I hope this classifies as advanced tech.
I've finally decided to try to build a custom EFI setup for my 351C 4v Ford. I know there are several places that i can get intakes and fuel rails modified to fit this motor but i'd like to try to do it myself. I think i can save a little money and make a learning experience out of it. Here is the background of the vehicle, drivetrain, and my goals.
Vehicle- 1937 Ford Coupe approx. 25-2700lbs
Drivetrain-351C 4v closed chamber heads, Roller rockers, 10.1 compression, comp xe roller cam 224/230 on a 110LSA, and pretty close to long tube headers. TCI AOD transmission with stall to match motor, with a 9 inch with 3.90 gears.
Goals-The motor should make plenty of power to move such a light car around, but i'm mainly wanting drivability. This is a streetrod with Air, Mustang II suspension and with the overdrive its meant to go on long trips. It currently has a carb and i'm wanting to go EFI mainly for drivability and hopefully a bump in fuel economy.

I don't know a whole lot about fuel injection but here is my plan. I was thinking about running a 351C torker intake. Heres is pic of what one looks like. http://www.mustangmods.com/ims/u/2057/4484/53696.jpg
I found some injector bungs that look like they'd work, here is what i found.
http://www.mustangmods.com/ims/u/2057/4484/53697.jpg
Now i was thinking that i could just use a die and cut threads on those injector bungs and drill and tap the intake and thread them in. Would that work? Is that a reasonable idea? I do have access to a great aluminum welder so i could get them welded in, but drilling and tapping would allow me to do all the work myself. I've read that the injectors ideally need to be at a 25 degree angle. Would just mounting the bungs flush on the top of the intake runner work? I assume it would have to work as good or better than the current carb'ed setup. 93 LT1's get by with batchfire injection and i'd think what i'm planning to do isn't any worse than that. Would this be a bad idea? After i get over those problems i need to come up with some fuel rails. Where should i go to get these? i've seen ones that need to have the injector holes bored in them but is this something any machine shop can do? It would be nice if i could just find some stock fuel rails off of a V8 and modify them, possibly a BBC as the heads/intakes are very similiar to the 351C. I figured i'd just make a "power pipe" to mount the TB and MAF on. Its basically just a tube with a Carb flange on one end and a TB flange on the other.
For the engine management system i was thinking i could run a 5.0 mustang wiring harness/ecm since they have the same firing order and i could just use an electronic ignition distributor out of a 460 to control the fire. This way i could use the MAF, TB and everything else off the stang setup. I'm just looking for a setup that would let the car run and drive like a newer car, be cost effective and not sacrifice to much power. Thanks for your input guys.

 

I'll let the people who are more knowledgeable about modifying intakes have their say, but I've done a fair amount of research on the difference(s) between batch fire and sequential fire EFI setups. I came across this article that (for me at least) settled the debate about which is "better:"

Timed vs. Batch

Sequential is a bit of a misnomer. Technically, all EFI systems are sequential in that once all cylinders have been injected, the sequence starts from the beginning again. A better term would be timed, implying that the starting and finishing of the injection pulse is timed with the intake valve opening. The idea behind this is to spray fuel only when airflow in the intake runner is established. This is supposed to mix fuel and air better and reduce manifold wall wetting. The other injection strategy is batch fired where several injectors are triggered simultaneously and not timed to the intake valve open period. In effect, the fuel sits in the runner for a short period of time before the valve opens and the airflow carries the mixture into the cylinder. Some people are dismayed that anyone would use the batch fired method however, there were tens of millions of Bosch and Bosch derivative systems sold in the '60s, '70s, and '80s which worked just fine using batch firing. It is a very well proven concept indeed. The SDS is also a batch fired system. The timed concept was developed mainly for tougher emission laws and EPA cycle testing where much of the cycle is run at low rpm and part throttle, where the time available to inject is long and the injector pulse is short.

Performance Applications

Performance applications are somewhat different from stock applications. Rpms are generally much higher, fuel flow rates are much higher and emissions usually take a back seat to power output. As rpm increases, the amount of time available to inject the fuel decreases. This is true whether the system is timed to valve opening or batch fired. The batch fired system has the advantage of being able to inject fuel for the entire period of crankshaft rotation whereas the timed system technically only has the time available that the air is flowing in the intake runner. This is determined mainly by the camshaft characteristics. On an average performance cam having 220 degrees of intake duration measured at .050 valve lift, the sequential system has only 61% of the time to inject the fuel as the batch fired system. As such, true, timed, sequential systems must have larger injectors fitted for a given hp. It should be remembered that there is little airflow and velocity in the port and runner until the valve is open a fairly significant amount. Starting the injection sequence early and finishing late, partially negates the supposed advantages of timed injection. On a high revving engine, there are only a few milliseconds available to inject before the next cycle begins. On the other side of the coin, with batch fired injection, the amount of time that the fuel sits in the port shortens as rpm increases. In the end, there are no significant differences in top end, wide open throttle, horsepower between batch fired and timed systems. We have also not seen any significant differences in fuel economy between the two strategies. Emissions at part throttle are likely to be better with timed injection as this is what it was developed for. On performance applications, emissions are often not an issue and most engines not equipped with a catalyst will not pass a modern emissions standard anyway.

