belt configuration options

[caveman69]

I have a 77 Bronco that runs okay, but I tore down an 85 5.0 today that I'd like to install in this Bronco. The original engine has power steering, and AC. I would like to retain that on the 5.0 roller cam engine. Should I retain the original three vee belt configuration or use the Mustang's serpentine belt or go to the Explorer serpentine set up?

Also, I plan to run a carburetor. Which intake and carburetor would be best suited for this application? I am planning to use aluminum heads and would like to come close to the Blueprint 361hp engine specs.

My other Broncos need some attention. My 74 with a 351 has developed a fuel leak. New hose is here and needs to be replaced. I moved the 73 out of the shop today to make room to work on the 5.0 and it now has no brakes. I'll try to bleed them and see if that solves the problem. The 68 that I've had for 31 years is running hot, but only when it is run at 60 mph for extended time (4.10's and 235's). I replaced all of the cooling system recently except for the radiator.

 

[Broncobowsher]

For the '85 engine you will need the later balance crank damper. Really the best options is one you have not listed, the '96-01 5.0 Explorer front drive. Well known for being a great package in a Bronco. Tons to love about it. You get a great package that has A/C, power steering, and a really good alternator. Even better is a cooling fan that really works.

The down side, no provision for a mechanical fuel pump. But a Carter P4070 pump can fix that.

If you try to keep the original 3 belt setup you will need a, aftermarket damper that has the right bolt pattern for the old pulleys (3-bolt) but the later balance (50-oz-in)
The mustang belt drive doesn't package very well. I forget the details, it has been forced into working, but it has never been one that people try to use.

 

[nvrstuk]

what bowsher said. You are money and miles ahead going with the Exploder serp setup. HUGE benefits from alt amperage, p/s placement and no belt squeal, and most important is it cools so well and fits perfect as an added bonus. Really no drawback other than it's not an attractive setup. Ditch the 3 v-belts... archaic.

4bbl and intake. Hard to go wrong with and Edelbrock Performer 4bbl intake. Good packaging since it it fits under a Bronco hood with an Edelbrock or Holley Truck Avenger. The BEST carb for a Bronco is the Quadrajet. Guy named Bruce in Arizona still builds them at his shop- (I sold many of these back b4 most of us went EFI or SEFI). They are the best off road carb and best for mileage because of the fuel bowl design and the small front venturi's. They give you great throttle response and mileage. I have rebuilt and tried almost every carb on a Bronco before I started building Q-jets in the mid 90's. If you tore down the 5.0 the best bang for making your HP goals is to put a good roller cam in it in case this '85 doesn't have one. (it should as I think that was the first year). Newer cam design WILL make a large difference in HP goals along with the 4bbl, intake, good headers/exhaust... did I mention cam??

 

[Broncobowsher]

I think the modern heads are even more amazing than the modern cam grinds, but that is going deep down that rabbit hole and likely to be WAY out of a budget build. Unless the stock heads need rework, than it turns into a mild price bump for better heads.

'85 is the first year for the roller block. All 302/5.0 engines got the block, only the HO actually got the cam and lifters.

The rest of this is personal preference on carbs, I'm not a huge fan of carbs. I recently got a new 2-stroke motorcycle and even that I was looking for EFI over the carb. Here is my take on carbs...

Not all Q-jets are the same. Not all builders are actually good at it. The Q-jet is a really good design. I'll even say the peak of pre-emissions OEM carb design. It was intended to replace the three 2-barrel setups for performance, great drivability, good economy, mass production. Great design that lasted into the emissions days and was in use right up until EFI took over. But a 302 Q-jet manifold is rare. I think Offy has/had one and that was it. To put a Q-jet on a regular 4-barrel intake needs an adapter, that adds height and the flow is only okay. That opens the gate for standard 4-barrel carbs. The Autolite 4100 (4-barrel version of the stock 2-barrel) is generally regarded as really good. But hard to find a good one these days. I've owned a couple of Edelbrock/Carter AFB. Was never really impressed with them. But I also know there is a ton of new stuff in the past couple decades I have not really followed up on. Add a wide band O2 sensor and you can spend some time dialing most of them in.

My go to choice would be an Edelbrock intake (this I do really like) and the flavor of the month Holley based carb. Vacuum secondary in the 600 CFM range. If you have the hood room (running a body lift) I would step up to a performer air gap. Adding the "RPM" to either hurts hood clearance a little more but would be my choice with better heads.

