Autolite 4100 question
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Lead Driver
Joined: Mar 2008
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From: Near Los Angeles
Autolite 4100 question
Anyone know if the screw in filter in the front of the carb reduces fuel psi coming into the carb?
I can't use the filter b/c it hits my v.cover. Now with two different 4100's I'm having probs with fuel flowing past the needle/seats. Needles are vitron. I've tried three sets. I've adjusted floats from top to bottom, with no effect.
Measured psi into carb at 4 or 4.5, can't remember which. That shouldn't be a problem.
I can't use the filter b/c it hits my v.cover. Now with two different 4100's I'm having probs with fuel flowing past the needle/seats. Needles are vitron. I've tried three sets. I've adjusted floats from top to bottom, with no effect.
Measured psi into carb at 4 or 4.5, can't remember which. That shouldn't be a problem.
Elder User
Joined: Feb 2012
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another prospective.
I hope I'm not embarrassing my self but, Has anyone asked..what kind of float ur using? I use brass myself. I can't imagine a good tight float NOT sealing of 4-5# of fuel pressure..I can remember when we would use up to 8psI or so in carbs back in the day and not have problems..(when everything ran a carb, and most all floats were brass...) just another look at the problem
also i don't think you want to adjust the float too low..there won't be enuf fuel in the bowl to effectively "float" the float which gives the pressure to close the needle. When that float is "immersed"..it can exert a lot of pressure...
also i don't think you want to adjust the float too low..there won't be enuf fuel in the bowl to effectively "float" the float which gives the pressure to close the needle. When that float is "immersed"..it can exert a lot of pressure...
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Lead Driver
Joined: Mar 2008
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From: Near Los Angeles
Thanks for the responses. I guess my point is that no one knows the psi coming out the oem filter going into the carb. After experiencing spurting past the needles/flooding on two 4100's, regardless of where I set the float level, with both brass floats and the neoprene ones, with 4 different sets of needles/s, I can only reason that the oem filter is not there only to filter, but to cut psi to a manageable level as well.
It took one of the inline crowd, mounting it 90* to the engine, to figure that out. (Hopefully that is the problem.)
Wow, the forum blocked the link to my auto blog in my sig! Interesting.
It took one of the inline crowd, mounting it 90* to the engine, to figure that out. (Hopefully that is the problem.)
Wow, the forum blocked the link to my auto blog in my sig! Interesting.
Tuned
Joined: Jun 2003
Posts: 307
Likes: 1
From: South Florida
Thanks for the responses. I guess my point is that no one knows the psi coming out the oem filter going into the carb. After experiencing spurting past the needles/flooding on two 4100's, regardless of where I set the float level, with both brass floats and the neoprene ones, with 4 different sets of needles/s, I can only reason that the oem filter is not there only to filter, but to cut psi to a manageable level as well.
It took one of the inline crowd, mounting it 90* to the engine, to figure that out. (Hopefully that is the problem.)
Wow, the forum blocked the link to my auto blog in my sig! Interesting.
It took one of the inline crowd, mounting it 90* to the engine, to figure that out. (Hopefully that is the problem.)
Wow, the forum blocked the link to my auto blog in my sig! Interesting.
Any restriction in the feed, whether it be 90s, filters, bends, fittings or just long runs will ALWAYS reduce the pressure, just like the water faucet.
As I mentioned in another thread, install a positive working regulator with a return to tank, it's flow that you need, not pressure. The fuel pump is a very, very crude regulator of sorts, being a variable displacement pump. I've set carbs up with as little as 2psi and they run great floored all the way to redline. You don't need more fuel than that.
Posting Guru
Joined: Mar 2006
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this sounds strange.
i'm running a 4100 on my Galaxie, but i can't remember off the top of my head if i have a screw-in filter on it or not. i'll check it this weekend.
but- on my I6, i'm running the stock fuel pump/paper filter straight into a 2100- no screw-in filter. its doing fine.
i'm running a 4100 on my Galaxie, but i can't remember off the top of my head if i have a screw-in filter on it or not. i'll check it this weekend.
but- on my I6, i'm running the stock fuel pump/paper filter straight into a 2100- no screw-in filter. its doing fine.
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Lead Driver
Joined: Mar 2008
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From: Near Los Angeles
BTW, I found the brass bushings for the 4100 throttle shaft. I guess I can't get away from Mike's Carburetors. He is the only guy who has them.
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Posting Guru
Joined: Mar 2006
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this sounds strange.
i'm running a 4100 on my Galaxie, but i can't remember off the top of my head if i have a screw-in filter on it or not. i'll check it this weekend.
but- on my I6, i'm running the stock fuel pump/paper filter straight into a 2100- no screw-in filter. its doing fine.
i'm running a 4100 on my Galaxie, but i can't remember off the top of my head if i have a screw-in filter on it or not. i'll check it this weekend.
but- on my I6, i'm running the stock fuel pump/paper filter straight into a 2100- no screw-in filter. its doing fine.
No screw-in filter on the 300 with the 2100.
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Lead Driver
Joined: Mar 2008
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From: Near Los Angeles
I'm itching to get back to my 4100 'spreadbore' experiment, and/or my 1.08 (480 cfm) 4100.
Postmaster
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From: Spokane, WA
Carbed Ford Message Board • Index page
Don't know if you are familiar with that site but it may have some info on your Autolite carb.
Don't know if you are familiar with that site but it may have some info on your Autolite carb.
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