Complication and Expense

Batch fired EFI systems are far less complicated from a software and hardware standpoint so it stands to reason that they will be less expensive to purchase and easier to program. Timed systems require camshaft timing information for the ECU either derived from a camshaft sensor or a multiple input signal from the crankshaft sensor. Timed systems also require a drive transistor for each injector, a separate trigger wire for each injector, cam timing specs, injector response time specs, cylinder firing order and the software to process the information. The person programming also requires a lot more knowledge on how all these aspects inter-relate to each other and the wiring for the injectors becomes much more complicated. If any of these steps are omitted or misunderstood, the timed system is no longer timed. Additionally, there are some aspects about intake port flow that very few people would have a clue about. You'd really be taking a bunch of guesses about when to start injecting and stop injecting the fuel. Is all this worth the trouble on the average performance/race application for little or no gain in hp? Would YOU understand how to hook up and program a sequential/timed system? I think those questions have already been answered. The batch fired system merely requires a tach frequency. Generally, for each ignition pulse, there is a fuel pulse. There are less wires to run and no complicated timing software to figure out. Very simple and it works very well.

http://72.14.207.104/search?q=cache...us&ct=clnk&cd=1

 

An alternative view, supporting the benefits of sequential.

http://www.motec.com/products/ecu/tutorial.htm

 

One thing to consider is that its possible to time a sequential system to inject fuel at lower rpm after the overlap event at tdc. At least time it so that the fuel arrives in the chamber after the exhaust valve closes. This should improve idle quality and economy. This strategy is a compromise because as rpm increases the flow will continue after the intake valve closes and the fuel will wait in the port until the next cycle. The Motec example offers quite a bit of flexibilty but their systems are out of my budget. FAST XFI allows for switch selectable tuneups so conceivably you could have an interstate cruise specific tune with the injector timing offset calibrated for your cruise rpm and then have a performance tune with an earlier opening point for higher rpm operation. With a wide powerband or high rpm a sequential system will still have the characteristics associated with a batch fire system. There is a limited ammount of time between cycles and much of the fuel at higher rpm will be injected when the valve is closed. Once again the FAST XFI could be setup on a switch for batchfire as well and then compared on a dyno and the street for best drivability and power.

BTW I would check eBay for a 300-13 Holley Strip Dominator for the 4v Cleveland motor assuming you have decent hood clearance.

 

I love the cleveland motors, circle track monster(this is a chevy page...I know, sue me) But I'm thinking you would be better off with a 302 stroked to 331 if you want the displacement. This will be cheaper, more parts to choose from, and factory EFI/management availible.

 

The main advantage to sequential on a performance setup is the ability to individually control cylinder trims. In my opinion unless you are trying to tweek something to within an inch of its life this isn't worth it (if you are spend the money on an aftermarket efi capable of sequential). Also do you feel you have the ability (and equipment-either be god reading plugs, or individual cylinder EGT's with a wideband in each bank) to set those individual trims? If you want a car to run great and get great fuel economy, then batch will work just fine. Depending on your comfort zone there are solutions out there that will work much better than a factory mustang maf computer, that will ultimately cost about the same (run speed density you don't have to worry about maf).
On my turbo 2.3 mustang, with a batch fire system that I run open loop (didn't want to leave the wideband in all the time) so I can lean cruise, I have improved my fuel economy 3mpg over the factory computer.

The threading the bungs isn't such a good idea. I would just purchase them and get the holes drilled and them fitted up in the intake, and then take it to be welded. If you do all the fitment, it should run less than 1 hr labor. Also be sure to have something welded down to secure the fuel rail to. You can either buy fuel rail stock, or maybe the mustang fuel rail will work (I don't know that much about clevelands). A site with some good general efi fabrication info is: www.sdsefi.com
Just go to the tech. articles on the website. Even if their computer doesn't appeal to you, the actual mechanical advice is great. The mustang throttle bodies work well because they are round and easy to mount. Try to get on off a newer 4.6 car, they are 5mm bigger than a 5.0 .

