stone
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Post by stone on May 3, 2019 13:34:18 GMT -5
I have a 79 F-150 with a new (not rebuilt) 351 modified engine and a 4 bbl Edelbrock 600 CFM carb and I have a question.
I know a dirty carb can be an issue, and since the four bbl seldom gets used, is it wise to occasionally open it up to get some clean fuel running through it? Or am I just looking for an excuse to hear that sound
I was also told that the 351 modified does not like the Edelbrock carb, that I should change it out for a Holley?
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Post by Ronv69 on May 3, 2019 13:49:52 GMT -5
The brand or model of carb is not as important as having it set up right. My 69 Roadrunner got a hemi transplant, and it didn't come with carbs. The factory manifold was set up for Carter AFBs, but the Hemi specific carbs weren't available. I acquired a pair for the Cadillac 425 engine and had them set up by a Mopar Nascar mechanic. Dynoed @ 625hp at the wheels. If you have doubts about the carb setup, get it to a knowledgeable mechanic who knows how to set up a hot rod carb. PS My 73 F150 had a 360 with 390 GTA heads and cam with Hooker headers. It had a Holly 650 and would out run a 454 Chevy easily. I believe that the Edelbrock carbs are copied from the Holly's, and should be able to be set up for any engine. The engine doesn't know or care where the air fuel mixture is coming from. Make sure that the carb, manifold and heads are matched.
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Post by slowroll on May 3, 2019 13:51:26 GMT -5
I have a 79 F-150 with a new (not rebuilt) 351 modified engine and a 4 bbl Edelbrock 600 CFM carb and I have a question.
I know a dirty carb can be an issue, and since the four bbl seldom gets used, is it wise to occasionally open it up to get some clean fuel running through it? Or am I just looking for an excuse to hear that sound
I was also told that the 351 modified does not like the Edelbrock carb, that I should change it out for a Holley?
I've been an engine guy for my whole life, rebuilt a bunch of racing and airplane engines, so I guess I qualify as a motorhead  not a bad idea to open it up once in a while. The only place fuel will sit is actually in the main jets to the top 2 barrels, the float chamber is common to all 4 usually. It won't take long, there isn't much fuel in that passageway. Truth is, it will gradually bleed out just from air leakage, but opening it up once in a while will do it faster, besides fun. Can't answer your other question though. I believe Holleys were standard on those, so there is that.
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Post by sperrytops on May 3, 2019 13:52:11 GMT -5
The brand or model of carb is not as important as having it set up right. My 69 Roadrunner got a hemi transplant, and it didn't come with carbs. The factory manifold was set up for Carter AFBs, but the Hemi specific carbs weren't available. I acquired a pair for the Cadillac 425 engine and had them set up by a Mopar Nascar mechanic. Dynoed @ 625hp at the wheels. If you have doubts about the carb setup, get it to a knowledgeable mechanic who knows how to set up a hot rod carb. Ron, I presume you don't use this for commuting.
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Post by Deleted on May 3, 2019 13:55:50 GMT -5
When I did a full restoration on a ‘68 Firebird I got rid of Pontiacs ported manifold and used an Edelbrock intake manifold, with the proper adapter/spacer with a Holley 850 double pump carburator/4 barrel. Constantly tweaking the mixture. Finally I installed an in-line gas filter alongside the carburetor and the end result was worth the effort. No more bogging down. I made sure at least twice a week I’d get on it a bit and blow out all 4 barrels of the 850.
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Post by Deleted on May 3, 2019 21:17:27 GMT -5
The Carter AFB is fine for the ford much less hassle than a Holly. The trick is this if the manifold plenum dividing the banks goes all the way to top it needs to ground down about half way. Use a vacuum gauge to set the timing and the carburetor when it pulls the most vacuum at the lowest RPM it is set.
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Post by Ronv69 on May 3, 2019 22:00:55 GMT -5
The brand or model of carb is not as important as having it set up right. My 69 Roadrunner got a hemi transplant, and it didn't come with carbs. The factory manifold was set up for Carter AFBs, but the Hemi specific carbs weren't available. I acquired a pair for the Cadillac 425 engine and had them set up by a Mopar Nascar mechanic. Dynoed @ 625hp at the wheels. If you have doubts about the carb setup, get it to a knowledgeable mechanic who knows how to set up a hot rod carb. Ron, I presume you don't use this for commuting. I had to sell it during the gas crisis of 1973. My first wife used it for commuting while her Pontiac was in the shop. She got this wild look in her eyes when she got in it. Supreme power on the freeways. I needed money, it needed a fuel pump, and a guy offered me $850 for it. Just don't say a word.
