Best Build for Early Bronco

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MPGmustang

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So, just a future reference for me... getting my research together...

In the future I would like to build a Early Bronco (66-77) with a 250 and Alum head...

250 block - because I can put the v8 c4 behind it
alum head - I've always wanted one, but never did get one (might have to put one on the self)

Goal on Bronco Build

1inch Body Lift
2.5 inch Suspension Lift
35 x 12.5 r 17 tires (on bead locks)
C4 stock trans
4.56 gears, possibly 4.88 gears (thinking of 36/37 inch tires)
Cut wheel wells... the tires have to fit somewhere...
Wagon top
d44 front axle with e locker
9 inch rear axle with e locker
HydroBoost Brakes... uses power steering.


the 250 needs
AC
Power Steering pump
ALT
Water pump
4bbl intake (Affordable Fuel Injection with programmable computer)
DS2 re-curved for CAM
stock rockers
6 to 2 to 1 exhaust (CI headers are amazing)

so here is my dilemma.... the CAM... which one?
... IT has to run smooth, have power, and not be hard to tune.
I need torque, lots of torque for the whole range.... and great throttle response
Cruising speeds at 70mph should turn 2900-3100 rpm max
so
35t/4.56g = 3066rpm
36t/4.56g = 2980rpm
37t/4.88g = 3103rpm

all pushing a barn door down the road.


So I need torque at 3k rpm, and peak HP close to that also... it won't be a high rev motor, but a work horse in the lower rpm range... I'm guessing it won't see more than 4250 rpm if built right... okay maybe 4500-5k... but shouldn't need to. So I know carb restriction will be required to boost air velocity and throttle response.

Things to fix,
rear sump required - grap bottom half of 170 oil pan, weld to top 250 pan, different oil pick up... modify crank bolt
can't get a keyway for the cam, so I'll have to play with the crank pin... I figure the stock 4* advance would be best... maybe 6* for chain slack.
brackets for the accesories... want to convert a old school AC compressor for a tire pump for air up on trails (bead locked tires can go down to 1-2psi for snow) and still run modern AC...

Everything else I think is standard...
 
Howdy Back Mpg:

Interesting build, but give this a think. Given your engine goals I'd suggest you rethink the head. An Aluminum head is overkill. While very cool it really comes alive at higher rpms. You need a low speed grunt head that is capable of higher compression ratio- in the neighborhood of 9+:1, and a cam to match, with good vacuum and torque. I'd suggest a wide base two barrel. My preference would be an Autolite 2100 from a 351 dbf of about 350 cfm. These carbs are very simple, reliable, relatively cheap, tunable, well vented for off angle operation and easy to rebuild. They also have the lever linkage for the tranny downshift rod.

The above with a C4 tranny along with a cam in the 250 to 260 duration designed for torque and good vacuum would complete the package. Check it out.

The above will also be a bunch cheaper on your wallet- if that matters to you. That's my two cents, for what it's worth. What do you think?

Adios, David
 
sadly I'm dead set on the alum head, the intake can be a 2bbl, that's fine... but the alum head, as it's a toy and eye candy, is required... lol :eek:

I would like a 9-9.5 CR... I think that is ideal.

I'll be going gm TBI, probably the 2bbl with a restrictor plate under it to lower the cfm... thinking 350 cfm too, maybe 300.

I too was thinking 258 cam with 112 LC, or 264 cam with maybe a 114 LC... I think I might do a different brand than clay smith, haven't looked into any yet. just rough experience with their last cam.

my current 5.0 ho EFI doesn't have the down shift, works just fine without one imo... but it does have an aggressive shift kit... maybe the c4 will need one too.. btw my current bronco is for sale... looking for a 66.
 
is it too much to have power in the lower band too??

in the end, it's a beat-up-wash-off toy, the engine I want enough power where I'm not stuck going grandpa slow everywhere, I know these engines have the power, and the head will unlock that potential, i've seen it. so as a toy, I want to build the alum + 250 as the best team I can...

from your post, it sounds like you recomend a 2v log conversion
 
In my opinion, your wheel/tire combo looks like a rock crawler build, but your c4 will restrict your build from being good in both low RPM crawling and high speed/low RPM freeway driving. I'm assuming since that's the issue the guys on my bronco forum have complained about with V8s. I can't give personal experience as I don't crawl, and my bronco doesn't work...