 

[Johnnyb]

I agree with all of the above! The factory v belt setup and old school Ford alternators are simply inferior. The explorer system works great. An electric fuel pump way back close to the tank will help to alleviate vapor lock issues as well.
Don't forget about the 50 Oz balance flywheel!

 

[jamesroney]

Wow. Nice echo chamber here.

I have run the Explorer serpentine. And I have run ever V belt configuration known to man. And at the end of the day, I am here to tell you that there is NO single "best" solution. The answer is always: It depends.

What was not mentioned above, (because people confirm their own bias...) is the NOT trivial water pump inlet location. Ford passenger cars swapped water inlet on the water pump to the driver's side in 1970. It coincided with the power steering pump belt priority on the cars. So 1970 and later 302's in anything other than a Bronco or Econoline got a Driver's side water inlet, and a passenger side timing pointer. If you have a new radiator, or if you like oddball hoses, or if you don't mind being unable to see the timing pointer, and if you don't mind the fan hitting the radiator, or the fan hitting the lower pulley...then fine. Also as stated, the 1985+ loses the fuel pump drive. And yes, you can always DOWNGRADE to an electric pump. Keep in mind that people who like electric pumps, fans, and doo-dads consider an electric pump an upgrade. People that like simplicity, durability, and conformity consider an electric pump a downgrade.

The other problem with the 1970-85 Ford 302 configuration is the change from 3 bolt to 4 bolt on the damper. But it isn't JUST the number of bolts. The 4 bolt damper has a protrusion on the hub that pushes the lower pulley out about 5/8 of an inch. So the timing marks are in the wrong place, the damper is too long, and none of the pulleys fit. If you make the mistake of running the passenger car damper and lower pulley...(v-belt or serpentine) there simply is no room for the fan between the lower pulley and the radiator. So Don't.

Keep in mind that Ford moved the water pump shaft centerline up when they changed the inlet location. Not good, not bad...but different.

The ultimate solution is to determine exactly how many accessories you intend to run. As soon as you say "Air conditioning compressor" then you've made the decision for yourself. The ONLY cost effective, durable, high performance, solution to include an AC compressor is the Explorer serpentine with water pump, timing cover, damper and accessories.

As soon as you say: No AC, ...the optimized solution is a 3 bolt conversion damper, and the 1973-77 Bronco V belt configuration. The Bronco V belt configuration happens to be almost identical to the 1968 Mustang with PS solution. I run v belts on all of my SEFI conversions. I like the redundancy of multiple belts, so that I can remove either one and continue to drive.

The whole point is to get the crankshaft pulley away from the radiator so that you can run a fan on the front that can move enough air to keep the Bronco running cool. This has been solved countless times by the vendors and enthusiasts on this site. Please don't try to re-invent the wheel. It has been invented. Round works best...

 

[ntsqd]

Generally aluminum heads allow more static CR than do iron heads, so that alone is a step in the right direction. Current intake port design is a lot better than previous designs regardless of the cyl head material. Roller cams, for the same lift and duration specs as a flat tappet cam, have more area under the curve. That's a gain.

When you look at the Explorer front cover and water pump assembly with any understanding of hydraulic flow it is clearly a superior design to all of the preceding designs. The only reason that I'd not run that system would be because some set of rules required a mechanical fuel pump.

I don't see an electric pump as a down-grade from a mechanical pump. Among other things I see it as one fewer point where heat can be injected into the fuel. It is true that there is a vast array of bad choices that can be made in electric pumps, most of them go by popular aftermarket names. Chose carefully. I agree with him that the pump that Mr. Bowsher suggested is a good choice. My own preference is for one of the slightly higher pressure pumps (15-20 psi) intended to be used with a TBI system, along with a by-passing fuel pressure regulator and a return fuel system. For a carb I'd locate the regulator as close to the carb as I could reasonably get it.

ETA: Put one of these pressure switches int he control system for an electric fuel pump: https://www.summitracing.com/parts/crt-a68301 One terminal is power to the pump, one terminal is supply power for the pump, and the last terminal supplies power while cranking and little to no oil pressure. If you run out of a oil pressure, say something bad were to happen, the pump will stop and not continue to feed the fire. While I'm at it, I use this fuel filter on all of my projects: https://www.summitracing.com/parts/wix-33481 O-Ring bump to -6AN adapter fittings are easy to get.

