Getting more power out of the 351w

bigmuddy · Sep 23, 2017

many good articles are using the cast gt40 or 40p heads particularly if you are just going to do a mild build.

At any rate, do the cam and the axles gears and you will be amazed.

bigmuddy · Sep 23, 2017

subscribing...

Godwick · Sep 23, 2017

Thanks all for feedback. Just put the 4.11 gears in a couple years ago and not too keen to go lower and throw the $2k it cost to get it done again if I can help it. If I can't help it, so be it, but will definitely throw heads and cam In there before I do.
I am also curious about a properly mated low rpm turbo, though I'm not sure I could fit one under the hood and have no idea where to start that search.

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rguest3 · Sep 23, 2017

Godwick - I would go with the Trick Flow 170 or AFR 165 Heads. - AFR 165s are my choice

Flat Top Pistons and Moly rings for about 10 to 1 Compression with heads of choice.

Roller Cam under 220 Duration and about .500 lift - Comp Cam XE258HR-12 is my choice (208, 216 Duration)

Your exhaust should be good. - BC Headers with 2 1/2" Pipes for exhaust is my choice

EFI - FiTech and other TBs are very good choice now. 4B Intake and minimal wiring. FAST EZ-EFI 2.0 on the Ford Multi-Port is my current Favorite. Compared to your Carb, EFI is for reliability not really power increase.

Combination of parts installed is best. Just heads, or just Cam usually does not work so well.

4.11 Gears with NV3550 and 32s would be minimal gearing for that combo.

You most likely will need a 1" body lift to clear your stock hood.

5001craig · Sep 24, 2017

Edelbrock Performer RPM is what I'm running and I am really happy with it. I chose it after riding in a truck with a stock rebuilt motor with this kit from Edelbrock--includes the cam, heads and intake matched for the HP and TQ they advertise. My engine builder was happy with it and when I matched the engine to the correct 3K stall in my C4 it works great.

Godwick · Sep 24, 2017

I gave a ring to comp cams and they recommended a custom grind for me that was less than their off-the-shelf next step up. I will probably pull the trigger on a custom ground cam with tw170s to bump compression when I have the money and will report back. But first I need to figure out my alignment issues, horn, leaky auxiliary fuel tank, and spotty fuel gauge! Ah, broncos...

blubuckaroo · Sep 24, 2017

Godwick said:
Well, I figured it's time to start another one of these threads. I know that there will be a lot of opinions, but I'm curious as to the gurus' best thoughts on where my money should go next for the bronco.

I am hoping to make this bronco a hoot to drive but don't want to modify the hood if I can help it.

Right now the bronco has a stock 96 351w roller cam (a remanufacturing job from Tristar engines), stock cam, stock heads.

2.5" ceramic headers from Broncohut, 2-into-1 exhaust with cutout and walker quiet flow;

MSD electronic distributor - springs to fully open at 2000rpm;

650cfm edelbrock 4-barrel; Edelbrock performer air intake manifold.

nv3550 transmission and 4.11 gears. 32" BFG AT2

The bronco is torquey off the line but winds out at about 5-10mph, which makes 2nd better to start in, but the torque really isn't there to start in 2nd all the time.

I am considering going with some Twisted Wedge 170s with a 58cc combustion chamber to bump up my compression ratio and a new cam. I am wondering if this will be a noticeable enough change to justify the cost.

Any thoughts appreciated!

-H

I had to go back to the start of this thread, because I'm confused again...
If I'm understanding, you want to eliminate the use of first gear on a NV3550?
The NV3550 isn't like a NV4500 or ZF which are really a four speed with a granny gear. The NV3550 is a real five speed tranny. Meant to start in first gear.
I own a NV3550, and yes first gear is a bit low, but it isn't a granny gear that should be routinely skipped over when starting out. Yes, I skip first gear on occasion too, but it's usually when I'm starting out downhill.

Godwick · Sep 24, 2017

Well, it's a good and fair question. I think others might be right about the gearing as well because to me, the nv3550 is a good tranny, but starting out in first is fine but winds out so quick that in order to drive like I like, I am quickly hunting for second. Which, of course, means that I'd prefer to start in second unless im in the parking lot or traffic. Trouble is, torques not really there for 2nd gear starts. It's ok, but not on an incline.

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roundhouse · Sep 25, 2017

Godwick said:
Well, it's a good and fair question. I think others might be right about the gearing as well because to me, the nv3550 is a good tranny, but starting out in first is fine but winds out so quick that in order to drive like I like, I am quickly hunting for second. Which, of course, means that I'd prefer to start in second unless im in the parking lot or traffic. Trouble is, torques not really there for 2nd gear starts. It's ok, but not on an incline.