I think the CI head would work well for low end grunt, especially with a custom long tube intake for ram effect. I have half a mind to toss one of my 250s in my bronco, though I don't want to deal with the extra welding.
 
MPGmustang":skpucssc said:
no not listed, just 'for sale' on the windows....
Click to expand...
More for curiosity than anything else, how much are you asking? I assume rough tub, rust through floor pans, and some rust on the rockers? That seems to be the state of broncos...everywhere.

Mine, the PO riveted sheet over the rusty floors, then THOSE rusted through. The tops of my rockers look fine, but I have diamond plate skid plates bolted on, and I'm terrified to pull them. That being said, virtually no denting on the body, just surface rust.
 
not a rock crawler, a snow-lizard.... an Arizona snow truck, some camping, toy, I'm not a rock crawler. so the range doesn't matter too much for me. it's all about floating ontop of the snow and that's dependent on shoes.. oh and I do have 'low' for snow too so that helps. but no rock crawling.

it has no rust, clean tub, it's locked front and back, 2.5 SL, 2 BL, d44, bb9inch, 5.0 EFI HO 90's mustang eng, c4, j-case, family roll cage, asking 10.5k... looking around, as there is no rust anywhere and runs great, I could probably ask 12k and get 10k if it was online... the roof has surface rust.... nothing cancerous... oh and no rockers, rock sliders are brand new (being install today actually) oh and some wonderful hood shocks
 
This isn't your only bronco you're trying to sell, is it? I recall you kinda having two.
 
correct, already sold the 66... that was a rust bucket... my 75 has been rust free from PO's PO... it's solid...

but the Bronco I want the 250 in won't be this bronco... I wanna get another one and start from the ground up my way. I would love to keep the 75, but it's wrong timing.
 
Use the closest Clay Smith or Schneider regrind cam to the floowing 8 cams.

1. Stock Aussie 1985 XF EFI 4.1 Cam, There is an EECiv compliant cam which meets those requirements. Its designed around 1.73:1 rocker ratio.

2.The RV2 - Ford Crossflow six cylinder Inproved throttle Hwy Cam - Carby & EFI engine # 14221 crow cam 109 deg lob sep, 205/209 duration at .050" which is as far as you can go http://www.kustombitz.com.au/p/8626715/ ... gines.html

3.The 1966-1997 240/300 cam (268° advertised duration but only 192° @ .050").
4. Crane Cam #503905. 260/272 (adv), 204/216 (.050), 112 LSA
5. Isky #331M (248/248, 194/194, 108LSA)
6. Isky #331262 (262/262, 208/208, 108LSA)
7. Comp H252 (252/252, 206/206, 110)
8. Comp H260 (262/262, 212/212, 110 LSA)


You can still go up to 1.6:1 plain or 1.65:1 roller rockers. As long as the port mismatches go the way of the stock 300

"Ford designed their ports and manifolds such that

A.the intake port is bigger than the intake manifold outlet and
B. the Exhaust manifold inlet is bigger than the exhaust port. That way
C.there are no edges in the direction of flow"


The Classic in lines head and a four hole induction system will work fine.
 
oh X,

you always make it technical...

yes I was thinking close to stock, maybe little extra, I like the 258, and 264 range, or 204-212 @.50, 1.5 rr is all I want, nothing fancy, don't even want the roller tip. on all your LSA's, that seems too agressive, I thought 112 was more torque and smoothness, I had a 264/274 110 csc in the mustang 200ci, I could never get it to run right. even with a ds2 recurve (which made it run better). so i don't want a dual grind, besides, with intake and headers I won't have flow problem that dual grind remedies.

maybe the 194/194 @.50 would be best, measuring 248/248 with a 110 or 112 LSA... possible bump DCR with more CR say 9.5-9.8 and run pump 87 gas...

oh that's another thing, it has to run pump 87 gas... hmmm
 
some days I want to punch the fine folks that created Internet Exploder, right in the face.. (because I have to retype this now)

From the Bronco Buster Section.
I bought a Bronco!
Old/sold 1966

Current 1975


On the '75, what did they do with the bottom of the body when they removed the rockers?

