SmallBlockFloyd

Yeah. I was actually thinking of running a sump with a LP fuel pump intank, feeding to a fuel filter, then to a 1/4-1/2 gallon 'resivior' tank, that would then be fed to the HP fuel pump. That way, I should be able to effectively negate the effects of heavy braking/corning, and not feeding the injectors. I was also going to run a baffled sump, just for the benefit of the doubt.

As for the injector sizing formula, you mentioned 'BSFC'. I do not understand that abreviation. Could you elaborate please? I don't want to go too big, as I was thinking 24-30# injectors, 30 being the biggest I would go. I am staying n/a and fairly stock. I am planning to put a torquey cam in it, with 1800-5000 rpm range or so, giving me plenty of room to romp, while still being in the middle of the power band, while cruising down the highway *3.25's + .78 overdrive* should put me right at about 2500-2600 rpm's to turn 75 mph. I think 24# injectors will do just fine. I am to understand, that high impedance 24# injectors from ford would be 'blue tops'?

Thank you guys for all of your help, thoughts and insightful experience.

SmallBlockFloyd

Well, double post time. I googled a injector size guide, and found a webpage that gave estimated calculations, based on simple numbers, such as power lvl, cylinders, et cetera. I plan on making about 325-350 horses with the cleveland, so it was sitting right around 28# injectors. So, I guess I should grab a pair of 30# injectors, and use those? I would run 24#'s but based on that chart, they should only be good to support about 310-320 ponies at the wheels. I don't want to max out my injectors, as that is bad on the entire system.

Anyone have any recomendations? Sorry for the double post, but thanks for all the help.

rmodel65

idk all the exact standards for injectors and the power levels but if your gonna start gathering swap parts, look for a lincoln mark 8 they have 24lb injectors from the factory

SmallBlockFloyd

Alright, what colour are they, so i can compair the advertised # of injector to the colour of the top?

rmodel65

blue also efi 460 come with 24lbs iirc

Norm Peterson

"BSFC" is Brake Specific Fuel Consumption, and is given in units of lbs per HP per hour. It's a measure of engine efficiency. Typical values might be 0.5 foraverage normally aspirated engines and 0.6-ish for forced induction. Injector sized should also give the pressure that the flow rate is associated with. If you're borderline between two injector sizes, go with the smaller and bump the fuel pressure up a little. IOW, an injector rated at 30# at 40 psi will flow almost 32 at 45 psi. The pump can handle long-term a little more than the 43-ish that I recall was common, but don't go overboard on that either.

I *think* the injectors that came with the Accel SuperRam on my 350 SBC are 30# and no, I don't think you'd want to go any bigger than that either. I went through all that math even though my calibration software had a "get started" routine that gave you a fuel map that was good for . . . getting the engine to start and run. I even called the tech line about the injector numbers, but it's been 10 years or so since then and I don't remember them off the top of my head. Fresh, that engine was probably upper 300's for HP and torque, so maybe it was aimed just a little higher on the rpm scale than what you're looking at. 10.2:1, AFR 190cc heads, hydraulic roller cam with mid two-teens intake duration and 0.5" lift if that helps.

I also think you can build an EFI engine up a little differently than a carbed motor. The EFI is so much better at the low rpm's that you don't have to compromise quite as much up top to still have good idle and off-idle behavior. You just can't get too wild with the cam unless you're running Alpha-N (I think that's what it's called).


Norm

67 evil eleanor

If you are going to use a Mega Squirt, then why not a low impadence say in a #42? Will the MS not support these? Sumitt sells sumps thatcan be installed in an old style tank. You will need some good wellding skills, but these seem to work well (unless you get smacked in the rearend). Adequate fuel delivery is a must also, so the proper fuel pump size is an absolute. Like Norm says, you can get some serious HP out of one of these and it will remain very mild mannered.Heres how I done mine.
http://i140.photobucket.com/albums/r...r/mikes009.jpg

67mustang302

(horsepower * BSFC) / (# of injectors * duty cycle) = lb/hr injectors needed. duty cycle is usually 80% or .8 and BSFC for a typical n/a engine is around .5, if it's tuned really well, with an efficient engine, then .45ish. for a Cleveland with stock heads etc .5 BSFC if tuned right is a good value to use.

SmallBlockFloyd

Thanks for all the help guys. I figured up a bit. I am going to run 24# blue tops from a 460, and I am going to run a sump, with an inline low pressure pump, then a fuel filter which is feeding to a 'swirl pot', or 'accumulation tank', that i am going to bolt/screw to the pass. fender skirt(wheel well), with four -8an nipples on it. the swirl pot is going to be 8"tall,6wide,4thick, and after figuring it will be 3.8x5.8x7.3 for the fuel return nipple, it will hold aprox 7/10th's of a gallon of gas.

The reason being it will have more than plenty fuel to feed the injectors, incase of a 'slosh' away from the mild pump. After the swirl pot, I am going to run a high pressure pump (55psi, yeah it's high but I couldn't find any pumps i liked around 40-45psi, so i will detune this one down to about 45-50psi) and should be good. I don't want to run 42# injectors because they are too big. i couldn't even use them. Megasquirt can run both high and low impedance, but I couldn't find anything i was satisfied with. I /could/ buy up two 'sets' of 'green tops' from the 2.3T cars(30# low imp. injectors), but i decided that with what I was running at the time being, 24# would be fine, and I can always step up injectors very easily.

I know the 'swirl pot' is a bit 'big', but i am using it to prevent vapor locking the system aswell, as it drains back to the filler neck onthe tank, which i am installing a T on. Then the drain back from the fuel rails will drain into the swirl pot i have, until it hits the 'overflow' height, and drains back into the tank. I just need to setup both pumps on a relay and setup a 'kill switch' so if there is a collision it will shut itself off. Then, I just need to get everything. The biggest pita is going to be getting everything set up and i just get this feeling that building my own fuel/spark maps for the cleveland are going to be a blast... a blast right into angryville...

Thank's for all the help and recommendations, James.