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Getting more power out of the 351w

Godwick

Sr. Member
Joined
May 14, 2011
Messages
407
Loc.
Santa Barbara, CA
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
 
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Timmy390

Bronco Guru
Joined
Jan 1, 2011
Messages
5,609
Loc.
Conway, AR
The stock cam isn't a bad one....
Explorer F4TE-6250-BA Hydraulic Roller
Intake at 1.6 rocker ratio .422" lift 256 duration
Exhaust at 1.6 rocker ratio .448" lift 266 duration
1.7 rockers is .449 intake and .476 Exhaust
116 lobe separation

Stock heads should be E7's which aren't that bad either.
64cc
Runner Volumes: Est. 135cc int. 45cc exh.
Valve Sizes: 1.78" intake 1.45" exhaust

If you're just looking for a compression bump, Get a set of GT40P heads. They will be ready to run with the stock cam as it's the same cam as was installed in the Explorers. GT40P's can be had on the cheap. I got a pare for $35 each off a wrecked 2001 Mountaineer. P's will require stock explorer exhaust manifolds or Bronco Hut headers. I'm running the headers.....
60cc
Runner Volumes: 155cc int. est. 55cc exh.
Valve Sizes: 1.85" intake 1.46"


Really good head info here
http://www.fordmuscle.com/archives/2000/05/heads/index.php
Tim
 
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Godwick

Godwick

Sr. Member
Joined
May 14, 2011
Messages
407
Loc.
Santa Barbara, CA
Thanks for the info.
Did the stock engine come with 1.6 ratio roller rockers? It doesn't sound like a head and cam swap will get me that much then.

Hmm...
 

Cortez

Bronco Guru
Joined
Jan 29, 2009
Messages
1,193
Subscribed...I'm running a stock 351 and want to get a little more out of it too.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
4:11 gearing but what is the tire diameter? At what speed is peak torque. tire and axle gearing is very important especially with an overdrive. Fix the axle gearing and your power will wake up. Much better money spent.
 
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Godwick

Godwick

Sr. Member
Joined
May 14, 2011
Messages
407
Loc.
Santa Barbara, CA
4:11 gearing but what is the tire diameter? At what speed is peak torque. tire and axle gearing is very important especially with an overdrive. Fix the axle gearing and your power will wake up. Much better money spent.

Good point. I run 32" All terrains
 

Timmy390

Bronco Guru
Joined
Jan 1, 2011
Messages
5,609
Loc.
Conway, AR
Thanks for the info.
Did the stock engine come with 1.6 ratio roller rockers? It doesn't sound like a head and cam swap will get me that much then.

Hmm...

Should be stock 1.6 but NOT roller rockers. Roller cam only.
I think you can pick up pretty good over the stock numbers 205 hp @ 3500 328 ft/lb @ 2200

I'm running a 96 van block stock bottom end 20 over Comp 35-349-8/XE264HR, GT40P heads, EFI with GT40 upper and lower intakes. 95 Mustang ECU with tune and per desk top dyno, 310 hp @ 4500 and 420 ft/lb @ 3500

I think the key is the right combo of parts. An engine is an air pump. you need more air in and more air out to make power so intake, cam, heads and exhaust have to work together.

Tim
 
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Godwick

Godwick

Sr. Member
Joined
May 14, 2011
Messages
407
Loc.
Santa Barbara, CA
Should be stock 1.6 but NOT roller rockers. Roller cam only.
I think you can pick up pretty good over the stock numbers 205 hp @ 3500 328 ft/lb @ 2200

I'm running a 96 van block stock bottom end 20 over Comp 35-349-8/XE264HR, GT40P heads, EFI with GT40 upper and lower intakes. 95 Mustang ECU with tune and per desk top dyno, 310 hp @ 4500 and 420 ft/lb @ 3500

I think the key is the right combo of parts. An engine is an air pump. you need more air in and more air out to make power so intake, cam, heads and exhaust have to work together.

Tim

How fun is it to drive? I'm willing to consider the EFI route if it adds significant enough power. I guess the question is which direction is the best bang for the buck?
EFI? heads and cam? Blower?
 

Timmy390

Bronco Guru
Joined
Jan 1, 2011
Messages
5,609
Loc.
Conway, AR
I think it's fun....but everyone's definition of fun is different...I plan to be upgrading to 33's on 17 in rims in the coming months. I can feel a difference between the stock cam and E7's vs. the new cam and GT40P's.

Not sure you can get a blower under the hood.....maybe an older style Paxton for a mustang? Still more air in means more air has to get out......

Tim
 

AZ69EB

Sr. Member
Joined
Jun 8, 2006
Messages
680
EFI's main purpose is to give you drive ability, reliability, lower emissions, and more fuel efficiency. You can always add a blow through carb and a blower with 4 to 6 pounds of boost with a lower compression stock engine to make some really big hp's.
 