Regarding all the accessories you want
Air compressor
Air conditioning
Power Steering (also for hydroboost brakes)
Alternator

Were you going to run V-belts or hoping for Serpentine?
If you are going the V-belt route, check out this thread.
[url=http://www.fordsix.com/forum/viewtopic.php?f=1&t=19664:rh9dnua7 said:
a/c brackets -- FordSix Forum[/url]":rh9dnua7]
pikesan":rh9dnua7 said:
Here's what it looks like in my build. Made some stand-offs to move the alternator away from the header. Came out pretty good! The longer belt needs to be about 1/2" shorter, but other than that, it's time to clean and paint.

ac-alt-setup.jpg


It looks like the alternator is still sitting on the header. It's just the angle. There's 4" between them.
Click to expand...
Click to expand...
And this one, they are closely related, this second one shows a York compressor instead of a Sanden
Stock A/C unit & dual headers?
And this 250 that is sitting in my Dad's barn has almost everything you are looking for..
York compressor, Alternator, Power Steering, just missing a Sanden bracket, I'd fab up something for right above the PS pump, where the smog pump used to be.



Someday y'all will see me on a 'hoarders' show, I'll be the redneck smiling the whole time telling a story about each and every car part that is torn from my fingers..
 
MPGmustang":dhov3uqk said:
oh X,

you always make it technical...

yes I was thinking close to stock, maybe little extra, I like the 258, and 264 range, or 204-212 @.50, 1.5 rr is all I want, nothing fancy, don't even want the roller tip. on all your LSA's, that seems too agressive, I thought 112 was more torque and smoothness, I had a 264/274 110 csc in the mustang 200ci, I could never get it to run right. even with a ds2 recurve (which made it run better). so i don't want a dual grind, besides, with intake and headers I won't have flow problem that dual grind remedies.

maybe the 194/194 @.50 would be best, measuring 248/248 with a 110 or 112 LSA... possible bump DCR with more CR say 9.5-9.8 and run pump 87 gas...

oh that's another thing, it has to run pump 87 gas... hmmm
Click to expand...

:D :rolflmao: :LOL:


I've been in this game a long time, and don't have to change my posts...viewtopic.php?p=89877.

I under-cammed my X-flow 250, and it loved it, but Ford were able to make 268 and 272 degree cams work on the bigger I6's because they did a bizzilion dollars of testing....FrenchTown Flyer's and Buddy Rawls posts only fortified what I was told by 200 and 250 stalwarts in the late 80's.

The 250 US engine with 12 port Classic Inlines head has a practically 4" stroke, and is more like a Big Six despite its narrower bore spacings

It loves the stock Ford Big Six 300 cubic inch cam as much as the 240 and 4.9 EFI do
Lift at Valve, 50 thou opening SAE Duration, Lobe Center, Timing and lob ramps in inches
0.397”/0.397” 192/192 268/268 110deg 18 70 58 30 @.006”

viewtopic.php?f=2&t=71080

All the Crow Cams 250 x-flow ones are on 112 centers, because most are autos, and Crows cam technology is further ahead than the earlier concepts.

Any 250 is no longer just a short deck US 200, so all comparisons change. The 250 can cope with a lobe center of 109. It did so in 87 unleaded fuel form in all 1985-1993 EFI overhead valve 250's. The Aussie carb 200 and 250 used a 108 or 111 lobe center, but loved a 109 center because it had 6.27" rods, and one of the most racy rod to stroke ratios of any engine anywhere.


I get technical for a reason. There are no wrong cams, only wrong engine combinations. A US 250 with Classic Inlines head copes with big ports because it has better mixture motion. The cam recommendations are based on big port 250 and 300 sixes

In 1987, an otherwise stock EFI 4.1 could run a 280 degree cam with T5 and 2.77:1 gears with 25" tires.

If you wanna live in the dark ages...stick with the stock 250 and 335/Cleveland era 256 to 258 duration cam. Ford used 109 lobe centers in both the 4.1 and 4.9 EFI's on both sides of the pond, subject to years, probably decades of I6 development work.

