347 stroker combo... good or bad???

Discussion in 'Fox 5.0 Mustang Tech' started by Sonicaceman, Feb 26, 2009.

  1. ok, i've been scratching my head about this for a while. i've been working on my 93 mustang for about five years now. i've put on all the goodies. heads, cam, intake, cai, throttle body ignition, gears, stroker, coil, intake manifold, headers, full exhaust, custom chip, dyno tune, you name it. here is a break down of what i have.

    gt-40 upper lower intake manifold
    roush 200 cast iron heads
    anderson afm-n3 roller special (was given with car)
    mac long tube headers
    mac 2.5" full exhaust with high flow cats
    msd 6a
    fenderwell cai
    70mm professional products throttle body
    3.73 gears
    347 stroker kit
    sct custom chip
    dyno tune on md dyno tuner
    proform electric fan

    tell me why this only got 260 rwhp with a cam that has a 2500-6000 rpm range with my max hp at only about 5000rpm?????

    I have been having problems with the msd working right, the car completely shuts down sometimes, disconnected it works fine, but i'm losing a lot at the top end rpms w/o it, could a malfunctioning ignition kill hp numbers this bad???
  2. we'll need more info on your complete combo: what size fuel injectors and fuel pump? you'll want at least 24# injectors and a 190 or 255 lph in-tank walbro with an adjustable fuel pressure regulator... i'm not sure how your car was properly dyno tuned without one. also, is your MAF calibrated to the injectors? i'm assuming your tuner recommended all of this already if he's at all good at what he does...
  3. 347 combo

    yeah i forgot a couple things, i do have these also

    24 lb injectors,
    76mm c&l maf
    255 fuel pump

    but yeah the maf is calibrate for the injectors, and fuel shouldn't be an issue
  4. 347 more stufff

    of course i have all the normal stuff you need, i always forget somethings, like i forgot the 1.6 rocker arms i have to, i don't have an adjustable fuel pressure regulator, but i really don't need one if the guys at the shop tune it up with the dyno, and put all the info. in my custom chip, i took the a/c off as well, and i have underdrive pullies too. RV engines from alexander ny did my short block and jons automotive in batavia ny did the dyno tune with rick vania from rv engines.

    any more questions??
  5. i beg to differ about not needing the fuel pressure regulator, especially with the 255 lph pump, you'll probably be getting some pressure "creep" without one...

    i'd troubleshoot the ignition system and make sure it is working properly, if you're having the trouble you described there's probably something up in the wiring where you're losing spark somewhere

    then i'd check the specs on that cam, i can't find the "afm n-3 roller special" item number on the AFM website, but that's the brain of the motor, if you're saying it "came with the car" and wasn't designed specifically for the combo you're running, that could be your problem

    it could be a supercharger or nitrous cam for all you know :shrug:

    i'd also be inclined to say that gt40 intake manifold is restrictive for a 347, but that's up for debate...
  6. Yeah that does sound a lil low although I wouldn't expect huge numbers from your set-up though. The intake is not the issue, but you combo is very mild and kind of mismatched. What is your compression ratio? What type of a dyno was it? They can give varying numbers depending on the type used. I would think if your having issues with the MSD, that that is probably the issue.

    Edit: I just seen where you said it was a md dyno, I take it that means mustang dyno, in which case it is a loading dyno. I wouldn't expect much more than 300 out of your set-up then.
  7. 347 combo

    thanks for the info. maybe i should invest in a fuel pressure regulator, just didn't think it was a must have, my mustang guy said i really didn't need one, so i took his word for it, he's been racing and building stangs for 20+ years, but i guess it wouldn't hurt. i've thought about changing the cam out, and maybe going with a edelbrock rpm II which is good through 6500 rpms, pretty pricey though. i'm kind of on a fixed budget and i was really trying to squeak out the 300rwhp number. the cam wasn't in the car when i got it it was given to me with the car, and the guy was setting it up to drag race, so i'm sure it's set up for all out full throttle, because that's when it kicks ass when i'm driving it. i am also going to replace my harness to my coil that plugs into the msd, and redo some of the wiring.

