I would like to know if a two-barrel intake manifold from a stock 351w will fit on a 351w with fuel injection. I don't want to hastle with the EFI on this 1990 F-250 4X4. If the intakes are interchangable, will I have problems with the computer? thanks for any input. Big Al

 

[updated:LAST EDITED ON 16-Apr-02 AT 11:57 PM (EST)]It will basically fit, but one thing leads to another so it would be best to have the whole carbed engine there for all the little things. You need to change the distributor out for an older style duraspark II to take the timing control away from the computer, which will be severely crippled by the time you take a bunch of the sensors off. Have you figured out what you are going to do about the fuel system?

 

For fuel I heard that I need to plug up the return line into the gas tank and use an electric fuel pump. But I might just swap out the whole motor. In that case; will a 1979 351w block the fit on the 1990 5 speed manual transmission? do I have to change all the electrical or can I just cut and paste wires? Thanks again, Big Al

1979 F-250 4X4 SuperCab
1980 F-250 4X4
1986 F-150 4X4 SuperCab
1990 F-250 4X4

 

I hope you have your inspecters license, because if you convert it to carb it won't pass inspection. Besides EFI is more reliable and more efficient as far as horsepower and milage. Why would you wan't to go back? EFI isn't really more complicated to figure out then carburation, it's just different.

-Jon

 

I go back and forth myself. EFI starts easier and runs good when everything is right. But when things go wrong it can get complicated and expensive in a hurry. A good ole carb, while being more of a pain to start on cold mornings, is simplicity in itself.

I think the best way to handle the fuel delivery situation is to get an older fuel tank made for a carb. Otherwise, unless you take the EFI fuel pump out of the tank, you will have to suck fuel through it. If you change engines completely, or swap timing covers on the later engine, you could run the mechanical fuel pump. Some guys on here have used the factory EFI fuel pump with a regulator, and claim to have success. But to do this you will have to rig up a way to start the fuel pump when the engine is started. Right now, the computer tells the fuel pump to cut on when it get's a signal from the efi distributor.

 

 

YOU COULD CHANGE OVER BUT FROM EXPERIENCE I HAVE TO TELL YOU THAT YOU WILL NEVER BE ABLE TO GET YOUR TIMING RIGHT NOR GET THE ENGINE TO RUN GOOD AT IDLE. I CONVERTED A 5.0 OUT OF A CROWN VIC TO PUT INTO A 1984 FORD F 150, YES IT DID RUN BUT POORLY AT IDLE. I LATER LEARNED THAT THE CAM IN YOUR ENGINE HAS A HIGHER LIFT ON ITS LOBES AND IS SPECIFICALLY DESIGNED TO BE USED WITH YOUR EFI ENGINE. YOU HAVE TO CHANGE IT. MY 5.0 RAN POORLY AFTER THE CONVERSION AND PINGED UNDER LOAD. I TOOK IT TO SEVERAL DEALERS AND THEY ALL SAID THE SAME THING. IT RAN HOT AND I COULD NOT GET THE CARB TUNED TO THE ENGINE. EITHER I WAS TOO RICH OR TOO LEAN THERE WAS NO IN BETWEEN. ULTIMATELY THE ENGINE SPARK KNOCKED SO MUCH A SPARK PLUG FAILED AND WENRT THROUGH MY NO 3 PISTON AND RUINED THE ENGINE.MY ADVICE IS TO STICK WITH EFI.

 

I wouldn't say that... I have done plenty of efi swaps to carb in older rigs. I took a 88 mustang roller 5.0 and threw a carb on it along with the 5 speed and put it in a 1980 ford f100. The thing screamed and I NEVER had a problem with pinging. The rig is still running with over 130k on the motor so I disagree with the cam idea.

If you are serious in this swap I would suggest going with a decent carb. Don't go buy a cheap rebuilt or used carb and expect it to run right. If you don't know much about jetting I would stick with a 650 CFM four barrel or smaller. Most two barrel carbs is actually get worse gas mileage because the primarys are larger than those on a four barrel (granted you keep your foot out of the secondaries!)

As far as the timing goes as long as you swap to the old ignition system you wont have any problems related to timing!

I emplore you to just learn about the EFI system rather than swapping out. I was in the same boat as you about a year ago until I began to read the posts on this site, it has helped me out plenty!!!

