injector size?

Mustang88LXKid

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Oct 18, 2003
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I plan on rebuilding my 88 5.0 engine, with mass air along with these mods

185cc AFR Cylinder Heads
C&L 76mm Mass Air Meter with Truflow Inlet pipe
March Ram Air
CHP Spyder Intake Manifold (with the rails and power elbow)
Moroso Oil Pan
new pistons, may new connecting rods
70mm Accufab Throttle body
not a drastic cam, (daily driver)
3.73 Rear Gears
So my question is what size of injectors should I get using all those mods what should I get? I don't want them to be too small or too big because that can make me lose horse power. So please help me.

Thank you,

Matt
 
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like stangbear said, the heads are too big for n/a, maybe a set of 165's?

i'd probably go with a set of 24lb injectors. they should be adequate til you make any more major changes. a couple of musts are a nice adjustable pressure regulator and a fuel pressure gauge
 
Are you guys sick? The 185s are WAYYY not too big for a 302. Stick with the 24# and get a decent regulator. Whoever told you that the 185s are too small, must be smoking crack. Now if you stroke it, the 30# would be a good idea...........
 
JJFIVEOH said:
Are you guys sick? The 185s are WAYYY not too big for a 302. Stick with the 24# and get a decent regulator. Whoever told you that the 185s are too small, must be smoking crack. Now if you stroke it, the 30# would be a good idea...........

i think u need to retype that for it to be understandable...u say the 185s are wayyy NOT to big? meaning they are OK?? but then u wrote, who told u 185s are too small? too big/small which is it? no one mentioned the 185s being too small. They are way to big for a bolt on cat, which we think he has/will have
 
JJFIVEOH said:
Are you guys sick? The 185s are WAYYY not too big for a 302. Stick with the 24# and get a decent regulator. Whoever told you that the 185s are too small, must be smoking crack. Now if you stroke it, the 30# would be a good idea...........
AFR was who told me when I talked to their tech on the phone. In fact, he said that on a NA combo 302 I would LOSE horsepower. To much airflow can hurt, just like too much exhaust, or too much fuel pressure. I'm with everyone else who said get 165's. Mustang88LXKid- check out this page for your injector size Q's:
http://www.pro-flow.com/tech info/sizing.htm
 
It's not that any particular head is too big or too small. However, to take advantage of the big ports/valves on the 185's the engine has to be built to rev. At high rpm is where the larger heads can be used to good advantage (serious solid roller lifter/big spring pressure/non-stock ignition/forged everything RPM). That's also true of the spyder intake he's talking about. The challenge is he says he wants a mild cammed daily driver. With those heads and that intake on 302 cubic inches, low rpm flows are going to have very low velocity, which will likely result in a car that is anything but a fun daily driver. So, Matt, you seem to have some mismatched parts here IF you're trying to build a not-too-drastic daily driver. Take these guys advice - go with the 165's, and I'll add, get a long-runner intake -there are a million to pick from. If you're looking to keep some decent bottom end in the motor I'd go with one of the Cobra/Explorer/GT40 trio. Also, I'd recommend you hook up with one of the pros and get a custom cam. They can educate you as to how these components work best together, which based on your suggested combo would help with your understanding. If you make those changes 24# injectors will be just fine; Perhaps 30's if the car is going to spend a lot of time at the track.
 
Ok, well I have been reading the MM&FF magazine and they tested 185cc AFR heads on a normal 5.0 block that was not stroked and had a carborated setup. (I don't remember the exact issue but I can look it up). But they recomended those heads because they had over 100 horse bolt on with a new oil pan, carb, comp cam. So would I want the 165's instead, because they don't put out the same output as the 185's, but I would like to see your reponses to this.

Thank
Matt
 
Kid - you're referring PEAK hp gains; go back and see if they have data on HP/torque down below 3000 rpm. That's what's gonna make a nice daily driver - not peak power. A normally aspirated 302 that makes 450 HP at 6500 rpm doesn't make a whole bunch of torque/power at 1500 rpm. You can't have it both ways - unless you increase displacement or add boost. To get the power/torque down a bit lower in the rev range, you need the smaller heads and the longer runner manifolds.