    ANY SUGGESTIONS ON GOOD 347 COMBOS IF I WERE TO CHANGE THIS IN THE FUTURE????? thanks again for all the input.

    edit : here is a pic of my cam spec sheet
  8. Was the cam degree'd in or was it just shoved in straight up?
  9. heads cam intake

    on the dyno tune did they look at the A/R and if so was it good. what do u have the timing at. i would change the the heads,intake,put a off road h pipe on it. i looked and did not find the cc of the head but it does say that its a CARB head so thats telling me that comp ratio has not changed much. on the fender well cai was it a kit that plugged in or did u have to cut the stock ones make the wires longer. before u spend alot of money i would change the cheaper things before u spend alot of money. if it was me i would go to a set of trick flow heads,system max intake.
  10. The cam spec's give it away. The duration @ 0.050 is 218/226, that is good for a powerband to 6,000 on a 302. The advertised duration is 280/288, which is pretty long compared to the duration @.050 indicates an older lobe profile. Cam would work good on a mild 302 but not a 347 with a 200cc intake runner. You can do way better with the cam. Remember 302 parts 302 power.
  11. whats your CR? what pistons are they?. Maybe you bought low compression blower pistons
  12. i made 290/320 on a mustang dyno with 302 and tfs top end. He should have made at least 330-340
  13. 347 combo

    i just want to say you guys are all awesome and i really apreciate all the suggestions.

    Okay i will try to get to everything that everyone asked. This is a 93' fuel injected 347 stroker motor. The cam was degreed in and the short block was blueprinted buy RV Engines in Alexander NY. The cam was something that the last owner had and was planning on putting in the car. it was a 302 at the time when the first owner had it. My cold air intake is a fenderwell kit, the same as the bbk, mac just a cheapo off the shelf, they are the same i tried both no difference. My timing is at 10 degrees I believe and i am running a stock distributor, not sure if that really matters. I've been reading a lot up pretty much proving that the 347's like the high rpms, i was very ignorant when I did the build on this and i probably waisted a lot of cash instead of going with proven setups like the trick flow kit, the ford top end kit or all edelbrock components or one of the anderson setups, they look pretty promising. I've spent thousands to achieve a measly 260 rwhp, to say the least i'm kind of annoyed. I'm almost at the point where i want to start over i thought having more cubic inches would usually mean more power but it's all dependant on the h/c/i. i have some good components but not the right stuff.

    The Big question here is what would be the first thing to spend my money wisely on if i change something????
  14. buy a good set of heads, a cam that will suit it better, one of those comp stroker cams maybe? and get a new intake, rpm or trick flow track heat. then you'll make hella power yo. like someone said above, your h/c/i would be cool for a mild 302, but a stroker, no way.
  15. A 347 doesn't just give you gobs of hp, its all about your combo. With your top-end on his short-block yeah probably 330. But look at his set-up, plus I did ask for his compression ratio. For all we know the cr could be really low as well. I have had two 347's and they were on opposite ends of the spectrum as far as rwhp and rwtq.
  16. 2500-6000 rpm range in a 302 is ~ a 2175-5220 rpm range in a 347. The areas you might want to consider are heads and cam. The following is a 331 the owner was having problems trying to make it perform.


    Same 331 with the changes noted at the bottom.......


    Difference was night and day on the street for the owner, and it ended up costing him a T5 transmission.
  17. what rwtq did it make?

    Something is still screwed up regardless of what people try to pass off on here.

    You SHOULD be making at least 280-290rwhp and probably 340-350rwtq on a mustang dyno and higher if its a dynojet.

    Ditch the intake and buy a systemax if you plan on keeping it a 347.

    You can keep the heads but all world products heads are terrible as cast. The lip around the seats and guides leave a lot to be desired and I have seen a set of Roush 200 heads ported by Chris Howe over at Jon Kaase flow ~310 @ .600.

    I have also seen a home-ported set of Roush 200s make 280rwhp with a stock shortblock 302. Stock cam with 1.7s . . .

    We would need to see the dyno graph before really figuring out what the deal with that "347" is.
  18. i would also up grade to a bigger injector 24s are good for a 302 -306 but not a 347 exspecialy if you ever plan on spraying it i have a 12.1 comp 347 with canfeild heads holley systemax intake 70 mm tbody and 30s with a 255 intank pump and have to have the fp set at 55 just for it to run half way good thats why i orderd some 42s
  19. Yep, it is not just the heads/cam/intake package.
  20. 347 combo

    okay here is the dyno sheet and i know everyone is going to say i said 260 but you have to account for the 13 hp that is put on as drag, thats what i was told, anyway it is going to say 247 which is even worse. not sure what the compression ration is pretty close to what stock would be i guess, 10-1 maybe. i believe i have keiths black pistons nothing crazy didn't have the money went with the hypertetic pistons not forged, i guess you get what you pay for, they haven't broke yet.

    here is the dyno sheet