Fuel Injection to 4 barrel

[ordo]

I have a 1985 Dodge dually with a damaged block and piston. It has a 4 barrel carb.

I purchased a 1990 360 which has throttle body injection. (Also a automatic trans.)

I want to keep the exchange simple and use my old intake and 4 barrel.

I was told that the camshaft that is with my donar 360 FI has a different profile due to the fuel injection,....... and that it may not run well,!! He was not sure of his facts however.

Is this camshaft a problem for my intended exchange?

Anyone done this before?

Thanks gordon

[rumblefish360]

It should do very well. If it was the reverse, FI on to a older carb engine, It may not work so well. The computer doesn't accept much change or do it well.
Most FI camshafts I have noticed are a wider centerline`which would leed to a melloer idle and higher vaccum signal.
Take all the linkage and swap it over. Take note on it's positions and take pictures to match it up when you reinstall it.

[ordo]

Thanks for a very complete answer. Donar engine is sitting on pallet with the fuel injection intact. (It is out of a one ton van with automatic.) I will take throttle body off donar 360 tomorrow.

Then I shall install the carb etc. onto the donar and drop it into the 1985 dually.

Subject recipient truck truck is a 1985 dually. It was/is the carbed from the factory. By the way linkage is with the broken 360 which I am about to pull out of the 85 dually. Gordon

Main thing is,.... I am doing the FI to Carb so should be a piece of cake. eh?

[TK]

Cake.
The 4bbl will actually run better on the FI360, than the Carb 360. Good cam, being a roller and all, more bang for your duration.
Also, being a 90 360, it should have 308 heads, which are real nice flowing. All in all, it should run like a raped ape!
Adding a simple timing chain, and slightly bigger cam, would really wake it up too, if you want to spend a bit more extra time and money.

[dwc43]

Originally Posted by ordo

I have a 1985 Dodge dually with a damaged block and piston. It has a 4 barrel carb.

I purchased a 1990 360 which has throttle body injection. (Also a automatic trans.)

I want to keep the exchange simple and use my old intake and 4 barrel.

I was told that the camshaft that is with my donar 360 FI has a different profile due to the fuel injection,....... and that it may not run well,!! He was not sure of his facts however.

Is this camshaft a problem for my intended exchange?

Anyone done this before?

Thanks gordon

Just swap the intake and carb and that part of it will work fine. What these other two missed is the rest of the swap that must be done. You must use the front timming chain cover,chain, and fuel pump eccentric (sp) cause the FI engine has no way to mount your mechanical fuel pump. The hole wherer the pump would go is solid and uncut on the FI engine.

[TK]

Huh, are you sure? There is a plate on the ones I have seen...........

Pump eccentric I did forget, kudo's to dwc, the "timming"(ed), eccentric turkeybutt!
You forgot to ask him what carburator he was using dw.........you OK?

[dwc43]

If it's stock, it's a 2bbl or a Thermoquad. Either one is good, but the TQ is best.

[TK]

I knew it! I knew it!

[ordo]

Originally Posted by dwc43

If it's stock, it's a 2bbl or a Thermoquad. Either one is good, but the TQ is best.

HEY, thanks to all,!!

By the way,.. it has a Rochester quadrajet. And, Yes thank you, we will be changing out thw front cover together with offset for pump. Probably put on a new timing chain and check the bearings considering we will be dropping the pan. Gordon

[dwc43]

Must be a late build year. I did not think they put the quadrajunk on there at all. It should have went straight from Tq to Fi tbi. I'd replace it with a thermoquad and you will see much more power and better fuel milage too.

[titan]

Um, wouldn't the fuel injected engine have a roller cam which did not have a snout on it for a mech. fuel pump eccentric?

[dwc43]

The early engines had roller cams and they have a snout for the fuel pump. Same cams used in the 318 E58 police car engines and they used mechanical fuel pumps.

[rumblefish360]

I wasn't aware that T-Q's were used so late. Must be a southern thing, LOL.
QJ's are used in most later years.
Also, the ecentric deleate I know was a Magnum engine thing. I have not seen a late model engine that was a LA without a fuel pump or had a chance to work on a FI engine.

