302 to 5.0 HO EFI Swap Advice Needed

Discussion in '1974 - 1978 Mustang II Talk & Tech' started by gregski, Aug 3, 2010.

  1. An EFI conversion is definately on my list of things to do with my 1976 302, but it is a bit down the road so I haven't done my homework yet, just some preliminary Googling. However I have come accross a deal I don't think I can pass up, so can you guys tell me if I should get the parts off of this 1992 5.0 HO automatic. I mention automatic because I heard the more desirable swap is for the manual (with the A9L computer) so you don't have the tranny sensor throwing a check engine light since you have no where to plug it into.

    I am hesitant because the HO's came with roller cams, and I think mine is a flat tapped, (though I read somewhere that maybe all 5.0's were HO during that erra 88-91) also the HO's have a different firing order (same as the 351) right?


    Upper Intake
    Lower Intake
    Throttle Body
    Wiring Harness
    ECU E9AF-14A624-AA
    Fuel Rails (maybe)
    Fuel Injectors (maybe)
    Fuel Injector Harness (maybe)

    No Mass Air Flow Meter (Bummer)


    1. Does the 5.0 have a flat tapped cam and the HO has a roller cam, among other differences?

    2. Can I mate the 5.0 HO distributor with my 302 stock cam, and will that change the firing order?

    3. Can I use my stock D50E A3B heads someone said they are better than the 5.0 heads? I do own a set of 5.0 E7TE ie 1987 heads as well, would I have to use those instead?

    4. I really don't know what determines the firing order is it the distributor, or is it the distributor/cam combination?

    I don't want to get these parts if it means convertng my engine to a roller cam engine, if I have to do that I might as well just drop a complete 5.0 engine in. But then again I have no idea what I am talking about so somebody set me straight, please.
  2. Pretty much yes. Roller cams started appearing in 302s around 1986. To run a roller cam in your D5 block, you'll have to go with a retrofit roller cam kit utilizing special roller lifter that do not require the factory 302 lifter retainer 'spider' that bolts to the lifter valley.

    Yes. The distributor itself has noting to do with the firing order. The camshaft dictates the firing order. However the HO dizzy probably has a steel gear (forged), which should work with the std. cast 302 cam. But to run a roller cam you need to have a steel gear on the dizzy no matter what type of dizzy it is.

    All depends on what compression ratio you desire. The combustion chambers between each pair of heads may be quite a bit different. I believe the E7TEs will outflow the D5s when the same porting job is done to them.

    Cam only, distributor has nothing to do with it. You can re-arrange the plug wires in any order as long as it conincides with the firing order of the cam.
  3. FYI

    In case I haven't said this already:

    Dano78 YOU IS DA MAN !!!

    ... and now for a clerification, so if I understand correctly my stock cam will change the 5.0 HO firing order 1-3-7-2-6-5-4-8 to 1-5-4-2-6-3-7-8 the 302 firing order, so will the HO ECM comprehand that and will it be happy?

    On the other hand if I decide to just go with the 5.0 components then there is no change, as both engines use the same firing order 1-5-4-2-6-3-7-8.
  4. You got me on that one. Nothing I have is computer controlled. I've done this many-a-time with carbed engines. Running a 351W cam in the 302 in my Ranchero.
    So that's a good question, if the computer will freak out or not. Otherwise, yes, use the firing order that comes with the cam.

    There has shown to be a few hp gains from running the 5.0HO/351W firing order vs. the stock 289/302 firing order. Just some thought. If you have an H.O. computer, I'd stuff in an H.O. 5.0 or 351W camshaft, myself.
  5. EFI Parts List

    What the he11 for $100 bucks I went ahead and bought all this stuff. I know what you are thinking, are you kidding us, you asked all those questions for $100 bucks, you need to get smacked upside the head... whoa wait a second, don't tell me you guys never bought a part for $50 bucks and spent $500 trying to get it installed and working, LOL...

    1. Upper Intake
    2. Lower Intake
    3. Throttle Body
    4. Throttle Position Sensor
    5. Idle Air Control Sensor
    6. EGR Valve
    7. EGR Valve Sensor
    8. TFI Distributor
    9. Spark Plug Wires
    10. Fuel Rails
    11. Fuel Injectors
    12. Fuel Injector Wiring Harness
    13. Main Engine Wiring Harness
    14. ECM - Computer
    15. Oxygen Sensor(s)
    16. Coil
    17. Hardware

    No Mass Air Flow Meeter, (that's the only biggy that's missing) and the air intake tube, etc. At this point I am thinking I may consider trading this stuff for a non HO setup to keep my conversion simple, any takers?

