No throttle 460......

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Mar 25, 2005 | 09:09 AM

BSnBS747

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No throttle 460......

I just dropped a 71 lincoln 460 into my 1980 F250 Custom 4x4, it origionally had a 400 in it...the swap went pretty easy, just dropped right in...but when i went to fire it up it was revving really high (so it sounded, my tach doesnt work, had open headders too)....sounding like it was pushing 4-4500 rpm...my old 400 would probably blow up at that rpm...I cant seem to get the high idle down enough, Ive played with the carb screws some and that helped a little....I wanna say it was just warming up....so I decided to take it to the street...then when I got out of the driveway and press the gas pedal......it really didnt even wanna move, it started moving when the pedal was almost to the floor...I think its just all in getting the carb dialed in, and/or adjusting the throttle linkage...any thoughts would be appreciated, and any thoughts or tricks on getting a carb dialed in....the carb is a Motorcraft 4bbl, maybe about a 550-600 cfm.....stock carb.

Thanks for your time,
BSnBS747

Mar 28, 2005 | 09:30 AM

smoke n tires

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sounds like maybe a vac leak, check all the lines and also check down the carb if the plates are closed, if not then thats the problem.

Mar 28, 2005 | 09:57 AM

BSnBS747

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Thanks, I was told that too this weekend, but I cant seem to find it...I was dinkin with it over the weekend between tornados ;-) and noticed that after it runs real smooth for about 20 to 30 seconds, fuel starts bubbling up out of the fuel bowl tubes and then drowns out and then ends with a light blast of air out of the top of the carb...kinda like a whale at the ocean....I also noticed vapors coming from underneath the carb between the carb and spacer...a buddy of mine said that it sounded like my electric choke was stuck....Im thinkin about just breaking down and buying a new Holley 600......it couldnt hurt cause I think this is the carb that came off of that 71 lincoln i snatched the motor out of....that things older than I am...hehe.

Mar 29, 2005 | 01:02 PM

smoke n tires

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i would try adjusting the float levels and then try it. sounds like the floats are to high. if you buy a new carb id go to a 750. a 460 is a lot of CI and with higher comp. and later mods you will be glad you did. my stock 460 runs like a scalded dog with a 750 holley. HOLLEY is the key to power.........

Mar 31, 2005 | 01:26 PM

BSnBS747

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Okay, I found the leak...it was just a bad carb to spacer gasket...I replaced it with a little thicker one, which seemed to seal it up...I got it running smooth last night and let it run for about 20 minutes or so just to see what it would do before I took to the streets...after that I put it in drive and then it just stalled and died...it was kinda like hitting a green pine cone with your lawn mower, where the mower just stops...It runs good until you put any kinda gas pedal to it...you have to ease your foot down to rev it up or it will stall on you...I set the carb and timing to where there is no smoke or very little black smoke coming out of the tail pipe, its just a bit on the rich side, but thats better than on the lean side....Right? Im hoping its just all in the carb and not in anything major...Im gonna swap it out with my old 400s 2 barrel just to see what it does...cause I know that one works before I shell out a few hundred bucks for a new one...Thanks for your help.

Keith

Apr 2, 2005 | 03:49 PM

SwOkcOffRoader

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definitly sounds like carbs problems, that carb is loading up and flooding itself....too bad your not in oklahoma city, i can get rebuilt 750 Holleys for 150 bucks, the smaller 600's and 650's are only 95 bucks......granted they arent new, but i bought my 780 vacuum secondary on my 460 4 years ago and have only had to rebuild it once, and i NEVER have to adjust it like so many anti-Holley people say has to be done on them all the time........if you just want a truck that runs and drives buy a 650 vac sec., if you want a truck with some ***** put a 750 vacuum secondary Holley on it, set the timing at 12* BTDC at 650rpms with the vacuum advance unhooked and plugged....then let us know how it runs..........wait, thats a 71 460?? maybe the timing should be at 8-10* BTDC, check the engine decal......

Apr 4, 2005 | 09:59 AM

BSnBS747

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Yep...thats what it was...the carb. Now ive got another issue...I can only top out at around 65 mph...I was talking with a friend of mine and he said that i need to change the gears in the transmission, is this true?...Im running the stock C6 that came in the truck...Here is the before motor swap setup...400 backed up by a C6 to a 205 transfer case...out back are the stock 3.54 gears...You can hear the trans wind up pretty good when at highway speeds...I dont want to change the rearend gears cause they gave me decent gas mileage, but I wanna get the trans in tune with the motor so Im not the slowest one on the block...Any suggestions? Thanks.

Keith