[dwc43]

Originally Posted by rumblefish360

I wasn't aware that T-Q's were used so late. Must be a southern thing, LOL.
QJ's are used in most later years.
Also, the ecentric deleate I know was a Magnum engine thing. I have not seen a late model engine that was a LA without a fuel pump or had a chance to work on a FI engine.

Somewhere right there in that modle range the tq was gone and the quadrajunk went on police cars and most everything else had a2bbl on it. Guess this one got lucky. You know how Mopar screws things up and builds stuff that is not supposed to be available. Like a 4 dr Sattelite with a Hemi in it. lol!!

[rumblefish360]

LOL, it's true, just check the box. I like the T-Q over the Q-J.

[dwc43]

No doubt Tq over quadrajunk anyday. I ran Freddies Chevelle SS one night at Winchester and took it to a 5th place finish. Might have done better if it had not busted a shock. Matter or fact all four were leaking. HE had a quadrajunk on this one cause he wanted to try the holley on his other car. On one lap I came out of turn 2 and matted it like I had been all night. This car was really hooked up and I was not afraid to get rough with it either. Anyhow, comming out of 2 the sec. on the qjunk did not open when I matted it. All of a sudden it came on full force and the rear broke loose. I rode the berm sideways all the way down the back stretch and never lifted out of it till I hit turn3. Got lucky really, but I really hate those carbs.

[George G. Leverette]

Does Hughes have an adapter to make the mechanical fuel pump work in these applications?

[dwc43]

There is no adapter or any need for one. You just use the timming chain cover and eccentric (sp) from any stock LA and put it on the tbi fi roller cam engine. That's all. If you swap ove a magnum to carb you'll need an electric pump or a different cam.

[rumblefish360]

Originally Posted by dwc43

If you swap over a magnum to carb you'll need an electric pump or a different cam.

If you use a different cam, as in one with longer snout, or normal as your used to it, the the timing cover needs to be replaced with a older LA vesion. And then you can use the mech pump.

[ordo]

Good stuff fellas,. I do have some thermoquads I may have one rebuilt which has the right flow for this setup. Gordon

[TK]

And I still say there will be a hole for the eccentric, and a plate where the pump goes.................
Seen too many like that.
And Thermoquads only wish they had half the reliability that a Q-Jet does................only carbn I have ever seen that will go 200,000 miles and not be touched. Good carb, don't fool yourselves.

[ordo]

Quadrajets, they are long life with nary a problem. I felt I may get a little more HP out of thermoquad. Gordon

[TK]

It is possible, but on a mild motor, you may not ever know.
Q-jet pretty much works the same as the thermo/AFB................and acts the same too.
One float bowl seems to be the demise, but it sure works good offroad!

[dwc43]

The quadrajunk does not work like a TQ at all. It's o.k. on a stock chevy but that's about it. It's too small for Mopar small blocks too. The Tq will flow more cfm than the quadrajunk and it meters fuel much better too. The Tq is also much more throttle respsonsive than the quadrajunk.

[rumblefish360]

Weren't some Q-j's rated at a smaller CFM, like 650 on 305 engines. Edelbrock has a 795 offering.

[dwc43]

I think Freddy told me they are 625, but either way they are small and the big block carb is not much bigger and it's real hard to find.

[TK]

They are both metering rod carbs.............and 625 is NOT to small for a mild 318/360..........
You will have to explain how a thermoquad will be more responsive. From what I have felt, both work almost identical.

[dwc43]

First off, no one mentioned metering rods. I said they meter the fuel differently and they do. And if you would bother to look inside the prim of a TQ you will see a doubly booster ring that supposrts air flow and fuel flow at different low speed rpms along with the smaller prim blade that is what gives it it's superior low rpm throttle response. Then the larger sec. kick in and the way they meter fuel and air makes it even better.

[TK]

You better look again, TQ, QJ, and AFB all have the same basic design in the mains...............
Again, what in the design makes hem more/less responsive?

[dwc43]

I just told you. And those three carbs do not work the same. If you believe so you will never learn anything.