New Improvements

I love this forum and all the input ive gotten on previous threads. I bought my Bronco about 6 months ago and have been working on getting it to perform in the mountain of colorado (6600-10000ft elevation) depending on where im driving.

Heres what Ive done. Any thing else anybody knows that will help boost performance please chime in. I am aware im not fixing up a hot rod but I want to get power from whereever i can.

New:
Radiator
Distributor
Alternator
(removed) Air conditioning
(removed) Air Pump
Flowmaster Super 44 Muffler
Gutted Cats
Holly 500CFM 2 BBl carb
Brake Master Cyclinder
EGR Gasket replaced

And plenty of little stuff like caps, checking vacuum lines, spark plugs/wires, new air filter (thought maybe uprgrading that as well), etc etc.


Im not car savvy, I needed a 4 wheel drive and fell in love with my 1000$ 1985 Ford Bronco II XLT. I Havent stopped pumping money into it, and would like to stop (gf wants me to stop mostly) , but I want it to have a bit more highway/up hill power. Am I shooting for something that cant really happen with this engine or is there something im missing?

Also, Im not totally convinced the carb is tuned 100% since I bought a nicer one from stock and performance only slightly increased plus my gas mileage is still a little low (plus gassy smell). How do i, where do i go, to make sure the carb is where it needs to be. Can I just do it myself with a tachometer?

Thanks everyone!

Setting the carb is pretty easy, should be instructions about everywhere on how to set it. Your carb is huge though, I have a 500CFM carb on my 5.0HO and it is jetting/rodded down (Edebrock)... and it is even a 4bbl. Most guys opt for the Holley 350 for a 2.8... and even those run big. IIRC the stock one is around 280.

Also keep in mind 32 years ago that thing had 110 raging horses brand new. Double that now is considered underpowered in a small SUV... so don't set your sights too high. My fience's 2008 Edge has 265hp... and I noticed it was kind of huffing and puffing in the mountains of Colorado 2 years ago in the Denver/Estes Park area.

Snowgoon said:

but I want it to have a bit more highway/up hill power

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What gearing do you have in the axles? Apart from what you've already done and/or an engine swap you don't have a ton of options.

Going to something like 4.10 or 4.56 will help with this, although it will move your RPM's higher at highway speeds.

85_Ranger: the 500 CFM wont hurt it will it? My mechanic (who constantly reminds me i have a bronco not a ferrari hp wise) and I messed around and ended up jetting it at 61000, if im not mistaken. With a carb am I stuck not being able to drive it between elevations. Most power issue i have occur going up steep grades where i either have keep it in a high 2nd gear or low sluggish 3rd until i level out.

BlackII: If im maxed out thats okay, I want to hold off on the engine swap for a bit (future goal but dont want to be murdered every time my gf looks at the account and sees NAPA).

I dont travel out of the vail valley much with it but would love to be able to go further over passes if need be. Also any info or advise on lifts? It will most likely be the next stage plus half doors as such. I cant find much for spare doors where I live, most of the broncos here are gone or owned and being refurbished already. Do you guys have an online catalog you go through?

Snowgoon said:

85_Ranger: the 500 CFM wont hurt it will it? My mechanic (who constantly reminds me i have a bronco not a ferrari hp wise) and I messed around and ended up jetting it at 61000, if im not mistaken. With a carb am I stuck not being able to drive it between elevations. Most power issue i have occur going up steep grades where i either have keep it in a high 2nd gear or low sluggish 3rd until i level out.

BlackII: If im maxed out thats okay, I want to hold off on the engine swap for a bit (future goal but dont want to be murdered every time my gf looks at the account and sees NAPA).

I dont travel out of the vail valley much with it but would love to be able to go further over passes if need be. Also any info or advise on lifts? It will most likely be the next stage plus half doors as such. I cant find much for spare doors where I live, most of the broncos here are gone or owned and being refurbished already. Do you guys have an online catalog you go through?

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Just saying, out of the box my 500CFM 4bbl was too big/rich for my 302. You are putting a 500CFM 2bbl on a 171. Just using round numbers most of the time mine runs on the primaries, call it 250cfm. You are trying to run on 500cfm all the time, it isn't going to help it. Your engine can only pull so much air thru the carb and even less at high altitude.

You might check into putting a bigger engine in it really, either a 4.0 or a 5.0 would be my recommendation. Check out BlackBII's thread, he just put an Explorer drivetrain in his Ranger.

LMCtruck, Rockauto (go to the vender forum, TRS gets a 5% discount code), James Duff, Broncograveyard, Summit Racing, Jegs, Streetside Auto, all good places to get RBV parts in addition to my favorite place... Junkyards.

A Weber progressive 2 barrel seems like a great choice for the 2.8, and I know people in the past have mentioned adapting them. Not sure what they actually did to get them bolted together though - I can't recall seeing an adapter to do it.

Is that carb off a 400c.i. small block chev? Way to big. For the 2.8 you need the Offy 4bbl manifold and a Holley 390 cfm 4 bbl. This setup, although getting tough to find, works pretty well. Go to broncocorral and look up wildbill 32, I think he has the manifold. Next step, find some explorer axles and regear them.

Non feedback 2150 1.08 venturi 2bbl carbs are out there too, either from Mustang II/Pinto or low performance 302s from the same era

85_Ranger4x4 said:

Non feedback 2150 1.08 venturi 2bbl carbs are out there too, either from Mustang II/Pinto or low performance 302s from the same era

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You are correct, I guess the first response should have been to do the duraspark conversion, still the best mod for the 2.8!

Thanks for keeping the posts coming. Ill look into the duraspark conversion soon. Ill also post some pics and videos. Even with the 500CFM (jetted 61, thinking of going to 58 for gas mileage). I only get 11-14mpg right now but the roads out here are 75 speed limit and hilly, not great for old car gas mileage.

Shes been roaring lately but we found a gap between the intake manifold and the carb because i need a new intake manifold spacer thats a better fit than what came stock.

I feel like for the yr and HP shes running top the only issue i find is steep grades. Have to stay in second till 40mph then when i pop to 3rd it stays at speed but wont gain much more until i level out again.


Pics and some vids to come

Snowgoon said:

Thanks for keeping the posts coming. Ill look into the duraspark conversion soon. Ill also post some pics and videos. Even with the 500CFM (jetted 61, thinking of going to 58 for gas mileage). I only get 11-14mpg right now but the roads out here are 75 speed limit and hilly, not great for old car gas mileage.

Shes been roaring lately but we found a gap between the intake manifold and the carb because i need a new intake manifold spacer thats a better fit than what came stock.

I feel like for the yr and HP shes running top the only issue i find is steep grades. Have to stay in second till 40mph then when i pop to 3rd it stays at speed but wont gain much more until i level out again.


Pics and some vids to come

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Looking forward to it. I am getting back into action by getting my '84 on the road again. I have all the components for a Duraspark conversion and can't wait to see the difference it makes.

If you end up doing the conversion there are a lot of resources here and I will be posting pics myself in my thread for reference.

dirtcowboy said:

You are correct, I guess the first response should have been to do the duraspark conversion, still the best mod for the 2.8!

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When a new dizzy is on the done list I took for granted DS had been done.