Wow, been running with no secondaries... Pics included
06-19-2007, 10:54 AM
#21
3rd Gear Member
Thread Starter
Join Date: Jul 2006
Location: Kentucky
Posts: 913
RE: Wow, been running with no secondaries... Pics included
ORIGINAL: stocksuspension
actually uve been running ur secondaries at all times, the spring controls theopensing of the secondaries!!!
actually uve been running ur secondaries at all times, the spring controls theopensing of the secondaries!!!
ORIGINAL: 1985stang
Well, I tore into my old carb today (waiting for new one from UPS) and found out that I have had no secondaries for almost a year. I say this because ever since I bought the car, the performance has never noticeably dropped off (it was already horrible i guess). So basically I've been running on only primaries and that's why it doesn't pull into high rpm's whatsoever. So what I'm wanting to know is, can the car be hurt from only running primaries. Also, how much better is it gonna feel when i'm driving (I thought it was pretty quick before) with the new carburetor? Here are a few pics, notice how the secondary pump diaphram looks like it got chewed up by a dog...
[IMG]local://upfiles/44794/180D724EA91C44A08AD17F8E5A65C9ED.jpg[/IMG]
[IMG]local://upfiles/44794/AA551BC69DEF4BE3B381B8F17093A70F.jpg[/IMG]
[IMG]local://upfiles/44794/637998E9877D463BA45FFA7AB62F4734.jpg[/IMG]
[IMG]local://upfiles/44794/7F515F52741C467EB1CCEA7F3160C7EB.jpg[/IMG]
[IMG]local://upfiles/44794/E8A2768D9B4240669D05B1D7A2D32B1E.jpg[/IMG]
Well, I tore into my old carb today (waiting for new one from UPS) and found out that I have had no secondaries for almost a year. I say this because ever since I bought the car, the performance has never noticeably dropped off (it was already horrible i guess). So basically I've been running on only primaries and that's why it doesn't pull into high rpm's whatsoever. So what I'm wanting to know is, can the car be hurt from only running primaries. Also, how much better is it gonna feel when i'm driving (I thought it was pretty quick before) with the new carburetor? Here are a few pics, notice how the secondary pump diaphram looks like it got chewed up by a dog...
[IMG]local://upfiles/44794/180D724EA91C44A08AD17F8E5A65C9ED.jpg[/IMG]
[IMG]local://upfiles/44794/AA551BC69DEF4BE3B381B8F17093A70F.jpg[/IMG]
[IMG]local://upfiles/44794/637998E9877D463BA45FFA7AB62F4734.jpg[/IMG]
[IMG]local://upfiles/44794/7F515F52741C467EB1CCEA7F3160C7EB.jpg[/IMG]
[IMG]local://upfiles/44794/E8A2768D9B4240669D05B1D7A2D32B1E.jpg[/IMG]
06-19-2007, 10:59 AM
#22
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Join Date: Jul 2006
Location: Kentucky
Posts: 913
RE: Wow, been running with no secondaries... Pics included
ORIGINAL: 67mustang302
A bone stock 302 will never draw the full 600cfm is all I was saying. A vac secondary 600works well(if tunedproperly)and leaves room to grow. I was just saying the reason you may have never noticed the loss of the secondaries is because they may have never been coming in enough for you to notice them missing. If you hooked up a flowmeter to a stock 302, it's doubtful it'd even draw 475cfm at peak power, especially if it's old and a little worn out. And don't get me wrong, I'm not saying those carbs that Ford used stock are bad, cuz they're actually very good carbs and can handle pretty much anything you can throw at it for a n/a daily driver, and do it with reliability. And not to pick at you or anything, but on that Holley page if you look at the 595cfm example, that was for an engine turning 8,000rpm with 85% VE and it required about 600cfm. Your engine is prolly at MOST 85% VE and turning nothing near 8,000rpm, more like 4,500rpm and 80% VE, which means it needs way less than 600cfm. But again, that doesn't mean 600cfm won't work, just that it may explain why you never really noticed the loss of the secondaries over time. You should feel a gain in top end power with the new carb though, even if only small