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Post by Ronv69 on May 3, 2019 22:16:05 GMT -5
The Carter AFB is fine for the ford much less hassle than a Holly. The trick is this if the manifold plenum dividing the banks goes all the way to top it needs to ground down about half way. Use a vacuum gauge to set the timing and the carburetor when it pulls the most vacuum at the lowest RPM it is set. The thing about the Holly/Edelbrock carbs is that they are almost infinitely adjustable. Carters and Quadrajets are a pain to change anything on.
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Post by Ronv69 on May 3, 2019 22:26:43 GMT -5
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Post by Deleted on May 4, 2019 1:28:21 GMT -5
This older guy still has what it takes......
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Post by Deleted on May 4, 2019 4:19:52 GMT -5
Quadrajet set it and forget it take a welding tip cleaner to the back jet to upsize em a bit. Holly has always been over rated but they used to be cheap I see not so much anymore. The OEM 2bbl carb was probably about 425cfm and yes Ford loved 2bbl carbs. If the truck has a mild RV cam it will use every bit of 600cfm. The 351m heads are what hold it back such a terrible design. The good heads are 4bbl Ausssie head and good luck finding those. Be happy it is not a 351W those had small valves and big smog ports hanging down on the exhaust side and just could not breath. The exhaust system on the truck is plenty and unless a manifold cracks is not worth headers, Melling offers a nice kit www.melling.com/parts-lookup/ costs 150 bucks not bad for a cam and lifter set and it will work with the stock springs and press in studs. Oh and you would want new valve keepers. Still cheaper than playing guess what carb I need and finding someone to properly set it up. Now the carb you have will match the cam you have and the truck will have a better power band and just a few more horses. The 79 ford had the square headlight instead of the round up front and is a good looking truck.
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Post by simnettpratt on May 4, 2019 5:11:48 GMT -5
You shouldn't even need a reason to open it up  I got my Miata to average 19mpg on public roads, and was working on 18, but there's too many 40mph straightaways in regular driving.
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Post by simnettpratt on May 4, 2019 5:18:16 GMT -5
This is what I mean  
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stone
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Post by stone on May 4, 2019 6:16:19 GMT -5
![]() Wow! There is a lot of good info here. Maybe I should have clarified, Fi-Fi is just a utility truck now, the Ohio salt killed her  I only drive her a few thousand miles a year and my only goal is to improve on the 9 MPG.
Here she is in 1991 when I bought her.
And here she is in 1999 after a full restoration due to Ohio salt.
I would be embarrassed to show a picture her now.
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Post by Deleted on May 4, 2019 15:22:18 GMT -5
That's pretty fuel good mileage for a 4x4 of that era so yeah take her out and make her bark. That is to say blow the soot off the exhaust valves.
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stone
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Post by stone on May 4, 2019 15:33:24 GMT -5
That's pretty fuel good mileage for a 4x4 of that era so yeah take her out and make her bark. That is to say blow the soot off the exhaust valves. Oh, she barks! When I first had the new motor put in she got 12 MPG and I would love to get that back.
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Post by qmechanics on May 4, 2019 15:46:08 GMT -5
Did someone say Motorhead?
Yes yes I am a gear head...
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Post by Ronv69 on May 4, 2019 16:18:30 GMT -5
Quadrajet set it and forget it take a welding tip cleaner to the back jet to upsize em a bit. Holly has always been over rated but they used to be cheap I see not so much anymore. The OEM 2bbl carb was probably about 425cfm and yes Ford loved 2bbl carbs. If the truck has a mild RV cam it will use every bit of 600cfm. The 351m heads are what hold it back such a terrible design. The good heads are 4bbl Ausssie head and good luck finding those. Be happy it is not a 351W those had small valves and big smog ports hanging down on the exhaust side and just could not breath. The exhaust system on the truck is plenty and unless a manifold cracks is not worth headers, Melling offers a nice kit www.melling.com/parts-lookup/ costs 150 bucks not bad for a cam and lifter set and it will work with the stock springs and press in studs. Oh and you would want new valve keepers. Still cheaper than playing guess what carb I need and finding someone to properly set it up. Now the carb you have will match the cam you have and the truck will have a better power band and just a few more horses. The 79 ford had the square headlight instead of the round up front and is a good looking truck. I replaced a bad factory 2 barrel on a 351 Torino with a 350 cfm Holly 2 brl, and there's a huge difference in the bores. Difference between a 20ga and a 10ga. No way the factory carb could have been over 275 or so.