 

My applicaton combines a large shot of dry nitrous on top of an emissions friendly 381ci stroker. Sort of the best of both worlds..... good fuel economy, very mild street manners, low emissions in the bands that are emissions-tested, on a 500flywheelHP setup, plus the ability to simply add 300HP at the flip of a switch. The flexibility of the MoTeC, including the injector timing ability allows that.

I don't pretend to understand the relationship of end-of-event injector timing to driveability, economy, emissions, or torque/power, but the guy who tunes it seems to know what he is doing. Throw in large injectors, running at less than 70% DC at 800HP and 7,000RPM and it seems to make the cost of the MoTeC stuff (and I bought a used ECU for 50% of original cost) worth the money.

Batch fire isn't as bad as it seems, with respect to the fuel "waiting for the air flow".... its going to be vaporized by the heat off the back of the valve. A seemingly more important concern would be loss of some of that fuel as it reaches vapor phase and expands, possibly causing reversion in the intake runner.

Nitrous complicates the issue, particularly with respect to direct port sytems. Here you're adding fuel and cold nitrous continuously, much of the time dumping on the back of the closed inlet valve. The dry approach, using a thoroughly dispersed spray before the plenum, and large injectors timed to intake valve opening, resolves this issue as well, since now you have no nitrous or fuel flow unless the valve is open (except at the upper limits of RPM).

Is sequential fire important if all you are after is high HP? I don't think so.

 

So with the Motec you tell it where you want the injection event to end then? Or is it user selectable? (end event vs. start)

 

I really like the idea of a m880.. but its really expensive.... 5k for a computer system doesn't come cheap.

 

I have the M48Pro. It has "end of injection" tables, as a function of RPM and load. I think the newer 800/880 series may have selectable "end" or "start".

 

The 351C is staying as its rebuilt and currently running in the car. The car originally had a carb'ed 302 in it that was going to get injected but we decided to rebuild the 351C and swap it into place. 351C's are cool and i don't want it to be just like any other street rod with a SBC or SBF in it. There is something about seeing Big Block sized heads on a small block ford that just makes you stare at it in amazement.

Is there any reason not to drill and tap the bungs? i don't see why its such a bad idea, but i can get them welded. I'm not arguing i'm just thinking of making my life easier. I've done some looking and 4.6 fuel rails look like they have a possibility of working. I just need to find out the port spacing on the 4.6 and see if they're close to the 351C port spacing. I think the 5.0 ecm and harness would cost me little to make it work on my car. They cars have the same firing order, i can get a distributor to drop right in and work with the ecm. I could use all the sensors off of the 5.0 and not to mention i have access to a salvage yard where i get parts for free and he has several 5.0's. I figured i would want the MAF setup as it would work better at helping the ecm adjust for the cam and big heads of the 351C. I don't plan on running a batch fire setup, i was just suggesting that the injector pointed to the floor of the intake could be no worse than a batchfire setup. I also know the 5.0's have little 19lb injectors and small TB's but i figured i would just try to get the setup running first. If the setup ran well i'd upgrade the injectors and the TB. I believe on stangs you have to get the MAF calibrated to the injector size so i want to wait on all that extra cost to see if i can get the damn thing running first.

 

The 5.0 mustang mafs meter approximately enough air for 290hp. Above that, the air/fuel ratio is a guess. With the 19lb injectors, that is also about the most power you can safely make. Also, the calibrated maf/injector combo has slight driveability issues because the computer no longer knows how much load the engine is under. Oem harnesses are typically more complex than required simply to make the car run (emmisions and such) and you will have some research and work to do to make it run properly. Tuning solutions for the ford ecm are also more expensive/complex than a gm.
I have converted old cars to fuel injection using oem computers and harnesses, and I have used standalones. I personally will never use a oem harness and computer again. For the money you can sell an a9l, harness, and maf for, plus the cost of upgrading the maf later you can buy a inexpensive standalone. This is just my opinion, but it is the best advice I have to give.

On the injector bungs, I just think the required angles the threaded setup will force, as well as the trouble of 2 additional "machining" operations that aren't really necessary would be more trouble to gain nothing. It could work just fine but why reinvent the wheel.

 

I've only seen one, and that was in George Baxter's 30th SS. And it didn't belong to George, it was on loan from Second Street Speed. It's gross overkill for a drag car, with capabilities like fly-by-wire, traction control, 4-cam variable timing, and a bunch of other programmable functions - most of which are avaialable at an "extra" fee to have them turned on.