Build Plan - Feedback welcome

[66BroncoDD]

Well, I'm on the precipice of starting the engine build. I figure that while I have everything apart I might as well make sure the engine is right.

What i have is a 1966 Bronco with the 170. My plan is to keep the factory 3 speed, Dana 20 T case, and 9" rear with 4.11 gears and a limited slip diff (all of which will be rebuilt).

The engine build is going to start with an early 70s 200cid from a mustang. From there this is what I am looking at adding. I would be interested to know 1) if this system will work for what I want (reliable and stout daily driver that isn't too bad on my wallet at the gas pump), 2) what kind of horsepower and torque you would guess it would produce, and 3) what rebuild kits you have used that you would recommend:

Head – find a head from a ‘77-‘80 200/250 (then mill head .060”, flatten exhaust flange surface, smooth and polish the combustion chamber)
Aluminum Water pump (and add an electric fan. I'm guessing the milling would put compression in the neighborhood of 9:1?)
Valve Train – I'm considering adjustable rockers, but I'm not sure if it's worth the cost
Intake valves – 3 angle valve job & valve back cut
Valve spring retainers – from 4.0 v6 (P/N E6TZ 6A536A)
Pistons - I'm considering flat top pistons.
Head bolt washers – Mr. Gasket (#87 7/16)
Ignition – I like the DUI, but it is pricey. Is it worth the cost over a duraspark II?
Carburetor – Autolite 2100 (1.02 245 CFM)
Exhaust – port divided and header + high flow muffler
Cam - #H-214/290 -2s-12 (Crane Cams)

Any advice you have would be appreciated.

 

[chad]

Sounds like fun.
No advice. Just a question or 2 -
What size tires & what kinds of traffic ("...stout daily driver...")?
Are the parts available to rebuild that near 50 y/o LS rear? I'm surprised
that was available in '66. Congrats on the score, don't see em much but that
1st yr had lots of surprises (air bag suspension available factory from Firestone).

 

[66BroncoDD]

What size tires & what kinds of traffic ("...stout daily driver...")?
Are the parts available to rebuild that near 50 y/o LS rear? I'm surprised
that was available in '66. Congrats on the score, don't see em much but that
1st yr had lots of surprises (air bag suspension available factory from Firestone).

1) at the moment I have 33x12.50x15s, but I am looking at narrowing that a little and going with a larger wheel. Maybe 285/75/16.
Stout daily driver means that most days we'll run kids to school and drive to work (less than 10 miles medium traffic). Also has to be able to take us all fishing, hunting, kayaking, camping, and the occasional light wheeling.

2) I had a dangling participle or other such grammatical faux pas :nono: . I'll be adding an aftermarket LS to the original 9" with 4.11 gears. Once again, I'll have it open, might as well put it back together right.

 

[chad]

With kids & 'medium traffic' U might wanna upgrade the brakes & put in some seat belts.
Mine has lap belts (1970) but I went up to discs all round. Kids are 17 & 27 now so
I guess it's for myself now. That was 1983...

 

[66BroncoDD]

With kids & 'medium traffic' U might wanna upgrade the brakes & put in some seat belts.

Those are both on the slate. Front disk conversion and booster up front. O have corbeau seats that I picked up dirt cheap for the front for a little extra comfort and support.

 

[bmbm40]

Are you going to direct mount the Autolite or use an adapter?

 

[66BroncoDD]

Are you going to direct mount the Autolite or use an adapter?

I was going to go adaptor. $90 seems reasonable compared to the mill work that I would have to get done. Of course I'm not hard set on that. I see you have direct mount in your future plans. Why direct mount?

Also the alternator upgrade seems like a good idea too.

 

[bmbm40]

http://classicinlines.com/DynoSwap.asp
This link should take you to some dyno results to show results from the direct mount carb.

 

[bmbm40]

http://classicinlines.com/CarbChoice.asp
This link talks about the increase in low rpm torque as opening up the carb hole increases air velocity and low end torque is good for a Bronco because they usually weigh at least 3800 pounds.
However going to a mildly warmed up 200 is going to be quite a bit more power than the 170, you may want to drive it for awhile and see what you think. One thing you may want to consider is the carb from a 250, like the Carter at 210 cfm or the new 1 barrel from Classic Inlines, mounted on your large log head with your other planned mods. No hood clearance issues with an adapter.
A couple of times the thought crossed my mind to not direct mount the 1.08 on the late model head that I bought simply because my stock 250 powered Bronco doesn't feel as if it is lacking in power. I suspect I will anyway cause I have never known more power to hurt anything and I am going from a 30" tire to a 31".

 

[MustangSix]

I wouldn't spend a lot of effort smoothing and polishing the chambers. Looks nice, but gets you little or nothing in performance.