BanditBronco

Sr. Member
Joined
Jul 2, 2008
Messages
689
I honestly don't think you will be that floored by any top end upgrades. The amount of Woohoo's you get for you money just isn't there. I am not saying don't do it, I have, and I got my limited woohoo's, but the horsepower to money ratio just isn't impressive. Boost is definitely impressive but it comes with some trade offs, not a lot of cons of you ask me. I am surprised there are not more boosted broncos, probably because boost availability for small block fords isn't the greatest. I wish I had a better more straight forward answer but I don't. Do head research and cam research till the search button doesn't work anymore, then buy some and create your own opinion. Or boost it and I will watch and smile.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
Compression does wonders. Aluminum heads let you run a little more compression for the same octane that iron heads can do.
 

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
I'm going to say it again and get blasted again...
This is the difference between the 347 and the 351W. They'really similar in displacement but way different in performance.
A stock 351W is torqey, but not peppy. There's just too much rotating mass.
The best thing you can do with a 351W is to capitalize on the torquey characteristics. Small runners, short duration cam, and small carb.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
I'm going to say it again and get blasted again...
This is the difference between the 347 and the 351W. They'really similar in displacement but way different in performance.
A stock 351W is torqey, but not peppy. There's just too much rotating mass.
The best thing you can do with a 351W is to capitalize on the torquey characteristics. Small runners, short duration cam, and small carb.

And choke a 351 like that and it will never be peppy. Those choices cripple a 351 so the 347 looks better in a comparison. Put good parts on a 351, and it will run great. A couple pounds of crankshaft weight means nothing when the inertia of the whole vehicle is put into play. Unless you have a very light overall vehicle you won't notice it. And if you really wanted to kill inertia even more than a light crank (not a good idea in a Bronco) there are some aluminum flywheels that really remove inertia and let engines spin up (and down) quick.

Good flowing heads to let the air move. Compression to get the pop out of the fuel. A mild enough cam to keep the low RPM cylinder pressures. You have a fun engine.
 

bigmuddy

Contributor
Bronco Guru
Joined
Dec 28, 2004
Messages
7,001
Loc.
Marthasville Missouri
Well let me chime in here and add my thoughts as I am going through the same issues.
I have a new crate stock rebuild non-roller engine. Engine has a .60 overbore and has dished pistons making it a low compression 8.5.1 This hooked to a ZF tranny.

So took it over to a local machinist and he suggested a small upgrade, Gt40P head rebuilt with better springs, 1.6 roller rockers. I am capping it off with the 93 cobra upper and lightning lower with a 65 throttle body.

The 58cc head is going to bring compression up to around 9.1.1 or maybe 9.5? and the cam will provide a better torque profile.

So, more to the story: I currently run an 88 mustang HO motor EFI with the Explorer upper and lower, stock cam and stock heads. MY TORQUE is fantastic on the low end and I can pull all day long between 2nd and 4th gear. However, hauling a smallish trailer on the interstate becomes an issue in 5th gear. But I also run 35s and 4.56 gears.

Your issue really isn't the engine it's your gearing. I frankly could have regeared to a 5.13 gear and likely been perfectly happy but my gears just aren't that old and I can do the engine work but not the gearing sooo, I am doing the engine swap. Plus I got a crazy deal on the engine and am selling my old one so my costs really come down.

Do the engine upgrades but you really aren't going to be happy until you fix the gearing IMO>
 

AZ69EB

Sr. Member
Joined
Jun 8, 2006
Messages
680
You want a fun and put a smile on your face driver. Don't forget that we are working with engine technologies that are decades old and trying to push a 4K pound plus bronco. That includes our main stream choices for EFI. Even a bad arse stroked out 408 don't put down the hp & torque of some of the modern stock engines being driven on street now days.
My favorite thing is a big, bad bronco that has a LOUD exhaust. It doesn't mean it's fast. Just loud. But, everyone is smiling when it is driving down the street. Another good example of this is H&D motorcycles with open pipes. Their loud, put a smile on your face, but not fast.

Basically, unless you dropping some major coin, a slightly modified Ford Focus can blow your doors off on the street nowadays. But, I will have a bigger smile driving my bronco! It's all about your expectations and your wallet.
 

AZ69EB

Sr. Member
Joined
Jun 8, 2006
Messages
680
FYI - The TW170's are s great choice with 58cc for your bronco. These heads will allow you to the room to grow if you decide to stroke it down the road. There are s couples of places you can send the TW170 to be reworked to fit any future needs. Basically, your not wasting your money if or when you decide go a different direction. I would not waste my money on any stock iron head unless I plan to keep the bronco stock.
 

needabronco

Bronco Guru
Joined
Jul 2, 2004
Messages
6,411
Loc.
Prescott/Farmington
My suggestion is to try a cam swap first, if your not happy, I'd go with either heads, or gearing next. Heads will let it breath better but probably won't give you as much 'seat of the pants' fun as gears.

Gearing will get you more pep all day long. 32"s and 4.11's and an NV3550 is geared to high IMO. I'd honestly go with 4.56's or even 4.88's that way when you decide to go to 33's or even 35's your not going to need to regear again. With 4.88's you'll have a great crawl ratio and your 5th gear will still be good for cruising on the highway.
 
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