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Post by Deleted on May 4, 2019 21:05:37 GMT -5
Depends not the underwear the Autolite/Ford 2100/2150 came in all kinds of sizes depending on the cam and they used those 2bbls for almost 30years. The 4bbl were the 4100/4150?. Remember OEM is about compromise or balanced power and a balance of longevity of other parts of the drive train. They came in 8 sizes 0.098 - 190 cfm, 1.01 - 240 cfm, 1.02 - 245 cfm, 1.08 - 287 cfm, 1.14 - 300 cfm, 1.21 - 351 cfm, 1.23 - 356 cfm, 1.33 - 424 cfm and that does not account for the various jet sizes just the air flow. There are very few folks around who fully understand the Ford part numbering system. Everything is not all the same even though it fits. Take a look at power valve they all interchange between Holly and Autolite at one time there were hundreds that has been condensed down to a dozen part numbers. How can that be, Autolite carbs are Holley in disguise. The Holly 4150 was stock on the Tbird But Ford wanted a one piece body because the 4150 bowls leaked like a sieve that's how the 4100 Autolite came about a one piece body set it and forget it. Autolite 4bbl starting with the 352 are 600cfm man the money you could have saved.
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Post by trailboss on May 4, 2019 21:18:01 GMT -5
I have been a motorhead at heart, to frugal to be one in practice....my brother in law had cars featured in Hot rod magazine, but the money involved has quelled my participation....Doesn't stop me from lusting.
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Post by Ronv69 on May 4, 2019 22:44:16 GMT -5
The carbs are easy to work on. You can clean it in the kitchen in a couple of hours and put a kit in it. If it was tuned to your engine when you got it you should still be good. Count the turns to tighten the adjustment screws before you remove them. If it's really dirty you might had to use one less turn out from where it is. I have done this dozens of times and it should fix you right up. Triple check all vacuum lines and plugs.
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Post by Ronv69 on May 4, 2019 22:47:27 GMT -5
Depends not the underwear the Autolite/Ford 2100/2150 came in all kinds of sizes depending on the cam and they used those 2bbls for almost 30years. The 4bbl were the 4100/4150?. Remember OEM is about compromise or balanced power and a balance of longevity of other parts of the drive train. They came in 8 sizes 0.098 - 190 cfm, 1.01 - 240 cfm, 1.02 - 245 cfm, 1.08 - 287 cfm, 1.14 - 300 cfm, 1.21 - 351 cfm, 1.23 - 356 cfm, 1.33 - 424 cfm and that does not account for the various jet sizes just the air flow. There are very few folks around who fully understand the Ford part numbering system. Everything is not all the same even though it fits. Take a look at power valve they all interchange between Holly and Autolite at one time there were hundreds that has been condensed down to a dozen part numbers. How can that be, Autolite carbs are Holley in disguise. The Holly 4150 was stock on the Tbird But Ford wanted a one piece body because the 4150 bowls leaked like a sieve that's how the 4100 Autolite came about a one piece body set it and forget it. Autolite 4bbl starting with the 352 are 600cfm man the money you could have saved. After some research, I find that they rated carbs differently in the olden days, along with everything else. I bow out of further discussion because of irrelevance.
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andythebeagle
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Post by andythebeagle on May 7, 2019 23:50:01 GMT -5
I spent 20 years as a flat rate line mechanic in dealerships in Rochester, NY. My last venture into anything that was not stock, was a 1968 Pontiac GTO. 421 with all the add ons and 2 Holley 850 Double Pumpers. It was a monster that was difficult to control. You'd easily loose the rear end any time you gassed on it, regardless of what gear you had it in.
I'm saying that to make the point. Open it up. Let it do what it can. You'll figure it out quick enuf.
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