I would instead concentrate on working in the bowls below the valves, especially on the exhaust side. There are a lot or humps and bumps that can come out of there. There's a particularly large bump on most heads where an air injection port is supposed to go. Eliminate that altogether then reduce ans smooth the valve guide area so that it's not such an obstruction.

 

[chad]

"...working in the bowls below the valves, especially on the exhaust side...large bump on most heads where an air injection port is supposed...reduce ans smooth the valve guide area..."

Is that just for the 200 or all the sm six heads?

 

[MustangSix]

Pretty much all of them from 144-250. Some just don't suck as much as the others. The exhaust ports are so small you can barely poke a finger thru them and the edges where the machining stops and the casting begins in the bowls is really bad. I'd also toss in a three angle valve job as well.

I've always said that these are miserable heads. They need a lot of port work to pull any kind of horsepower out of them. That's why the aluminum head is so attractive. You can have more $$$$ in machine work and parts trying to make the stock iron head work than the alloy head costs. that

 

[CobraSix]

Well, I'm on the precipice of starting the engine build. I figure that while I have everything apart I might as well make sure the engine is right.

What i have is a 1966 Bronco with the 170. My plan is to keep the factory 3 speed, Dana 20 T case, and 9" rear with 4.11 gears and a limited slip diff (all of which will be rebuilt).

The engine build is going to start with an early 70s 200cid from a mustang. From there this is what I am looking at adding. I would be interested to know 1) if this system will work for what I want (reliable and stout daily driver that isn't too bad on my wallet at the gas pump), 2) what kind of horsepower and torque you would guess it would produce, and 3) what rebuild kits you have used that you would recommend:

Head – find a head from a ‘77-‘80 200/250 (then mill head .060”, flatten exhaust flange surface, smooth and polish the combustion chamber)
Aluminum Water pump (and add an electric fan. I'm guessing the milling would put compression in the neighborhood of 9:1?)
Valve Train – I'm considering adjustable rockers, but I'm not sure if it's worth the cost
Intake valves – 3 angle valve job & valve back cut
Valve spring retainers – from 4.0 v6 (P/N E6TZ 6A536A)
Pistons - I'm considering flat top pistons.
Head bolt washers – Mr. Gasket (#87 7/16)
Ignition – I like the DUI, but it is pricey. Is it worth the cost over a duraspark II?
Carburetor – Autolite 2100 (1.02 245 CFM)
Exhaust – port divided and header + high flow muffler
Cam - #H-214/290 -2s-12 (Crane Cams)

Any advice you have would be appreciated.

Adjustable Rockers are nice. I wouldn't splurge on the roller tipped, just try to find some stock ones. They show up from time to time, in the neighborhood of $100-$150. I think they are worth it, if only from ease of set up. But I hate shimming rockers...

3 Angle job will probably not yield really noticeable results on this stage engine with a log head IMO. If you are spending more than $100 on it, I'd pass personally. Might be better if you plan for some power adders later.

Head bolt washers, consider just getting some studs. Easier to mount the head with them, and better clamping. IIRC, a set of 302 studs will work, just with a few left overs.

Ignition. Stick with the DS2. While the DUI may yield a few more HP, which this build, it's probably only 1-2. The DS2 is a massive upgrade from the stock points. The the money saved from the valve job or the DUI, and buy a hotter coil plus an MSD. Open the plug gap and enjoy.

Autolite 2100. Can't beat them once you get them dialed in. Solid carbs, great atomization, and reliable. 245 may just a tad on the high side for a stock carb, but it's tough to find the .98 venturis, so the 1.02 should be good. Plus you are upgrading the cam which should use the 245 well.

Port divider...is a divisive subject. I ran without, then with, then without again on the same combo. Honestly, no real noticable difference. if you are there with the head off, might as well, won't cause any harm. I would recommend ceramic coating the headers though. Will increase exhaust flow and reduce engine bay temperatures significantly.

Cam: Personally, I like the H198-270, but I don't like lumpy profiles. Others may chime in here and maybe a 276 duration isn't too bad. Then again, that's 276 and .040" of lift vice the normal of .050" of lift, so it may be closer to 270 which isn't so bad. The extra valve lift will wake the engine up, and with the 245 Carb, should be a good fit.

my HP guess is around the 80-90 RWHP mark. 90% of that will come from the cam and carb. Ignition will just make it nicer to drive.

Enjoy!

 

[bmbm40]

I forgot one important item if you don't already have it get a copy of the Falcon Performance Manual- lots of good information. Performance and maintenance resource I am constantly referring to mine for specs like casting numbers to id large log heads etc.

