who here has swapped a non HO 302 for a HO 302??

I am getting a longblock mustang engine (hopefully) to replace the non HO 5.0L in my 1991 F-150, and I could use some know how.

I know for sure you need another computer. Would one from a Mustang work??

 

I did it in my 92, and it is a whole different truck now. I didnt have to change the computor,and my truck runs just fine. There is really nothing to it. I used my truck intake and all the accessories. Who told you you had to change the computor?
If you have any questions post them on here or feel free to E-mail me.

 

you have to change the computer because:

1.) different injector firing order (but i was told that our trucks fire all 4 injectors at once??)

2.) different firing order - ignition/spark plugs

3.) our injectors are smaller 14lbs/hr instead of a HOs 19lbs/hr. so the injectors have to be cleaned.

4.) you tell me what you did exactly, a non HO firing order is:
1-5-4-2-6-3-7-8 .... and a HO firing order is:
1-3-7-2-6-5-4-8 after the 351W roller motor.

Trust me I know that a 5.0 HO is a roller motor with a 351W cam. I had 2 stangs with that engine and one without the HO config.

 

oh, and it says that you wish not to receive e-mails through this board when I went to e-mail you.

 

ive heard of some people re-routing or re-wiring tehir injectors in order to keep the same firing order.

 

ya but what's this "batch" injection to where 4 injectors fire at once.. WTF!?

 

Just change your plug wires to the HO(351) firing order.
Unless I am mistaken truck injectors ARE 19lb just like the mustang.
Yes your truck will fire 4 at once JUST LIKE IT DID BEFORE.
It fires one side then the other side- but the cam has nothing to do with it. Trust me IT WILL WORK!

I have an 86 mustang shortblock(true flat top pistons) with 89 mustang heads in my 92 F150.

My local ford dealer said that I would have to convert to mass air or my truck wouldnt run. Well- It does run-GREAT!

If you have any questions my E-mail is mandc@iland.net

 

lets figure this out here:

non HO motor batch firing system.
1-5-4-2-6-3-7-8 ..

this means injectors:
1.)1-4 injectors fire, bank 1
5.)5-8 inj. fire, bank 2
4.)1-4, b1
2.)1-4, b1
6.)5-8, b2
3.)1-4, b1
7.)5-8, b2
8.)5-8, b2

and this wouldn't work because on a HO motor:
1-3-7-2-6-5-4-8
this means injectors:
1.)1-4 injectors fire, bank 1
3.)1-4, b1
7.)5-8, inj. fire, bank 2
2.)1-4, b1
6.)5-8, b2
5.)5-8, b2
4.)1-4, b1
8.)5-8, b2

so batch bank firing order is:
1,2,1,1,2,1,2,2 and what I would need is:
1,1,2,1,2,2,1,2 ->you know if you push this lines to the right 2 places and wrap around you get:
1,2,1,1,2,1,2,2..

** what i am saying is that when the truck computer is firing for number 5's bank of injectors for #5 cyl, #3 will be really coming up for the intake and that is the opposite side of the engine, SAME goes for numbers 7 and 4 **

#3/5 & 7/4 pistons come up at the same time but are doing a different valvetrain action, and the injectors work with the valvetrain pattern, even if it is batch it has to fire on the correct side of the motor. -- any ideas ??

in batch injection, does each injector have its own 2 wires or are they daisy chained/hard wired together per bank??

 

Batch firing order is b1,b2,b1,b2 ect. Fuel does not have to be introduced right when the intake valve is opening! It isnt this way with the truck cam and it wont be with the HO cam.
Think about a throttle body injected vehicle- They dont squirt fuel only when the intake valve is opening.

 

hmm.. that does make sense.

well then how the hell is it efficient, and when it meters the fuel going out, it calculates the fuel * 4 injectors?? In other words, since it uses time to calculate how much fuel in milliseconds, it must have to say okay Xms * 4 injectors gives me this must fuel..

anyways, that just seems very strange. but if it just goes b1,b2,etc repeat.. over and over, than I it works.

 

Yeah the fuel just kinda sits in the intake for a little while until the intake valve opens and sucks it in. Batch firing is not AS efficient as sequential injection, but it does work. Trust me if you do the swap you will not be dissapointed.
I have a 92 4x4 extended cab 302 and my brother in law has a 92 extended cab 4x4 351 and mine will consistatly beat his.
Mine revs higher and pulls much stronger now than it ever did before.

Good luck

 

I am going to bring this back up again. I know this post is a year and a half old...but....

I was wondering if anyone else has installed a HO engine lately with some input.

I just got a 87 F150 that I might install a roller motor that I have.

 

I'll just chime in that you should swap ECM's, but you don't have to. If you swap wiring harnesses, then you you do have to swap ECM's. Most of the batch fired 5.0's use 14 pound injectors which are fired every other stroke (two times per cylinder per 4 strokes). Sequential fires through 19 pound injectors one time per 4 strokes.

What other questions did you have?

 

I did the swap in my 1990 F150 extended cab about 6 months ago. You don't need to swap the computer just swap plug wires to 5.0 H.O. firing order. Both motors use same 19 lbs injectors. Use the Mustang distributor because it has a steel gear for the roller tappet cam. The truck cam is a flat tappet and requires an iron gear. All other truck accessories will bolt right up. Keep in mind the H.O. cam has a slightly higher powerband than the truck cam. You'll notice a slight decrease in low rpm torque depending on your rear end ratio.

 

Thanks for the input. I knew about the dist. gear, but alot of people overlook that one.

Thanks again