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Discussion Starter #1
well, FINALLY got around to swapping in the GT40 heads and the mustang GT 5.0 cam in this week.
i am a little disappointed in the performance that it gave the bronco 5.0 engine...
it does seem to have a little more power down low but a definite gain above 4000rpm's.
from reading the cam sticky thread, i thought the GT 5.0 cam was going to be the cats meow!!
should i shop for a different cam that comes on sooner or is it even possible to get real low end from a 5.0?
 

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Man of endless projects
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did you do a valvejob on the heads? might have burnt valves.

my understanding is that the mustang cams are for high end since there a hell of a lot lighter than a truck. probably better in a 351 like the lightning's had since it would have better low end already. but I not a cam guy so don't take my word
 

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Discussion Starter #3
yeah, fresh 3 angle valve job before putting them on...new timing set(lots of slack in the one i took off) and new style EV6 injectors.
don't get me wrong, it does run better but i was hoping for a bit more seat of the pants power/torque.
 

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This is what I gleaned from the interwebs...

Stock mustang 5.0 HO cam specs:

210-214 (depending on year) I / 210 E duration @.050
.444/.444 lift
LSA 115

If I am wrong feel free to correct me.

Duration #s are decent, but lift #s are kinda weenie, and lift is where you get your torque from. Obviously, this cam would perform best in a lighter vehicle, and in mid to upper rpm's.

Adding a set of 1.7 rockers would increase your lift to .472, and probably be your best bet for some more torque out of the current setup.

Most truck/rv/torque cams have relatively lower duration, and higher lift #s.

That being said, a stock displacement NA 302 is never gonna be a torque monster.
 

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Eric
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If you're on a budget, try an Explorer 5.0 cam. It has very comparable #'s to a mild performance cam from Comp.

Mustang GT cam (F1ZE-AA):
Lift: .444/.444
Duration: 276*/266*
LSA: 116*
With E7 heads: 205 HP @ 4,200 RPM / 275 Lb-Ft. TQ @ 3,000 RPM

Explorer 5.0 cam (F4TE-6250-BA):
Lift: .422/.448
Duration: 256*/266*
LSA: 116*
With GT40P heads: 215 HP @ 4,200 RPM / 288 Lb.-Ft. TQ @ 3,300 RPM

1993 Mustang Cobra cam (with 1.7 rockers) (F3ZE-6250-CA):
Lift: .479/.479
Duration: 270*/270*
LSA: 115*
With GT40 heads: 235 HP @ 4,600 RPM / 280 Lb.-Ft. TQ @ 4,000 RPM

Comp Cams XE258HR:
Lift: .480/.480
Duration: 258*/264*
LSA: 114*

The Comp cam has a duration event very close to that of the Explorer cam. Typically, you want to keep your duration figures as low as possible for more torque. Lift is, usually, associated with HP. Imagine the Explorer cam with 1.7 rockers. ;)

However, the GT40's stock valve springs will only tolerate so much lift before you experience coil bind. The GT40P springs are even worse. For the, regular, GT40 springs you should keep the lift under .500 and the P springs should be limited to around .480.

To get serious grunt, though, you need to increase the crank throw (stroke).
Just look up the stock TQ figures for a 1978 Ford 400 (351M with increased stroke). Hits peak TQ at, like, 1,500 RPM. Rediculous.

My $0.02,
Eric
 

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Discussion Starter #7
Thanks for the input guys!!
found a roller 351w about 4 hrs away with 200k miles on it...would it be better/cheaper to just get that, freshen it up a bit and drop an RV cam in it w/my GT40 heads???
my poor old 302 has about 200k on the bottom end right now...
wouldn't i get quite a bit more torque out of the 351?
 

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I have the 5.0HO cam in mine with GT40X heads. With the towing torque converter IT IS soft on the bottom end. I do have excellent "driving" power as it only takes a small amount of the accelerator pedal to hit the speed limit.

I think (and have posted since I have actual experience with it) there are better cams. I plan to upgrade to a custom cam and matching torque converter once I finally spring for mass air. I have gathered lots of the parts needed, mostly just need to buy the NEW stuff now.

If you can afford it, just buy the 351, even better heads, intake, headers and swap when you have completed everything. As long as your 302 is still getting on you have all the time you need.

JMHO
tim
 

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Eric
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Also, might think about a re-gear for the diffs. Those 33's aren't doing you any favors in the "rotational force required" department. 4.10's would get you back to stock drivetrain relation and 4.56's would put a smile on your face. Then, you'd see what your engine improvements have, actually, accomplished. Plus, a re-gear would provide TQ multiplication across the entire power band; not just low or high-end. Not to mention how you'd improve 4WD low that includes the transfer case gear reduction.

Eric
 

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Discussion Starter #10
Silver70,
i know your right...that's a $2000 ticket i don't think my financial adviser(wife) would bite off on!! besides that, the closest shop that does that kind of stuff is 2hrs away.
all excuses aside, i know that would be the best route!
 