 

[66BroncoDD]

I forgot one important item if you don't already have it get a copy of the Falcon Performance Manual- lots of good information. Performance and maintenance resource I am constantly referring to mine for specs like casting numbers to id large log heads etc.

Got it and read it a few times already

 

[bmbm40]

You probably already know about classicbroncos.com but just in case you don't it is the best early Bronco website in my opinion. You can go there to get a list of parts and instructions to do the disc brake conversion on your D30. I got my parts at the picnpul on half price day and ended up having about 200-250 in the whole job. It is a big improvement.

 

[chad]

"...to do the disc brake conversion on your D30..."
not sure U want the rears too - I used:
'85 cj Rotors
'85 el derado Calipers (due to havin a 2nd piston for the e-brake) &
a mark XIIIIIIII MasterC for the extra resovure space for the added B. fluid.
(pardon my spelling)

 

[66BroncoDD]

You probably already know about classicbroncos.com but just in case you don't it is the best early Bronco website in my opinion. You can go there to get a list of parts and instructions to do the disc brake conversion on your D30. I got my parts at the picnpul on half price day and ended up having about 200-250 in the whole job. It is a big improvement.

I'm Earthguy on that forum. Good forum, but not much love for the sixes.

 

[bmcgc1960]

I bought a new set of 144 intake valves to use as exhaust valves on my 200 off ebay for $20.

I would spend my money there instead of the port divider.

 

[xctasy]

First up, a 200 is better than a 170 Early Bronco, so your on the right track baby. 17.3 % more capacity will help, but 46.7% will help a lot more, and a 250 is, based on the bigger bore and stroke, exactly 46.7% bigger. They call em 200's and 250's but they are 199.5 and 249.5 cube engines


Second, an I6 community networks, but the advice you've been given is go 300 I6 or V8. That's not my advice, I'd go 1971-1993 250 high mount Aussie 250 block with the stock Top loader bell-housing an 160 teeth flywheel used in the Ozzy Falcon, Cortina and Transit vans, but you don't have any of those in the US. You frame has limitations for 4.9 I6 or some V8's. The Windsor 302 is the best economic swap, and anything else will mean you'll have to talks with chad and bmbm40. Or you'll be speding good money after bad.


Thirdly, I've driven an lot of underpowered Fords in my time, but the Early Bronco is the only one that has insufficient cubes for the chassis. I've driven a 138 cube I6 GM six, it came out with 77.9 hp and 2.95/1.68/1:1 gears, and just 24" tires with 3.9 gears and a trim 2550 pounds. I fitted a set of 3.45:1 gears, and a wide ratio 3.18/2.0/1.38/1:1 four speed, and never looked back In stock trim, it was a dog even with a 3.9:1 axle ratio. Good, wider gearing with more gears fixes some aspects of a too small engine.

Even a 2450 pound Fairmont or Mustang 2.3 four cylinder is better than a 3.3 Early Bronco because with a a Fox body at least has gear ratios and axle gearing sorted out to cope with a gutless 85 hp engine. Not so the 200 EB!

Fourthly, irrespective of what engine parts or budget you have, everything needs to be totally revised to go with a 250, or get a 200 fitted with turbo or supercharger, because based on the wide ratio 3 speed gearing, tires and lack of cubic inches, the Early Bronco won't get out of its own way. Everyone except chad and bmbm40 jimmyv65 here have failed to make a 250, or 200 turbo or supercharged Early Bronco work as a reliable entity. That's observational fact.

I'm really worried that a 200 cube I6 won't cope with big wheels a 3 speed Top Loader and and modern driving conditions. Kirkallen143 did have aT3 60 turbo equipped 200 Bronco, and has gone back to non turbo with H pipe and headers. You need to figure out if something like his build will suit you, and do some soul searching, then some benchmarking. I guess you need to think it all through more. Maybee he got tired of blowing four Felpro head gaskets without boost retard and 15 psi.

I know you've spent a bunch of time reading everything, but the following are must re-read poster childs for proper I6 Bronco's. Aint know way I'd ever operate a 200 Bronco unless its boosted.

Broncitis memberlist.php?mode=viewprofile&u=8974
his photobucket http://s717.photobucket.com/user/bronci ... t=3&page=1
and viewtopic.php?f=48&t=52505

and kirkallen143 memberlist.php?mode=viewprofile&u=1778
his earlier Turbo 200 on viewtopic.php?t=31065



Then go research MPGmustang's ways

viewtopic.php?f=36&t=67847&p=551101#p551101


See as well First Fox. viewtopic.php?f=22&t=71606


And maybee this if its in your budget https://www.youtube.com/watch?v=xH8sf0Q_MJs

Wishing you good fortune isn't the answer here, its all about cubic inches and having a better combination than what you started with.