Ford Australia spent 100 million dollars on the X-flow engine from 1976 to 1993, the 1985 cam profile was the culmination of 9 years of development, yet it looked awfully like the stock 4.9 Big Six cam.

Ford had a generic 252 cam used on all cooking 221-302 v8's and I6's.

With the US 250, Cleveland 302/351 and the Aussie X-flows, they went to a 256-258 degree item on the base engines.

With the XF EFI, they got a 272 degree cam which is quite a decent item with a smooth idle, but plenty of extra power and torque still low in the rev range.

From the Master of All Things Six's Gregory's 226 Falcon/Fairmont/Fairlane'LTD Australian shop manual

MustangSix":dhov3uqk said:
From the XF-ZL-FE shop manual:

Carbed engines:

IO @ 22 BTDC @ .10mm lobe lift
IC @ 56 ABDC @ .15mm lobe lift
EO @ 58 BBDC @ .10mm lobe lift
EC @ 20 ATDC @ .15mm lobe lift

EFI Engines:

IO @ 24 BTDC @ .06mm lobe lift
IC @ 68 ABDC @ .12mm lobe lift
EO @ 62 BBDC @ .06mm lobe lift
EC @ 30 ATDC @ .12mm lobe lift

Lobe lift = 5.97mm (.235")
Rocker arm ratio = 1.73

The EFI cam is pretty stout for a stock cam.
Click to expand...

Federal Mogal's specs on stock replacement EFI cam had it at 109 degrees, stock carb 200/250 X-flow was 111

CS-6017 = use as standard replacement in efi or mild carb engine
CAM LIFT VALVE LIFT DEG.DUR @ .050 LOBE SEP
-------------------------------------------------------------------------------
INT 0.246 0.426 201 109
EXH 0.237 0.410 193 109
You need to copy the 87 octane 8.8:1 162 hp, 246 lb-ft X-flow 85-92 EFI specs, a factory EECIV engine. Half a second faster over the Quarter mile than the 149 hp XE EFI, all of it in the cam timing. 2.5% more torque everywhere with a bigger cam. Basically, the XF engine lasted from October 1985 to March 1993.

the old recommendation was the 14602 Crow Cam, very close to the stock EFI cam spec, but with just a bit more lift. I think the EFI cam may have a bit more duration on the intake.

Crow Cams have superseded the 14602 cam to a 14221
specs
VALVE TIMING ADV DUR .050 DUR VALVE LIFT
IN.26/60 266 205 .472
EX.66/25 271 209 .485
POWER RANGE 1400-4200
improves throttle response .good highway cam for mild or stock engines
Use Speed Pro lifter HT900(VL35) or HT900r(VL67RH) antipump-up lifter, they were the industry standard part numbers in most places



Minimum cam CROW CAMS
14771 specs IN.19/59 258 ADV DUR 200 .050 DUR .458"V LIFT
EX.63/19 262 ADV DUR 205 .050 DUR .470" V LIFT
POWER RANGE 1200-4000 based on 1.73:1 rocker ratio
 
xctasy":11wzub25 said:
There are no wrong cams, only wrong engine combinations.
Click to expand...
This is what paralyzes me- dumping money into a mess that just doesnt work.
 
X, I can't follow that. I pick out pieces and think you're speaking other car term to me... no offense, it's me.

In the end, I want an engine with the alum head, headers, and c4 pushing a barn door down the road @ 70MPH... at roughly 3-3.1k rpm on 35's or 36's, possible 37's.

I will have a low range gear that is 2.46 ratio of the output. so slow trails are fine, I'll probably won't be in low much.

what cam would best fit my scenario?

I'm guessing the torque I want at roughly 1200, maybe 1400 rpm, and I don't think it will have a problem at higher rpm as the alum head won't hold it back. so the TB will be limiting the RPM's on it's CFM. or possibly a plate under the TB... it'll most likely be a 2bbl, a simple 350cfm GM 2bbl TBI on alum head with 2bbl intake. I'm guessing on that flow rating. with that TBI, it will be in the 'sweet spot' for most of it's range on A/F ratio.