I ran a range of Holleys and a Carter 625 CFM AFB on the Ranchero. For acceleration and top end the Holleys had it for sure. For economy and part throttle drive-ability the AFB could not be beat by any of the 2 and 4 bbl Holleys. I was in the process of setting up trying a Q-Jet on it when the car sold, so never got to try that. I had hopes that it would be even better than the AFB.
Tuning the AFB was hopeless until I built a spreadsheet that guided me through all of the possible combinations of metering rods & jets. The Edelbrock instructions are pretty good, but the spreadsheet had more possible options listed, which allowed me to achieve a better final tune.
Note that AFB/Edelbrocks have their float bowls in the worst possible place for an off-road carb. No way would I ever run one on a vehicle that would experience steep angles in any direction. Maybe, MAYBE if I dry-sumped it, but this is not the thread to talk about that as it is VERY esoteric.

 

[nvrstuk]

Problem with simplicity of a manual fuel pump James is they don't make any good ones anymore. There are a dozen posts here & 5x that many on other social media sites/forums with guys running manual fuel pumps for a week & they died. 2 months is a record I think- garbage. Want dependability - go name brand electric unless you like changing fuel pumps on the side of the road.

QJet compared to ANY other carb-especially Holley is so superior off road it should be in it's own class.
Holleys are worthless off camber. Great road only carb & should just use your wife's plant watering can & pour fuel in thru the 4150 flange hole. Yeah- that bad in comparison.

Truck Avenger allows you to drive over curbs going to the mall w/o engine stumbling. Next best in comparison to Qjet for on/off road.

Yes you need a 1/2" thick adapter but ??

Waterpump again... like TS said, Exploder design flows is better.

... intended use?

 

[jamesroney]

Problem with simplicity of a manual fuel pump James is they don't make any good ones anymore. There are a dozen posts here & 5x that many on other social media sites/forums with guys running manual fuel pumps for a week & they died. 2 months is a record I think- garbage. Want dependability - go name brand electric unless you like changing fuel pumps on the side of the road.

QJet compared to ANY other carb-especially Holley is so superior off road it should be in it's own class.
Holleys are worthless off camber. Great road only carb & should just use your wife's plant watering can & pour fuel in thru the 4150 flange hole. Yeah- that bad in comparison.

Truck Avenger allows you to drive over curbs going to the mall w/o engine stumbling. Next best in comparison to Qjet for on/off road.

Yes you need a 1/2" thick adapter but ??

Waterpump again... like TS said, Exploder design flows is better.

... intended use?

I've also heard horror stories about bad imported fuel pumps, but never about the Carter M60454 (screw together) mechanical pump. AMK and Scott Drake still sell the diaphragm kit. So those should be in service for at least another decade.

I have owned at least one Sunbeam Tiger since 1987, so I have bought every electric fuel pump known to man. Not sure I agree with your dependability assessment. Just swapped out another P4070 Carter last winter. They are good for about 5 years. The electric fuel pump sits about 3 inches above the muffler, and about 3 feet from your right ear. I am convinced that the submersible in tank georotor pumps provide the longest service life.

I have been running a Mallory Comp 116 FI external georotor pump in my 5.0 EFI powered Willys since 1995. So that's 30 solid years.

Quadrajet for the win.

 

[caveman69]

Thank you all for your knowledge and taking the time to share your experiences and advise. This '77 will not see much offroad if any. I intend to use it to drive a day or so a week and do want to retain the AC. This one is a pretty nice (not show quality) with the Ranger package, no lift, carpet, ps, auto, power brakes-pretty much the opposite of my 68 170ci, three on the tree, uncut Bronco.

 

[DirtDonk]

There was one mention of the auto light 4100, but not sure if everybody knows that Summit Racing has their own branded carburetor that looks (so probably is) identical to the Autolite 4100.
Don’t have a link, but there was a really fun episode of Engine Masters where they compared three cheap carburetors. Check it out.

 

[nvrstuk]

You're right James, the only good electric fuel pump is a submerged one. Mainly physics and being quiet. I never gave a frame mounted one a second thought. Walbro- not a knock off. I buy them direct or from TanksInc.
I'll have to recommend the mech pump to all the guys behind the posts that are crying for a pump that lasts more than a month or two. Good to know!