A bone stock 302 will never draw the full 600cfm is all I was saying. A vac secondary 600works well(if tunedproperly)and leaves room to grow. I was just saying the reason you may have never noticed the loss of the secondaries is because they may have never been coming in enough for you to notice them missing. If you hooked up a flowmeter to a stock 302, it's doubtful it'd even draw 475cfm at peak power, especially if it's old and a little worn out. And don't get me wrong, I'm not saying those carbs that Ford used stock are bad, cuz they're actually very good carbs and can handle pretty much anything you can throw at it for a n/a daily driver, and do it with reliability. And not to pick at you or anything, but on that Holley page if you look at the 595cfm example, that was for an engine turning 8,000rpm with 85% VE and it required about 600cfm. Your engine is prolly at MOST 85% VE and turning nothing near 8,000rpm, more like 4,500rpm and 80% VE, which means it needs way less than 600cfm. But again, that doesn't mean 600cfm won't work, just that it may explain why you never really noticed the loss of the secondaries over time. You should feel a gain in top end power with the new carb though, even if only small
06-19-2007, 01:45 PM
#23
6th Gear Member
Join Date: Dec 2006
Location: Citrus County, FL
Posts: 8,007
RE: Wow, been running with no secondaries... Pics included
im looking at the 570 for my 289 build...... maybe right outta the gate you should put the jets from the 4180 into the new 4160 since thats how ford had it. probably run better that way.
06-19-2007, 04:07 PM
#24
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Join Date: Jan 2007
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RE: Wow, been running with no secondaries... Pics included
ORIGINAL: 2 kwik
you could have put a small sheet metal screw in the linkage and they would have work all for about .25 cents
and that diapham is like 7.95... so, how about just giving me that carb?
you could have put a small sheet metal screw in the linkage and they would have work all for about .25 cents
and that diapham is like 7.95... so, how about just giving me that carb?
06-19-2007, 04:18 PM
#25
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Join Date: Jan 2006
Location: new jersey
Posts: 6,635
RE: Wow, been running with no secondaries... Pics included
ORIGINAL: stocksuspension
actually uve been running ur secondaries at all times, the spring controls theopensing of the secondaries!!!
actually uve been running ur secondaries at all times, the spring controls theopensing of the secondaries!!!
06-22-2007, 02:10 AM
#26
2nd Gear Member
Join Date: Aug 2006
Posts: 317
RE: Wow, been running with no secondaries... Pics included
then y is it when u run a lighter spring ur secondaries open sooner!!
ORIGINAL: HACKGT350
actually he hasnt been running them at all. its called vacuum secondaries for a reason and the diaphram was all chewed up which creates a vacuum leak so no secondaries
ORIGINAL: stocksuspension
actually uve been running ur secondaries at all times, the spring controls theopensing of the secondaries!!!
actually uve been running ur secondaries at all times, the spring controls theopensing of the secondaries!!!
06-22-2007, 02:27 AM
#27
6th Gear Member
Join Date: Apr 2007
Location: California
Posts: 10,468
RE: Wow, been running with no secondaries... Pics included
I run the 570 Street Avenger on my 302, and it makes plenty of top end, I like it for a small street carb. And yeah, I'm sure you'll pull past 2,500 rpm now, not that stock engines had that much top end anyway....you could get some heads to go with that shiny new carburetor! As far as secondaries opening without a spring....if the diaphragm is torn, no spring at all would still not make the secondaries open, the diaphragm chamber wouldn't draw a vacuum to pull the secondaries open with. If you have a leak, you have no vacuum
As far as secondaries opening without a spring....if the diaphragm is torn, no spring at all would still not make the secondaries open, the diaphragm chamber wouldn't draw a vacuum to pull the secondaries open with. If you have a leak, you have no vacuum
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