I'm thinking of using the 250 block as it has the v8 bellhousing. even tho, I know the 200 would fit better. the great thing is, I can weld on the mounts myself. downside, the 250 bottom will be fab'd, oil sump and pan.

CoupeBoy, yup you found my thread... the 75 has come a ways from that first picture, still one of my favorites when I first drove it home after 2 months of marriage... now it's for sale.... I'll have to post a new pic up of the truck some time.
For the location of the accesories, I've thought of a close to that setup... I like the sanden AC, on the low P, with the York above it... then move the PS to the low Driver side, and Alt above that. my reasoning... the sandon is modern, can take the heat from the exhaust side, the York compressor isn't on all the time and it can draw cool air from a straw located elsewhere, the ALT on my mustang always died of heat, it's not as thick as the york, and there are mini alts out there with same output. the PS, needs to be there, brackets are already good for that, which I might lower 2-4 inches... I might move the alt below and raise the PS, but think higher is the way to go.... I think that setup is the best, the real question is the alt and the Dizzy... the engine direct drives the water pump, PS and Sandon AC, the Sandon drives the york, and the PS drives the Alt, unless I can pull off a 3 grove on the crank, and the alt is below the PS... I'm jealous you have what you do... I have no parts, I let them go with the mustang.
 
MPGmustang":1jf2ym5n said:
I'm jealous you have what you do... I have no parts, I let them go with the mustang.
Click to expand...
I am a hoarder, but I never actually get to "do" anything. My IT job keeps me busy during the day, wife, family, and farm keep me busy at night. Luckily I get to collaborate with other forum member to create things. To date I have not used a single one of them myself.

I guess I never gave much though to heat soak and accessories, good thinking though.
As far as belt type and routing, what thoughts have you given to that?
Every accessory could use v-belts.
With your arrangement, I think you'd have to pay attention to using the AC and compressor at the same time, you'd have major belt slippage (assuming they share a belt)
If you ran two belts on them, you'd reduce the risk of slippage but then you'd need a third belt for the accessories on the driver side.

But you have a decent amount of responsibility for the driver side accessories too, you can't really afford to lose Power steering (steering/brakes) or alternator.

You could run a serpentine belt, I thought a serp York compressor would be difficult, but apparently not, check out this thread, he puts a York on a 4.2 for the same reason, shows the part number for the York serp pulley.
'90 4.2 W/Serp. OBA Build -- JeepForum.com

There are two ways that you can put a 144/170/200 into your bronco and still use a SBF bellhousing.
1. The documented process of using an early 80's Big Bell 200 and making an adapter plate. Adapt a V8 Bellhousing -- FordSix.com Tech Section
2. Be my guinea pig. Small Six to Small Block Ford Adapter Plate -- FordSix Forum

I've got just two last things to sort out. Making an adapter plate that is the thickness of the bellhousing adapter plate for a crank spacer. And finding the correct longer bolts for attaching the SBF Flywheel or flexplate to the small six crank.
 
correct me if I'm wrong....

C4's have remove able bell housing. the i6 mustang C4 can remove it's BH. the v8 in bronco's can remove it's BH...

would the input shafts be swapped???

then keep the i6 input shaft, BH, and plug up to a v8 c4.... it sounds like it should work...

that adapter plate you made might work for me... very interesting. I would love to test it out, but test time is much later.
 
MPGmustang":1sif880i said:
correct me if I'm wrong....

C4's have remove able bell housing. the i6 mustang C4 can remove it's BH. the v8 in bronco's can remove it's BH...

would the input shafts be swapped???

then keep the i6 input shaft, BH, and plug up to a v8 c4.... it sounds like it should work...

that adapter plate you made might work for me... very interesting. I would love to test it out, but test time is much later.
Click to expand...

Yes to most of what you said above the exceptions are the input can also stay depending on the torque converter that's used ie there are two different splines an early version used up to 1971, and the better 72 up. Next is the 200's and smaller I6's along with the smaller Bell Housing used a different flex plate and a torque converter with the ring gear attached all can be easily swapped in and bolted together. Good luck. :nod:
 
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