I've dreamed about owning a Tiger. Loved them since Agent 86 aka, Maxwell Smart had one! lol Still a favorite of mine. I'd buy one if they weren't $50k for a grade 3 condition. Any pics?

 

[ntsqd]

Was told when I was a teenrager by a Tiger owner up the street and around the corner that the Achilles Heel of Tigers (& Alpines for that matter) is the holes for the 4 bolts that hold the front suspension cross-member to the rest of the car are notorious for cracking and breaking out around the bolt head. No idea of the validity of that.
Worked with a guy who was in the process of putting a Honda S2000 power-train in an Alpine. And occasionally drove his pseudo-Tiger to work. That his 6'8" frame or his son's 6'10" frame comfortably fit in those cars was a marvel to me. Windshield was completely useless, but they fit.

 

[jamesroney]

You're right James, the only good electric fuel pump is a submerged one. Mainly physics and being quiet. I never gave a frame mounted one a second thought. Walbro- not a knock off. I buy them direct or from TanksInc.
I'll have to recommend the mech pump to all the guys behind the posts that are crying for a pump that lasts more than a month or two. Good to know!

I've dreamed about owning a Tiger. Loved them since Agent 86 aka, Maxwell Smart had one! lol Still a favorite of mine. I'd buy one if they weren't $50k for a grade 3 condition. Any pics?

Here’s me with the original owner this year. He took it apart for a color change, and after a few years, he turned 85 and realized he wasn’t able to finish it. So I finished it. I’ll sell it someday, but having too much fun now. And there's a v-belt to keep the thread on topic.

 

[DirtDonk]

We never actually had to change the plugs in my friend's green Tiger, but we did try to remove the glovebox liner once. To see if we could access the #4 plug!
His was a 260 if I remember correctly. Don't remember the exact year ('66 maybe?), but it sure was fun to scoot around the neighborhood in not long after we got our driver's licenses!

 

[nvrstuk]

#4 plug huh? I remember the V8 Monza's needing to pull the PS mtr mount to change the plug. It had a V belt too... Sweet Tiger James!! Let me know when you are ready to sell it.

 

[caveman69]

what bowsher said. You are money and miles ahead going with the Exploder serp setup. HUGE benefits from alt amperage, p/s placement and no belt squeal, and most important is it cools so well and fits perfect as an added bonus. Really no drawback other than it's not an attractive setup. Ditch the 3 v-belts... archaic.

4bbl and intake. Hard to go wrong with and Edelbrock Performer 4bbl intake. Good packaging since it it fits under a Bronco hood with an Edelbrock or Holley Truck Avenger. The BEST carb for a Bronco is the Quadrajet. Guy named Bruce in Arizona still builds them at his shop- (I sold many of these back b4 most of us went EFI or SEFI). They are the best off road carb and best for mileage because of the fuel bowl design and the small front venturi's. They give you great throttle response and mileage. I have rebuilt and tried almost every carb on a Bronco before I started building Q-jets in the mid 90's. If you tore down the 5.0 the best bang for making your HP goals is to put a good roller cam in it in case this '85 doesn't have one. (it should as I think that was the first year). Newer cam design WILL make a large difference in HP goals along with the 4bbl, intake, good headers/exhaust... did I mention cam??

I've been looking for an Explorer 5.0. I found one with the front dress, minus the air compressor that is supposed to be in operable condition for $600. Is that a reasonable price to pay to get the front dress with the option to resell the parts I do not use? I'll likely use the block and crank from the mustang engine. I appreciate the guidance.

 

[nvrstuk]

If it's tight, meaning air filter & any and ALL valve cover & or engine holes (vacuum line attachments) so no moisture in liquid form can get in you are probably OK. How many miles? No at least a half dozen guys that bought used with 150+K miles & no, not any internal engine issues.

 

[caveman69]

If it's tight, meaning air filter & any and ALL valve cover & or engine holes (vacuum line attachments) so no moisture in liquid form can get in you are probably OK. How many miles? No at least a half dozen guys that bought used with 150+K miles & no, not any internal engine issues.

It is supposed to have 120000 miles and the guy I got it from said it was destined to go into his cj5, but he opted for an AMC304 instead. Regardless of if it runs, it has the front dress, intake and ecm which should allow me to recoup some of my money. I picked it up this afternoon.

 

[nvrstuk]

SCORE!