Good Luck!

 

Well, it has been a while.
I am sorry you disagree with me and I respect your opinion but,
You have to understand that all 5.0 302 cid engines are not exactly alike. They are built for specific specs for various applications. A Crown vic 5.0 has a different valve train, piston size, bore, stroke and cam. The 5.0 that has been used for most F-150's is true to the same. If you were to take a 5.0 mustang GT engine and place it in say an F-150 you would not notice a difference in performance unless you hooked your 6,000 pound camper behind you then you would realize that horse power and torque are totally in their own world though of course they are related. The 5.0 Crown vic engine screamed in the car I pulled it out of and only had 60,000 miles on it and it was so clean you could eat off it. The only thing I did out side pulling the upper and lower intake off of it and swapping the intake off of my old engine was of course changing the timing cover so I could use a mechanical fuel pump. I ran a good ford carb that came off of my old engine and the distributor also. My old engine ran great it just had bad oil pressure so I got the crown vic from a buddy for $200 dollars for a cheap engine swap. So to wrap my experience up, in theroy the EFI 5.0 should have ran fine with the hardware swap but it did not. I did take the truck not only to a Ford racing engine builder that has been building 900 hp engines for over 20 years (I presume that he would really know his stuff, which he does) and he was the guy that educated me on the fact that all 5.0 engines are not the same. I also took it directly to my local ford dealer which could not figure out why I could not get this rig set up right. (They had it for almost a week!) Yes another guy might have done a swap and had success, but it is like playing Russian roulette. You really need to know your stuff when you start frankensteining things or you could be in for one heck of a head ache! My advise to you is simply very similar with the guy that doesn't agree with me, Use the EFI. It really would cost you about the same time to install because you would not have to fiddle with stripping the old engine down to its core and would actually save you some money, not to mention the head ache! All you have to do really is use the car or trucks computer that the engine came out of and convert your fuel tank to the EFI electric fuel pump set up and you can find after market suppliers that carry painless wire harness systems for the conversion. Believe me, you are not the first person to put an EFI engine in a vehicle that did not originally come with EFI. I am pretty sure that hundreds of EFI swaps happen every day. And as for the cam it was too big for the carb I was using. Good luck!

 

[QUOTE]Originally posted by beasleybub1
[B]Well, it has been a while.
I am sorry you disagree with me and I respect your opinion but,
You have to understand that all 5.0 302 cid engines are not exactly alike. They are built for specific specs for various applications. A Crown vic 5.0 has a different valve train, piston size, bore, stroke and cam.

That is incorrect, all 302's have a 3 inch stroke, and a 4.0002" bore from the factory. You are correct about the rest of the differences, but they are not severe enough to cause the problems you speak of. No factory cam was too radical to run in any vehicle on the street. You need to use a quality carburetor, as was mentioned before, and make sure you know how to set up a distributor. TK

 

i did this on an 88 f150 because i had the parts laying around. what you need to do is find a vacuma advancy distributer and if you want simplicity and ease of install use points i myself went with a msd electroinic one. the carb intake will bolt right in I used an edelbrack i had laying around. as for the fuel i used a mallory fuel pressure requlater because this retained stock pumps and all you have to do is plumb in tin to the return line and presser lines. the hardest part of it all for me was removing all of they old wires laying around.

 

you can also use the stock intake pump with a carb.

Simply bypass the high pressure pump on the frame rail, and rewire the intank pump to stay on with the key.

This is how my truck has been set up for 3 years, with no problems.

 

red_rocket
for my own knowledge, I thought the electric efi pumps came on regardless of weather the computer was functional or not? I heard of a fellow who just unhooked his computer and installed an fuel pressure regulator without rewiring the efi pump. Again not doubting just trying to clarify this subject. Thanks

 

yes, they will come on regardless of the computer being in it or not.

But, with the dual pump setup on the trucks, the low pressure pump in the tank only comes on for a few seconds, to prime the high pressure pump on the frame rails.

By bypassing the high pressure, and just running off the in tank pump, you will get low pressure to the motor, but only for a few seconds then the pump kicks off. To eliminate this, you have to bypass a relay under the dash.

as you said, installing a regulator up top would work just as well, with out having to bypass the relay.

 

red_rocket
Thats what I thought, appreciate it. Later