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I have a NV3550 with an EFI 302 , 4.11s and 35s
If you got the right exhaust
The one/ two shift is quite satisfying

blubuckaroo · Sep 25, 2017

One thing I do like about the low 1st gear ratio on a NV3550 is when I'm driving in really heavy slow traffic, I can chug along in 1st without riding the clutch.
Try that with a factory three speed tranny!
Also, I can let the clutch out in first gear without even touching the gas pedal.

Godwick · Sep 25, 2017

Yes, I like those things as well. I suppose it will be even better with more torque.

77RHINO · Sep 28, 2017

I read a bunch of 351 threads on here and asked around when building mine and ended up with the following parts as well as some you already have:

'96 351 bored .030 over
stock crank and rods
flat top pistons (+6.50cc KB brand) with valve reliefs
GT40X aluminum heads (64cc chambers)w/ beehive springs
.047" thick head gaskets
XE 266 HR-12 (Comp 35-514-8) RPM range 1500-5500
Scorpion roller rockers
Ford racing hyd roller lifters
factory '77 ignition and coil
Ford distributor (gear from '96, shaft and pickup from '83, funnel from '77 and cap from '78
Edel. 650 carb
Carter m6588 Mech fuel pump
performer intake
1" spacer (heat issues)
WH longtube headers and dual exhaust
Runs on premium fuel
compression is probably around 9.5 - 9.8 I believe
NV3550 w/4.56s and 33s (moving to 35s soon)
Old school Duff traction bars to assist with axle wrap

I love the engine and it pulls super hard, but I have been constantly fighting vacuum/PCV issues with major oil consumption even with roughly 180-195 psi when I did a compression test. Part of this I believe is due to terrible baffles in the 351 scripted valve covers I have.

Godwick · Sep 28, 2017

I hear ya on those bronco script valve covers. Put them on mine when the engine was new and would occasionally hear this ticking sound. Had me freaked that something was wrong internally with the engine. Pulled the covers and saw the baffle had broken free and was rattling around in there! Wouldn't recommend them, as you might guess. I wound up just running without baffles and no problems yet.

I'm expecting around the same compression as you with my dished pistons and going to a 58cc head. Sorta wish I went deeper on the gear too, now that I'm on the other side of things.

Thanks for the info. Are you happy with your cam choice or do you wish you would have gone for off-idle power?

77RHINO · Sep 28, 2017

I feel like I have plenty of off-idle power as it sits, my current idle is probably set around 6-650 rpms and jumps up to 1500 pretty quick. After reading plenty on here about the powerband of a small-block ford, I tried to pick a cam that was matched up pretty evenly throughout the band and have some pep above and below the band as well. I'm thinking that once I move to 35s I will sit about 23-2400 rpm on the highway, which seems to be a pretty good spot for mine. I am currently around 26-2700 or so at 70 with 33s and feel that I'm far enough into the band I could drop a few rpms and still cruise easily and save a little fuel consumption. It will easily go faster than I need it to, I built it to be able to be alot of fun around town and when I drive to the hunting camp (4 hours away) not be drone deaf either. I read threads on here and spent 2 years pretty much saving for parts and learning how to build it so that I'd only have to do it once.

I am still learning carb tuning, fuel delivery and ignition timing, because one can band-aid the other and it pretty much just takes experience to know which issue comes from what. I have rich spots and flat spots as well as dieseling/run-on/hard starts if I put 87 or 89 fuel in there. I also have to pay attention to the different ratings of spark plugs. I toss this up to more of a learning experience rather than incompatibility of parts though.

blubuckaroo · Sep 29, 2017

77RHINO said:
I love the engine and it pulls super hard, but I have been constantly fighting vacuum/PCV issues with major oil consumption even with roughly 180-195 psi when I did a compression test. Part of this I believe is due to terrible baffles in the 351 scripted valve covers I have.

I've had issues too with the cheesy oil baffles on some aluminum valve covers.
I added an oil filter extension to mine to get the PCV valve further from the valve cover. It did the trick, and makes oil changes a lot easier too.
http://www.jegs.com/p/Mr-Gasket/Mr-Gasket-Oil-Filler-Extension-Tube/975695/10002/-1

Getting more power out of the 351w

bigmuddy

Bronco Guru

bigmuddy

Bronco Guru

Godwick

Sr. Member

rguest3

Bronco Guru

5001craig

Bronco Guru

Godwick

Sr. Member

blubuckaroo

Grease Monkey

Godwick

Sr. Member

roundhouse

Bronco Guru

blubuckaroo

Grease Monkey

Godwick

Sr. Member

77RHINO

Full Member

Godwick

Sr. Member

77RHINO

Full Member

blubuckaroo

Grease Monkey

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