FI 331 stroker experts needed...UPDATE-need more help!

[rednck21]

bought a rig with a 331 and need some help tuning it. it doesnt seem like it has the power it should have. it runs good, just not very strong. the install with done the correct way with high and low pressure pumps and ryans harness. it also has a mallory fuel pressure regulator on it. im thinking a good place to start is to run a fuel pressure gauge so i can see it while driving to check for a constant 40psi? any ideas and or suggestions??? heres a quick build list...

Ford 331 Stoker built by Keith Craft Racing
Balanced and Blue printed short block
skat cast steel crank, eagle I beam rods, JE flat top pistons
GT40 Iron Heads
Roller valve train
Isky cam shaft
RJM full engine harness
24lb Ford Motorsport Injectors
Pro-M 75mm MAF

 

[408mako]

What ECU is in it? Is it tuned for the motor? But yes check fuel & timing. What Ignition System?

 

[Broncobowsher]

That sounds very close to my Ranger engine
330" stroker built by myself
Eagle crank and rods, KB dished pistons
N352 heads (better then the GT40 but still iron)
Al roller
Isky cam (mine was lised powerband of 2-6k, forgot specs)
Reworked Ford harness
24 LB motorsports injectors
Lightening 80mm MAF

I also have...
Explorer intake
custom chip
70 or 65mm throttle body depending on the day
Very open exhaust (1-⅝ headers, 2½ pipe merged into a single 3½" pipe all the way back and a muffler you could drop a beer bottle through without touching the sides.

It ran like a 2-stroke, even after the tune. I could pull away from a stop sign at half throttle and it had less power then the stock 4.0 the Ranger had. No traction issues. Economy sucked, emissions failed even with a cat. But swing that tach past the 3k mark and it suddenly came alive. Little dust on the road and hitting 2nd would light the tires until you lifted or it hit third.

I recently did some work, did a small cam change (little less duration, little more lift) and it woke up. Power all over the place. Lost maybe 500 RPM or less on top. Idle is way better, overall the new cam fixed everything. And that was without even going back for a new tune.

So do you know what Isky cam you have? It may be like the one I had.

Oh, Pull your distributor now and look at the gear. Isky roller cams are gound on cast blanks. If you use a roller distributor gear they will self destruct. Hence the reason for the recent engine work and new cam at 2,000 miles. What an unpleasant surprise.

 

[rednck21]

its got an A9L computer in it and MSD ignition. ive got the spec sheet for the cam...what do you need to know about it? the grind is RR-257/265 HYD

 

[Broncobowsher]

That is one grind less then what I ran. I had the 265/275.
your cam http://www.iskycams.com/timingchart.php?product_number=371257/265
My old cam http://www.iskycams.com/timingchart.php?product_number=371265/275

I really never like the old cam. And the self destructing distributor gear was all the more reason for it to come out. The numbers on paper look good, but in vehicle action was less then desired. You may have the same issues.

When you are ready, find a dyno shop that can custom tune that computer to better match the parts installed. Almost nothing about the motor is stock anymore, so a stock tune isn't ideal.

What intake are you running? Stock 5.0 is a bit restrictive for the added cubes and good flowing cam/heads.

 

[needabronco]

I could be wrong here, but I'm pretty sure the A9L computer is tuned for a 19lb injector and a 55 or 60mm MAF, you could be sending the wrong info to the computer from the 24lb injectors and 75mm MAF, which could explain the poor economy and less than stellar performance, unless of coarse the A9L has been re-tuned for those upgrades. Like Bowsher say's sounds like you need some time at the dyno shop for a chip.

 

[rednck21]

its some sort of aftermarket unit....looks like a knock off of an edelbrock. the PO said the ports and such were matched and polished or something along those lines.

 

[needabronco]

That looks like a Typhoon, which is an Edelbrock RPM knockoff. Your problem could very well just be a mismatch of parts. The cam could very well be the problem, as could mismatched injectors and MAF like I said.

I'd also be suspect of the port match and/or port and polish job. If done correctly a port match just straightens out the flow. If a port/polish job doesn't match the engines needs, or too much material is removed you WILL lose all of your low and most likely mid-range power. Do you know if you can find out who did the heads? Or take off the upper intake manifold and see if it looks like there was a lot of material removed.

I did this once on a VW engine, I hogged out the heads waayy too much and lost all of my low and mid range, it ran like a raped ape from about 5000-7000+ rpms, but that didn't do too much for the street.

 

[rednck21]

all the machine work, porting, and polishing, etc was done by kieth craft racing. it originally had a E303 cam in it, but the PO took it out and installed the current cam mentioned above. he said it was waaay to radical for the street. so i guess what i need to do is take this thing to an engine tuner to calibrate everything on a dyno..?

 

[Trey Taylor]

There is a place here in Memphis called Dynospeed. These guys were on Trucks! this weekend tuning that red Lighting that they are building up. Anyway the web site is Dynospeedracing.com and the # 901-373-1197. I bet they can help you or if want you can sell me the truck and I can run it over there to them. Anyway let me know what happens. Thanks, Trey

 

[kb6677]

Blane,
The shop we used to tune the 392 is in Anderson, SC. Advanced Tuning Systems. His name is Rick and # is 864 332 0955. I rec. him highly. Tell him Karl in the white eb with red flames rec. him to you.
HTH,
Karl

 

[justinoshea]

im thinking a good place to start is to run a fuel pressure gauge so i can see it while driving to check for a constant 40psi?

The regulator should have a vacuum hose going to the manifold, an fuel pressure is a function of manifold pressure. it only moves about 5 psi, highest at no vacuum (WOT).

The first thing I would do is pull the codes. one of the best aspects of EFI is it's self-test capability.

You should not 'need' a custom tune or chip IF the MAF is calibrated to the injectors, unless it has a big cam (sounds like it doesn't). however, taking it to good shop may uncover other issues too.

 

[rednck21]

i did notice today that when you turn the key on the press gauge reads 40psi during the 2 second pump cycle. when it stops the pressure goes back down. i do need to get a backlfow valve put on it. theres a local mustang shop i need to call that dyno tuned my brown 67. i tried calling today, but they were closed;D

 

[Ryan]

http://fordfuelinjection.com/?p=41
http://fordfuelinjection.com/?p=71

 

[rednck21]

thanks for the links ryan. ive spent hours and hours reading on your website;D


i made an appointment today with the local mustang shop to dyno tune the bronco thursday morning. i know i dont have a mod motor, but the local pushrod guru merged with them about a year ago and i talked with him on the phone today. the same guy that tuned my brown 67, just in a different shop.

http://modularpowerhouse.com/


ill let yall know what happens...

 

[Broncobowsher]

Have you checked your distributor gear for excessive wear from that isky cast roller cam yet?

 

[rednck21]

no i havent. ive never pulled a distributor and i dont know what to look for, so im a little hesitant about doing it.

 

[rednck21]

ok, so i talked myself into it;D no clue what im looking for, but everything looked ok...

 

[Broncobowsher]

If I get a little time tonight I will try and find my collection of damaged parts and try for some pictures. Don't hold your breath, I am not expecting enough time to pull that off.

 

[rednck21]

carnage pics are good;D does mine look ok?