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I had a Mustang cam in my bronco. it was slow off the line. After 3000 RPM it was a monster. My suggestion to you is to swap a cam if you want more low torque. I was amazed how much power I picked up with a different cam. The big thing is these are trucks not cars. And if you read the fine print about a Mustang cam you need to degree the camshaft either 3° advance or something like that. You can read specs all day, and try and tell yourself that mustang cam is comparable to Loblaw blah Bob blah bbottom line you want more torque get a different cam
 

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Eric
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A few special tools and you can rebuild your own stuff. I bought a press and related tools years ago to do a 9" for a buddy because I wanted to learn how and he was afraid of it. Talked to people, researched the crap out of it, and worked with a pro for one rebuild. Bottom line: the rebuild/set-up was successful and is, still, going strong. It's in a drag car, so, it sees some use.

I figured, "Great... I just bought all this stuff for one rebuild. What a waste." About 10 years and around a dozen diffs later, it's still paying for itself. ;)

About to start another rebuild here soon. For my Bronco this time. I think all the tools cost me around $300.

If this, still, is absolutely not an option, I'd go with the above-mentioned Comp cam. It's got all the lift of the Cobra cam and the low duration figures of the Explorer cam. Best of both worlds and is not over-the-top so your computer should be happy.

Just saying,
Eric
 

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Man of endless projects
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since you have a cam for higher rpm, you might now need a higher stall torque converter so you can cake advantage of the cam. might call a place like that makes torque converters and give them as much info about your setup to find what stall speed is best for you


EDIT: didn't see your using a manual
 

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Discussion Starter #14
well guys, a little update...
i ended up getting the 95 351w roller motor. planning on doing a rebuild/refresh over the cold snowy winter. this one WILL have a 4x4/high torque cam in it before it goes in!!

Silver70, i've watched/helped a guy do re-gearing back in my jeep days and have done a little diff work on this BKO but borrowed the stuff to do it...i suppose i might as well just invest in the case spreader/dial indicator etc. and do it myself. like you said, it'll prob pay for itself after word gets out that i do re-gearing...

i CAN"T afford alum heads for the 351w, will/would the GT40 heads i just put on the 5.0 be better than the stock 351 heads since it's not going to be a rev monster??
 

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The Anti Yam!
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i CAN"T afford alum heads for the 351w, will/would the GT40 heads i just put on the 5.0 be better than the stock 351 heads since it's not going to be a rev monster??
GT40 heads are superior to the stock E7TE heads. Have them ported if you can.

Ready to have your dreams crushed?

With most engines, the "Choke Pont" restricting the engines power is the heads. You would be far, far better off with a stock short block and good aftermarket heads than you would be with the most expensive custom ground cam there is and stock heads.

For example, on a 302 the "Choke Point" is the exhaust port on the stock E7TE heads. Any gains you get from any other modification will be minimized if you do not address the heads.

Now, the EFI truck 351w is a little special. It's "Choke Point" is the intake manifold and it's small runners... Even with the exact same E7TE heads!

The intake is that bad. So unless you swap the intake, your not going to get anywhere near the maximum from your other performance mods. It does make decent torque because of how long the runners are, but it just falls flat on it's face as the RPM's increase.

Compare the 5.0 truck and 5.8 intake gaskets in the photo.



And remember, those aren't entirely to scale. The difference is much greater when you look at it in person.
 

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Discussion Starter #18
UUUGH!!!!!
so take the upper from the 5.0, trace the pattern onto the lower and GRIND THE $hIT out of it and use the "now matched" 5.8 lower w/the 5.0 upper?!! :))

really tho...i'm not really looking for a screamer, just want the BKO to be able to get out of it's own way AND not have to shift down to 3rd gear when going up hills on the highway... i know, RE-GEAR!! thats coming soon to a 95 BKO near me!
i just couldn't pass up a $300 roller 351!

oh, btw, what would a cobra harness, eec and 24lbs injectors and maf do for it??
 

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Nothing really, unless you did more engine modifications to justify the bigger injectors.
Fuel injectors support power they do not make power.

It would give you room to grow if you added aluminum heads and a better intake in the future, but I do not think you would see any gains with just those items given your current setup
 

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The Anti Yam!
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UUUGH!!!!!
so take the upper from the 5.0, trace the pattern onto the lower and GRIND THE $hIT out of it and use the "now matched" 5.8 lower w/the 5.0 upper?!! :))
Uhh, no.

Get a better intake (Car or Truck style)

You have to make a choice. Save up and do it right, or don't. :shrug
I spent two years researching and saving to build my engine before I purchased a single part.

oh, btw, what would a cobra harness, eec and 24lbs injectors and maf do for it??
At this point, nothing. Also the Cobra EEC is notorious for being extremely "Conservatively" programed.
 
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