    More pictures available here: Small Block Ford 302 V8

  6. I question that, actually. I got curious about firing orders a couple years ago, and did a few hours of research (I love the internet). It turns out there are only two possible firing order configurations for a V8 engine. Every single V8 made anywhere in the world has either the same firing order as a 302, or the same as a 351W, and those two firing orders are simply mirror images of each other.

    Every time I bring this up, I get arguments, but I swear my research is sound. The reason people think this can't be right is because other manufacturers use different numbering sequences. But, they also number the cylinders in a different pattern. Once you convert all of them to the same pattern, the sequences match up. I was methodical, and looked at GM, Dodge, Ford, and even a Porsche 928, a Rover V8, and a late model Toyota V8. All the same once you map them out.

    The reasoning is that the order in use provides the best balance. There are two other firing orders that look like they should work on paper (also mirror images of each other), but apparently they generate more vibration than the two in use.

    Yes, I'm a geek.
  7. Great Input

    Great input Steel Steeds, and you're not a geek, you're a resource, that or we're all geeks!

    I was telling my friend today, that you know how there is so much crap on how to fix your computer problems, and computers have only been around for 20 years, well I tell him cars have been around for 100 years so 5 times as long, so there is at least 5 times as much bad information on cars. So thank you for setting the record straight. I'm all about getting to the truth of the matter and dispelling any myths and misconceptions.
  8. Ok Geek, you're right there. There are only 4 ways to fire a 90* V8 4 stroke engine...(that I know of) and that doesn't count running it backwards, as some SB Chevys were designed to do for racing. I figured that most all V8s were the same firing order, obvoiusly numbered differently.

    The hp gains with the 351W f.o. was more of a top end gain. Probably because it was the lesser evil of the vibrations between the two firing orders. That- and I do remember reading theory on exhaust pulses and how they are effected at high rpm vs. different firing orders. I believe this info was stock car/Nascar related.

    I can tell you this, there is a definate exhaust note difference between a 351W and a 289/302 firing order. :nice:
  9. The E9 ECU used sequential fuel injection. It is timed to match the valve events of the cam, so no, I wouldn't recommend using that ECU with your old cam.

    The '87-'88 ECU used bank to bank firing, so you could use one of them, but they were also speed density, not mass air, so you would need a complete speed density set up. And unless you match the exact airflow of what it was designed for, it won't run very well because it works off of look up tables to determine ignition advance and fuel at a given rpm and manifold pressure, not actual measurements of what the engine needs. Not recommended.

    The easiest thing to do would be to get a 5.0 roller shortblock.

    Ford engineers were aware of the benefits of the 351W firing order even before they developed the 302 from the 289, but management chose not to switch over for cost reasons.

    I'm going by memory here, so please make an allowance for my old worn out brain. The reason the 351W firing order is better is because of the way it loads the crank bearings, although the differnce was fairly small. I've tried to lay it out on paper, but I can't see the difference, so I'll try to find the article that explained the justification.

    Ford couldn't justify the expense and tooling time of changing the firing order on the 302 because it wasn't a torque monster anyway, so the improvement in wear wouldn't be realized until the car was ready for the scrap heap. The 351W however with it's long stroke and torque by design warranted the change.

    Whether or not a 9,000 rpm cup engine could benefit power wise from one firing order over another is debatable. I have no experience with such high dollar or high revving engines, so I'm left with just my opinion. I'd have to say I'm very skeptical.
  10. I seem to remember reading the same about the 351W firing order reducing stress on the front most crank bearings.

    Also, I'd be wary of using the gear on the distributor designed for the roller cam. Swap it out for a cast gear if you're going to run it with a slider cam. The distributor gear is supposed to be the sacrificial gear and needs to be made out of a similar or softer metal than the cam gear. The factory steel gear on the distributor for the roller cam will wear the cam gear out.

    I went through hell trying to be "cheap" with my Mach 1 when I put the roller 5.0 longblock in it. First tried an '85 5.0L distributor which was supposed to have a steel gear on it. It came from the parts store with a cast gear and wore out within 1000 miles. Second I tried a bronze gear from summit which made it 20K miles. After that I finally spent the whole $70 on a steel gear that's still working fine to this day.

    oh...and...in my opinion the engine/wiring part of converting to EFI is the easy part ... make sure you post what you come up with for fuel. I like seeing how other people do it. I've done two methods, one with a low pressure electric pump near the tank and a high pressure pump + EFI lines from the fender well to the engine. The other has a tank modified for an in-tank pump (and spare tire well modified to clear) and braided stainless teflon lines running to the engine. If I got a 3rd try at it, I'd just have a sump with AN fittings added to the tank and run an external high pressure pump back near the tank.