one to keep the line out of the way. Well that's interesting. My 4160 is relatively new...purchased only about 2 years ago, and it has the two angled barbs like the upper right hand picture above. I can tell you that the bottom barb on mine is full manifold vacuum as that is the port I used for my vacuum gauge when I was getting everything set up. I wouldn't be able to use it for the distributor in my situation as I would have full vacuum advance at idle. My 4160 is fairly new also, 2 years old max, I think. 3 ports, two full vacuum and one timed spark vacuum source. Link to comment Share on other sites More sharing options...
kramttocs Posted April 19, 2020 Author Share Posted April 19, 2020 My 4160 is fairly new also, 2 years old max, I think. 3 ports, two full vacuum and one timed spark vacuum source. Hmm, this is a quick fuel variant so it has some extra adjustability but wouldn't have expected the vacuum ports to be different. So forgetting the pcv big port on the back, either of you mind posting some photos of yours? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted April 20, 2020 Share Posted April 20, 2020 Hmm, this is a quick fuel variant so it has some extra adjustability but wouldn't have expected the vacuum ports to be different. So forgetting the pcv big port on the back, either of you mind posting some photos of yours? I can take pictures of my 600 and 750 in the morning, if you like. Both are basic 4160 style carbs. The 750 has a quick change secondary, and K&N stub stack. Additionally it is fitted with a Motorcraft choke element. Link to comment Share on other sites More sharing options...
Rembrant Posted April 20, 2020 Share Posted April 20, 2020 So forgetting the pcv big port on the back, either of you mind posting some photos of yours? I have the large port in the back supplying the vacuum to my brake booster. The side timed port supplies the distributor vacuum advance, and then I have the two 45* angle ports at the base in the front...one small, one large. The large one I have connected to my PCV valve, and the small one goes to my air cleaner. That's it for vacuum lines on my 302. I can take some pics no problem, but see below some pics from one of my Holley carb books. I have 3 of these for coffee table reading, but mine is connected as per these pictures. Mine is just a basic 4160 with vacuum secondaries and electric choke. Link to comment Share on other sites More sharing options...
kramttocs Posted April 20, 2020 Author Share Posted April 20, 2020 So forgetting the pcv big port on the back, either of you mind posting some photos of yours? I have the large port in the back supplying the vacuum to my brake booster. The side timed port supplies the distributor vacuum advance, and then I have the two 45* angle ports at the base in the front...one small, one large. The large one I have connected to my PCV valve, and the small one goes to my air cleaner. That's it for vacuum lines on my 302. I can take some pics no problem, but see below some pics from one of my Holley carb books. I have 3 of these for coffee table reading, but mine is connected as per these pictures. Mine is just a basic 4160 with vacuum secondaries and electric choke. Thanks! The two 45 degree ones at the base of mine are very similar in size and match the Cast Billet Model photo (middle left). I don't really know much about the QF ones but still a little surprised those two ports behave differently despite still being 4160's. Jim - if you get a chance, I'd be interested in looking at some photos of yours also. Link to comment Share on other sites More sharing options...
Rembrant Posted April 20, 2020 Share Posted April 20, 2020 I don't really know much about the QF ones but still a little surprised those two ports behave differently despite still being 4160's. I don't know much about the QF carbs either, but the shop that built my 302 said they use them all the time and were very happy with them. The reason the topic came up was I asked them what carb they would have installed on my engine, and they said QF (instead of the basic 4160 that I supplied to them). Edit: Now that I look at all the pictures, it looks like QF carbs must use different bases. See in the picture I posted about from the Holley book that there is one slot machined in the base for the two barbs? They are both on the same manifold vacuum. But when I go back up and look at your pictures, it shows separate slots machined for the two ports. Very interesting. Hope I didn't cause any confusion here Scott. I would have assumed that Holley would use the same bases, but I guess not. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted April 20, 2020 Share Posted April 20, 2020 I don't really know much about the QF ones but still a little surprised those two ports behave differently despite still being 4160's. I don't know much about the QF carbs either, but the shop that built my 302 said they use them all the time and were very happy with them. The reason the topic came up was I asked them what carb they would have installed on my engine, and they said QF (instead of the basic 4160 that I supplied to them). Edit: Now that I look at all the pictures, it looks like QF carbs must use different bases. See in the picture I posted about from the Holley book that there is one slot machined in the base for the two barbs? They are both on the same manifold vacuum. But when I go back up and look at your pictures, it shows separate slots machined for the two ports. Very interesting. Hope I didn't cause any confusion here Scott. I would have assumed that Holley would use the same bases, but I guess not. I only know QFT Dominators. QFT were a breakaway company, started by a former employee. But they had QC issues, with carbs sent out with debris and such. At least they were still American made. Another cup, and ill go get those pics... Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted April 20, 2020 Share Posted April 20, 2020 I only know QFT Dominators. QFT were a breakaway company, started by a former employee. But they had QC issues, with carbs sent out with debris and such. At least they were still American made. Another cup, and ill go get those pics... As promised, from the grange.... Link to comment Share on other sites More sharing options...
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